FREQUENCY AND PATTERN OF INFECTIOUS AGENTS IN BLOOD CULTURE ISOLATES AND THEIR ANTIMICROBIAL SUSCEPTIBILITY PROFILES IN A TERTIARY CARE HOSPITAL: A SIX-MONTH STUDY
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Keywords
Blood culture, Antimicrobial resistance, ESBL, Bacteremia, Tertiary care hospital
Abstract
Bloodstream infections represent significant healthcare challenges requiring rapid identification of causative organisms and knowledge of antimicrobial resistance patterns for appropriate therapy. Institution-specific epidemiological data regarding blood culture isolates guide empirical antibiotic protocols and infection control measures. This study determined the frequency and pattern of infectious agents isolated from blood cultures at a tertiary care hospital in South India.
Methods: A retrospective observational study was conducted at Dr. Pinnamaneni Siddhartha Institute of Medical Sciences, Krishna (Andhra Pradesh) from March 2019 to August 2019. All positive blood culture isolates from 312 patients were analyzed. Organism identification was performed using VITEK-2 automated system, and antimicrobial susceptibility testing was conducted following CLSI guidelines. Statistical analysis included descriptive statistics and chi-square tests.
Results: A total of 385 positive isolates were obtained from 312 patients. Gram-negative bacteria predominated at 56.1%, with Escherichia coli (14.0%) and Klebsiella pneumoniae (12.5%) as most common gram-negatives. Staphylococcus aureus (16.6%) was the most frequent gram-positive organism. Multidrug-resistant isolates were identified in 59.3% of gram-negative bacteria, with 43.5% producing extended-spectrum beta-lactamase (ESBL). Methicillin-resistant gram-positive bacteria comprised 42.0% of gram-positive isolates. Intensive care unit patients contributed 30.1% of positive cultures. Polymicrobial bacteremia occurred in 23.4% of cases.
Conclusion: Substantial antimicrobial resistance rates necessitate institution-specific empirical protocols incorporating carbapenems and combination therapy for gram-negative bacteremia management.
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Dr. Deepa Mathur
Assistant Professor, Department of Pathology, Dr. Pinnamaneni Siddhartha Institute of Medical Sciences, Krishna (Andhra Pradesh)