Mecillinam resistance in Escherichia coli: dissociation of growth inhibition and morphologic change.
The resistance of mecillinam of Escherichia coli strain RF292, which was isolated from a patient during relapse of septicemia, was investigated. Although strain RF292 underwent morphologic change at the same concentration of mecillinam as the wild-type strain (RF81) and a revertant strain (RF293), RF292 was 128-fold more resistant than RF81 or RF293 to growth inhibition by mecillinam. The resistance of RF292 was associated with a 15%-35% longer generation time and a 30%-35% smaller cell volume than RF81 or RF293. The latter two strains. When growing slowly under nutritionally deprived conditions, assumed a mecillinam-resistant phenotype. Thus, resistance of E. coli to growth inhibition by mecillinam can occur in association with a slow growth rate and a small cell volume of either hereditary or environmental origin.
D000328:Adult; D000560:Amdinocillin / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D004927:Escherichia coli Infections / Q000188:drug therapy; D006801:Humans; D008297:Male; D009154:Mutation / Q000187:drug effects; D010397:Penicillanic Acid / Q000494:pharmacology*; D010403:Penicillin Resistance; D010641:Phenotype; D018805:Sepsis / Q000188:drug therapy
D000900:Anti-Bacterial Agents; D010397:Penicillanic Acid; D000560:Amdinocillin