Antimicrobial susceptibility and distribution of TEM and CTX-M genes among ESBL-producing klebsiella pneumoniae and pseudomonas aeruginosa causing urinary tract infections

ABSTRACT

Extended spectrum beta lactamases [ESBLs] have been observed in nearly all the species of family Enterobacteriaceae. The enzymes are plasmid mediated and are derived from broad-spectrum beta lactamase TEM and CTX- M by a limited number of mutations. This study was undertaken to characterize ESBL producers among Klebsiella pneumoniae and Pseudomonas aeruginosa by PCR, which were initially screened by phenotypic method. A cross-sectional study was performed to evaluate 180 strains [30 K. pneumoniae and 150 P. aeruginosa] isolated from urine culture of hospitalized patients [Amir Al-Momenin Hospital, Zabol, south-eastern Iran] suffered from urinary tract infections during a period of six months. The prevalence of ESBL producing K. pneumoniae and P. aeruginosa was evaluated by disk diffusion test and polymerase chain reaction [PCR] by detecting TEM and CTX-M gene. The results of the study revealed that the prevalence of ESBL producing P. aeruginosa and K. pneumoniae by disk diffusion test was 13.3% for P. aeruginosa and 66.6% for K. pneumoniae. Seventy five percent and 65% of K. pneumoniae harboured the gene TEM and CTX-M, respectively. Forty five percent of P. aeruginosa isolates harboured the gene TEM but none of them demonstrated the gene CTX-M using PCR method. ESBL producing P. aeruginosa and K. pneumoniae isolates showed a high prevalence in this study. Therefore it seems that continuous surveillance is essential to monitor the ESBLs producing microorganisms in hospitals and community