TABLE 1.

Phenotypic and genotypic features of S. aureus and CoNS control strains

Identification no.eStrainMIC (μg/ml) ofa:Positive (+) or negative (−) result for the following geneb:
OXAcMUPd16S rRNAmupAmecAnuc
1MSSA (ATCC 29213)0.250.12++
2MUP-susceptible S. aureus (ATCC 25923)0.250.25++
3MRSA (ATCC 33591)>2560.12+++
4H-MuR-MRSA-80>256>1,024++++
5H-MuR-MRSA-85>256>1,024++++
6H-MuR-MRSA-221>256>1,024++++
7L-MuR-MRSA-218>25616.0+++
8L-MuR-MRSA-246>25612.0+++
9H-MuR-MSSA-120.12>1,024+++
10H-MuR-MSSA-170.25>1,024+++
11H-MuR-MSSA-260.25>1,024+++
12H-MuR-MR-CoNS-P14>256>1,024+++
13H-MuR-MS-CoNS-P150.19>1,024++
14H-MuR-MS-CoNS-P160.19>1,024++
15S. epidermidis (ATCC 14990)0.120.12+
16S. saprophyticus (ATCC 13518)1.54.0+
17S. haemolyticus (ATCC 29970)0.190.38+
18S. lugdunensis1.00.25+
19S. sciuri (ATCC 29060)1.50.38+
20S. simulans (ATCC 27851)0.380.19+
21S. xylosus (ATCC 29971)1.00.5+
22S. pyogenes (ATCC 19615)NDND
  • a The MIC was determined by the E-test according to the manufacturer's instructions. ND, not done.

  • b 16S rRNA, Staphylococcus genus specific; mupA, determinant of H-MuR; mecA, determinant of MET resistance; nuc, S. aureus species specific.

  • c For the OXA E-test, MICs of ≤2 μg/ml indicate susceptibility and MICs of ≥4 μg/ml indicate resistance in S. aureus, and MICs of ≤0.25 μg/ml indicate susceptibility and ≥0.5 μg/ml indicate resistance in CoNS; however, MICs of 0.5 to 2 μg/ml and negative results for the mecA gene were also recorded as susceptibility in CoNS (26).

  • d For the MUP E-test, MICs of ≤4 μg/ml indicate susceptibility, MICs of ≥512 μg/ml indicate H-MuR, and MICs of 8 to 256 μg/ml indicate L-MuR in both S. aureus and CoNS (2, 8, 10).

  • e Identification numbers in first column correspond to lane numbers in Fig. 2B.