TY - JOUR
T1 - Staphylococcus aureus accessory gene regulator (agr) group II
T2 - Is there a relationship to the development of intermediate-level glycopeptide resistance?
AU - Sakoulas, George
AU - Eliopoulos, George M.
AU - Moellering, Robert C.
AU - Novick, Richard P.
AU - Venkataraman, Lata
AU - Wennersten, Christine
AU - DeGirolami, Paola C.
AU - Schwaber, Mitchell J.
AU - Gold, Howard S.
PY - 2003/3/15
Y1 - 2003/3/15
N2 - We previously determined that all 6 Staphylococcus aureus strains with confirmed intermediate-level resistance to glycopeptides (glycopeptide intermediate S. aureus [GISA]) from the United States that we tested belonged to accessory gene regulator (agr) group II. In the present study, we found that 56% of surveyed bloodstream methicillin-resistant S. aureus isolates (n = 148) at our hospital were agr group II, whereas only 24% of methicillin-susceptible S. aureus isolates (n = 33) were agr group II (P = .001). Population analysis of genetically engineered agr-null and parent wild-type strains of groups I, II, and IV revealed that, when agr function is lost, the agr group II knockout S. aureus was most likely to develop glycopeptide heteroresistance after growth in 1 μg/mL but not 16 μg/mL vancomycin. This strain was unique in showing decreased autolysis after growth in these conditions. This study suggests that some S. aureus strains have an intrinsic survival advantage under a glycopeptide selective pressure, which is possibly related to reduced autolysis after exposure to subinhibitory concentrations of glycopeptide.
AB - We previously determined that all 6 Staphylococcus aureus strains with confirmed intermediate-level resistance to glycopeptides (glycopeptide intermediate S. aureus [GISA]) from the United States that we tested belonged to accessory gene regulator (agr) group II. In the present study, we found that 56% of surveyed bloodstream methicillin-resistant S. aureus isolates (n = 148) at our hospital were agr group II, whereas only 24% of methicillin-susceptible S. aureus isolates (n = 33) were agr group II (P = .001). Population analysis of genetically engineered agr-null and parent wild-type strains of groups I, II, and IV revealed that, when agr function is lost, the agr group II knockout S. aureus was most likely to develop glycopeptide heteroresistance after growth in 1 μg/mL but not 16 μg/mL vancomycin. This strain was unique in showing decreased autolysis after growth in these conditions. This study suggests that some S. aureus strains have an intrinsic survival advantage under a glycopeptide selective pressure, which is possibly related to reduced autolysis after exposure to subinhibitory concentrations of glycopeptide.
UR - http://www.scopus.com/inward/record.url?scp=0037443852&partnerID=8YFLogxK
U2 - 10.1086/368128
DO - 10.1086/368128
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C2 - 12660939
AN - SCOPUS:0037443852
SN - 0022-1899
VL - 187
SP - 929
EP - 938
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
IS - 6
ER -