title: Prevalence and characterization of extended-spectrum cephalosporin-resistant nontyphoidal Salmonella isolates in adults in Saint Petersburg, Russia (2002-2005).
abstract: We studied the prevalence of resistance to extended-spectrum cephalosporins (ESC) among 1,078 Salmonella enterica isolates collected from adults admitted to Botkin Hospital, St. Petersburg, Russia, for gastroenteritis between 2002 and 2005. Only two ESC-resistant isolates were detected, giving a low percentage of strains resistant to ESC (0.2%). One multidrug-resistant (MDR) isolate of the Virchow serotype produced a CTXM-3 extended-spectrum beta-lactamase (ESBL). The bla(CTX-M-3) gene was located downstream from an ISEcp1 element, on an 80-kb conjugative plasmid. The Virchow isolate possessed a class 1 integron with a 2.2-kb gene cassette (dhfrXII-orfF-aadA2). The second ESC-resistant isolate belonged to serotype Newport, was also MDR and produced a CMY-2 cephamycinase. This CMY-2-producing isolate (also called Newport MDR-AmpC) possessed a class 1 integron with a 1-kb gene cassette including a new variant of the aadA gene, aadA24. A large plasmid (>125 kb) was involved in transfer of the bla(CMY-2) gene. The ESC-resistant S. enterica isolates detected in this study were different from those (S. enterica serotype Typhimurium DT193 producing CTXM-4 or CTX-M-5 ESBLs) involved in several nosocomial outbreaks between 1994 and 2003 in Russia. This is the first description of both CTX-M-3 ESBL-producing S. enterica and Newport MDR-AmpC in Russia.
authors.affiliation: Laboratory of Intestinal Infections, Pasteur Institute of St. Petersburg, St. Petersburg, Russia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Egorova
authors.forename: Lydia
authors.initials: L
authors.lastname: Kaftyreva
authors.forename: Patrick A D
authors.initials: PA
authors.lastname: Grimont
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Weill
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics; D002511:Cephalosporins / Q000494:pharmacology*; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D004196:Disease Outbreaks; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial; D024901:Drug Resistance, Multiple, Bacterial; D005759:Gastroenteritis / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D012426:Russia / Q000453:epidemiology; D019779:Salmonella enterica / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism; D001618:beta-Lactamases / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002511:Cephalosporins; C417271:beta-lactamase CTX-M-3; C048795:AmpC beta-lactamases; D001618:beta-Lactamases