Multidrug Resistance in Bacterial Isolates from Pus Samples: A Hospital-based Descriptive Cross-sectional Study

Abstract

Introduction: Antimicrobial Resistance (AMR) is a growing public health threat. Multidrug-resistant (MDR) bacteria, initially associated with healthcare-associated infections, have now spread and become a major cause of community-acquired infections, as well. Therefore, there is a need for monitoring MDR bacterial infections in healthcare settings to establish policies for antimicrobial therapy and effective infection prevention strategies. As pyogenic infections were a major burden of infectious diseases in our healthcare setup, the present study was conducted. Aim: To estimate the prevalence of Multidrug Resistance (MDR) and Extensive Drug Resistance (XDR) in bacterial isolates from pus samples. Materials and Methods: The present hospital-based descriptive cross-sectional study was conducted in the Microbiology Laboratory, SMBT Hospital, Nashik, Maharashtra, India, from June 2022 to May 2023. A total of 360 bacterial isolates from pus samples received from the General Surgery, Orthopaedics and Otorhinolaryngology Departments were tested for antimicrobial susceptibility according to the Clinical and Laboratory Standards Institute (CLSI) 2023 guidelines. Isolates were classified as MDR and XDR as per standard definitions. All Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) isolates were tested for Ampicillinase C (AmpCs) production by disk approximation test and double disk synergy test. Microsoft Excel 2013 was used for data analysis. Results: The prevalence of MDR and XDR in Gram-negative bacteria was 175 (68.8%) and 120 (47.2%), respectively. The prevalence of MDR and XDR Staphylococcus aureus (S. aureus) was 59 (67%) and 10 (11.3%), respectively. The prevalence of Methicillin Resistant S. aureus (MRSA) was 45.4% (n=40). Out of the total 111 isolates of E. coli and K. pneumoniae, five isolates were AmpC beta-lactamase producers (4.5%). Conclusion: In the present study, a high prevalence of MDR was observed in both Gram-negative and Gram-positive bacteria isolated from different pus samples. This is an alarming situation, and further in-depth studies need to be conducted to assess the association of MDR bacterial infections with particular sites and types of infections to develop effective therapeutic and infection control policies.