An enzyme that catalyzes the formation of dihydropteroate from p-aminobenzoic acid and dihydropteridine-hydroxymethyl-pyrophosphate. EC 2.5.1.15.
Sulfathiazole is a short-acting, sulfa-based antibiotic drug that is used to treat various bacterial infections, but its use has become limited due to the emergence of drug-resistant bacteria and adverse effects such as allergic reactions and blood disorders.
A class of phosphotransferases that catalyzes the transfer of diphosphate-containing groups. EC 2.7.6.
An aminobenzoic acid isomer that combines with pteridine and GLUTAMIC ACID to form FOLIC ACID. The fact that 4-aminobenzoic acid absorbs light throughout the UVB range has also resulted in its use as an ingredient in SUNSCREENS.
A long acting sulfonamide that is used, usually in combination with other drugs, for respiratory, urinary tract, and malarial infections.
An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 1.5.1.3.
Compounds based on 2-amino-4-hydroxypteridine.
One of the FOLIC ACID ANTAGONISTS that is used as an antimalarial or with a sulfonamide to treat toxoplasmosis.
A species of PNEUMOCYSTIS infecting humans and causing PNEUMOCYSTIS PNEUMONIA. It also occasionally causes extrapulmonary disease in immunocompromised patients. Its former name was Pneumocystis carinii f. sp. hominis.
A genus of ascomycetous FUNGI, family Pneumocystidaceae, order Pneumocystidales. It includes various host-specific species causing PNEUMOCYSTIS PNEUMONIA in humans and other MAMMALS.
Agents used in the treatment of malaria. They are usually classified on the basis of their action against plasmodia at different stages in their life cycle in the human. (From AMA, Drug Evaluations Annual, 1992, p1585)
Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.
A sulfanilamide that is used as an antibacterial agent.
Infections with species in the genus PNEUMOCYSTIS, a fungus causing interstitial plasma cell pneumonia (PNEUMONIA, PNEUMOCYSTIS) and other infections in humans and other MAMMALS. Immunocompromised patients, especially those with AIDS, are particularly susceptible to these infections. Extrapulmonary sites are rare but seen occasionally.
Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.
A sulfone active against a wide range of bacteria but mainly employed for its actions against MYCOBACTERIUM LEPRAE. Its mechanism of action is probably similar to that of the SULFONAMIDES which involves inhibition of folic acid synthesis in susceptible organisms. It is also used with PYRIMETHAMINE in the treatment of malaria. (From Martindale, The Extra Pharmacopoeia, 30th ed, p157-8)
A group of compounds that contain the structure SO2NH2.
A species of protozoa that is the causal agent of falciparum malaria (MALARIA, FALCIPARUM). It is most prevalent in the tropics and subtropics.
A pulmonary disease in humans occurring in immunodeficient or malnourished patients or infants, characterized by DYSPNEA, tachypnea, and HYPOXEMIA. Pneumocystis pneumonia is a frequently seen opportunistic infection in AIDS. It is caused by the fungus PNEUMOCYSTIS JIROVECII. The disease is also found in other MAMMALS where it is caused by related species of Pneumocystis.
Malaria caused by PLASMODIUM FALCIPARUM. This is the severest form of malaria and is associated with the highest levels of parasites in the blood. This disease is characterized by irregularly recurring febrile paroxysms that in extreme cases occur with acute cerebral, renal, or gastrointestinal manifestations.
Compounds based on 4-aminobenzenesulfonamide. The '-anil-' part of the name refers to aniline.
Deoxyribonucleic acid that makes up the genetic material of protozoa.
This drug combination has proved to be an effective therapeutic agent with broad-spectrum antibacterial activity against both gram-positive and gram-negative organisms. It is effective in the treatment of many infections, including PNEUMOCYSTIS PNEUMONIA in AIDS.
Transferases are enzymes transferring a group, for example, the methyl group or a glycosyl group, from one compound (generally regarded as donor) to another compound (generally regarded as acceptor). The classification is based on the scheme "donor:acceptor group transferase". (Enzyme Nomenclature, 1992) EC 2.
A bacteriostatic antibacterial agent that interferes with folic acid synthesis in susceptible bacteria. Its broad spectrum of activity has been limited by the development of resistance. (From Martindale, The Extra Pharmacopoeia, 30th ed, p208)
Benzoic acids, salts, or esters that contain an amino group attached to carbon number 4 of the benzene ring structure.
Inhibitors of the enzyme, dihydrofolate reductase (TETRAHYDROFOLATE DEHYDROGENASE), which converts dihydrofolate (FH2) to tetrahydrofolate (FH4). They are frequently used in cancer chemotherapy. (From AMA, Drug Evaluations Annual, 1994, p2033)
One of the short-acting SULFONAMIDES used in combination with PYRIMETHAMINE to treat toxoplasmosis in patients with acquired immunodeficiency syndrome and in newborns with congenital infections.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.
The ability of fungi to resist or to become tolerant to chemotherapeutic agents, antifungal agents, or antibiotics. This resistance may be acquired through gene mutation.
The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).
The functional hereditary units of protozoa.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
A species of bacteria that causes ANTHRAX in humans and animals.
A protozoan parasite that causes vivax malaria (MALARIA, VIVAX). This species is found almost everywhere malaria is endemic and is the only one that has a range extending into the temperate regions.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
A member of the vitamin B family that stimulates the hematopoietic system. It is present in the liver and kidney and is found in mushrooms, spinach, yeast, green leaves, and grasses (POACEAE). Folic acid is used in the treatment and prevention of folate deficiencies and megaloblastic anemia.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
Proteins found in any species of protozoan.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Enzyme that catalyzes the first step of the tricarboxylic acid cycle (CITRIC ACID CYCLE). It catalyzes the reaction of oxaloacetate and acetyl CoA to form citrate and coenzyme A. This enzyme was formerly listed as EC 4.1.3.7.
Derivatives of BENZOIC ACID that contain one or more amino groups attached to the benzene ring structure. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include the aminobenzoate structure.
Substances that reduce the growth or reproduction of BACTERIA.
Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.
Deoxyribonucleic acid that makes up the genetic material of fungi.

Plasmodium falciparum: selection of serine 108 of dihydrofolate reductase during treatment of uncomplicated malaria with co-trimoxazole in Ugandan children. (1/266)

In vivo testing for resistance of Plasmodium falciparum to co-trimoxazole (trimethoprim/sulfamethoxazole) was performed in Uganda in 41 children with uncomplicated malaria, and blood samples were screened before and after treatment for polymorphisms in the antifolate target genes for dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS). Selection towards a specific genotype at some codons of the DHFR and DHPS genes was observed in samples collected after exposure to co-trimoxazole drug pressure. The alleles 51-isoleucine, 59-arginine, and 108-serine of DHFR were significantly associated with clinical resistance, as was allele 581-alanine of DHPS. Resistance against antifolate combinations probably requires resistance-related polymorphisms in both the DHFR and the DHPS genes. In addition, it appears that the trimethoprim-resistant DHFR genotype differs from that for pyrimethamine at residue 108.  (+info)

2.0 A X-ray structure of the ternary complex of 7,8-dihydro-6-hydroxymethylpterinpyrophosphokinase from Escherichia coli with ATP and a substrate analogue. (2/266)

The X-ray crystal structure of 7,8-dihydro-6-hydroxymethylpterinpyrophosphokinase (PPPK) in a ternary complex with ATP and a pterin analogue has been solved to 2.0 A resolution, giving, for the first time, detailed information of the PPPK/ATP intermolecular interactions and the accompanying conformational change. The first 100 residues of the 158 residue peptide contain a betaalpha betabeta alphabeta motif present in several other proteins including nucleoside diphosphate kinase. Comparative sequence examination of a wide range of prokaryotic and lower eukaryotic species confirms the conservation of the PPPK active site, indicating the value of this de novo folate biosynthesis pathway enzyme as a potential target for the development of novel broad-spectrum anti-infective agents.  (+info)

Pyrimethamine-sulfadoxine efficacy and selection for mutations in Plasmodium falciparum dihydrofolate reductase and dihydropteroate synthase in Mali. (3/266)

To assess pyrimethamine-sulfadoxine (PS) efficacy in Mali, and the role of mutations in Plasmodium falciparum dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) in in vivo PS resistance, 190 patients with uncomplicated P. falciparum malaria were treated with PS and monitored for 56 days. Mutation-specific polymerase chain reactions and digestion with restriction endonucleases were used to detect DHFR and DHPS mutations on filter paper blood samples from pretreatment and post-treatment infections. Only one case each of RI and RII level resistance and no cases of RIII resistance or therapeutic failure were observed. Post-PS treatment infections had significantly higher rates of DHFR mutations at codons 108 and 59. No significant selection for DHPS mutations was seen. Pyrimethamine-sulfadoxine is highly efficacious in Mali, and while the low level of resistance precludes assessing the utility of molecular assays for in vivo PS resistance, rapid selection of DHFR mutations supports their role in PS failure.  (+info)

Sulfonamide resistance in clinical isolates of Campylobacter jejuni: mutational changes in the chromosomal dihydropteroate synthase. (4/266)

The characterization of the genetic basis of sulfonamide resistance in Campylobacter jejuni was attempted. The resistance determinant from a sulfonamide-resistant strain of C. jejuni was cloned and was found to show 42% identity with the folP gene (which codes for dihydropteroate synthase, the target of sulfonamides) of the related bacterium Helicobacter pylori. The sequences of the areas surrounding the folP gene in C. jejuni showed similarity to those of the areas surrounding the corresponding gene in H. pylori. The folP gene of C. jejuni, which mediates the resistance, was observed to show particular features when it was compared to other known folP genes. One of these features is the presence of two pairs of direct repeats (15 and 27 bp) within the coding sequence of the gene. Comparison of the C. jejuni folP genes that mediate susceptibility and resistance revealed the occurrence of mutations that changed four amino acid residues. Resistance of C. jejuni to sulfonamides could be associated with one or several of these four mutational substitutions, which all occurred in the five different resistant isolates studied. The codon for one of these changed amino acids was found to be located in the second direct repeat within the coding sequence of the gene. The change made the repeat perfect. The transformation of both the resistance and the susceptibility variants of the gene into an Escherichia coli folP knockout mutant was found to complement the dihydropteroate synthase deficiency, confirming that the characterized sulfonamide resistance determinant codes for the C. jejuni dihydropteroate synthase enzyme. Kinetic measurements established different affinities of sulfonamide for the dihydropteroate synthase enzyme isolated from the resistant and susceptible strains. In conclusion, sulfonamide resistance in C. jejuni was shown to be associated with mutational changes in the chromosomally located gene for dihydropteroate synthase, the target of sulfonamides.  (+info)

Low-dose treatment with sulfadoxine-pyrimethamine combinations selects for drug-resistant Plasmodium falciparum strains. (5/266)

A total of 252 children were enrolled in a drug trial to assess the effect of minimal doses of sulfadoxine (Sdx) and pyrimethamine (Pyr). Parasite samples isolated from these patients were analyzed before and after treatment to investigate the level of drug-resistant strains. The parasite genes encoding dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) were assayed for point mutations that are associated with resistance against drugs. Before treatment, Pyr(r) genotypes of the DHFR gene were found in 42% of all samples, 8% of the patients harbored a mixed parasite population and 50% had a sensitive DHFR genotype. In terms of the DHPS gene, we found mutations in 45% of the parasites. Twenty-four percent had a Ser(436) mutation, and 26% had a Gly(437) mutation. Recrudescent parasites were highly enriched for both Pyr(r) and Sdx(r) strains after treatment (P < 0.001 and P = 0.029, respectively).  (+info)

Novel expansions of the gene encoding dihydropteroate synthase in trimethoprim-sulfamethoxazole-resistant Streptococcus pneumoniae. (6/266)

A study of eight sulfonamide-resistant clinical isolates of Streptococcus pneumoniae revealed chromosomal mutations within the gene encoding dihydropteroate synthase that play a role in conferring resistance to sulfamethoxazole. The presence of the suld mutation, found previously only in a laboratory mutant, was shown to occur in three of the wild-type clinical isolates. The duplication of Ser(61), the other previously defined mutation in the dihydropteroate synthase gene of S. pneumoniae, was observed in only one of the isolates characterized. We report two previously unidentified amino acid alterations, namely, a duplication of Arg(58) and Pro(59) and an insertion of an arginine residue between Gly(60) and Ser(61) in trimethoprim-sulfamethoxazole-resistant strains. The significance of these mutations was confirmed by site-directed mutagenesis and by the transformation of a susceptible strain of S. pneumoniae to sulfamethoxazole resistance. Two resistant isolates did not contain any mutations within the gene encoding dihydropteroate synthase. The results presented suggest the independent generation of resistant mutations among South African clinical isolates. It is also proposed that the mechanism of sulfonamide resistance in S. pneumoniae involves the expansion of a specific region within dihydropteroate synthase, which probably forms part of the sulfonamide binding site.  (+info)

Point mutations in dihydrofolate reductase and dihydropteroate synthase genes of Plasmodium falciparum isolates from Venezuela. (7/266)

The present study was designed to characterize mutations in dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) genes of Plasmodium falciparum in the Bolivar region of Venezuela, where high levels of clinical resistance to sulfadoxine-pyrimethamine (SP, Fansidar; F. Hoffman-La Roche, Basel, Switzerland) has been documented. We used a nested mutation-specific polymerase chain reaction and restriction digestion methods to measure 1) the prevalence of DHFR mutations at 16, 50, 51, 59, 108, and 164 codon positions, and 2) the prevalence of mutations in the 436, 437, 581, and 613 codon sites in DHPS gene. In the case of the DHFR gene, of the 54 parasite isolates analyzed, we detected the presence of Asn-108 and Ile-51 in 96% of the isolates and Arg-50 mutation in 64% of the isolates. Each of these mutations has been associated with high level of resistance to pyrimethamine. Only 2 samples (4%) showed the wild type Ser-108 mutation and none showed Thr-108 and Val-16 mutations that are specific for resistance to cycloguanil. In the case of DHPS gene, we found a mutation at position 437 (Gly) in 100% of the isolates and Gly-581 in 96% of the isolates. The simultaneous presence of mutations Asn-108 and Ile-51 in the DHFR gene and Gly-437 and Gly-581 in the DHPS gene in 96% of the samples tested suggested that a cumulative effect of mutations could be the major mechanism conferring high SP resistance in this area.  (+info)

Plasmodium falciparum resistance to sulfadoxine/pyrimethamine in Uganda: correlation with polymorphisms in the dihydrofolate reductase and dihydropteroate synthetase genes. (8/266)

The efficacy of sulfadoxine/pyrimethamine (S/P) in treatment of uncomplicated falciparum malaria in Africa is increasingly compromised by development of resistance. The occurrence of active site mutations in the Plasmodium falciparum gene sequences coding for dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS) is known to confer resistance to pyrimethamine and sulfadoxine. This study investigated the occurrence of these mutations in infected blood samples taken from Ugandan children before treatment with S/P and their relationship to parasite breakthrough by day 7. The results confirm the occurrence of mutations in DHFR and DHPS that were significantly selected under S/P pressure at day 7: a combination of alleles 51-isoleucine and 108-asparagine in DHFR, and 436-serine, 437-alanine, 540-lysine and 581-alanine in DHPS, appears to play a major role in the development of in vivo resistance in P. falciparum strains against S/P. Therefore, earlier results derived from isolates from hyperendemic areas in Tanzania were confirmed by this investigation.  (+info)

Dihydropteroate synthase is a bacterial enzyme that plays a crucial role in the synthesis of folate, an essential nutrient for many organisms, including bacteria. The enzyme catalyzes the reaction between pteridine and para-aminobenzoic acid (pABA) to form dihydropteroate, which is then converted into folate.

Inhibition of this enzyme by drugs such as sulfonamides has been a successful strategy for developing antibiotics that target bacterial folate synthesis while sparing the host's metabolism. This makes dihydropteroate synthase an important target in the development of antimicrobial therapies.

Sulfathiazole is a type of antibiotic that belongs to the class of medications called sulfonamides. It works by interfering with the growth of bacteria in the body. Specifically, it inhibits the bacterial enzyme responsible for producing folic acid, an essential component for bacterial growth and reproduction.

Sulfathiazole is used to treat a variety of bacterial infections, including urinary tract infections, respiratory infections, skin and soft tissue infections, and ear infections. It's available in various forms, such as tablets, capsules, and topical creams or ointments.

It's important to note that the use of sulfonamides like sulfathiazole has declined over time due to the emergence of bacterial resistance and the availability of alternative antibiotics with better safety profiles. Additionally, adverse reactions such as skin rashes, allergic reactions, and gastrointestinal symptoms may occur in some individuals taking sulfathiazole.

Diphosphotransferases are a group of enzymes that catalyze the transfer of a diphosphate group from a donor molecule to an acceptor molecule. These enzymes play important roles in various metabolic pathways, including the synthesis of nucleotides, lipids, and carbohydrates.

The systematic name for this type of reaction is "diphosphate-group transferase." Diphosphotransferases can be further classified based on the specific type of donor and acceptor molecules involved in the reaction. For example, nucleoside diphosphate kinases are a subclass of diphosphotransferases that transfer a diphosphate group from a nucleoside triphosphate (such as ATP) to a nucleoside diphosphate (such as ADP), generating two molecules of nucleoside triphosphate.

It's worth noting that while the term "diphosphotransferases" is sometimes used in the scientific literature, it is not a widely recognized or commonly used term in medical or biochemical nomenclature. Instead, enzymes are typically classified and named based on the specific reaction they catalyze, using standardized nomenclature systems such as the Enzyme Commission (EC) numbering system.

4-Aminobenzoic acid, also known as PABA or para-aminobenzoic acid, is an organic compound that is a type of aromatic amino carboxylic acid. It is a white, crystalline powder that is slightly soluble in water and more soluble in alcohol.

4-Aminobenzoic acid is not an essential amino acid for humans, but it is a component of the vitamin folic acid and is found in various foods such as meat, whole grains, and molasses. It has been used as a topical sunscreen due to its ability to absorb ultraviolet (UV) radiation, although its effectiveness as a sunscreen ingredient has been called into question in recent years.

In addition to its use in sunscreens, 4-aminobenzoic acid has been studied for its potential health benefits, including its possible role in protecting against UV-induced skin damage and its potential anti-inflammatory and analgesic effects. However, more research is needed to confirm these potential benefits and to determine the safety and effectiveness of 4-aminobenzoic acid as a dietary supplement or topical treatment.

Sulfadoxine is an antimicrobial drug, specifically a sulfonamide. It is defined in medical terms as a long-acting synthetic antibacterial that is used to treat and prevent various bacterial infections. Sulfadoxine works by inhibiting the growth of bacteria through interfering with their ability to synthesize folic acid, an essential component for their survival.

It is often combined with pyrimethamine (a dihydrofolate reductase inhibitor) to treat and prevent malaria caused by Plasmodium falciparum, particularly in areas where there is resistance to other antimalarial drugs. The combination of sulfadoxine and pyrimethamine is known as a "sulfonamide-pyrimidine" or "SP" treatment.

Sulfadoxine should be used with caution, as it can cause serious side effects such as severe skin reactions, blood disorders, and allergic reactions. It is also not recommended for use in people who have an allergy to sulfonamides or who are breastfeeding infants younger than two months of age.

Tetrahydrofolate dehydrogenase (EC 1.5.1.20) is an enzyme involved in folate metabolism. The enzyme catalyzes the oxidation of tetrahydrofolate (THF) to dihydrofolate (DHF), while simultaneously reducing NADP+ to NADPH.

The reaction can be summarized as follows:

THF + NADP+ -> DHF + NADPH + H+

This enzyme plays a crucial role in the synthesis of purines and thymidylate, which are essential components of DNA and RNA. Therefore, any defects or deficiencies in tetrahydrofolate dehydrogenase can lead to various medical conditions, including megaloblastic anemia and neural tube defects during fetal development.

Pterins are a group of naturally occurring pigments that are derived from purines. They are widely distributed in various organisms, including bacteria, fungi, and animals. In humans, pterins are primarily found in the eye, skin, and hair. Some pterins have been found to play important roles as cofactors in enzymatic reactions and as electron carriers in metabolic pathways.

Abnormal levels of certain pterins can be indicative of genetic disorders or other medical conditions. For example, an excess of biopterin, a type of pterin, is associated with phenylketonuria (PKU), a genetic disorder that affects the body's ability to metabolize the amino acid phenylalanine. Similarly, low levels of neopterin, another type of pterin, can be indicative of immune system dysfunction or certain types of cancer.

Medical professionals may measure pterin levels in blood, urine, or other bodily fluids to help diagnose and monitor these conditions.

Pyrimethamine is an antiparasitic medication that is primarily used to treat and prevent protozoan infections, such as toxoplasmosis and malaria. It works by inhibiting the dihydrofolate reductase enzyme, which is essential for the parasite's survival. By doing so, it interferes with the synthesis of folate, a vital component for the growth and reproduction of the parasite.

Pyrimethamine is often used in combination with other medications, such as sulfonamides or sulfones, to increase its effectiveness and prevent the development of drug-resistant strains. Common side effects of pyrimethamine include nausea, vomiting, loss of appetite, and headache. It is important to note that pyrimethamine should only be used under the supervision of a healthcare professional due to its potential for serious side effects and interactions with other medications.

"Pneumocystis jirovecii" is a species of fungus that commonly infects the lungs of humans, leading to a serious respiratory infection known as Pneumocystis pneumonia (PCP). This fungal infection primarily affects individuals with weakened immune systems, such as those with HIV/AIDS, cancer, or organ transplant recipients. The organism was previously classified as a protozoan but has since been reclassified as a fungus based on genetic analysis. It is typically acquired through inhalation of airborne spores and can cause severe illness if left untreated.

"Pneumocystis" is a genus of fungi that are commonly found in the lungs of many mammals, including humans. The most well-known and studied species within this genus is "Pneumocystis jirovecii," which was previously known as "Pneumocystis carinii." This organism can cause a serious lung infection known as Pneumocystis pneumonia (PCP) in individuals with weakened immune systems, such as those with HIV/AIDS or who are undergoing immunosuppressive therapy.

It's worth noting that while "Pneumocystis" was once classified as a protozoan, it is now considered to be a fungus based on its genetic and biochemical characteristics.

Antimalarials are a class of drugs that are used for the prevention, treatment, and elimination of malaria. They work by targeting the malaria parasite at various stages of its life cycle, particularly the erythrocytic stage when it infects red blood cells. Some commonly prescribed antimalarials include chloroquine, hydroxychloroquine, quinine, mefloquine, and artemisinin-based combinations. These drugs can be used alone or in combination with other antimalarial agents to increase their efficacy and prevent the development of drug resistance. Antimalarials are also being investigated for their potential use in treating other diseases, such as autoimmune disorders and cancer.

Drug resistance, also known as antimicrobial resistance, is the ability of a microorganism (such as bacteria, viruses, fungi, or parasites) to withstand the effects of a drug that was originally designed to inhibit or kill it. This occurs when the microorganism undergoes genetic changes that allow it to survive in the presence of the drug. As a result, the drug becomes less effective or even completely ineffective at treating infections caused by these resistant organisms.

Drug resistance can develop through various mechanisms, including mutations in the genes responsible for producing the target protein of the drug, alteration of the drug's target site, modification or destruction of the drug by enzymes produced by the microorganism, and active efflux of the drug from the cell.

The emergence and spread of drug-resistant microorganisms pose significant challenges in medical treatment, as they can lead to increased morbidity, mortality, and healthcare costs. The overuse and misuse of antimicrobial agents, as well as poor infection control practices, contribute to the development and dissemination of drug-resistant strains. To address this issue, it is crucial to promote prudent use of antimicrobials, enhance surveillance and monitoring of resistance patterns, invest in research and development of new antimicrobial agents, and strengthen infection prevention and control measures.

Sulfamerazine is a type of antibiotic known as a sulfonamide. It works by interfering with the ability of bacteria to produce folic acid, which is necessary for their growth and survival. Sulfonamides like sulfamerazine are often used to treat a variety of bacterial infections, including respiratory tract infections, skin and soft tissue infections, and urinary tract infections.

Sulfamerazine is typically prescribed as an oral medication, and it may be given alone or in combination with other antibiotics. As with all medications, sulfamerazine can cause side effects, including nausea, vomiting, diarrhea, and skin rashes. It's important to take this medication exactly as directed by your healthcare provider, and to complete the full course of treatment even if you start feeling better before all of the medication is gone.

It's worth noting that sulfonamides have been associated with rare but serious side effects, including allergic reactions, blood disorders, and liver damage. If you experience any unusual symptoms while taking sulfamerazine, be sure to contact your healthcare provider right away.

"Pneumocystis infection" is most commonly caused by the microorganism Pneumocystis jirovecii, which can lead to a serious lung infection known as pneumocystis pneumonia (PCP). This infection primarily affects individuals with weakened immune systems, such as those with HIV/AIDS, cancer, or organ transplant recipients.

The microorganism that causes Pneumocystis infections was previously classified as a protozoan but is now considered a fungus. It exists in the environment and can be found in the lungs of healthy individuals without causing illness. However, in people with compromised immune systems, it can replicate and cause pneumonia, which can be life-threatening if not treated promptly.

Symptoms of PCP include cough, shortness of breath, fever, and difficulty breathing. Diagnosis typically involves microscopic examination of respiratory samples, such as sputum or lung fluid, to detect the presence of the organism. Treatment usually consists of antimicrobial medications, such as trimethoprim-sulfamethoxazole (TMP-SMX), pentamidine, or atovaquone. Preventive measures, such as prophylaxis with TMP-SMX or other medications, may be recommended for individuals at high risk of developing PCP.

A drug combination refers to the use of two or more drugs in combination for the treatment of a single medical condition or disease. The rationale behind using drug combinations is to achieve a therapeutic effect that is superior to that obtained with any single agent alone, through various mechanisms such as:

* Complementary modes of action: When different drugs target different aspects of the disease process, their combined effects may be greater than either drug used alone.
* Synergistic interactions: In some cases, the combination of two or more drugs can result in a greater-than-additive effect, where the total response is greater than the sum of the individual responses to each drug.
* Antagonism of adverse effects: Sometimes, the use of one drug can mitigate the side effects of another, allowing for higher doses or longer durations of therapy.

Examples of drug combinations include:

* Highly active antiretroviral therapy (HAART) for HIV infection, which typically involves a combination of three or more antiretroviral drugs to suppress viral replication and prevent the development of drug resistance.
* Chemotherapy regimens for cancer treatment, where combinations of cytotoxic agents are used to target different stages of the cell cycle and increase the likelihood of tumor cell death.
* Fixed-dose combination products, such as those used in the treatment of hypertension or type 2 diabetes, which combine two or more active ingredients into a single formulation for ease of administration and improved adherence to therapy.

However, it's important to note that drug combinations can also increase the risk of adverse effects, drug-drug interactions, and medication errors. Therefore, careful consideration should be given to the selection of appropriate drugs, dosing regimens, and monitoring parameters when using drug combinations in clinical practice.

Dapsone is a medication that belongs to a class of drugs called sulfones. It is primarily used to treat bacterial skin infections such as leprosy and dermatitis herpetiformis (a skin condition associated with coeliac disease). Dapsone works by killing the bacteria responsible for these infections.

In addition, dapsone has anti-inflammatory properties and is sometimes used off-label to manage inflammatory conditions such as vasculitis, bullous pemphigoid, and chronic urticaria. It is available in oral tablet form and topical cream or gel form.

Like all medications, dapsone can cause side effects, which may include nausea, loss of appetite, and headache. More serious side effects, such as methemoglobinemia (a blood disorder that affects the body's ability to transport oxygen), peripheral neuropathy (nerve damage that causes pain, numbness, or weakness in the hands and feet), and liver damage, can occur but are less common.

It is important for patients taking dapsone to be monitored by a healthcare provider to ensure safe and effective use of the medication.

Sulfonamides are a group of synthetic antibacterial drugs that contain the sulfonamide group (SO2NH2) in their chemical structure. They are bacteriostatic agents, meaning they inhibit bacterial growth rather than killing them outright. Sulfonamides work by preventing the bacteria from synthesizing folic acid, which is essential for their survival.

The first sulfonamide drug was introduced in the 1930s and since then, many different sulfonamides have been developed with varying chemical structures and pharmacological properties. They are used to treat a wide range of bacterial infections, including urinary tract infections, respiratory tract infections, skin and soft tissue infections, and ear infections.

Some common sulfonamide drugs include sulfisoxazole, sulfamethoxazole, and trimethoprim-sulfamethoxazole (a combination of a sulfonamide and another antibiotic called trimethoprim). While sulfonamides are generally safe and effective when used as directed, they can cause side effects such as rash, nausea, and allergic reactions. It is important to follow the prescribing physician's instructions carefully and to report any unusual symptoms or side effects promptly.

'Plasmodium falciparum' is a specific species of protozoan parasite that causes malaria in humans. It is transmitted through the bites of infected female Anopheles mosquitoes and has a complex life cycle involving both human and mosquito hosts.

In the human host, the parasites infect red blood cells, where they multiply and cause damage, leading to symptoms such as fever, chills, anemia, and in severe cases, organ failure and death. 'Plasmodium falciparum' malaria is often more severe and life-threatening than other forms of malaria caused by different Plasmodium species. It is a major public health concern, particularly in tropical and subtropical regions of the world where access to prevention, diagnosis, and treatment remains limited.

"Pneumonia, Pneumocystis" is more commonly referred to as "Pneumocystis pneumonia (PCP)." It is a type of pneumonia caused by the microorganism Pneumocystis jirovecii. This organism was previously classified as a protozoan but is now considered a fungus.

PCP is an opportunistic infection, which means that it mainly affects people with weakened immune systems, such as those with HIV/AIDS, cancer, transplant recipients, or people taking immunosuppressive medications. The symptoms of PCP can include cough, shortness of breath, fever, and difficulty exercising. It is a serious infection that requires prompt medical treatment, typically with antibiotics.

It's important to note that PCP is not the same as pneumococcal pneumonia, which is caused by the bacterium Streptococcus pneumoniae. While both conditions are types of pneumonia, they are caused by different organisms and require different treatments.

Malaria, Falciparum is defined as a severe and often fatal form of malaria caused by the parasite Plasmodium falciparum. It is transmitted to humans through the bites of infected Anopheles mosquitoes. This type of malaria is characterized by high fever, chills, headache, muscle and joint pain, and vomiting. If left untreated, it can cause severe anemia, kidney failure, seizures, coma, and even death. It is a major public health problem in many tropical and subtropical regions of the world, particularly in Africa.

Sulfanilamides are a group of synthetic antibacterial agents that are chemically related to sulfanilic acid. They work by inhibiting the growth of bacteria, particularly Gram-positive cocci, and have been used in the treatment of various bacterial infections such as pneumonia, meningitis, and urinary tract infections.

Sulfanilamides are absorbed well from the gastrointestinal tract and are distributed widely throughout the body tissues. They are excreted mainly in the urine, and their action is enhanced by acidic urine. Common side effects of sulfonamides include skin rashes, nausea, vomiting, and headache. Rare but serious side effects include blood disorders, liver damage, and Stevens-Johnson syndrome.

Sulfanilamides have been largely replaced by newer antibiotics due to the emergence of drug-resistant bacteria and the availability of safer and more effective alternatives. However, they are still used in some cases, particularly for the treatment of certain parasitic infections and as topical agents for skin infections.

There doesn't seem to be a specific medical definition for "DNA, protozoan" as it is simply a reference to the DNA found in protozoa. Protozoa are single-celled eukaryotic organisms that can be found in various environments such as soil, water, and the digestive tracts of animals.

Protozoan DNA refers to the genetic material present in these organisms. It is composed of nucleic acids, including deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), which contain the instructions for the development, growth, and reproduction of the protozoan.

The DNA in protozoa, like in other organisms, is made up of two strands of nucleotides that coil together to form a double helix. The four nucleotide bases that make up protozoan DNA are adenine (A), thymine (T), guanine (G), and cytosine (C). These bases pair with each other to form the rungs of the DNA ladder, with A always pairing with T and G always pairing with C.

The genetic information stored in protozoan DNA is encoded in the sequence of these nucleotide bases. This information is used to synthesize proteins, which are essential for the structure and function of the organism's cells. Protozoan DNA also contains other types of genetic material, such as regulatory sequences that control gene expression and repetitive elements with no known function.

Understanding the DNA of protozoa is important for studying their biology, evolution, and pathogenicity. It can help researchers develop new treatments for protozoan diseases and gain insights into the fundamental principles of genetics and cellular function.

Trimethoprim-sulfamethoxazole combination is an antibiotic medication used to treat various bacterial infections. It contains two active ingredients: trimethoprim and sulfamethoxazole, which work together to inhibit the growth of bacteria by interfering with their ability to synthesize folic acid, a vital component for their survival.

Trimethoprim is a bacteriostatic agent that inhibits dihydrofolate reductase, an enzyme needed for bacterial growth, while sulfamethoxazole is a bacteriostatic sulfonamide that inhibits the synthesis of tetrahydrofolate by blocking the action of the enzyme bacterial dihydropteroate synthase. The combination of these two agents produces a synergistic effect, increasing the overall antibacterial activity of the medication.

Trimethoprim-sulfamethoxazole is commonly used to treat urinary tract infections, middle ear infections, bronchitis, traveler's diarrhea, and pneumocystis pneumonia (PCP), a severe lung infection that can occur in people with weakened immune systems. It is also used as a prophylactic treatment to prevent PCP in individuals with HIV/AIDS or other conditions that compromise the immune system.

As with any medication, trimethoprim-sulfamethoxazole combination can have side effects and potential risks, including allergic reactions, skin rashes, gastrointestinal symptoms, and blood disorders. It is essential to follow the prescribing physician's instructions carefully and report any adverse reactions promptly.

Transferases are a class of enzymes that facilitate the transfer of specific functional groups (like methyl, acetyl, or phosphate groups) from one molecule (the donor) to another (the acceptor). This transfer of a chemical group can alter the physical or chemical properties of the acceptor molecule and is a crucial process in various metabolic pathways. Transferases play essential roles in numerous biological processes, such as biosynthesis, detoxification, and catabolism.

The classification of transferases is based on the type of functional group they transfer:

1. Methyltransferases - transfer a methyl group (-CH3)
2. Acetyltransferases - transfer an acetyl group (-COCH3)
3. Aminotransferases or Transaminases - transfer an amino group (-NH2 or -NHR, where R is a hydrogen atom or a carbon-containing group)
4. Glycosyltransferases - transfer a sugar moiety (a glycosyl group)
5. Phosphotransferases - transfer a phosphate group (-PO3H2)
6. Sulfotransferases - transfer a sulfo group (-SO3H)
7. Acyltransferases - transfer an acyl group (a fatty acid or similar molecule)

These enzymes are identified and named according to the systematic nomenclature of enzymes developed by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology (IUBMB). The naming convention includes the class of enzyme, the specific group being transferred, and the molecules involved in the transfer reaction. For example, the enzyme that transfers a phosphate group from ATP to glucose is named "glucokinase."

Sulfamethoxazole is a type of antibiotic known as a sulfonamide. It works by interfering with the ability of bacteria to produce folic acid, which is necessary for their growth and survival. Sulfamethoxazole is often combined with trimethoprim (another antibiotic) in a single medication called co-trimoxazole, which is used to treat a variety of bacterial infections, including respiratory tract infections, urinary tract infections, and skin and soft tissue infections.

The medical definition of Sulfamethoxazole can be found in various pharmaceutical and medical resources, here are some examples:

* According to the Merck Manual, Sulfamethoxazole is a "synthetic antibacterial drug that inhibits bacterial synthesis of folic acid by competing with para-aminobenzoic acid for the enzyme dihydropteroate synthetase."
* According to the British National Formulary (BNF), Sulfamethoxazole is a "sulfonamide antibacterial agent, active against many Gram-positive and Gram-negative bacteria. It is often combined with trimethoprim in a 5:1 ratio as co-trimoxazole."
* According to the National Library of Medicine (NLM), Sulfamethoxazole is a "synthetic antibacterial agent that is used in combination with trimethoprim for the treatment of various bacterial infections. It works by inhibiting the bacterial synthesis of folic acid."

It's important to note that, as any other medication, Sulfamethoxazole should be taken under medical supervision and following the instructions of a healthcare professional, as it can cause side effects and interact with other medications.

Para-aminobenzoates are a group of compounds that contain a para-aminobenzoic acid (PABA) molecule. PABA is an organic compound that is related to benzoic acid and aminobenzoic acid. It is not an essential nutrient for humans, but it does play a role in the metabolism of certain bacteria.

Para-aminobenzoates are often used as ingredients in sunscreens because PABA absorbs ultraviolet (UV) light and can help protect the skin from sun damage. However, para-aminobenzoates can cause skin irritation and allergic reactions in some people, so they have largely been replaced by other UV-absorbing compounds in modern sunscreens.

In addition to their use in sunscreens, para-aminobenzoates are also used in the treatment of various medical conditions. For example, they may be used as a topical agent to treat fungal infections or as a systemic therapy to treat rheumatoid arthritis and other inflammatory conditions.

It is important to note that para-aminobenzoates should not be confused with paracetamol (also known as acetaminophen), which is a commonly used pain reliever and fever reducer. While both compounds contain the word "para," they are chemically distinct and have different uses in medicine.

Folic acid antagonists are a class of medications that work by inhibiting the action of folic acid or its metabolic pathways. These drugs are commonly used in the treatment of various types of cancer and certain other conditions, such as rheumatoid arthritis. They include drugs such as methotrexate, pemetrexed, and trimetrexate.

Folic acid is a type of B vitamin that is essential for the production of DNA and RNA, the genetic material found in cells. Folic acid antagonists work by interfering with the enzyme responsible for converting folic acid into its active form, tetrahydrofolate. This interference prevents the formation of new DNA and RNA, which is necessary for cell division and growth. As a result, these drugs can inhibit the proliferation of rapidly dividing cells, such as cancer cells.

It's important to note that folic acid antagonists can also affect normal, non-cancerous cells in the body, particularly those that divide quickly, such as cells in the bone marrow and digestive tract. This can lead to side effects such as anemia, mouth sores, and diarrhea. Therefore, these drugs must be used carefully and under the close supervision of a healthcare provider.

Sulfadiazine is an antibacterial drug, specifically a sulfonamide. It is chemically described as 4-amino-N-(2-pyrimidinyl)benzenesulfonamide. Sulfadiazine works by inhibiting the bacterial synthesis of dihydrofolic acid, which is essential for bacterial growth and reproduction.

It is used to treat a wide range of infections caused by susceptible bacteria, including urinary tract infections, respiratory infections, and certain types of meningitis. Sulfadiazine is often combined with other antibiotics, such as trimethoprim, to increase its effectiveness against certain bacteria.

Like all sulfonamides, sulfadiazine can cause side effects, including skin rashes, allergic reactions, and stomach upset. It should be used with caution in people who are allergic to sulfa drugs or have kidney or liver disease. Additionally, it is important to note that the use of sulfonamides during pregnancy, especially during the third trimester, should be avoided due to the risk of kernicterus in the newborn.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

A point mutation is a type of genetic mutation where a single nucleotide base (A, T, C, or G) in DNA is altered, deleted, or substituted with another nucleotide. Point mutations can have various effects on the organism, depending on the location of the mutation and whether it affects the function of any genes. Some point mutations may not have any noticeable effect, while others might lead to changes in the amino acids that make up proteins, potentially causing diseases or altering traits. Point mutations can occur spontaneously due to errors during DNA replication or be inherited from parents.

Fungal drug resistance is a condition where fungi are no longer susceptible to the antifungal drugs that were previously used to treat infections they caused. This can occur due to genetic changes in the fungi that make them less sensitive to the drug's effects, or due to environmental factors that allow the fungi to survive and multiply despite the presence of the drug.

There are several mechanisms by which fungi can develop drug resistance, including:

1. Mutations in genes that encode drug targets: Fungi can acquire mutations in the genes that encode for the proteins or enzymes that the antifungal drugs target. These mutations can alter the structure or function of these targets, making them less susceptible to the drug's effects.
2. Overexpression of efflux pumps: Fungi can increase the expression of genes that encode for efflux pumps, which are proteins that help fungi expel drugs from their cells. This can reduce the intracellular concentration of the drug and make it less effective.
3. Changes in membrane composition: Fungi can alter the composition of their cell membranes to make them less permeable to antifungal drugs, making it more difficult for the drugs to enter the fungal cells and exert their effects.
4. Biofilm formation: Fungi can form biofilms, which are complex communities of microorganisms that adhere to surfaces and are protected by a matrix of extracellular material. Biofilms can make fungi more resistant to antifungal drugs by limiting drug penetration and creating an environment that promotes the development of resistance.

Fungal drug resistance is a significant clinical problem, particularly in patients with weakened immune systems, such as those with HIV/AIDS or cancer. It can lead to treatment failures, increased morbidity and mortality, and higher healthcare costs. To address this issue, there is a need for new antifungal drugs, as well as strategies to prevent and manage drug resistance.

Microbial drug resistance is a significant medical issue that refers to the ability of microorganisms (such as bacteria, viruses, fungi, or parasites) to withstand or survive exposure to drugs or medications designed to kill them or limit their growth. This phenomenon has become a major global health concern, particularly in the context of bacterial infections, where it is also known as antibiotic resistance.

Drug resistance arises due to genetic changes in microorganisms that enable them to modify or bypass the effects of antimicrobial agents. These genetic alterations can be caused by mutations or the acquisition of resistance genes through horizontal gene transfer. The resistant microbes then replicate and multiply, forming populations that are increasingly difficult to eradicate with conventional treatments.

The consequences of drug-resistant infections include increased morbidity, mortality, healthcare costs, and the potential for widespread outbreaks. Factors contributing to the emergence and spread of microbial drug resistance include the overuse or misuse of antimicrobials, poor infection control practices, and inadequate surveillance systems.

To address this challenge, it is crucial to promote prudent antibiotic use, strengthen infection prevention and control measures, develop new antimicrobial agents, and invest in research to better understand the mechanisms underlying drug resistance.

Genes in protozoa refer to the hereditary units of these single-celled organisms that carry genetic information necessary for their growth, development, and reproduction. These genes are made up of DNA (deoxyribonucleic acid) molecules, which contain sequences of nucleotide bases that code for specific proteins or RNA molecules. Protozoan genes are responsible for various functions, such as metabolism, response to environmental stimuli, and reproduction.

It is important to note that the study of protozoan genes has contributed significantly to our understanding of genetics and evolution, particularly in areas such as molecular biology, cell biology, and genomics. However, there is still much to be learned about the genetic diversity and complexity of these organisms, which continue to be an active area of research.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Polymerase Chain Reaction (PCR) is a laboratory technique used to amplify specific regions of DNA. It enables the production of thousands to millions of copies of a particular DNA sequence in a rapid and efficient manner, making it an essential tool in various fields such as molecular biology, medical diagnostics, forensic science, and research.

The PCR process involves repeated cycles of heating and cooling to separate the DNA strands, allow primers (short sequences of single-stranded DNA) to attach to the target regions, and extend these primers using an enzyme called Taq polymerase, resulting in the exponential amplification of the desired DNA segment.

In a medical context, PCR is often used for detecting and quantifying specific pathogens (viruses, bacteria, fungi, or parasites) in clinical samples, identifying genetic mutations or polymorphisms associated with diseases, monitoring disease progression, and evaluating treatment effectiveness.

'Bacillus anthracis' is the scientific name for the bacterium that causes anthrax, a serious and potentially fatal infectious disease. This gram-positive, spore-forming rod-shaped bacterium can be found in soil and commonly affects animals such as sheep, goats, and cattle. Anthrax can manifest in several forms, including cutaneous (skin), gastrointestinal, and inhalation anthrax, depending on the route of infection.

The spores of Bacillus anthracis are highly resistant to environmental conditions and can survive for years, making them a potential agent for bioterrorism or biowarfare. When inhaled, ingested, or introduced through breaks in the skin, these spores can germinate into vegetative bacteria that produce potent exotoxins responsible for anthrax symptoms and complications.

It is essential to distinguish Bacillus anthracis from other Bacillus species due to its public health significance and potential use as a biological weapon. Proper identification, prevention strategies, and medical countermeasures are crucial in mitigating the risks associated with this bacterium.

"Plasmodium vivax" is a species of protozoan parasite that causes malaria in humans. It's one of the five malaria parasites that can infect humans, with P. falciparum being the most deadly.

P. vivax typically enters the human body through the bite of an infected Anopheles mosquito. Once inside the human host, the parasite travels to the liver where it multiplies and matures. After a period of development that can range from weeks to several months, the mature parasites are released into the bloodstream, where they infect red blood cells and continue to multiply.

The symptoms of P. vivax malaria include fever, chills, headache, muscle and joint pain, and fatigue. One distinctive feature of P. vivax is its ability to form dormant stages (hypnozoites) in the liver, which can reactivate and cause relapses of the disease months or even years after the initial infection.

P. vivax malaria is treatable with medications such as chloroquine, but resistance to this drug has been reported in some parts of the world. Prevention measures include using insecticide-treated bed nets and indoor residual spraying to reduce mosquito populations, as well as taking prophylactic medications for travelers visiting areas where malaria is common.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Anti-infective agents are a class of medications that are used to treat infections caused by various microorganisms such as bacteria, viruses, fungi, and parasites. These agents work by either killing the microorganism or inhibiting its growth, thereby helping to control the infection and alleviate symptoms.

There are several types of anti-infective agents, including:

1. Antibiotics: These are medications that are used to treat bacterial infections. They work by either killing bacteria (bactericidal) or inhibiting their growth (bacteriostatic).
2. Antivirals: These are medications that are used to treat viral infections. They work by interfering with the replication of the virus, preventing it from spreading and causing further damage.
3. Antifungals: These are medications that are used to treat fungal infections. They work by disrupting the cell membrane of the fungus, killing it or inhibiting its growth.
4. Antiparasitics: These are medications that are used to treat parasitic infections. They work by either killing the parasite or inhibiting its growth and reproduction.

It is important to note that anti-infective agents are not effective against all types of infections, and it is essential to use them appropriately to avoid the development of drug-resistant strains of microorganisms.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

Folic acid is the synthetic form of folate, a type of B vitamin (B9). It is widely used in dietary supplements and fortified foods because it is more stable and has a longer shelf life than folate. Folate is essential for normal cell growth and metabolism, and it plays a critical role in the formation of DNA and RNA, the body's genetic material. Folic acid is also crucial during early pregnancy to prevent birth defects of the brain and spine called neural tube defects.

Medical Definition: "Folic acid is the synthetic form of folate (vitamin B9), a water-soluble vitamin involved in DNA synthesis, repair, and methylation. It is used in dietary supplementation and food fortification due to its stability and longer shelf life compared to folate. Folic acid is critical for normal cell growth, development, and red blood cell production."

Genotype, in genetics, refers to the complete heritable genetic makeup of an individual organism, including all of its genes. It is the set of instructions contained in an organism's DNA for the development and function of that organism. The genotype is the basis for an individual's inherited traits, and it can be contrasted with an individual's phenotype, which refers to the observable physical or biochemical characteristics of an organism that result from the expression of its genes in combination with environmental influences.

It is important to note that an individual's genotype is not necessarily identical to their genetic sequence. Some genes have multiple forms called alleles, and an individual may inherit different alleles for a given gene from each parent. The combination of alleles that an individual inherits for a particular gene is known as their genotype for that gene.

Understanding an individual's genotype can provide important information about their susceptibility to certain diseases, their response to drugs and other treatments, and their risk of passing on inherited genetic disorders to their offspring.

An allele is a variant form of a gene that is located at a specific position on a specific chromosome. Alleles are alternative forms of the same gene that arise by mutation and are found at the same locus or position on homologous chromosomes.

Each person typically inherits two copies of each gene, one from each parent. If the two alleles are identical, a person is said to be homozygous for that trait. If the alleles are different, the person is heterozygous.

For example, the ABO blood group system has three alleles, A, B, and O, which determine a person's blood type. If a person inherits two A alleles, they will have type A blood; if they inherit one A and one B allele, they will have type AB blood; if they inherit two B alleles, they will have type B blood; and if they inherit two O alleles, they will have type O blood.

Alleles can also influence traits such as eye color, hair color, height, and other physical characteristics. Some alleles are dominant, meaning that only one copy of the allele is needed to express the trait, while others are recessive, meaning that two copies of the allele are needed to express the trait.

I'm sorry for any confusion, but "Protozoan Proteins" is not a specific medical or scientific term. Protozoa are single-celled eukaryotic organisms, and proteins are large biological molecules consisting of one or more chains of amino acid residues. Therefore, "Protozoan Proteins" generally refers to the various types of proteins found in protozoa.

However, if you're looking for information about proteins specific to certain protozoan parasites with medical relevance (such as Plasmodium falciparum, which causes malaria), I would be happy to help! Please provide more context or specify the particular protozoan of interest.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Molecular structure, in the context of biochemistry and molecular biology, refers to the arrangement and organization of atoms and chemical bonds within a molecule. It describes the three-dimensional layout of the constituent elements, including their spatial relationships, bond lengths, and angles. Understanding molecular structure is crucial for elucidating the functions and reactivities of biological macromolecules such as proteins, nucleic acids, lipids, and carbohydrates. Various experimental techniques, like X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy (cryo-EM), are employed to determine molecular structures at atomic resolution, providing valuable insights into their biological roles and potential therapeutic targets.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

Aminobenzoates are a group of chemical compounds that contain an amino (NH2) group and a benzoate (C6H5COO-) group in their structure. They are widely used in the pharmaceutical and cosmetic industries due to their various properties, such as ultraviolet light absorption, antimicrobial activity, and anti-inflammatory effects.

One of the most well-known aminobenzoates is para-aminobenzoic acid (PABA), which is a naturally occurring compound found in some foods and also synthesized by bacteria in the human gut. PABA has been used as a topical sunscreen agent due to its ability to absorb ultraviolet B (UVB) radiation, but its use as a sunscreen ingredient has declined in recent years due to concerns about skin irritation and potential allergic reactions.

Other aminobenzoates have various medical uses, such as:

* Antimicrobial agents: Some aminobenzoates, such as benzalkonium chloride and cetylpyridinium chloride, are used as antiseptics and disinfectants due to their ability to disrupt bacterial cell membranes.
* Analgesic and anti-inflammatory agents: Aminobenzoates such as methyl salicylate and acetaminophen (paracetamol) are commonly used as pain relievers and fever reducers.
* Vitamin B supplements: PABA is a component of folic acid, which is an essential vitamin for human health. Some people take PABA supplements to treat or prevent various conditions, such as graying hair, rheumatoid arthritis, and vitiligo, although there is limited scientific evidence to support these uses.

It's important to note that some aminobenzoates can be toxic in high doses or with prolonged exposure, so they should be used under the guidance of a healthcare professional.

Anti-bacterial agents, also known as antibiotics, are a type of medication used to treat infections caused by bacteria. These agents work by either killing the bacteria or inhibiting their growth and reproduction. There are several different classes of anti-bacterial agents, including penicillins, cephalosporins, fluoroquinolones, macrolides, and tetracyclines, among others. Each class of antibiotic has a specific mechanism of action and is used to treat certain types of bacterial infections. It's important to note that anti-bacterial agents are not effective against viral infections, such as the common cold or flu. Misuse and overuse of antibiotics can lead to antibiotic resistance, which is a significant global health concern.

Enzyme inhibitors are substances that bind to an enzyme and decrease its activity, preventing it from catalyzing a chemical reaction in the body. They can work by several mechanisms, including blocking the active site where the substrate binds, or binding to another site on the enzyme to change its shape and prevent substrate binding. Enzyme inhibitors are often used as drugs to treat various medical conditions, such as high blood pressure, abnormal heart rhythms, and bacterial infections. They can also be found naturally in some foods and plants, and can be used in research to understand enzyme function and regulation.

Fungal DNA refers to the genetic material present in fungi, which are a group of eukaryotic organisms that include microorganisms such as yeasts and molds, as well as larger organisms like mushrooms. The DNA of fungi, like that of all living organisms, is made up of nucleotides that are arranged in a double helix structure.

Fungal DNA contains the genetic information necessary for the growth, development, and reproduction of fungi. This includes the instructions for making proteins, which are essential for the structure and function of cells, as well as other important molecules such as enzymes and nucleic acids.

Studying fungal DNA can provide valuable insights into the biology and evolution of fungi, as well as their potential uses in medicine, agriculture, and industry. For example, researchers have used genetic engineering techniques to modify the DNA of fungi to produce drugs, biofuels, and other useful products. Additionally, understanding the genetic makeup of pathogenic fungi can help scientists develop new strategies for preventing and treating fungal infections.

Dihydropteroate synthase is an enzyme classified under EC 2.5.1.15. It produces dihydropteroate in bacteria, but it is not ... Dihydropteroate synthase (EC 2.5.1.15) (DHPS) catalyses the condensation of 6-hydroxymethyl-7,8-dihydropteridine pyrophosphate ... Proteins containing this domain include dihydropteroate synthase (EC 2.5.1.15) as well as a group of methyltransferase enzymes ... and the dihydropteroate synthase gene". J. Bacteriol. 172 (12): 7211-7226. doi:10.1128/jb.172.12.7211-7226.1990. PMC 210846. ...
Sulfa Use, Dihydropteroate Synthase Mutations, and Pneumocystis jirovecii Pneumonia Cheryl R. Stein*, Charles Poole*, Powel ... Sulfa Use, Dihydropteroate Synthase Mutations, and Pneumocystis jirovecii Pneumonia. ...
It was assumed that 63 inhibits dihydropteroate synthase (which is involved in folic acid synthesis) by mimicking the substrate ... Contrary to PAS, the well-known sulfonamide inhibitors of the folate pathway dihydropteroate synthase are inactive ( ... The first mechanism was associated with low-frequency mutations in thymidylate synthase (thyA), confirming that 39 is involved ... Finally, 52 and its metabolite conferred mutations in TrpAB (tryptophan synthase) in residues spread throughout the protein ...
This study assessed the occurrence of microscopic and sub-microscopic P. falciparum parasitaemia, dihydropteroate synthase ... Sub-microscopic Plasmodium falciparum parasitaemia, dihydropteroate synthase (dhps) resistance mutations to sulfadoxine- ...
The PneumoGenius®kit (PathoNostics) allows the simultaneous detection of Pj mtLSU and dihydropteroate synthase (DHPS) ... PCR assay for the diagnosis of Pneumocystis pneumonia and the detection of Pneumocystis dihydropteroate synthase mutations in ...
Dihydropteroate synthase. GOSPT_103_00590 GOSPT_098_00050. FOLA. (NRULE_0147). Dihydrofolate reductase. GOSPT_046_00370. ...
Dihydropteroate synthase. trd_1325. DFR2. (NRULE_0148). Dihydrofolate reductase type 2. FOLB ...
DIHYDROFOLATE REDUCTASE AND DIHYDROPTEROATE SYNTHASE GENOTYPES ASSOCIATED WITH IN VITRO RESISTANCE OF PLASMODIUM FALCIPARUM TO ... relation between dihydropteroate synthase/dihydrofolate reductase genotypes, sulfadoxine plasma levels, and treatment outcome. ... DIHYDROPTEROATE SYNTHASE, AND P. FALCIPARUM CHLOROQUINE RESISTANCE TRANSPORTER GENES USING POLYMERASE CHAIN REACTION- AND ... RELATIONSHIP WITH PLASMA DRUG CONCENTRATIONS AND DIHYDROFOLATE REDUCTASE AND DIHYDROPTEROATE SYNTHASE GENOTYPES ...
PDB Description: dihydropteroate synthetase from bacillus anthracis. PDB Compounds: (A:) DHPS, Dihydropteroate synthase. SCOPe ... Superfamily c.1.21: Dihydropteroate synthetase-like [51717] (3 families) *. Family c.1.21.1: Dihydropteroate synthetase [51718 ... Protein Dihydropteroate synthetase [51719] (5 species). *. Species Anthrax bacillus (Bacillus anthracis) [TaxId:1392] [102103 ... d1twsa_ c.1.21.1 (A:) Dihydropteroate synthetase {Anthrax bacillus (Bacillus anthracis) [TaxId: 1392]} ...
8-dihydropteroate synthase, an enzyme involved in folic acid synthesis which is needed for purine nucleotide biosynthesis (Kidd ... and triazolopyrimidines are herbicides that inhibit acetolactate synthase (ALS), also called acetohydroxyacid synthase (AHAS), ... The 5-keto form inhibits 1-deoxy-D-xyulose 5-phosphate synthase (DOXP), a key component to plastid isoprenoid synthesis. ... Although plant death apparently results from events occurring in response to EPSP synthase inhibition, the actual sequence of ...
PDB Compounds: (A:) DHPS, Dihydropteroate synthase. SCOPe Domain Sequences for d1twwa_:. Sequence, based on SEQRES records: ( ... Superfamily c.1.21: Dihydropteroate synthetase-like [51717] (3 families) *. Family c.1.21.1: Dihydropteroate synthetase [51718 ... Protein Dihydropteroate synthetase [51719] (5 species). *. Species Anthrax bacillus (Bacillus anthracis) [TaxId:1392] [102103 ... PDB Description: dihydropteroate synthetase, with bound substrate analogue ptpp, from bacillus anthracis ...
Inhibition of dihydropteroate synthase. *. B.. Blockade of translocation of peptidyl-tRNA. *. C. ...
Pterin-sulfa conjugates as dihydropteroate synthase inhibitors and antibacterial agents. Bioorg Med Chem Lett Aug 15;26(16): ... Validation of Molecular Docking Programs for Virtual Screening against Dihydropteroate Synthase. J Chem Inf Mod 49 (2), 444-460 ... Identification and Characterization of an Allosteric Inhibitory Site on Dihydropteroate Synthase. ACS Chem Biol 9(6):1294-302, ... Structure-based design of novel pyrimido[4,5-c]pyridazine derivatives as dihydropteroate synthase inhibitors with increased ...
EC 2.5.1.15 (dihydropteroate synthase) inhibitor +. 46. EC 2.5.1.18 (glutathione transferase) inhibitor +. 1152. ... EC 2.5.1.29 (geranylgeranyl diphosphate synthase) inhibitor +. 0. EC 2.5.1.31 \{ditrans,polycis-undecaprenyl-diphosphate ... EC 2.5.1.48 (cystathionine gamma-synthase) inhibitor +. 0. EC 2.5.1.49 (O-acetylhomoserine aminocarboxypropyltransferase) ...
7,8-dihydropteroate synthase. GO Process (0). GO Function (0). GO Component (0) ...
... acetolactate synthase (ALS) (e.g. chlorsulfuron, imazapyr) and dihydropteroate synthase (asulam) for Orobanche control in ... This inhibitor of dihydropteroate synthase lethally then prevents folic acid biosynthesis in the parasite. Additionally, we ... Acetolactate synthase (ALS)-inhibiting imidazolinone and sulphonylurea herbicides have been found to be effective in ... High herbicide levels can be localized on or near seed of acetolactate synthase (ALS) resistant maize (Zea mays). The magnesium ...
Sulfa drugs work by inhibiting an enzyme called dihydropteroate synthase (DHPS). DHPS helps produce folic acid, which bacteria ... They work by inhibiting an enzyme called dihydropteroate synthase (DHPS). DHPS helps produce folic acid, which bacteria need in ...
I (Inhibition of Dihydropteroate Synthase). *K1 (Inhibition of Microtubule Assembly). *K2 (Inhibition of Microtubule ...
dihydropteroate synthase. NP_227856. 15642815. pMH2T7. 896880. TM0056. peptide ABC transporter substrate-binding protein. NP_ ... folylpolyglutamate synthase/dihydrofolate synthase. NP_227981. 15642940. pMH2T7. 896818. TM0009. hypothetical protein. NP_ ... tRNA pseudouridine synthase ACD. NP_229374. 15644322. pMH1. 898065. TM1411. helicase-related protein. NP_229212. 15644163. pMH1 ... tryptophan synthase subunit beta. NP_227953. 15642912. pMH2T7. 896993. TM0156. alkaline phosphatase. NP_227971. 15642930. ...
HRAC 18 (Inhibition of Dihydropteroate Synthase). *HRAC 19 (Auxin Transport inhibitor). *HRAC 22 (PS I Electron Diversion ) ...
Update on Dihydropteroate Synthase (DHPS) Mutations in Pneumocystis jirovecii Horra Padilla, Carmen de la; Friaza, Vicente; ...
Mutations in Plasmodium falciparum dihydrofolate reductase and dihydropteroate synthase and epidemiologic patterns of ... inhibiting the parasite enzyme dihydropteroate synthase (DHPS). There is marked synergy between these two classes of drugs when ... A mutation-specific PCR system to detect sequence variation in the dihydropteroate synthetase gene of Plasmodium falciparum. ... efficacy and selection for mutations in Plasmodium falciparum dihydrofolate reductase and dihydropteroate synthase in Mali. ...
Asulam also inhibits dihydropteroate synthase (DHP), an enzyme involved in folic acid required for biosynthesis of purine ... The second group inhibits deoxy-D-xylulose phosphate synthase (DOXP), a key component to plastid isoprenoid synthesis. These ... These herbicides inhibit acetolactate synthase (ALS), an enzyme involved in the synthesis of branch chain amino acids- ... 5-enolpyruvylshikimate-3-phosphate synthase). The enzyme is involved in the synthesis of three essential aromatic amino acids: ...
HRAC 18 (Inhibition of Dihydropteroate Synthase). *HRAC 19 (Auxin Transport inhibitor). *HRAC 22 (PS I Electron Diversion ) ...
HRAC 18 (Inhibition of Dihydropteroate Synthase). *HRAC 19 (Auxin Transport inhibitor). *HRAC 22 (PS I Electron Diversion ) ...
... pABA into intracellular folates and by detecting dihydropteroate synthase activity in reticulate body crude extract. ...
HRAC 18 (Inhibition of Dihydropteroate Synthase). *HRAC 19 (Auxin Transport inhibitor). *HRAC 22 (PS I Electron Diversion ) ...
... and dihydropteroate synthase (K00796) (Supplementary Table S5C).. Association Between Gut Microbiome and CD4 + T-Cell Counts. ... and enterobactin synthase component E (entE) (rho = −0.556, p = 0.0483). Additionally, current CD4 + T-cell count was inversely ...
Dihydropteroate synthase activity. Specific Function. Not Available. Gene Name. Not Available. Uniprot ID. Q27738. Uniprot Name ...

No FAQ available that match "dihydropteroate synthase"