[The incidence of extended spectrum beta-lactamases in Proteus mirabilis strains isolated in 2007-2009].

Proteus sp. rods are opportunistic human pathogens, isolated mainly from urinary tract infections. They are naturally susceptible to most antimicrobials. However, acquisition of genes for extended spectrum beta-lactamases on plasmids and irrational antimicrobial treatment increase amount of multidrug resistant strains and lead to their selection. The aim of this study was to evaluate production of ESBLs by double disc synergy test and antimicrobial susceptibility of P mirabilis strains by disc diffusion method. Strains included into the study were isolated from patients of dr A. Jurasz University Hospital No 1 in Bydgoszcz between 2007 and 2009. P mirabilis strains were isolated mainly from urine. In this study 10,4%, 18,7% and 14,4% ESBL(+) P mirabilis strains were isolated in 2007, 2008, 2009, respectively. Resistance to majority of the investigated antimicrobials was observed in ESBL(+) P mirabilis strains.