title: Epidemiology and molecular characterization of extended-spectrum beta-lactamase-producing Enterobacter spp., Pantoea agglomerans, and Serratia marcescens isolates from a Bulgarian hospital.
abstract: Forty-two extended-spectrum beta-lactamase (ESBL)-producing isolates of Enterobacter aerogenes, Enterobacter cloacae, Pantoea agglomerans, and Serratia marcescens, collected consecutively during the period January-November 2011 from the University Hospital in Varna, Bulgaria, were studied to characterize their ESBLs by isoelectric focusing, group-specific PCR, and sequencing. The epidemiological relationship was evaluated by random amplified polymorphic DNA analysis (RAPD). Transferability of ESBL genes was determined by conjugation experiments. Plasmid analysis was done by replicon typing and PstI fingerprinting. The overall rate of ESBL production was 20%. The most widespread enzyme was CTX-M-3, found in 64%. It was dominant in E. aerogenes (100%) and S. marcescens (83%). SHV-12, CTX-M-3, and CTX-M-15 were found among E. cloacae isolates in 50%, 35%, and 45%, respectively. Three main CTX-M-3-producing epidemic clones of E. aerogenes and S. marcescens have been detected. Among E. cloacae isolates, six different RAPD profiles were discerned. The plasmids harboring blaCTX-M-3 belonged to IncL/M type and demonstrated similar PstI fingerprinting profiles. IncFII plasmids were detected in two CTX-M-15-producing E. cloacae isolates. Our results demonstrate wide intrahospital dissemination of clonal E. aerogenes and S. marcescens isolates, carrying IncL/M conjugative plasmids.
authors.affiliation: 1 Department of Medical Microbiology, Faculty of Medicine, Medical University of Sofia , Sofia, Bulgaria .
authors.forename: Rumyana Donkova
authors.initials: RD
authors.lastname: Markovska
authors.forename: Temenuga Jekova
authors.initials: TJ
authors.lastname: Stoeva
authors.forename: Kalina Dineva
authors.initials: KD
authors.lastname: Bojkova
authors.forename: Ivan Gergov
authors.initials: IG
authors.lastname: Mitov
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015373:Bacterial Typing Techniques; D002031:Bulgaria / Q000453:epidemiology; D002648:Child; D003227:Conjugation, Genetic; D004754:Enterobacter / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D006761:Hospitals; D006801:Humans; D008826:Microbial Sensitivity Tests; D020636:Pantoea / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D010957:Plasmids; D016868:Serratia Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D012706:Serratia marcescens / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D018440:beta-Lactam Resistance / Q000235:genetics*; D001618:beta-Lactamases / Q000145:classification / Q000235:genetics*; D047090:beta-Lactams / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases