Bacterial pathogens isolated from blood cultures and their antibiotic susceptibility patterns in a tertiary care hospital

Abstract

Background: Bloodstream infections are still a significant cause of morbidity and mortality in children. Adequate knowledge of bacterial pathogens, timely blood culture results, and suitable antibiotic therapy are essential to reduce adverse outcomes. Understanding the nature of bacterial profile and their antibiotic susceptibility patterns are necessary to guide rational antimicrobial therapy and improve overall clinical outcomes in paediatric patients. Objectives: This study aimed to determine the spectrum of bacteria isolated from paediatric blood cultures and assess their antibiotic susceptibility profiles. Methods: A retrospective study was conducted from 1st January 2024 to 30th October 2024 at Bangladesh Shishu Hospital and Institute to determine bacteriological profile of paediatric blood cultures and their antibiotic susceptibility patterns. Data were collected from hospital records of 406 blood culture and sensitivity reports of children admitted to Bangladesh Shishu Hospital and Institute with suspected bacterial infection between January to October 2024.Of the 406 reports 177 were positive and remaining were negative. Identification of bacteria and their antibiotic susceptibility pattern were done according to standard microbiological methods. Results: Out of 406 blood samples submitted for culture and sensitivity, 177 (43.6%) yielded bacterial growth, of which 171 (96.6%) were Gram-negative bacilli, 5 (2.8%) were Gram-positive cocci, and 1 (0.6%) was Gram-negative coccobacillus. Among these positive cultures, Klebsiella pneumoniae (59.3%) was the predominant isolate followed by Acinetobacter spp. (19.8%) and Pseudomonas aeruginosa (13%). Double bacterial growth was detected in 4 samples (2.3%), all involving both Acinetobacter spp. and Klebsiella pneumoniae. Less frequently isolated organisms included Haemophilus influenzae (0.6%), Streptococcus pneumoniae (0.6%), Staphylococcus aureus (1.1%), Enterococcus spp. (1.1%), Flavobacterium spp. (1.1%), and Escherichia coli (1.1%). The antibiotic susceptibility profile showed that the isolated bacterial pathogens were most sensitive to Chloramphenicol (48.9%), followed by Cotrimoxazole (20.5%), Levofloxacin (20.2%), and Ciprofloxacin (12.8%). All Gram-positive cocci demonstrated complete (100%) susceptibility to Chloramphenicol, Vancomycin, and Linezolid, while 80% remained susceptible to Levofloxacin and 60% to Ampicillin/Amoxicillin and Penicillin. Conclusion: The findings of our study revealed a high frequency of Gram-negative bacilli, among which Klebsiella pneumoniae was identified as the most common pathogen. Overall antibiotic susceptibility was low. However, Chloramphenicol showed the highest effectivity against the organisms. Gram-positive cocci presented outstanding susceptibility to Chloramphenicol, Vancomycin and Linezolid.

DS (Child) H J 2024; 40(2): 7-13