LAUSR

BACKGROUND In this study, we investigated the occurrence of Extended Spectrum β lactamase (ESBL) genes coexisting with carbapenemase, AmpC and aminoglycoside resistance gene in uropathogens. METHODS The antimicrobial susceptibility testing was performed by Kirby Bauer disc diffusion method. The antibiotic resistance genes were detected by multiplex PCR. RESULTS Out of 1516 consecutive urine samples, 454 showed significant bacteriuria with a prevalence rate of 30% Escherichia coli (n = 340) was found to be the most predominant uropathogen followed by Klebsiella pneumoniae (n = 92), Pseudomonas aeruginosa (n = 10) and Proteus mirabilis (n = 9). Among the uropathogens, sixty-two ESBL-producers were identified containing blaCTX-M-15 (n = 32), blaCTX-M-15 + blaOXA-2 (n = 15), blaCTX-M-15 + blaOXA-2 + blaTEM-1 (n = 8), blaOXA-2 (n = 5), blaOXA-2 + blaSHV-76 (n = 1), blaTEM-1+SHV-76 (n = 1) and blaTEM-1 (n = 1). All ESBL genes were located on plasmid incompatibility types: HI1, I1, FIA + FIB, FIA and Y and were horizontally transferable. Among 62 ESBL-producers, 59 isolates harbored carbapenemase genes which included blaNDM-5 (n = 48) or a combination of blaNDM-5 + blaOXA-48 (n = 5), blaNDM-5 + blaIMP (n = 5) and blaNDM-5 + blaIMP + blaVIM (n = 1). The ESBL producing uropathogens also harbored 16S rRNA methylase genes which included rmtB (n = 9), rmtA (n = 4), rmtC (n = 1) and ArmA (n = 1). Moreover, the ESBL positive isolates also contained AmpC genes which includes CIT (n = 8) and DHA-1 (n = 1) genes. Imipenem and gentamicin have the lowest resistance rates among the uropathogens. CONCLUSION This is the first report showing the high prevalence of carbapenemase among ESBL positive isolates in this study area demanding regular surveillance for such resistance mechanisms which will be useful for health personnel to treat infection by multidrug resistant bacteria.