Antiobiotic resistance pattern of biofilm-forming uropathogens isolated from catheterised patients in Pondicherry, India.

BACKGROUND Microbial biofilms pose a public health problem for persons requiring indwelling medical devices, as micro-organisms in biofilms are difficult to treat with antimicrobial agents. Thus the present study includes biofilm formation and antibiotic resistance pattern of uropathogens in hospitalised patients with catheter associated urinary tract infections (UTI). METHOD This prospective analysis included 100 urine samples from catheterised patients with symptoms of UTI over a period of six months. Following identification, all isolates were subjected to antibiotic sensitivity using modified Kirby- Bauer disc diffusion method. Detection of biofilms was done by tube adherence method and Congo red agar method. RESULTS E.coli was found to be the most frequently isolated uropathogen 70%, followed by Klebsiella pneumoniae 16%, Pseudomonas aeruginosa 4%, Acinetobacter spp 2%, coagulase negative Staphylococci 6% and Enterococci Spp 2%. In the current study 60% of strains were in vitro positive for biofilm production. Biofilm positive isolates showed 93.3%, 83.3%, 73.3% and 80% resistance to nalidixic acid, ampicillin, cephotaxime and cotrimoxazole, respectively, compared to 70%, 60%, 35%, 60% resistance showed by biofilm non-producers for the respective antibiotics. Approximately 80% of the biofilm producing strains showed multidrug resistant phenotype CONCLUSION To conclude E.coli was the most frequent isolate, of which 63% were biofilm producers. The antibiotic susceptibility pattern in the present study showed quinolones were the least active drug against uropathogens. The uropathogens showed the highest sensitivity to carbapenems. The next best alternatives were aminoglycosides. Significant correlation between biofilm production and multi-drug resistance was observed in our study.