TABLE 2.
Phenotypic and genotypic characterization of comparator blood isolates, including phenotypic susceptibility testing and evaluation of chromogenic culture mediuma
| Isolate | Class | Result of molecular testing |
Result of susceptibility testing |
Result with MRSA screening agar(s): |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| PBP2a | mecA PCR | FOX DD, MH | OXA DD, MH | OXA GD, 2% NaCl MH | Spectra MRSA | HardyCHROM MRSA | Nonchromogenic MRSA screen | Other 3 agarsb | ||
| 1 | MSSA | – | – | S | S | S | – | – | – | – |
| 2 | MSSA | – | – | S | S | S | – | – | – | – |
| 3 | MSSA | – | – | S | S | S | – | – | – | – |
| 4 | MSSA | – | – | S | S | S | – | – | – | – |
| 5 | MSSA | – | – | S | S | S | – | – | – | – |
| 6 | MSSA | – | – | S | S | S | – | – | – | – |
| 7 | MSSA | – | – | S | S | S | – | – | – | – |
| 8 | MSSA | – | – | S | S | S | – | – | – | – |
| 9 | MSSA | – | – | S | S | S | – | – | – | – |
| 10 | BORSA | – | – | S | S | R | – | – | – | – |
| 11 | MSSA | – | – | S | S | S | + | – | – | – |
| 12 | BORSA | – | – | S | S | R | – | ++ | – | – |
| 13 | MSSA | – | – | S | S | S | – | – | – | – |
| 14 | MSSA | – | – | S | S | S | – | – | – | – |
| 15 | MSSA | – | – | S | S | S | – | – | – | – |
| 16 | MSSA | – | – | S | S | S | – | – | – | – |
| 17 | MSSA | – | – | S | S | S | – | – | – | – |
| 18 | MSSA | – | – | S | S | S | – | – | – | – |
| 19 | MSSA | – | – | S | S | S | – | – | – | – |
| 20 | BORSA | – | – | S | S | R | – | – | – | – |
| 21 | MSSA | – | – | S | S | S | – | – | – | – |
| 22 | MSSA | – | – | S | S | S | – | ++ | – | – |
| 23 | BORSA | – | – | S | S | R | – | + | – | – |
| 24 | MSSA | – | – | S | S | S | – | – | – | – |
| 25 | MSSA | – | – | S | S | S | – | – | – | – |
| 26 | BORSA | – | – | S | S | R | ++ | – | + | – |
| 27 | MSSA | – | – | S | S | S | – | – | – | – |
| 28 | MSSA | – | – | S | S | S | – | – | – | – |
| 29 | BORSA | – | – | S | S | R | – | – | – | – |
| 30 | MSSA | – | – | S | S | S | – | – | – | – |
| 31 | MSSA | – | – | S | S | S | – | – | – | – |
| 32 | MSSA | – | – | S | S | S | – | – | – | – |
| 33 | MSSA | – | – | S | S | S | – | – | – | – |
| 34 | BORSA | – | – | S | S | R | – | – | – | – |
| 35 | MSSA | – | – | S | S | S | – | – | – | – |
| 36 | MSSA | – | – | S | S | S | – | – | – | – |
| 37 | BORSA | – | – | S | S | R | – | – | – | – |
| 38 | MSSA | – | – | S | S | S | – | – | – | – |
| 39 | MSSA | – | – | S | S | S | – | – | – | – |
| 40 | MSSA | – | – | S | S | S | – | – | – | – |
| 41 | MSSA | – | – | S | S | S | – | – | – | – |
| 42 | MSSA | – | – | S | S | S | – | – | – | – |
| 43 | MSSA | – | – | S | S | S | – | – | – | – |
| 44 | MSSA | – | – | S | S | S | – | – | – | – |
| 45 | MSSA | – | – | S | S | S | – | – | – | – |
| 46 | MSSA | – | – | S | S | S | – | – | – | – |
| 47 | MSSA | – | – | S | S | S | – | – | – | – |
| 48 | MSSA | – | – | S | S | S | – | – | – | – |
| 49 | BORSA | – | – | S | S | R | – | – | – | – |
| 50 | MSSA | – | – | S | S | S | – | – | – | – |
| 53 | MSSA | – | – | S | S | S | – | – | – | – |
| 54 | MSSA | – | – | S | S | S | + | – | – | – |
| 55 | MSSA | – | – | S | S | S | – | – | – | – |
| 56 | MSSA | – | – | S | S | S | – | – | – | – |
| 57 | MSSA | – | – | S | S | S | – | – | – | – |
| 58 | MSSA | – | – | S | S | S | – | – | – | – |
| 59 | MSSA | – | – | S | S | S | ++ | – | – | – |
| 60 | MSSA | – | – | S | S | S | – | – | – | – |
| 61 | MSSA | – | – | S | S | S | – | – | – | – |
| 62 | MSSA | – | – | S | S | S | ++ | – | – | – |
a
Abbreviations: FOX, cefoxitin; OXA, oxacillin; DD, disk diffusion; GD, gradient diffusion; MH, Mueller-Hinton agar; P, positive; –, negative, not detected, or no growth; Det, detected; S, susceptible; R, resistant. Plus signs indicate growth abundance, as follows: rare growth (+), a few cells (++), or growth equal to that of the control strain (+++).
b
The agars MRSASelect II, BBL CHROMagar MRSA II, and chromID MRSA performed identically.