High rate of extended-spectrum b-lactamases among Enterobacteriaceae blood-culture isolates from Bulgarian hospitals

Abstract number: 1733_447

Keuleyan E., Markovska R., Schneider I., Kantardjiev T., Sredkova M., Ivanova D., Rachkova K., Markova B., Dragijeva E., Mitov I., Bauernfeind A.

Objectives: (1) To reveal the rate of ESBL producers among bacteraemia isolates. (2) To characterise the spectrum of ESBL genes and their possible spread.

Methods: Surveillance data have been obtained through the national programme BulStar since 1998. Eight hospitals from three towns provided 71 bacteraemia isolates in an ESBLs survey, conducted from 1996 to 2003. The Medical Institute-Ministry of the Interior (MIMI) served as a referral centre. ESBLs were determined and characterised by double disk synergy-, disk diffusion confirmatory- (CLSI, 2005) tests; conjugation was performed on solid medium; Isoelectric focusing and bioassay were followed by ESBL-group specific PCR and nucleic acid sequencing; RAPD was carried out to detect epidemiological relationships.

Results: ESBLs, 3% among Enterobacteriaceae from septicaemia in 1998, augmented up to 15% in E. coli, 35% in K. pneumoniae and 24% in S. marcescens during 2004 (BulStar); their rate at MIMI from 2003 to 2005 was: 6% –E. coli, 50% –K. pneumoniae and 33% –S. marcescens. The survey on ESBLs revealed the incidence of 3 groups: SHV-, TEM- and CTX-M; and 5 particular enzymes: SHV-12 (47%), SHV-2 (4%), TEM-3-like (19%), CTX-M-3 (14%) and CTX-M-15 (9%); 5 strains produced 2 ESBLs. The majority of the pathogens from MIMI and other Sofia hospitals produced SHV-12; TEM-3-like was found at the medical centre-Pleven. K. pneumoniae, the predominant species collected (60% of all blood-culture isolates), produced most frequently SHV-12 (29 out of 42 strains), followed by TEM-3-like (6), CTX-M-15 (3), CTX-M-3 and SHV-2 (by 1). Among 11 E. coli, CTX-M-15 ESBLs were most common (4), followed by TEM-3-like (2) and 5 strains produced combinations of 2 enzymes. S. marcescens (7 strains) produced CTX-M-3 (3), SHV-12 (2) and SHV-2 (2). Two small outbreaks and one larger could be identified. Most of the strains showed multiple resistance, e.g. 74% to aminoglycosides and ciprofloxacin, however they were susceptible to carbapenems.

Conclusion: A high proportion of Enterobacteriaceae strains (3–50%) isolated from patients with bacteraemia were shown to elaborate ESBLs from three groups, five different enzymes, which is worrying and represents one of the highest percentage in Europe. Strong attention should be paid at national and hospital level towards antibiotic use and Infection control.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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