SOURCE:

Faculty: Pharmaceutical Sciences
Department: Pharm. Microbio & Biotech

CONTRIBUTORS:

Nnajide, C. R.
DR Ugwu, M.
DR Iroha, I.

ABSTRACT:

Antibiotic resistance among uropathogens has been on the increase. Little is known about the molecular basis of antimicrobial resistance in bacteria isolated from UTI patients especially in south-eastern part of Nigeria. The main aim of the project was to characterize the enterobacterial uropathogens with respect to drug resistance in Awka, south-eastern Nigeria. The following enterobacterial uropathogens isolated from patients attending Chukwuemeka Odumegwu Ojukwu University Teaching Hospital, Awka were studied: E.coli (58), Salmonella spp. (15), K. pneumoniae (14), Citrobacter freundii (10) and Enterobacter aerogenes (3). Their antibiotic susceptibility patterns against major classes of antibiotics were evaluated using disk diffusion assay. The resistant uropathogens were analyzed for the presence of biofilm using modified Christensen method. The isolates were further screened and confirmed by multiplex PCR for the presence of beta-lactamases viz., ESBL, AmpC, carbapenemase and MBLs, which are known to be the major cause of resistance in these pathogens and fifty four (54) E.coli isolates were typed using Randomly Amplified Polymorphic DNA (RAPD) technique for the presence of ESBL. The antibiotic susceptibility of the isolates showed that most of the E. coli isolates were resistant to cefpodoxime, cotrimoxazole and meropenem but susceptible to the fluoroquinolones with the exception of ciprofloxacin. Salmonella isolates on the other hand, had a very good susceptibility profile to the 3rd generation cephalosporins but were resistant to ofloxacin and cotrimoxazole. Klebsiella pneumoniae isolates were resistant to cefpodoxime, cefotaxime and cotrimoxazole but sensitive to the fluoroquinolones. Biofilm producing isolates were 74% while the non biofilm formers were 26%. Screening tests for ESBL, MBL and AmpC production showed that 96 % were positive for ESBL production while 58 % were positive for AmpC and 35 of the E.coli were confirmed positive for ESBL production with PCR. The predominant ESBL gene was blaTEM with blaSPM being the most predominant MBL gene. Some organisms had co-expression of genes. Out of the 21 isolates that were screened positive for AmpC production, only one was confirmed positive by PCR. Nine out of 10 K.pneumoniae that was screened to be positive for ESBL production were confirmed positive by PCR. All the 10 C. freundii were positive for ESBL genes. The study showed high prevalence of drug resistant genes among the enterobacterial uropathogens.