Evidence for an efflux pump mediating multiple antibiotic resistance in Salmonella enterica serovar Typhimurium.

ABSTRACT: The mechanism of multiple antibiotic resistance in six isolates of Salmonella enterica serovar Typhimurium recovered from a patient treated with ciprofloxacin was studied to investigate the role of efflux in the resistance phenotype. Compared to the patient's pretherapy isolate (L3), five of six isolates accumulated less ciprofloxacin, three of six isolates accumulated less chloramphenicol, and all six accumulated less tetracycline. The accumulation of one or more antibiotics was increased by carbonyl cyanide m-chlorophenylhydrazone to concentrations similar to those accumulated by L3 for all isolates except one, in which accumulation of all three agents remained approximately half that of L3. All isolates had the published wild-type sequences of marO and marR. No increased expression of m

SUBMITTER: Piddock LJ 

PROVIDER: S-EPMC101613 | biostudies-literature | 2000 Nov

REPOSITORIES: biostudies-literature