title: High prevalence of CTX-M-15-producing O25b-ST131 Escherichia coli clone in Bulgarian hospitals.
abstract: According to the European Antimicrobial Resistance Surveillance System project results, Bulgaria has become one of the European countries with dramatically increasing rates of extended-spectrum beta-lactamase (ESBL) producers. The aim of this work was to investigate the epidemiology of ESBL-producing Escherichia coli clinical isolates in Bulgaria, collected from seven clinical centers in three towns, during two study periods: 2002-2003 and 2006-2009. For 193 ESBL-producing E. coli isolates random amplified polymorphic DNA (RAPD) analyses, phylogenetic typing, and screening for O25b-ST131 isolates were carried out. Antimicrobial susceptibility, ESBL-type and transferability of resistance determinants were analyzed. Four different ESBL-types, namely TEM-139, SHV-12, CTX-M-3, and CTX-M-15 were found. CTX-M-15 dominated, being found in 88% of the isolates. RAPD-typing revealed 35 types, among which type A dominated, comprising 65% of the isolates. Sixty-eight percent of the 193 isolates belonged to the O25b-ST131 clone, to the phylogenetic group B2, mostly showed RAPD-type A (92%) and were found in all participating hospitals. O25b-ST131 isolates predominantly produced CTX-M-15 (96%), and less SHV-12 (n=3) or TEM-139 (n=2). In conclusion, this study demonstrated for the first time the country-wide dissemination of a highly resistant B2 O25b-ST131 CTX-M-15 producing E. coli clone in Bulgaria.
authors.affiliation: Department of Microbiology, Medical University, Sofia, Bulgaria. markovska73@abv.bg
authors.forename: Rumyana
authors.initials: R
authors.lastname: Markovska
authors.forename: Ines
authors.initials: I
authors.lastname: Schneider
authors.forename: Dobrinka
authors.initials: D
authors.lastname: Ivanova
authors.forename: Emma
authors.initials: E
authors.lastname: Keuleyan
authors.forename: Temenuga
authors.initials: T
authors.lastname: Stoeva
authors.forename: Mariya
authors.initials: M
authors.lastname: Sredkova
authors.forename: Boyka
authors.initials: B
authors.lastname: Markova
authors.forename: Kalina
authors.initials: K
authors.lastname: Bojkova
authors.forename: Raina
authors.initials: R
authors.lastname: Gergova
authors.forename: Adolf
authors.initials: A
authors.lastname: Bauernfeind
authors.forename: Ivan
authors.initials: I
authors.lastname: Mitov
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002031:Bulgaria; D015780:Carbapenems / Q000008:administration & dosage*; D002999:Clone Cells; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D006801:Humans; D007525:Isoelectric Focusing; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D011159:Population Surveillance; D019105:Random Amplified Polymorphic DNA Technique; D018440:beta-Lactam Resistance / Q000187:drug effects / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases