The synthesis of virulence factors and other extracellular proteins by Staphylococcus aureus is globally controlled the agr locus, which encodes a two-component signaling pathway whose activating ligand an -encoded autoinducing peptide. cognate peptides produced some strains inhibit expression in strains, amino acid sequences peptide receptor are markedly different between such suggesting hypervariability-generating mechanism. Cross-inhibition gene represents type bacterial interference that...

Some bacterial pathogens elaborate and secrete virulence factors in response to environmental signals, others a specific host product, still no discernible cue. In this study, we have demonstrated that the synthesis of Staphylococcus aureus is controlled by density-sensing system utilizes an octapeptide produced organism itself. The activates expression agr locus, global regulator response. This involves reciprocal regulation genes encoding surface proteins those secreted factors. As cells...

[This corrects the article on p. 168 in vol. 40.].

We have previously identified a gene in Staphylococcus aureus, agr, whose activity is required for high-level post-exponential-phase expression of series secreted proteins. In this paper, we describe the cloning Escherichia coli by using an inserted transposon (Tn551) as probe. The cloned gene, consisting 241-codon open reading frame containing site insertion, was recloned to S. aureus vector, pSK265, and shown be functional aureus. Activity evaluated determinations alpha-hemolysin,...

The synthesis of virulence factors and other extracellular proteins responsible for pathogenicity in Staphylococcus aureus is under the control agr locus. A secreted agr-encoded peptide, AgrD, processed from AgrD gene product, known to be an effector self-strain activation cross-strain inhibition response. Biochemical analysis peptides isolated culture supernatants has suggested that they contain unusual thiol ester-linked cyclic structure. In present work, chemical used confirm mature a...

SUMMARY: Seventy-five mutants with alterations in penicillinase formation were isolated from a strain of Staphylococcus aureus inducible for penicillinase. The fell into three main categories on the basis activity and inducibility: (i) microinducible which formed decreased amounts but retained property inducibility; (ii) penicillinase-negative variants produced no detectable showed effect inoculum size penicillin resistance; (iii) strains wide range activities that enzyme constitutively....

Soon after methicillin was introduced into clinical practice in the early 1960s, resistant strains of Staphylococcus aureus (MRSA) appeared, bearing a newly acquired resistance gene, mecA , that encodes penicillin binding protein, PBP2a. MRSA have spread throughout world, and an investigation clonality 472 isolates by DNA hybridization performed. All could be divided six temporally ordered patterns, three these were subdivided chromomosomal transposon Tn 554 . Each pattern occurred...

Tst, the gene for toxic shock syndrome toxin-1 (TSST-1), is part of a 15.2 kb genetic element in Staphylococcus aureus that absent TSST-1-negative strains. The prototype, RN4282, flanked by 17 nucleotide direct repeat and contains genes second possible superantigen toxin, Dichelobacter nodosus VapE homologue putative integrase. It readily transferred to recA recipient, it always inserts into unique chromosomal copy sequence same orientation. excised circularized staphylococcal phages phi13...

The penicillinase plasmids, a series of extrachromosomal resistance factors in Staphylococcus aureus , were found to carry determinants inorganic ions as well penicillin and, some cases, erythromycin. Most the involved inhibitory but not lethal bacteria; markers conferred an increase by comparison with susceptible organisms between 3- and 100-fold, depending on ion involved. Separate genetic loci for arsenate, arsenite, lead, cadmium, mercuric, bismuth demonstrated. Resistance antimony zinc...

ABSTRACT Our understanding of staphylococcal pathogenesis depends on reliable genetic tools for gene expression analysis and tracing bacteria. Here, we have developed evaluated a series novel versatile Escherichia coli -staphylococcal shuttle vectors based PCR-generated interchangeable cassettes. Advantages our module system include the use (i) low-copy-number, high-copy-number, thermosensitive theta replicons selectable markers (choice erythromycin, tetracycline, chloramphenicol, kanamycin,...

ABSTRACT The pathogenicity of Staphylococcus aureus strains varies tremendously (as seen with animals). It is largely dependent on global regulators, which control the production toxins, virulence, and fitness factors. Despite vast knowledge staphylococcal molecular genetics, there still widespread dispute over what factors must come together to make a strain highly virulent. S. NCTC8325 (RN1 derivatives) widely used model for an incomparable wealth has accumulated in almost 50 years since...

ABSTRACT Antibiotics that interfere with DNA replication and cell viability activate the SOS response. In Staphylococcus aureus , antibiotic-induced response promotes high-frequency horizontal transfer of pathogenicity island-encoded virulence factors. Here we report β-lactams induce a bona fide in S. characterized by activation RecA LexA proteins, two master regulators Moreover, show are capable triggering staphylococcal prophage induction lysogens. Consequently, as previously described for...

The accessory gene regulator (agr) of Staphylococcus aureus is a global the staphylococcal virulon, which includes secreted virulence factors and surface proteins. agr locus important for in variety animal models infection, has been assumed by inference to have major role human infection. Although most clinical S. isolates are +, there several reports agr-defective mutants isolated from infected patients. Since it well known that genetically labile vitro, we addressed question whether...