Clinico-bacteriological profile of uropathogens with special reference to colistin susceptibility among Multi drug resistant isolates from a tertiary care hospital in South India

Abstract

Background: Identification of microorganisms causing urinary tract infections (UTI) and their antimicrobial susceptibilities for different antimicrobial agents is important for providing appropriate treatment to the patients with UTI. Thus, this study was aimed to study the microbiological profile of UTI cases, their antibiotic susceptibility profile and assessment of biofilm formation in bacteria isolated from catheterised patients. Methods: Mid-stream urine samples were collected and were subjected to microscopy and culture. All positive cultures were identified by MALDI-TOF and their antimicrobial susceptibility was determined using VITEK 2. The minimum inhibitory concentration (MIC) of colistin was determined by MIKROLA TEST® MIC colistin kit. Biofilm formation of organisms isolated from catheter associated UTI was performed by tissue culture plate method. Results: The commonest pathogen associated with UTI in this study was found to be Escherichia coli (68%), followed by Klebsiella pneumoniae (17%), Pseudomonas aeruginosa(5%), Enterococcus faecalis (3%), Acinetobacter baumannii (3%), Staphylococcus aureus (2%), Enterobacter cloacae (1%) and Proteus mirabilis (1%). Majority of Escherichia coli (47/67, 70.15%) and Klebsiella pneumoniae(5/17, 29.41%) isolates were found to be ESBL producers. Antimicrobial susceptibility testing showed that 59 % (59/100) isolates were multi drug resistant, 47 (79.66%) among them were E. coli followed by 11(18.64%) Klebsiella pneumonia and 1 (1.69%) Pseudomonas aeruginosa.One (5%) Klebsiella pneumonia isolate was found resistant to colistin. All 12 isolates from catheterized patients were found to be biofilm producers. Conclusion: Present study highlights increased resistance of uropathogens towards cefuroxime and norfloxacin in south coastal Karnataka.