Accessory gene regulator (agr) locus in geographically diverse Staphylococcus aureus isolates with reduced susceptibility to vancomycin. Export

@article{citeulike:3733425, abstract = {The majority of infections with glycopeptide intermediate-level resistant Staphylococcus aureus (GISA) originate in biomedical devices, suggesting a possible increased ability of these strains to produce biofilm. Loss of function of the accessory gene regulator (agr) of S. aureus has been suggested to confer an enhanced ability to bind to polystyrene. We studied agr in GISA, hetero-GISA, and related glycopeptide-susceptible S. aureus isolates. All GISA strains from diverse geographic origins belong to agr group II. All GISA strains were defective in agr function, as demonstrated by their inability to produce delta-hemolysin. Hetero-GISA isolate A5940 demonstrated a nonsense mutation in agrA that was not present in a pulsed-field gel electrophoresis-indistinguishable vancomycin-susceptible isolate from the same patient. Various other agr point mutations were noted in several clinical GISA and hetero-GISA isolates. A laboratory-generated agr-null strain demonstrated a small but reproducible increase in vancomycin heteroresistance after growth in vitro in subinhibitory concentrations of vancomycin. This was not seen in the isogenic agr group II parent strain in which agr was intact. The in vitro bactericidal activity of vancomycin was attenuated in the agr-null strain compared to the parent strain. These findings imply that compromised agr function is advantageous to clinical isolates of S. aureus toward the development of vancomycin heteroresistance, perhaps through the development of vancomycin tolerance.}, author = {Sakoulas, G. and Eliopoulos, G. M. and Moellering, R. C. and Wennersten, C. and Venkataraman, L. and Novick, R. P. and Gold, H. S.}, citeulike-article-id = {3733425}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/11959587}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=11959587}, comment = {GISA only arisen in prosthetic material. agr is accesroy gene regulator - quorum sensing. Geographically diverse hGISA and GISA isolates have similar changes in agr. agr polymorphisms split S. aureus into 4 groups}, issn = {0066-4804}, journal = {Antimicrobial agents and chemotherapy}, keywords = {glycopeptide, mrsa, quorum}, month = {May}, number = {5}, pages = {1492--1502}, posted-at = {2008-12-01 19:54:53}, priority = {2}, title = {Accessory gene regulator (agr) locus in geographically diverse Staphylococcus aureus isolates with reduced susceptibility to vancomycin.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/11959587}, volume = {46}, year = {2002} }

TY - JOUR ID - citeulike:3733425 L3 - citeulike-article-id:3733425 N2 - The majority of infections with glycopeptide intermediate-level resistant Staphylococcus aureus (GISA) originate in biomedical devices, suggesting a possible increased ability of these strains to produce biofilm. Loss of function of the accessory gene regulator (agr) of S. aureus has been suggested to confer an enhanced ability to bind to polystyrene. We studied agr in GISA, hetero-GISA, and related glycopeptide-susceptible S. aureus isolates. All GISA strains from diverse geographic origins belong to agr group II. All GISA strains were defective in agr function, as demonstrated by their inability to produce delta-hemolysin. Hetero-GISA isolate A5940 demonstrated a nonsense mutation in agrA that was not present in a pulsed-field gel electrophoresis-indistinguishable vancomycin-susceptible isolate from the same patient. Various other agr point mutations were noted in several clinical GISA and hetero-GISA isolates. A laboratory-generated agr-null strain demonstrated a small but reproducible increase in vancomycin heteroresistance after growth in vitro in subinhibitory concentrations of vancomycin. This was not seen in the isogenic agr group II parent strain in which agr was intact. The in vitro bactericidal activity of vancomycin was attenuated in the agr-null strain compared to the parent strain. These findings imply that compromised agr function is advantageous to clinical isolates of S. aureus toward the development of vancomycin heteroresistance, perhaps through the development of vancomycin tolerance. IS - 5 JF - Antimicrobial agents and chemotherapy SN - 0066-4804 EP - 1502 TI - Accessory gene regulator (agr) locus in geographically diverse Staphylococcus aureus isolates with reduced susceptibility to vancomycin. VL - 46 SP - 1492 KW - glycopeptide KW - mrsa KW - quorum N1 - GISA only arisen in prosthetic material. agr is accesroy gene regulator - quorum sensing. Geographically diverse hGISA and GISA isolates have similar changes in agr. agr polymorphisms split S. aureus into 4 groups AU - Sakoulas, G AU - Eliopoulos, GM AU - Moellering, RC AU - Wennersten, C AU - Venkataraman, L AU - Novick, RP AU - Gold, HS PY - 2002/05// UR - http://view.ncbi.nlm.nih.gov/pubmed/11959587 ER -