Extended-spectrum b-lactamases in the Czech Republic

Abstract number: P620

Hrabak J., Empel J., Bergerova T., Urbaskova P., Gniadkowski M.

Objectives: Extended-spectrum b-lactamases (ESBLs) are one of the most important mechanisms of resistance to newer generation b-lactams in Gram-negative bacteria. In the Czech Republic, there has not been done yet any molecular epidemiology study on ESBL-producing organisms. The objective of this analysis is to characterise ESBLs and ESBL producers in one of the biggest Czech hospitals, the University Hospital in Plzen.

Methods: In 2006, a 1-month survey of ESBL-producing bacteria was performed. Twenty-four non-repetitive isolates of Klebsiella pneumoniae (n = 10), Escherichia coli (n = 9), Providencia stuartii (n = 3), Enterobacter cloacae (n = 1) and Proteus mirabilis (n = 1) were collected. The isolates were typed by RAPD and used in conjugative transfer experiments for ESBL-mediated resistance. ESBLs were characterised by isoelectric focusing, bioassay, and PCR and sequencing of bla genes.

Results: At least seven different ESBL variants were identified in the isolates. SHV enzymes dominated in K. pneumoniae (SHV-5, SHV-12 and probably SHV-2), whereas CTX-M b-lactamases, mostly CTX-M-15, were predominant among E. coli. The CTX-M-15-encoding gene was preceded by the ISEcp1 element at a distance of 48 bp. TEM-type ESBLs were produced by the remaining strains; TEM-92 by all P. stuartii isolates, and TEM-132 – by E. cloacae. Genes coding for SHV-5, SHV-12, CTX-M-15 and TEM-132 were located on conjugative plasmids. A significant number of isolates (K. pneumoniae SHV-5, E. coli CTX-M-15 and P. stuartii TEM-92) appeared owing to clonal dissemination of producer strains.

Conclusions: This work showed a high diversity of ESBL variants in the Czech hospital, which included both globally-disseminated and more locale-specific enzymes.

This work was partially supported by a research project MSM 0021620819.