Volume 15, Number 10—October 2009
Dispatch
Escherichia coli as Reservoir for Macrolide Resistance Genes
Table 1
MICs of erythromycin and distribution of macrolide resistance genes among 190 Escherichia coli isolates from 5 countries*
| E. coli origin (no. isolates) | MIC of erythromycin, mg/L |
Gene, no. (%)† |
|||||
|---|---|---|---|---|---|---|---|
| Range | MIC50 | MIC90 | erm(B) | mph(A) | mph(B) | ||
| French Guiana, Amerindians (45) | 32–1,024 | 64 | 128 | 0 | 1 (2) | 0 | |
| Senegal, remote village (20) | 64–128 | 128 | 128 | 0 | 0 | 0 | |
| Niger, children (29) | 64–>1,024 | 256 | >1,024 | 0 | 9 (31) | 0 | |
| France, healthy nurses (49) | 16–256 | 64 | 128 | 0 | 2 (4) | 1 (2) | |
| France, ESBL isolates (10) | 64–1,024 | 128 | 1,024 | 0 | 3 (30) | 1 (10) | |
| Vietnam, ESBL isolates (37) | 32–>1,024 | 512 | >1,024 | 5 (13.5) | 19 (51) | 0 | |
| France, hospital isolates resistant to ampicillin and cotrimoxazole (100) | 32–>1,024 | 64 | >1,024 | 1 (1) | 13 (13) | 0 | |
*ESBL, extended-spectrum β-lactamase; MIC50, MIC at which 50% of isolates are inhibited; MIC90, MIC at which 90% of isolates are inhibited.
†No isolate contained the erm(A), erm(C), ere(A), ere(B), msr(A), or mef(A) genes.


