Epidemiological study of antimicrobial Susceptibility Pattern of Bacteria isolated from Positive Blood samples in Tertiary Care Hospitals Delhi NCR
Abstract
Bloodstream infections occurs when pathogenic microorganisms gain access to the bloodstream and may produce a systemic inflammatory response ranging from uncomplicated bacteremia to severe sepsis and septic shock. Our multi centre tertiary care hospitals Delhi- NCR from January 1, 2025, through December 31, 2025. Blood samples were processed in BacT/Alert (BioMérieux, France). Bottles that signaled positive were then subculture on blood, MacConkey, and Sheep Blood agar. These plates were incubated aerobically at 37°C and examined after 18-24 hours. Bacterial identification and Antimicrobial susceptibility was done by the Vitek 2 Compact system (BioMérieux, France). Reported as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Among the total 1453 samples, after exclusion of blood cultures positive with contaminants, as per standard definitions, 147 positive bacterial blood cultures were recorded between January 2025 and December 2025. 98 (66.67%) out of 147, 98 (66.67%) were male positive patient samples and 49 (33.33%) out of 147 were female positive samples. The male to female positive ratio 2:1. Gram-negative organisms predominated, accounting for 137 isolates (93.20%), while Gram-positive organisms accounted for 10 isolates (6.80%). Among the Gram-negative isolates, Pseudomonas aeruginosa was the most frequently isolated organism 39 (26.53%), followed by Escherichia coli 27 (18.37%). Among the Gram-positive organisms, Staphylococcus aureus was predominant 7 (4.76%), followed by Streptococcus pneumonia 1(0.68%) Antibiotic resistant pattern, the overall, high level of antimicrobial resistance among Gram-negative bacilli (GNBs), particularly to several commonly used β-lactam antibiotics. Resistance was highest to cefuroxime (85.71%), followed by Nalidixic acid (82.76%), Among the Gram-positive cocci (GPC) isolates demonstrate complete (100%) resistance to Penicillin.