Msadek, T., Kunst, F., Henner, D., Klier, A., Rapoport, G., Dedonder, R. (1990) Signal transduction pathway controlling synthesis of a class of degradative enzymes in Bacillus subtilis : expression of the regulatory genes and analysis of mutations in degS and degU. J Bacteriol 172: 824-834. ...
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Ahmed Ali Al-Tufaili*, Dr. Falah Salim Manhal, Dr. Ahlam Kadhem Naeem. ABSTRACT. Background: The generally accepted hypothesis today is that UPEC involved from nonpathogenic strains by acquiring new virulence factor from accessory DNA horizontal transfer located at the chromosome or plasmid level. Aim of study: investigate the genetic determination of some pathogenicity-associated virulence factors (PAVFs) genes such as fimH, hlyA and iucC genes in UPEC and capability of transferring of them from UPEC to related and non related species such as E.coli JM 109 and P. aeruginosa as well as evaluation of genes transferring effeciency. Method: During the period from May 2014 to November 2014.a total of 290 samples has been collected from patients suffering from Urinary tract infections (170 samples) and burn infections (120 samples) from Alzahraa and Alsadr teaching Hospital as well as private clinics analytical laboratories and Central Health Laboratory in Al-Najaf Al- Ashraf City Results: seventy ...
c-Jun is a member of the early mammalian transcriptional regulators belonging to the AP-1 family, which participates in a wide range of cellular processes such as proliferation, apoptosis, tumorigenesis, and differentiation. Despite its established role in cell survival upon stress, its participation in the stress response induced by bacterial infections has been poorly investigated. To study the potential role of c-Jun in this context we choose the widely studied α-toxin produced by Staphylococcus aureus, a pore-forming toxin that is a critical virulence factor in the pathogenesis of these bacteria. We analyzed the effect of α-toxin treatment in the activation, expression, and protein levels of c-Jun in A549 lung epithelial cells. Furthermore, we explored the role of c-Jun in the cellular fate after exposure to α-toxin. Our results show that staphylococcal α-toxin per se is able to activate c-Jun by inducing phosphorylation of its Serine 73 residue. Silencing of the JNK (c-Jun N-terminal Kinase)
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BioCentrum is a privately-owned biotechnology service and product provider. The company conducts its own research, development and implementation projects in the area of microbiology and protein chemistry. The special interest is focused on bacterial virulence factors as potential therapeutic targets for drug development and on antibacterial peptides exerting an antibiotic activity.
TY - JOUR. T1 - Discovery of Salmonella virulence factors translocated via outer membrane vesicles to murine macrophages. AU - Yoon, Hyunjin. AU - Ansong, Charles. AU - Adkins, Joshua N.. AU - Heffron, Fred. PY - 2011/6. Y1 - 2011/6. N2 - Salmonella enterica serovar Typhimurium, an intracellular pathogen and leading cause of food-borne illness, encodes a plethora of virulence effectors. Salmonella virulence factors are translocated into host cells and manipulate host cellular activities, providing a more hospitable environment for bacterial proliferation. In this study, we report a new set of virulence factors that is translocated into the host cytoplasm via bacterial outer membrane vesicles (OMV). PagK (or PagK1), PagJ, and STM2585A (or PagK2) are small proteins composed of ~70 amino acids and have high sequence homology to each other (,85% identity). Salmonella lacking all three homologues was attenuated for virulence in a mouse infection model, suggesting at least partial functional ...
TY - JOUR. T1 - Evaluation of Staphylococcus aureus virulence factors using a silkworm model. AU - Miyazaki, Shinya. AU - Matsumoto, Yasuhiko. AU - Sekimizu, Kazuhisa. AU - Kaito, Chikara. PY - 2012/1/1. Y1 - 2012/1/1. N2 - Previous studies have indicated that the silkworm model is useful for identifying virulence genes of Staphylococcus aureus, a human pathogenic bacterium. Here we examined the scope of S. aureus virulence factors that can be evaluated using the silkworm model. Gene-disrupted mutants of the agr locus, arlS gene and saeS gene, which regulate the expression of cell surface adhesins and hemolysins, exhibited attenuated virulence in silkworms. Mutants of the hla gene encoding α-hemolysin, the hlb gene encoding β-hemolysin, and the psmα and psmβ operons encoding cytolysins, however, showed virulence in silkworms indistinguishable from that of the parent strain. Thus, these S. aureus cytolysins are not required for virulence in silkworms. In contrast, the gene-disrupted mutants ...
FIG. 1. Immunoprecipitation studies with anti-VirB6, anti-VirB7, and anti-VirB9 antisera. (A) Isolation of VirB protein complexes from detergent-solubilized membrane extracts of wild-type A348. (B) VirB complexes isolated from PC1000(pSJB610). Lanes: αB6, αB7, and αB9, anti-VirB antisera; PI, preimmune serum; PA, protein A Sepharose (these were all used for precipitation); Sol. Prot., solubilized starting material for the precipitations; MW, molecular weight markers, with sizes in kilodaltons shown at left. Blots were probed with antiserum to the VirB proteins listed at the right. The cross-reactive material in the blot developed with anti-VirB10 antiserum is heavy-chain IgG, but native VirB10 (48 kDa) and VirB10′ (40 kDa) derived from translation from an internal Met were clearly distinguished from this background in the immunoblots. The IgG light chain also was immunoreactive and formed a nonspecific background in blots developed with the anti-VirB6, -VirB8, and -VirB9 antisera. ...
Bacterial pathogens regulate virulence factor expression at both the level of transcription initiation and mRNA processing/turnover. Within Staphylococcus aureus, virulence factor transcript synthesis is regulated by a number of two-component regulatory systems, the DNA binding protein SarA, and the SarA family of homologues. However, little is known about the factors that modulate mRNA stability or influence transcript degradation within the organism. As our entree to characterizing these processes, S. aureus GeneChips were used to simultaneously determine the mRNA half-lives of all transcripts produced during log-phase growth. It was found that the majority of log-phase transcripts (90%) have a short half-life (|5 min), whereas others are more stable, suggesting that cis- and/or trans-acting factors influence S. aureus mRNA stability. In support of this, it was found that two virulence factor transcripts, cna and spa, were stabilized in a sarA-dependent manner. These results were validated by
virB11, one of the 11 genes of the virB operon, is absolutely required for transport of T-DNA from Agrobacterium tumefaciens into plant cells. Previous studies reported that VirB11 is an ATPase with autophosphorylation activity and localizes to the inner membrane even though the protein does not contain the consensus N-terminal export sequence. In this report, we show that VirB11 localizes to the inner membrane even in the absence of other tumor-inducing (Ti) plasmid-encoded proteins. To facilitate the further characterization of VirB11, we purified this protein from the soluble fraction of an Escherichia coli extract by fusing VirB11 to the maltose-binding protein. The maltose-binding protein-VirB11 fusion was able to complement a virB11 deletion mutant of A. tumefaciens for tumor formation and also localized properly to the inner membrane of A. tumefaciens. The 72-kDa protein, purified from E. coli, exhibited no autophosphorylation, ATPase activity, or ATP-binding activity. To study the ...
Mono- and Stereopictres of 5.0 Angstrom coordination sphere of Arsenic atom in PDB 2vs0: Structural Analysis of Homodimeric Staphylococcal Aureus Virulence Factor Esxa
Given that antibiotics are losing effectiveness faster than replacements are being found, chemist Timothy Wencewicz suggests we try a new approach. Drugs that hobble the production of virulence factors, small molecules that help bacteria to establish an infection in a host, would put much less selective pressure on bacteria and delay the evolution of resistance. In Infectious Diseases he describes recent work on a target virulence factor.
Staphylococcus aureus are widespread bacteria that can cause different infectious diseases, including superficial, invasive, and life-threatening infections. Furtheremore, MRSA is prevalent in hospitals and the community and has become a major concern around the world.. Many different virulence factors, such as surface proteins, are involved in the pathogenesis of these bacteria. One of these important proteins is sasX that has many different roles in this process, including biofilm formation, which helps the bacteria in producing micro colonies and adhesion on the surfaces and bacterial resistance against unexpected conditions (11). Regarding recent studies, SasX had an important role in the pathogenesis of the asian population and ST239 colon (8) and based on its importance, even new studiese have focused on the role of SasX protein in immunization and vaccinaton (9). Furthermore, recent studies have shown that the sasX gene is spreading to other colonies and species (8, 12). On the other ...
Shop Limited host range VirA protein ELISA Kit, Recombinant Protein and Limited host range VirA protein Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and Antibody are available.
LINK TO PAPER HERE … Hmm … did you catch that? "HIGHLY SOPHISTICATED MECHANISMS FOR REGULATING VIRULENCE FACTOR EXPRESSION IN RESPONSE TO ENVIRONMENTAL SIGNALS OR BY REVERSIBLE MUTATIONS." So … just as Eric and Dylan were no doubt affected by their environment which in turn was partly to blame for their behavior, in the same way, B. Pertussis is ALSO affected by its environment in the human body and this environment has a direct effect on VIRULENCE FACTOR EXPRESSION, i.e. whether the bacterium is dangerous to humans or not. This definitely calls for more study. (Note to self: do a full blog research article on this). This is a fascinating topic in light of the info on microbe pleomorphism (must read Wiki article on this topic HERE) and the resulting virulence (or non-virulence) discovered by Antoine Bechamp way back in Pasteurs day. To explain simply the difference between Pasteur and Bechamp, Pasteur taught that "microbes - viruses and bacteria - are bad guys" and you need to have ...
Importantly, this effector-triggered immunity has been shown to be a powerful means of augmenting the defense response specifically to pathogens but not to harmless commensals, and makes a major contribution to how plants cope with microbial attack and restrict pathogen growth. Our previous work revealed in metazoans an innate immune pathway that specifically responds to virulence factors encoded by virulent bacteria that we referred to as AVI (Boyer et al., 2011, Diabate et al., 2015). The identification of such system with similarities to plant ETI is paradigm-shifting and indicates that animals like plants have evolved sophisticated strategies to gauge the virulent potential of microbes and respond commensurately (Stuart et al., 2013). Using the prototypal RhoGTPase targeting toxin CNF1 we proved that the animal host is able to monitor the activity of virulence factors (Boyer et al., 2011). Our initial work has been extended to SopE a Salmonella virulence factor activating RhoGTPases. SopE ...
The type 3 secretion systems (T3SSs) are virulence mechanisms used by various Gram-negative bacteria to overcome the host immunity. They are often target-cell contact induced and activated. Activation results in targeting of virulence effector substrates into host cells. One class of secreted substrates, translocators, are required for the intracellular targeting of the second class, the virulence effectors, into host target cells. T3SSs are mainly regulated at 2 levels; a shift from environmental to host temperature results in low level induction of the system whereas target cell contact further induces and activates the system. In the Yersinia T3SS, YopN, one of the secreted substrates, is involved in the latter level of activation. Under non-inducing conditions, YopN complexes with TyeA, SycN and YscB and this complex suppresses the T3SS via an unknown mechanism. When the system is induced, the complex is believed to dissociate and YopN is secreted resulting in the activation of the system. ...
Originally, TAL proteins are virulence factors of the plant-pathogen Xanthomonas spp. that are injected into plant cells via a type III secretion system in order to modulate transcription1. For this purpose, their c-terminal end contains a nuclear localisation signal (NLS) and an acidic activation domain. The central part of the TAL protein contains a number of almost similar repeats that mediate specific binding to target loci in the genome (see figure 10). In 2009, two groups have simultaneously pointed out that each of these repeats specifically binds to one base of the target DNA via two amino acids (aa 12 and 13), named the repeat variable diresidues (RVD) 2. Moreover, it has been shown that DNA binding of these proteins is highly modular, i.e. the number or order of bases in the target DNA can be changed by adjusting the number or order of the repeats in the TAL protein, respectively. It is still unclear, how the sequence of DNA binding modules and TALE activity correlate. The minimal ...
Virulence genes of pathogenic bacteria, which code for toxins, adhesins, invasins or other virulence factors, may be located on transmissible genetic elements such as transposons, plasmids or bacteriophages. In addition, such genes may be part of particular regions on the bacterial chromosomes, term …
Figure 2. As if microbes were puppeteers and we humans were the puppets, microbes can control what we eat by a number of marked mechanisms. Adapted from Alcock et al 2014.. People who have "desires" of chocolate have different microbial metabolites in urine from people indifferent to chocolate, despite having the same diet.. Dysphoria, id est, human discomfort until we eat food which improve microbial "welfare", may be due to the expression of bacterial virulence genes and perception of pain by the host. This is because the production of toxins is often triggered by a low concentration of nutrients limiting growth. The detection of sugars and other nutrients regulates virulence and growth of various microbes. These directly injure the intestinal epithelium when nutrients are absent. According to this hypothesis, it has been shown that bacterial virulence proteins activate pain receptors. It has been shown that fasting in mice increases the perception of pain by a mechanism of vagal ...
Electroporation was used to insert purified bacterial virulence effector proteins directly into living eukaryotic cells. Protein localization was monitored by confocal immunofluorescence microscopy. This method allows for studies on trafficking, function, and protein-protein interactions using active exogenous proteins, avoiding the need for heterologous expression in eukaryotic cells. ...
Biofilm formation is now recognized as a key virulence factor for a wide range of chronic microbial infections. While it has been well known for decades that bacteria and fungi in biofilms become highly tolerant of ...
The process of bacterial pathogenesis involves complex and dynamic responses from both pathogen and host. While the host can mount an array of defense mechanisms to counteract an infection, bacterial pathogens utilize a number of virulence mechanisms to help them in their quest to invade, colonize, and infect. The expression pattern of virulence factors such…
Reprezentanti: vancomicina, teicoplanina. Vancomicina Farmacocinetica: Se absoarbe limitat din intestin si se eliminara prin scaun dupa administrare orala. Dupa administrare i.v (500 mg), nivelul plasmatic este maxim dupa 1-2 ore (6-10 mcg/ml).
come-up, holding and cooling. We hypothesize that slow heating rate during come-up stage, as practiced ... objectives of this study are to understand how different heating rates during come-up stage could affect (1) ... heat-stress-response and virulence genes. Compared to fast heating rate, slow rate caused higher expression of heat .... ...
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The conventional method for lignin quantitation in the pulp industry is the Klason lignin and acid-soluble lignin test, which is standardized according to TAPPI[37] or NREL[38] procedure. The cellulose is first decrystallized and partially depolymerized into oligomers by keeping the sample in 72% sulfuric acid at 30 °C for 1 h. Then, the acid is diluted to 4% by adding water, and the depolymerization is completed by either boiling (100 °C) for 4 h or pressure cooking at 2 bar (124 °C) for 1 h. The acid is washed out and the sample dried. The residue that remains is termed Klason lignin. A part of the lignin, acid-soluble lignin (ASL) dissolves in the acid. ASL is quantified by the intensity of its UV absorption peak at 280 nm. The method is suited for wood lignins, but not equally well for varied lignins from different sources. The carbohydrate composition may be also analyzed from the Klason liquors, although there may be sugar breakdown products (furfural and 5-hydroxymethylfurfural). A ...
Citation. Linz B, Ivanov YV, Preston A, Brinkac L, Parkhill J, Kim M, Harris SR, Goodfield LL, Fry NK, Gorringe AR, Nicholson TL, Register KB, Losada L, Harvill ET. Acquisition and Loss of Virulence-associated Factors During Genome Evolution and Speciation in Three Clades of Bordetella Species.. BMC Genomics. 2016 Sep 30; 17: 767.. External Citation. Abstract. The genus Bordetella consists of nine species that include important respiratory pathogens such as the classical species B. bronchiseptica, B. pertussis and B. parapertussis and six more distantly related and less extensively studied species. Here we analyze sequence diversity and gene content of 128 genome sequences from all nine species with focus on the evolution of virulence-associated factors.. ...
Bacterial traits that contribute to disease are termed virulence factors and there is much interest in therapeutic approaches that disrupt such traits. What remains less clear is whether a virulence factor identified as such in a particular context is also important in infections involving different host and pathogen types. Here, we address this question using a meta-analytic approach. We statistically analyzed the infection outcomes of 76 experiments associated with one well-studied virulence factor - pyoverdine, an iron-scavenging compound secreted by the opportunistic pathogen Pseudomonas aeruginosa. We found that this factor is consistently involved with virulence across different infection contexts. However, the magnitude of the effect of pyoverdine on virulence varied considerably. Moreover, its effect on virulence was relatively minor in many cases, suggesting that pyoverdine is not indispensable in infections. Our works supports theoretical models from ecology predicting that disease severity
General Information: Isolated from a soil sample from Nepal. Causative agent of plague. Specific virulence factors are encoded within pathogenicity islands (PAIs) that are required for the invasive phenotype associated with Yersinia infections. One key virulence plasmid contained by the three human-specific pathogens is pCD1/pYv, which encodes a type III secretion system for the delivery of virulence proteins that contribute to internalization into the host cell. It is the causative agent of plague (bubonic and pulmonary) a devastating disease which has killed millions worldwide. The organism can be transmitted from rats to humans through the bite of an infected flea or from human-to-human through the air during widespread infection. Yersinia pestis is an extremely pathogenic organism that requires very few numbers in order to cause disease, and is often lethal if left untreated. The organism is enteroinvasive, and can survive and propagate in macrophages prior to spreading systemically ...
General Information: Specific virulence factors are encoded within pathogenicity islands (PAIs) that are required for the invasive phenotype associated with Yersinia infections. One key virulence plasmid contained by the three human-specific pathogens is pCD1/pYv, which encodes a type III secretion system for the delivery of virulence proteins that contribute to internalization into the host cell. This species is a food and waterborn pathogen that causes gastroenteritis (inflammation of the mucous membranes of the stomach and intestine) and is able to proliferate at temperatures as low as 4 degrees C. ...
Listeria monocytogenes is a common bacterium that causes human infections, like miscarriage and septicemia. Listeria uses specific virulence factors to produce proteins that will assist in invasion, replication, and escape. By manipulation of the virulence factors through knockout mutants, this study observed their role and importance in the infection and proliferation life cycle. JEG-3 cells, a human placental line, were infected with wild type Listeria or knockout mutants of individual virulence factors, Internalin A&B, Listeriolysin O, and ActA. Through Colony Forming Unit Assay, it was possible to analyze the number of colonies representing the number of Listeria bacteria after definitive time points. Each virulence factor did play a significant role in the growth and infection of Listeria in the JEG-3 cells as fewer colonies were found in the knockout mutant plates than the wild type. Each virulence factor affected a distinct portion of the invasion, replication, and escape cycle. The omission of a
ABSTRACT: Candida albicans is a classical example of causative agent for opportunistic fungal infection. Normally, it colonizes skin, gastrointestinal tract, genital, and mucosal membranes, but in certain condition it may responsible for diseases. This phenomenon was mainly associated with immunological status of the host. However, there were fndings that showed the possibility of putative virulence factors work on the transition of commensally to pathogenic role of the yeast. In this review, some virulence factors were discussed. Indeed, there were factors that may be considered as putative virulence factors of C. albicans. ...
Metagenomic technologies enable the study of microbial genetic material in human biomedical sample types such as stool, nasal, oral, urogenital, skin and bronchoalveolar lavage samples. In addition, environmental samples such as soil, water, air and biofilms can be also be analyzed. Metagenomic data can not only be used to examine healthy microbiomes and shed light on causes, effects, and future therapies for a variety of diseases, but it can also be useful to help understand the environments microbial biodiversity. QIAGEN provides next-generation sequencing technologies for metagenomics, as well as qPCR assays and arrays for verification of sequencing results and screening for specific bacterial species, virulence factor genes, and antibiotic resistance genes ...
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Complete Genome Sequences of Eight Helicobacter pylori Strains with Different Virulence Factor Genotypes and Methylation Profiles, Isolated from Patients with Diverse Gastrointestinal Diseases on Okinawa Island, Japan, Determined Using PacBio Single-Molecule Real-Time Technology ...
This material is based upon work supported in part by the Office of Research and Sponsored Projects and the National Science Foundation under Grant No. DUE-0963648 and CREST Grant No. HRD-1242122. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation (NSF). ...
Our laboratory studies the roles of sensory transduction in bacterial-host interactions. Genes and operons that encode virulence factors are often subject to coordinate regulation in response to environmental signals, and bacterial virulence factors frequently target host cell signaling pathways. Specific areas of interest include: a) biochemical analysis of signal transduction pathways in pathogenic bacteria, b) genetic organization of bacterial virulence regulons, and c) in vivo and in vitro studies of mechanisms of pathogenesis. We are also investigating mechanisms involved in the induction of cytotoxic T cell responses by Listeria monocytogenes (LM). In the course of these studies, we have developed a new class of live Listeria-based vaccines with activity against heterologous pathogens and tumors. In a third project, we have discovered a new class of retroelements, called "diversity generating retroelements," which are capable of generating vast amounts diversity in proteins involved in ...
Mariotti P, Malito E, Biancucci M, Lo Surdo P, Mishra RP, Nardi-Dei V, Savino S, Nissum M, Spraggon G, Grandi G, Bagnoli F, Bottomley MJ. Structural and functional characterization of the Staphylococcus aureus virulence factor and vaccine candidate FhuD2. Biochem J. 2013 Feb 01; 449(3):683-93 ...
This work provides both in vivo and in vitro evidence that S. aureus can survive inside PMN and that this ability is regulated, at least in part, by the global regulator, sar, which governs the synthesis and secretion of several virulence factors (2). These data extend observations made in vitro with PMN and macrophages in the 1950s and 1960s (11, 12, 13, 14) and support current in vitro studies of S. aureus invasion and survival in epithelial cells, endothelial cells, and osteoblasts (16, 17, 18). Taken together, these data clearly indicate that the pathogenesis of S. aureus infection involves both extracellular and intracellular locales. Moreover, our data suggest that S. aureus, like bona fide intracellular pathogens (26), has the ability to invade and survive inside the very cell that is responsible for its destruction. Our electron microscopy studies and those assessing invasion of epithelial cells (17) suggest a possible mechanism by which this could occur. In both epithelial cells and ...
This work provides both in vivo and in vitro evidence that S. aureus can survive inside PMN and that this ability is regulated, at least in part, by the global regulator, sar, which governs the synthesis and secretion of several virulence factors (2). These data extend observations made in vitro with PMN and macrophages in the 1950s and 1960s (11, 12, 13, 14) and support current in vitro studies of S. aureus invasion and survival in epithelial cells, endothelial cells, and osteoblasts (16, 17, 18). Taken together, these data clearly indicate that the pathogenesis of S. aureus infection involves both extracellular and intracellular locales. Moreover, our data suggest that S. aureus, like bona fide intracellular pathogens (26), has the ability to invade and survive inside the very cell that is responsible for its destruction. Our electron microscopy studies and those assessing invasion of epithelial cells (17) suggest a possible mechanism by which this could occur. In both epithelial cells and ...
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Expertise Antibiotic resistance Escherichia coli Virulence factors Role in StARE The University of Aveiro team will evaluate the efficiency of advanced water treatment processes in the removal of genes conferring resistance to antibiotics that are critically important to humans. We will use culture-dependent and independent approaches and our experiments will include the analysis of field…
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AB - Type IV pili (Tfp), which are key virulence factors in many bacterial pathogens, define a large group of multipurpose filamentous nanomachines widespread in Bacteria and Archaea. Tfp biogenesis is a complex multistep process, which relies on macromolecular assemblies composed of 15 conserved proteins in model gram-negative species. To improve our limited understanding of the molecular mechanisms of filament assembly, we have used a synthetic biology approach to reconstitute, in a nonnative heterologous host, a minimal machinery capable of building Tfp. Here we show that eight synthetic genes are sufficient to promote filament assembly and that the corresponding proteins form a macromolecular complex at the cytoplasmic membrane, which we have purified and characterized biochemically. Our results contribute to a better mechanistic understanding of the assembly of remarkable dynamic filaments nearly ubiquitous in prokaryotes ...
BioCentrum is a privately-owned biotechnology service and product provider. The company conducts its own research, development and implementation projects in the area of microbiology and protein chemistry. The special interest is focused on bacterial virulence factors as potential therapeutic targets for drug development and on antibacterial peptides exerting an antibiotic activity.
Inflammation mediated by the inflammasome and the cytokine IL-1β are some of the earliest and most important alarms to infection. These pathways are responsive to the virulence factors that pathogens use to subvert immune processes, and thus are typically activated only by microbes with potential to cause severe disease. Among the most serious human infections are those caused by the pathogenic streptococci, in part because these species numerous strategies for immune evasion. Since the virulence factor armament of each pathogen is unique, the role of IL-1β and the pathways leading to its activation varies for each infection. This review summarizes the role of IL-1β during infections caused by streptococcal pathogens, with emphasis on emergent mechanisms and concepts countering paradigms determined for other organisms ...
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The extent of the transfer of the adenosine 5-diphosphate ribose (ADPR) moiety of nicotinamide adenine dinucleotide onto elongation factor 2 (EF-2) catalyzed by Pseudomonas aeruginosa exotoxin A (PA-toxin) was dependent upon the presence of a reducing agent, dithiotheritol (DTT). The reaction requires DTT in low concentration (1 to 10 mM) and in the absence of DTT less product, ADPR-EF 2, was formed. PA-toxin was fully activated by treatment with a denaturing agent, sodium dodecyl sulphate (SDS), in conjunction with DTT. In the presence of activated toxin, the maximum transfer of ADPR onto EF-2 was observed when EF-2 had been previously reduced with DTT. Denaturation of EF-2 prior to reduction did not produce a further increase in its ability to act as a substrate for PA-toxin ...