Determination of effects of efflux pumps on resistance in extended spectrum beta lactamase (ESBL) producing Klebsiella pneumoniae

Klebsiella pneumoniae is held the most responsible for morbidity and mortality and the most frequently isolated Klebsiella species from hospital infections. Beta lactamase enzyme production that inactivates beta lactam antibiotics by hydrolyzing them is one of the most important resistance mechanism among many types of bacteria especially in Klebsiella pneumoniae. Efflux pump systems plays an important role in recent years as well as resistance occuring by enzymatic pathway. In this study it is aimed to study the effectiveness of acrA, ketM, kdeA, kexD and kpnEF efflux pump genes that involved in multidrug resistance in various clinical samples of 100 ESBL producing Klebsiella pneumoniae isolated between September 2013-July 2015. Determintation of identification of isolates was done by automated system and ESBL production was confirmed by combined disk test. Antibiotic susceptibility was done by disk diffusion test and 72% of these isolates resistant to ceftazidime, 79% to aztreonam, 54% to ciprofloxacin, 32% to ertapenem, 74% to tobramycin, 65% to tetracycline and all isolates resistant to ampicillin, ceftriaxone and cefotaxime. Expression levels of acrA, ketM, kdeA, kexD and kpnEF was determined by real time PCR. Expression level of acrA in ciprofloxacin susceptible strains is significantly increased as compared to resistant strains. Expression of RND type pump protein of kexD gene is significantly increased in tobramycin and aztreonam resistant strains as compared to susceptible strains.