Table 2.
Culture-based antibiotic resistance and presence (+) and absence (−) of AR gene elements observed with LAMP assays tested on Gene-Z cards with crude heat-lysed non-purified cell templates
| Isolate number | Phenotypic antibiotic resistance (MIC-μg/mL) | LAMP assay (T t, min) | ||||
|---|---|---|---|---|---|---|
| norA | ble | tetM | mecA | nuc | ||
| S. aureus Mu50 | Not tested | +(27) | +(21) | +(18) | +(22) | +(20) |
| AR131 | Amp (1), Pen (4), Rif (>4), Cli (>2), Ery (>4), Oxa (>8), Syn (>8), Tet (>16) | − | − | +(21) | − | − |
| AR132 | Amp (8), Pen (>8), Cip (>2), Ery (>4), Gat (4), Lev (8), Oxa (>8) | +(30) | − | − | +(24) | +(24) |
| AR133 | Pen (0.5), Cip (>2), Cli (>2), Ery (>4), Tet (>16) | − | − | +(25) | − | − |
| AR134 | Amp (>16), Pen (>8), Cef (>64), Cip (>2), Cli (>2), Ery (>4), Gat (8), Lev (>8), Oxa (>8) | +(26) | +(17) | − | +(18) | +(22) |
| AR135 | Amp (8), Pen (>8), Cef (>64), Cip (>2), Ery (>4), Gat (4), Lev (>8), Oxa (>8) | +(30) | +(19) | − | +(18) | +(21) |
| AR136 | Amp (>16), Pen (>8), Cef (>64), Cip (>2), Cli (>2), Ery (>4), Gat (>8), Lev (>8), Oxa (>8) | +(29) | +(18) | − | +(18) | +(22) |
| AR137 | Rif (>4), Cip (>2), Ery (>4), Gat (>8), Lev (>8), Syn (>4), Tet (>16), Tri (>4), Van (>128) | +(35) | − | −a | − | +(22a) |
| AR139 | Amp (>16), Pen (>8), Cef (>64), Cli (>2), Ery (>4), Gen (16), Oxa (>8) | − | − | − | +(26) | − |
| AR141 | Amp (>16), Pen (>8), Cef (>64), Cip (>2), Cli (>2), Ery (>4), Gat (>8), Lev (>8), Oxa (>8) | +(31) | +(16) | −a | +(22) | +(21) |
| AR142 | Amp (>16), Pen (>8), Cip (>2), Ery (>4), Gat (8), Lev (>8), Oxa (>8) | +(41) | +(31) | − | +(26) | +(28) |
| AR143 | Amp (>16), Pen (>8), Cef (>64), Cip (>2), Cli (>2), Ery (>4), Gat (8), Lev (>8), Oxa (>8) | +(35) | +(31) | −a | +(24) | +(20) |
Mean threshold time (T t, min) for three replicate reactions is listed in parentheses
Amp ampicillin, Pen penicillin, Rif rifampin, Cli clindamycin, Ery erythromycin, Oxa oxacillin, Syn quinupristin-dalfopristin, Tet tetracycline, Cip ciprofloxacin, Gat gatifloxacin, Lev levofloxacin, Cef ceftriaxone, Tri trimethoprim-sulfamethoxazole, Van vancomycin, Gen gentamicin
aAmbiguous results with endpoint image analysis; thus, images captured in real time were used for calls of presence and absence