A Study on Multidrug-Resistant Gram-Negative Bacilli from Urinary Samples in Patients of a Tertiary Care Centre

Urinary tract infections (UTIs), caused by microbial overgrowth in the urinary system, result in symptoms like fever, painful urination, and abdominal discomfort. Common pathogens include E. coli, Klebsiella pneumoniae, and Staphylococcus species, with rising antibiotic resistance posing a major health challenge. This study focuses on UTI cases at KR Hospital, Mysore, to track antimicrobial resistance trends. Conducted over six months (Sept 2024 - Feb 2025) at Mysore Medical College, the study involved adult and pediatric patients with suspected UTIs. Urine samples were cultured on Mac'Conkey, CLED, and blood agar to identify bacteria, with counts ≥10^5/mL indicating infection. Antimicrobial susceptibility was assessed using the Kirby–Bauer method, and multidrug-resistant (MDR) isolates were further tested for ESBL and MBL production. Data were analysed using SPSS. Out of 320 samples, 250 were positive for bacterial growth, with the highest number of MDR isolates in those aged 36-50. UTI prevalence was highest among females and those over 60, aligning with previous research. The study found 78.12% of isolates to be multidrug-resistant, with E. coli and Klebsiella pneumoniae as the primary pathogens. The study revealed major resistance to cephalosporins and penicillins, but sensitivity to colistin. Among MDR organisms, 28.8% were ESBL producers, and 12% were MBL producers, with the highest rates of ESBL production found in E. coli and among the 36-50 age group. Resistance was notable for cephalosporins and penicillins, but sensitivity was preserved for amikacin, gentamicin, piperacillin-tazobactam, cotrimoxazole, tetracycline and fosfomycin. Key words: Urinary Tract Infection; Antimicrobial Resistance; Escherichia coli; Multidrug-Resistant Bacteria