Unveiling the Silent Threat: The Rise of Β-Lactamase Enzymes in Gram-Negative Bacterial Isolates Identified From Sterile Body Fluids in an Indian Healthcare Institution

Abstract

Background Bacterial infections in sterile body fluids represent a significant clinical concern, particularly when caused by resistant pathogens. beta-lactamase-producing gram-negative bacteria, including extended-spectrum-lactamase (ESBL), metallo-beta-lactamase (MBL), and AmpC beta-lactamase producers, complicate treatment strategies, leading to poor patient outcomes. Infections in vulnerable patients, particularly in intensive care units (ICUs), are more susceptible to these resistant organisms, highlighting the need for urgent surveillance and effective antimicrobial strategies. Objectives The primary goal of this study was to assess the prevalence and antimicrobial resistance patterns of bacterial isolates from sterile body fluids, with a focus on beta-lactamase-producing gram-negative bacteria. The study further aimed to highlight the implications of antimicrobial resistance patterns in guiding effective empirical therapy and infection control strategies. Methodology A total of 180 sterile body fluid samples, including cerebrospinal fluid (CSF), pleural fluid, pericardial fluid, bile, peritoneal or ascitic fluid, and synovial fluid, were collected and processed for bacterial isolation. Standard microbiological procedures, including Gram staining, culture on appropriate media, and biochemical identification tests, were utilized to identify the isolates, followed by antimicrobial susceptibility testing (AST) using the Kirby-Bauer disk diffusion susceptibility test to determine resistance profiles, with particular attention to ESBL, MBL, and AmpC beta-lactamase production. Results Of the 180 samples, 27 (15%) showed bacterial growth, with Escherichia coli and Pseudomonas aeruginosa being the most frequently isolated pathogens. Testing for antimicrobial susceptibility showed notable resistance levels to commonly used antibiotics, including cefoperazone-sulbactam and piperacillin-tazobactam. ESBL production was found in 40.74% of the gram-negative isolates, and MBL production was present in 48.15%. The study recorded maximum resistance rates in CSF samples, indicating the critical need for rapid and accurate diagnostic methods. The resistance profiles of isolated pathogens revealed limited options for empirical treatment, underscoring the need for targeted antimicrobial stewardship strategies. Conclusion The study underscores the growing concern of multidrug-resistant gram-negative bacteria in sterile body fluid infections, particularly in vulnerable patient populations. The detection of ESBL, MBL, and AmpC-producing organisms highlights the urgency for enhanced surveillance, rapid diagnostics, and strict antimicrobial stewardship to mitigate the impact of these resistant pathogens. Copyright © 2025, Patel et al.