Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sera from patients with endocarditis and bacteremia due to Staphylococcus aureus were compared for peptidoglycan-binding capacity with those from normal blood donors. Those patients treated with beta-lactam antibiotics had higher antigen-binding levels than normal donors and patients treated exclusively with vancomycin (P less than 0.01). The factor responsible for this activity was purified by affinity chromatography from a normal donor and shown to be an immunoglobulin. Specificity studies indicated that the immunodominant determinant was a peptide sequence found in peptidoglycan precursors. Since soluble peptidoglycan molecules having the precursor peptide sequence are known to be secreted by some gram-positive bacteria like Micrococcus luteus when grown in the presence of beta-lactam antibiotics, these soluble molecules may constitute the "natural" immunogen. Such a hypothesis is consistent with the study of the peptidoglycan-binding capacities in the sera of these patients during the course of treatment. For most of the responding patients studied (four of four with bacteremia and seven of nine with endocarditis), a significant increase in peptidoglycan-binding capacity was observed in sera taken 1 to 5 weeks after the initiation of beta-lactam antibiotic therapy (compared with the initial serum studied). No such increase in the peptidoglycan-binding capacity over a similar time span was noted in the sera of people not receiving beta-lactam antibiotics (none of seven).
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PMID:Antibody levels to bacterial peptidoglycan in human sera during the time course of endocarditis and bacteremic infections caused by Staphylococcus aureus. 728 82

Streptococcus gallolyticus subsp. gallolyticus, a member of the group D streptococci, is normally found in the bovine rumen and human gut. It is an opportunistic pathogen that was recently determined to be a bacterial driver of colorectal cancer, in addition to causing other diseases, such as infective endocarditis, bacteremia, neonatal meningitis, and septicemia. As an emerging pathogen, not much is known about this bacterium, its virulence mechanisms, or its virulence regulatory pathways. Previous studies suggest that S. gallolyticus subsp. gallolyticus uses a ComRS pathway, one of many Streptococcus quorum-sensing circuitries, for competence. However, thus far, the ubiquitous ComABCDE pathway has not been studied, nor has its regulatory role in S. gallolyticus subsp. gallolyticus We therefore sought to study the S. gallolyticus subsp. gallolyticus ComABCDE quorum-sensing pathway and have identified its peptide pheromone, which is termed the competence-stimulating peptide (CSP). We further determined that this peptide regulates the production of bacteriocin-like inhibitory substances (BLISs), a phenotype that has been linked with the ComABCDE pathway in both Streptococcus pneumoniae and Streptococcus mutans Our data show that S. gallolyticus subsp. gallolyticus TX20005 produces a 21-mer CSP signal, which differs from CSP signals of other Streptococcus species in that its active form begins three residues after the double-glycine leader signal of the ComC precursor peptide. Additionally, our data suggest that this peptide might not be related to competence induction, as opposed to CSP signaling peptides in other Streptococcus species. This study provides the first evidence that S. gallolyticus subsp. gallolyticus utilizes quorum sensing to eliminate competitors, presenting a potential pathway to target this emerging human pathogen.IMPORTANCEStreptococcus gallolyticus subsp. gallolyticus is an emerging human pathogen known as a causative agent of infective endocarditis, and recently, of colorectal cancer. In this work, we revealed a functional quorum-sensing circuitry in S. gallolyticus subsp. gallolyticus, including the identification of the central signaling peptide pheromone, competence-stimulating peptide (CSP), and the regulatory role of this circuitry in the production of bacteriocin-like inhibitory substances (BLISs). This work uncovered a mechanism by which this bacterium outcompetes other bacterial species and thus provides a potential tool to study this opportunistic pathogen.
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PMID:Identification of Streptococcus gallolyticus subsp. gallolyticus (Biotype I) Competence-Stimulating Peptide Pheromone. 2944 Feb 56