Table 5.
Activity of crude extracts of isogenic E. coli with cloned β-lactamases
| Ertapenem | Meropenem | Imipenem | Doripenem | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Concentration of NaHCO3 (mmol/L) | 0 | 25 | 50 | Activity/50 mmol/L | 0 | 25 | 50 | Activity/50 mmol/L | 0 | 25 | 50 | Activity/50 mmol/L | 0 | 25 | 50 | Activity/50 mmol/L |
| OXA-1 | ND | ND | ND | ND | 8 % | 20 % | 100 % | 0.00203 | 25 % | 41 % | 100 % | 0.00358 | ND | ND | ND | ND |
| OXA-9 | ND | ND | ND | ND | ND | ND | ND | ND | ND | ND | ND | ND | ND | ND | ND | ND |
| OXA-48 | 23 % | 36 % | 100 % | 0.00465 | 42 % | 51 % | 100 % | 0.00782 | 32 % | 45 % | 100 % | 0.00680 | 31 % | 51 % | 100 % | 0.00554 |
| VIM-1 | 62 % | 74 % | 100 % | 0.00271 | 44 % | 49 % | 100 % | 0.00848 | 20 % | 43 % | 100 % | 0.00845 | 31 % | 40 % | 100 % | 0.00608 |
| KPC-2 | 63 % | 83 % | 100 % | 0.00292 | 42 % | 60 % | 100 % | 0.00872 | 35 % | 56 % | 100 % | 0.00872 | 31 % | 65 % | 100 % | 0.00437 |
Activity was determined as a slope of absorbance decrease in time
ND no activity against the antibiotic tested was detected (activity index <0.001)