Assessment of Antimicrobial Susceptibility Patterns and Empirical Therapy Coverage using a Hospital Antibiogram in a Tertiary Care Hospital

Antimicrobial resistance compromises the effectiveness of empirical antibiotic therapy and is one of the most critical global health challenges, particularly for resource-limited hospital settings. Empirical treatment decisions are based on outdated assumptions about susceptibility patterns, often resulting in treatment failure and further propagation of resistance. Hospital antibiograms should be an important input into empirical choices, but most available reports remain simply descriptive in nature and do not examine the adequacy of empirical coverage for prevalent pathogens. Linking susceptibility data to empirical antibiotic adequacy enables a more clinically meaningful tool for antibiotic stewardship.
Objectives
This study aims to describe the distribution and antimicrobial susceptibility of bacterial isolates in a tertiary care hospital and to assess the adequacy of empirical antibiotic coverage based on local susceptibility data.
Materials and Methods
This cross-sectional laboratory-based study was conducted at a tertiary care hospital. It included 837 non-duplicate bacterial isolates collected from various clinical specimens between September 2023 and September 2024. Antimicrobial susceptibility testing was done by the Kirby–Bauer disk diffusion technique and interpreted as per CLSI M39-A5 guidelines. Calculation of empirical coverage was done by mapping each pathogen to its standard first-line empirical regimen as per hospital and national guidelines, and coverage was expressed as a percentage of isolates susceptible to the selected agent.