Study of Multidrug-Resistant Gram-Negative Bacilli in Urinary Tract Infections and Their Antibiogram at a Tertiary Care Hospital

Abstract

Objective: To study the frequency of multidrug-resistant Gram-negative bacilli in urinary tract infections and antibiotic susceptibility pattern of multidrug-resistant Gram-negative bacilli in urinary tract infections.
 Methods: This study was conducted on urine samples received at the Department of Microbiology, Andhra Medical College, for a period of six months from August 2022 to January 2023. During the study period, a total of 3361 urine samples were processed and conventional microbiological techniques were used to isolate uropathogens. Antibiotic susceptibility was tested by the Kirby-Bauer Disc diffusion method and interpreted according to Central Laboratory Standard Institute (CLSI) guidelines 2022. Multidrug-resistant bacilli in this study were defined as Gram-negative bacilli that were resistant to at least one agent in three or more antibiotic classes.
 Results: Out of 3361 urine samples received from outpatient and inpatient departments of our hospital, 858 samples were culture positive-839 were Gram-negative isolates and 19 were Gram-positive isolates. Mean age was 40-60 y. Urinary tract infections were more common in females than males. Among Gram-negative bacilli isolated, Escherichia coli was the most common organism isolated-435(50.69%), followed by Klebsiella species-232(27.03%), Acinetobacter species-105(12.25%), Pseudomonas species-55(6.41%), Proteus species-10(1.16%), Citrobacter species-2(0.23%). Among Gram-positive cocci, Staphylococci-17(1.98%) and Enterococci-2(0.23%) were isolated. Out of 858 isolates, 177 (20.62%) were identified as multidrug-resistant bacilli and all were resistant to the drug groups Cephalosporins, Carbapenems and Quinolones. Most of the Multidrug-resistant gram-negative bacilli were sensitive to Fosfomycin and Nitrofurantoin.
 Conclusion: Multidrug-resistant Gram-negative bacilli in urinary tract infections have become a major health problem. Assessment of Risk factors, Surveillance of Resistance patterns and policies for proper use of antibiotics are urgently needed.