title: Extended-spectrum beta-lactamase-producing Enterobacteriaceae in Bulgarian hospitals.
abstract: The aim of the study was to describe the emergence, the spread, and the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in Bulgaria. Over eight years (1996-2003), 442 ESBL-screen-positive isolates were collected in nine medical institutions in four Bulgarian towns. Class A ESBLs of the SHV, TEM, and CTX-M groups were identified in seven species. SHV-type enzymes persisted during the whole study period, TEM-ESBLs appeared first in 1999, and CTX-M-types appeared first in 2001. The rate of CTX-M enzyme producers increased rapidly between 2001 and 2003, while the rate of SHV producers decreased. Six different ESBL-types were identified, namely, SHV-2, -5, and -12, CTX-M-3 and -15, and a new TEM-3-like variant (TEM-139). The most widespread enzymes were SHV-12, CTX-M-15, and CTX-M-3 found in seven centers. TEM-139 was identified mainly in one center. A trend for strains harboring more than one ESBL gene, for example, CTX-M + SHV, was observed since 2002. Plasmid fingerprinting and random amplified polymorphic DNA analysis typing revealed wide dissemination of identical plasmids among different bacterial species and hospitals, as well as clonal spread of ESBL producers. Our data contribute to clarify the dynamics in the prevalence of ESBLs in Bulgaria and demonstrate the importance of molecular procedures for their analysis.
authors.affiliation: Microbiology, Medical University, Sofia, Bulgaria.
authors.forename: Rumyana
authors.initials: R
authors.lastname: Markovska
authors.forename: Ines
authors.initials: I
authors.lastname: Schneider
authors.forename: Emma
authors.initials: E
authors.lastname: Keuleyan
authors.forename: Mariya
authors.initials: M
authors.lastname: Sredkova
authors.forename: Dobrinka
authors.initials: D
authors.lastname: Ivanova
authors.forename: Boyka
authors.initials: B
authors.lastname: Markova
authors.forename: Grozdanka
authors.initials: G
authors.lastname: Lazarova
authors.forename: Elisaveta
authors.initials: E
authors.lastname: Dragijeva
authors.forename: Encho
authors.initials: E
authors.lastname: Savov
authors.forename: Irina
authors.initials: I
authors.lastname: Haydouchka
authors.forename: Nasya
authors.initials: N
authors.lastname: Hadjieva
authors.forename: Lena
authors.initials: L
authors.lastname: Setchanova
authors.forename: Ivan
authors.initials: I
authors.lastname: Mitov
authors.forename: Adolf
authors.initials: A
authors.lastname: Bauernfeind
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002031:Bulgaria / Q000453:epidemiology; D016172:DNA Fingerprinting / Q000379:methods; D004755:Enterobacteriaceae / Q000145:classification / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D004756:Enterobacteriaceae Infections / Q000453:epidemiology* / Q000382:microbiology; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D019105:Random Amplified Polymorphic DNA Technique; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000145:classification / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases