Bacteriological Profile and Antibiogram of Urinary Tract Infections at a Tertiary Care Hospital in Kerala, India: A Retrospective Study

Abstract

Introduction: Urinary Tract Infections (UTIs) are caused by microbial invasion of the urinary tract, extending from the renal cortex of the kidney to the urethral meatus. Over the past years, resistance levels to the traditional drugs used for the treatment of UTIs have been gradually increasing. Therefore, a therapy based on the individual culture report and antibiotic sensitivity test is highly encouraged. Aim: To determine the age-wise and sex-wise prevalence of UTI, as well as to determine the bacteriological profile and antimicrobial sensitivity pattern of isolated uropathogens. Materials and Methods: This retrospective record-based study was conducted in the Department of Microbiology at Travancore Medical College in Kollam, Kerala, India. Samples were collected from patients with clinically suspected UTI attending the Outpatient Department (OPD) and Inpatient Department (IPD) of Travancore Medical College, Kollam, Kerela, India over a period of six months from July 2022 to December 2022. Both male and female patients with clinically suspected UTI were included in the study. The clinical diagnostic criteria included dysuria, frequency, urgency, and fever. Data were retrieved from the culture register maintained in the Microbiology laboratory, LIS (ELLIDER), and the WHONET software system. Urine culture was performed using a semiquantative technique. A growth of >105 Colony Forming Units (CFU)/mL was considered indicative of an active UTI with significant bacteriuria. Organisms were identified using Gram stain, motility testing, and biochemical reactions following standard microbiological techniques. Antimicrobial sensitivity testing was conducted using the Kirby-Bauer Disc diffusion method. The data were entered into a Microsoft Excel worksheet, and the results were analysed using simple descriptive statistics involving percentages and proportions using Statistical Package for Social Sciences (SPSS) software version 16.0. Results: Of the total 2,794 samples, 319 (11.4%) samples yielded significant bacteriuria. Among the positive samples, 204 (64%) were from females and 115 (36%) were from males. UTIs were most commonly seen in the age group of 61-80 years. Escherichia coli (E.coli), with 148 isolates (46.4%), was the predominant organism, followed by Klebsiella pneumoniae with 72 isolates (22.6%). E. coli showed the highest susceptibility to meropenem, with 137 isolates (92.6%), and imipenem, with 136 isolates (91.9%), followed by cefoperazone/sulbactam with 129 isolates (87.2%), and piperacillin/tazobactam with 128 isolates (86.5%). Klebsiella pneumoniae was most susceptible to imipenem, with 42 isolates (60%), followed by meropenem, with 29 isolates (41.4%). Most non fermenters were highly susceptible to carbapenems, cefoperazone/sulbactam, and piperacillin/tazobactam. Among the gram-positive organisms, Enterococcus spp. was the most frequently isolated, showing 100% sensitivity to vancomycin and linezolid. Conclusion: In this study, UTI was found to be more prevalent among elderly females. Gram-negative organisms were the most commonly isolated pathogens in UTI, with E. coli being the most frequent agent. Urinary pathogens exhibited resistance to commonly used antibiotics such as ampicillin, cephalosporins, quinolones, and cotrimoxazole. Based on this study, it can be concluded that the resistance to commonly used antibiotics is very high. Due to the changing trends in the sensitivity patterns of various antibiotics, it is important to understand the antibiogram of common isolates in a specific area or hospital to ensure better empirical treatment.