Proteus
Enterobacteriaceae
Escherichia
Proteus vulgaris
Guanosine Diphosphate Sugars
Proteus mirabilis
Morganella
TEM-24 produced by four different species of Enterobacteriaceae, including Providencia rettgeri, in a single patient. (1/191)
Four species of members of the family Enterobacteriaceae harboring extended-spectrum beta-lactamase (ESBL) were recovered in a single patient hospitalized in an intensive care unit. Among these isolates, we describe for the first time an ESBL-producing Providencia rettgeri strain. Bacteria from the same species were shown to be genetically related by pulsed-field gel electrophoresis analysis. These strains produced the same TEM derivative ESBL, characterized as TEM-24. This enzyme had the peculiarity of being encoded by a large conjugative plasmid of 180 kb, never previously described for such an ESBL. (+info)Molecular characterization of the genera Proteus, Morganella, and Providencia by ribotyping. (2/191)
The so-called Proteus-Providencia group is constituted at present by three genera and 10 species. Several of the recognized species are common opportunistic pathogens for humans and animals. Different methods based on the study of phenotypic characters have been used in the past with variable levels of efficiency for typing some species for epidemiological purposes. We have determined the rRNA gene restriction patterns (ribotypes) for the type strains of the 10 different species of the genera Proteus, Morganella, and Providencia. Visual inspection of EcoRV- and HincII-digested DNA from the type strains showed remarkably different patterns for both enzymes, but EcoRV provided better differentiation. Both endonucleases were retained to study a large number of wild and collection strains belonging to the different species. Clinical isolates of Proteus mirabilis, Proteus penneri, Morganella morganii, and Providencia heimbachae showed patterns identical or very similar to those of the respective type strains, so that groups of related patterns (ribogroups) were found to correspond to the diverse species. On the contrary, distinct ribogroups were detected within Providencia alcalifaciens (two ribogroups with both enzymes), Providencia rettgeri (four ribogroups with EcoRV and five with HincII), Providencia stuartii (two ribogroups with EcoRV), Providencia rustigianii (two ribogroups with HincII), and Proteus vulgaris (two ribogroups with both enzymes). The pattern shown by the ancient P. vulgaris type strain NCTC 4175 differed considerably from both P. vulgaris ribogroups as well as from the newly proposed type strain ATCC 29905 and from any other strain in this study, thus confirming its atypical nature. Minor differences were frequently observed among patterns of strains belonging to the same ribogroup. These differences were assumed to define ribotypes within each ribogroup. No correlation was observed between ribogroups or ribotypes and biogroups of P. vulgaris, P. alcalifaciens, P. stuartii, and P. rettgeri. Since, not only different species showed different rRNA gene restriction patterns, but also different ribogroups and ribotypes have been found in the majority of the species, ribotyping would be a sensitive method for molecular characterization of clinical isolates belonging to the genera Proteus, Morganella, and Providencia. (+info)Isolation of Providencia heimbachae from human feces. (3/191)
Providencia heimbachae was first described in 1986. It has been isolated from penguin feces and an aborted bovine fetus. To date, there has been no reported isolation of this organism from human specimens. We now report the isolation of P. heimbachae from the stool of a 23-year-old woman with idiopathic diarrhea. The identity of the human strain was determined biochemically and by DNA relatedness to the type strain of P. heimbachae. (+info)Crystal structure of penicillin G acylase from the Bro1 mutant strain of Providencia rettgeri. (4/191)
Penicillin G acylase is an important enzyme in the commercial production of semisynthetic penicillins used to combat bacterial infections. Mutant strains of Providencia rettgeri were generated from wild-type cultures subjected to nutritional selective pressure. One such mutant, Bro1, was able to use 6-bromohexanamide as its sole nitrogen source. Penicillin acylase from the Bro1 strain exhibited an altered substrate specificity consistent with the ability of the mutant to process 6-bromohexanamide. The X-ray structure determination of this enzyme was undertaken to understand its altered specificity and to help in the design of site-directed mutants with desired specificities. In this paper, the structure of the Bro1 penicillin G acylase has been solved at 2.5 A resolution by molecular replacement. The R-factor after refinement is 0.154 and R-free is 0.165. Of the 758 residues in the Bro1 penicillin acylase heterodimer (alpha-subunit, 205; beta-subunit, 553), all but the eight C-terminal residues of the alpha-subunit have been modeled based on a partial Bro1 sequence and the complete wild-type P. rettgeri sequence. A tightly bound calcium ion coordinated by one residue from the alpha-subunit and five residues from the beta-subunit has been identified. This enzyme belongs to the superfamily of Ntn hydrolases and uses Ogamma of Ser beta1 as the characteristic N-terminal nucleophile. A mutation of the wild-type Met alpha140 to Leu in the Bro1 acylase hydrophobic specificity pocket is evident from the electron density and is consistent with the observed specificity change for Bro1 acylase. The electron density for the N-terminal Gln of the alpha-subunit is best modeled by the cyclized pyroglutamate form. Examination of aligned penicillin acylase and cephalosporin acylase primary sequences, in conjunction with the P. rettgeri and Escherichia coli penicillin acylase crystal structures, suggests several mutations that could potentially allow penicillin acylase to accept charged beta-lactam R-groups and to function as a cephalosporin acylase and thus be used in the manufacture of semi-synthetic cephalosporins. (+info)Providencia stuartii genes activated by cell-to-cell signaling and identification of a gene required for production or activity of an extracellular factor. (5/191)
By utilizing reporter transposons, five Providencia stuartii genes that are activated by the accumulation of self-produced extracellular signals have been identified. These genes have been designated cma for conditioned medium activated. The presence of conditioned medium from stationary-phase cultures grown in rich media resulted in the premature activation of each gene in cells at early log phase, with activation values ranging from 6- to 26-fold. Preparation of conditioned medium from an M9 salts medium and fractionation by gel filtration chromatography resulted in fractions within the included volume which activated three of the cma fusions. In addition, depending on the reporter fusion, peak activity was found in different fractions. The partially purified factors activated in a dose-dependent manner. Characterization of the factors activating the cma fusions indicated that they were stable to heat, alkali, and acid. Furthermore, for each cma fusion, factor activity was not reproduced by the addition of homoserine lactone, homocysteine thiolactone, pyruvate, Casamino Acids, or alpha-ketoglutarate. The identities of three cma genes have been determined and revealed physiological roles in amino acid biosynthesis and nutrient import. To begin to address the pathways for production of or response to the extracellular factors, we have identified a locus, aarA, that is required for the activation of four cma fusions. The AarA product was required for factor activity in extracellular supernatants, indicating a possible role in biosynthesis or export. (+info)Fragmentation of 23S rRNA in strains of Proteus and Providencia results from intervening sequences in the rrn (rRNA) genes. (6/191)
Intervening sequences (IVSs) were originally identified in the rrl genes for 23S rRNA (rrl genes, for large ribosomal subunit, part of rrn operon encoding rRNA) of Salmonella enterica serovars Typhimurium LT2 and Arizonae. These sequences are transcribed but later removed during RNase III processing of the rRNA, resulting in fragmentation of the 23S species; IVSs are uncommon, but have been reported in at least 10 bacterial genera. Through PCR amplification of IVS-containing regions of the rrl genes we showed that most Proteus and Providencia strains contain IVSs similar to those of serovar Typhimurium in distribution and location in rrl genes. By extraction and Northern blotting of rRNA, we also found that these IVSs result in rRNA fragmentation. We report the first finding of two very different sizes of IVS (113 bp and 183 to 187 bp) in different rrl genes in the same strain, in helix 25 of Proteus and Providencia spp.; IVSs from helix 45 are 113 to 123 bp in size. Analysis of IVS sequence and postulated secondary structure reveals striking similarities of Proteus and Providencia IVSs to those of serovar Typhimurium, with the stems of the smaller IVSs from helix 25 being similar to those of Salmonella helix 25 IVSs and with both the stem and the central loop domain of helix 45 IVSs being similar. Thus, IVSs of related sequences are widely distributed throughout the Enterobacteriaceae, in Salmonella, Yersinia, Proteus, and Providencia spp., but we did not find them in Escherichia coli, Citrobacter, Enterobacter, Klebsiella, or Morganella spp.; the sporadic distribution of IVSs of related sequence indicates that lateral genetic transfer has occurred. (+info)Variation in expression of sex factor genes in the Proteus-Providencia group relative to Escherichia coli. (7/191)
Several instances of anomalous expression of genes introduced from Escherichia coli K-12 into Proteus mirabilis have been described. It is shown here that control of sex pilus synthesis directed by the F-like R factor R1 and its depressed derivatives R1-16 (O-C) and R1-19 (i-minus) is also anomalous in P. mirabilis. Piliation in cells bearing the depressed plasmids is expressed at a lower level than in E. coli K-12, and repression is absent in R1-carrying cells. Preliminary results show a similar effect in Providencia. In Proteus morganii, a similarly reduced level of piliation in R1-16-+ or R1-19-+ cultures is observed, but an intermediate level of repression occurs in R1-+ cultures. Less extensive data suggest that expression of the sex factor genes of an R factor of the N incompatibility group differs far less between E. coli and P. mirabilis hosts. Possible bases for these effects are discussed. (+info)Classification, identification, and clinical significance of Proteus, Providencia, and Morganella. (8/191)
This review presents the current taxonomy of the genera Proteus, Providencia, and Morganella, along with the current methods for the identification of each species within the three genera, incorporating both conventional biochemical and commercial methods. While all of these organisms are ubiquitous in the environment, individual case reports and nosocomial outbreak reports that demonstrate their ability to cause major infectious disease problems are presented. Lastly, anticipated antimicrobial susceptibility patterns are reviewed. Many of these organisms are easily controlled, but the advent of newer and more powerful antimicrobial agents has led to some problems of which laboratorians need to be aware. (+info)"Providencia" is a term that refers to a type of bacteria that can cause infections in humans. The scientific name for this bacterium is "Providencia stuartii." It is part of the Enterobacteriaceae family and is commonly found in the gastrointestinal tract of humans and animals.
Providencia stuartii can cause a variety of infections, including urinary tract infections, wound infections, and bloodstream infections. It is often resistant to many antibiotics, which can make it difficult to treat. People who are hospitalized, have weakened immune systems, or use catheters are at increased risk for Providencia infections.
It's important to note that while "Providencia" refers to a specific type of bacteria, the term is not typically used in medical diagnoses or treatment. Instead, healthcare providers would specify the type of infection and the name of the bacterium causing it.
'Proteus' doesn't have a specific medical definition itself, but it is related to a syndrome in medicine. Proteus syndrome is a rare genetic disorder characterized by the overgrowth of various tissues and organs in the body. The name "Proteus" comes from the Greek god Proteus, who could change his form at will, reflecting the diverse and ever-changing nature of this condition's symptoms.
People with Proteus syndrome experience asymmetric overgrowth of bones, skin, and other tissues, leading to abnormalities in body shape and function. The disorder can also affect blood vessels, causing benign tumors called hamartomas to develop. Additionally, individuals with Proteus syndrome are at an increased risk of developing certain types of cancer.
The genetic mutation responsible for Proteus syndrome is found in the AKT1 gene, which plays a crucial role in cell growth and division. This disorder is typically not inherited but instead arises spontaneously as a new mutation in the affected individual. Early diagnosis and management of Proteus syndrome can help improve patients' quality of life and reduce complications associated with the condition.
Proteus infections are caused by the bacterium Proteus mirabilis or other Proteus species. These bacteria are gram-negative, opportunistic pathogens that can cause various types of infections, including urinary tract infections (UTIs), wound infections, and bacteremia (bloodstream infections). Proteus infections are often associated with complicated UTIs, catheter-associated UTIs, and healthcare-associated infections. They can be difficult to treat due to their ability to produce enzymes that inactivate certain antibiotics and form biofilms.
Proteus infections can cause symptoms such as fever, chills, fatigue, and discomfort in the affected area. In UTIs, patients may experience symptoms like burning during urination, frequent urges to urinate, and cloudy or foul-smelling urine. Wound infections caused by Proteus can lead to delayed healing, increased pain, and pus formation. Bacteremia can cause sepsis, a life-threatening condition that requires immediate medical attention.
Treatment for Proteus infections typically involves antibiotics, such as fluoroquinolones, trimethoprim-sulfamethoxazole, or carbapenems. The choice of antibiotic depends on the severity and location of the infection, as well as the patient's overall health status and any underlying medical conditions. In some cases, surgical intervention may be necessary to drain abscesses or remove infected devices like catheters.
Enterobacteriaceae are a large family of gram-negative bacteria that are commonly found in the human gut and surrounding environment. Infections caused by Enterobacteriaceae can occur when these bacteria enter parts of the body where they are not normally present, such as the bloodstream, urinary tract, or abdominal cavity.
Enterobacteriaceae infections can cause a range of symptoms depending on the site of infection. For example:
* Urinary tract infections (UTIs) caused by Enterobacteriaceae may cause symptoms such as frequent urination, pain or burning during urination, and lower abdominal pain.
* Bloodstream infections (bacteremia) caused by Enterobacteriaceae can cause fever, chills, and sepsis, a potentially life-threatening condition characterized by a whole-body inflammatory response to infection.
* Pneumonia caused by Enterobacteriaceae may cause cough, chest pain, and difficulty breathing.
* Intra-abdominal infections (such as appendicitis or diverticulitis) caused by Enterobacteriaceae can cause abdominal pain, fever, and changes in bowel habits.
Enterobacteriaceae infections are typically treated with antibiotics, but the increasing prevalence of antibiotic-resistant strains of these bacteria has made treatment more challenging in recent years. Preventing the spread of Enterobacteriaceae in healthcare settings and promoting good hygiene practices can help reduce the risk of infection.
Enterobacteriaceae is a family of gram-negative, rod-shaped bacteria that are commonly found in the intestines of humans and animals. Many species within this family are capable of causing various types of infections, particularly in individuals with weakened immune systems. Some common examples of Enterobacteriaceae include Escherichia coli (E. coli), Klebsiella pneumoniae, Proteus mirabilis, and Salmonella enterica.
These bacteria are typically characterized by their ability to ferment various sugars and produce acid and gas as byproducts. They can also be distinguished by their biochemical reactions, such as their ability to produce certain enzymes or resist specific antibiotics. Infections caused by Enterobacteriaceae can range from mild to severe, depending on the species involved and the overall health of the infected individual.
Some infections caused by Enterobacteriaceae include urinary tract infections, pneumonia, bloodstream infections, and foodborne illnesses. Proper hygiene, such as handwashing and safe food handling practices, can help prevent the spread of these bacteria and reduce the risk of infection.
"Escherichia" is a genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that are commonly found in the intestines of warm-blooded organisms. The most well-known species in this genus is "Escherichia coli," or "E. coli," which is a normal inhabitant of the human gut and is often used as an indicator of fecal contamination in water and food. Some strains of E. coli can cause illness, however, including diarrhea, urinary tract infections, and meningitis. Other species in the genus "Escherichia" are less well-known and are not typically associated with disease.
Proteus vulgaris is a species of Gram-negative, facultatively anaerobic, rod-shaped bacteria that are commonly found in soil, water, and the human digestive tract. They are named after the Greek god Proteus, who could change his shape at will, as these bacteria are known for their ability to undergo various morphological changes.
Proteus vulgaris is a member of the family Enterobacteriaceae and can cause opportunistic infections in humans, particularly in individuals with weakened immune systems or underlying medical conditions. They can cause a variety of infections, including urinary tract infections, wound infections, pneumonia, and bacteremia (bloodstream infections).
Proteus vulgaris is also known for its ability to produce urease, an enzyme that breaks down urea into ammonia and carbon dioxide. This can lead to the formation of urinary stones and contribute to the development of chronic urinary tract infections. Additionally, Proteus vulgaris can form biofilms, which can make it difficult to eradicate the bacteria from infected sites.
In a medical context, identifying Proteus vulgaris is important for determining appropriate antibiotic therapy and managing infections caused by this organism.
Guanosine diphosphate sugars (GDP-sugars) are nucleotide sugars that play a crucial role in the biosynthesis of complex carbohydrates, such as glycoproteins and proteoglycans. Nucleotide sugars are formed by the attachment of a sugar molecule to a nucleoside diphosphate, in this case, guanosine diphosphate (GDP).
GDP-sugars serve as activated donor substrates for glycosyltransferases, enzymes that catalyze the transfer of sugar moieties onto various acceptor molecules, including proteins and lipids. The GDP-sugar synthesis pathway involves several enzymatic steps, starting with the conversion of nucleoside triphosphate (NTP) to nucleoside diphosphate (NDP), followed by the attachment of a sugar moiety from a donor molecule, such as UDP-glucose or TDP-rhamnose.
Examples of GDP-sugars include:
1. GDP-mannose: A nucleotide sugar that serves as a donor substrate for the addition of mannose residues to glycoproteins and proteoglycans.
2. GDP-fucose: A nucleotide sugar that is involved in the biosynthesis of fucosylated glycoconjugates, which have important functions in cell recognition, signaling, and development.
3. GDP-rhamnose: A nucleotide sugar that plays a role in the synthesis of rhamnosylated glycoconjugates, found in bacterial cell walls and some plant polysaccharides.
4. GDP-glucose: A nucleotide sugar that is used as a donor substrate for the addition of glucose residues to various acceptors, including proteins and lipids.
Dysregulation of GDP-sugar metabolism has been implicated in several diseases, such as cancer, neurodegenerative disorders, and bacterial and viral infections. Therefore, understanding the synthesis, regulation, and function of GDP-sugars is crucial for developing novel therapeutic strategies to target these conditions.
Proteus mirabilis is a species of Gram-negative, facultatively anaerobic, rod-shaped bacteria that are commonly found in the environment, particularly in soil and water. In humans, P. mirabilis can be part of the normal gut flora but can also cause opportunistic infections, particularly in the urinary tract. It is known for its ability to produce urease, which can lead to the formation of urinary stones and blockages.
P. mirabilis infections are often associated with underlying medical conditions such as diabetes, kidney disease, or urinary catheterization. Symptoms of a P. mirabilis infection may include fever, cloudy or foul-smelling urine, and pain or burning during urination. Treatment typically involves antibiotics that are effective against Gram-negative bacteria, although resistance to certain antibiotics is not uncommon in P. mirabilis isolates.
"Morganella" is a genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that are commonly found in the environment, including in soil, water, and the gastrointestinal tracts of animals. The most well-known species within this genus is "Morganella morganii," which can cause various types of infections in humans, particularly in individuals with weakened immune systems.
"Morganella morganii" is a common cause of healthcare-associated infections, such as urinary tract infections, wound infections, and bacteremia (bloodstream infections). It can also cause traveler's diarrhea and other types of gastrointestinal infections.
In addition to its clinical importance, "Morganella morganii" is also notable for its ability to produce a variety of enzymes, including proteases, lipases, and hemolysins, which can contribute to its virulence and invasiveness in humans. It is resistant to many antibiotics, making it a challenging organism to treat in some cases.
Urease is an enzyme that catalyzes the hydrolysis of urea into ammonia and carbon dioxide. It is found in various organisms, including bacteria, fungi, and plants. In medicine, urease is often associated with certain bacterial infections, such as those caused by Helicobacter pylori, which can produce large amounts of this enzyme. The presence of urease in these infections can lead to increased ammonia production, contributing to the development of gastritis and peptic ulcers.