Table 2

Resistance/virulence genes detected among 137 co-located nasal Staphylococcus aureus/CoNS pairs

Detected gene(s)Phenotypic resistance/traitNo isolates positive
n (%)
P valueNo S. aureus/CoNS pairs positive (n)
S. aureus n=137CoNS n=137
Antibiotic resistance gene blaZβ-lactam101 (73.7)92 (67.1)0.28974
fusB Fusidic acid2 (1.5)27 (19.7)0.0002*0
fusCFusidic acid31 (22.6)25 (18.2)0.1591
mecA Methicillin9 (6.5)18 (13.1)0.1031
ileS2 Mupirocin1 (0.7)11 (8.0)0.005*1
qac A and qac C Quartenary ammonium salts3 (2.2)29 (21.2)<0.0001*0
tet(K) and tet(M) Tetracycline13 (9.5)6 (4.4)0.1520
erm(C) Macrolide/lincosamide6 (4.3)5 (3.6)1.0000
msr(A) Macrolide2 (1.45)15 (10.9)0.002*1
mph(C) Macrolide015 (10.9)<0.0001*0
dfrS1 Trimethoprim019 (13.8)<0.0001*0
vga Streptogramin A1 (0.7)6 (4.3)0.1200
Virulence
 ACME-arc pH tolerance1 (0.7)44 (32.1)<0.0001*1
tst1Toxic shock toxin33 (24.1)2 (1.5)<0.0001*1
  • *Indicates a statistically significant result by Fisher’s exact test.

  • †Associated with SCC element (ccrA-1 and ccrB-1) in 13/137 S. aureus.

  • tst1 confirmed by PCR.

  • ACME, arginine catabolite mobile element; CoNS, coagulase-negative staphylococci.