Multi-hospital surveillance and antibiotic sensitivity among bacterial isolates of acute respiratory and enteric infection in underfive children in Dhaka, Bangladesh

Abstract

Acute lower respiratory tract infection (ARI), enteric fever and diarrhea remain the prevalent causes for mortality and morbidity of under-five children in Bangladesh. However, little information is available on true prevalence of the pathogens responsible for these diseases in under-five of Bangladesh and their susceptibility to antibiotics. In this work, we evaluated the bacterial causes of infection in children seeking care in two hospitals in Dhaka. This study utilized specimens collected as part of routine diagnostic purpose encompassing, nasal swab for ARI, stool for diarrhea, and blood for enteric fever. For isolation of the bacterial pathogens, conventional microbiological culture methods were used, followed by detection using appropriate biochemical and serological tests. For enteric fever, an additional immunological detection of Salmonella Typhi and Paratyphi specific IgA immune response in lymphocyte secretions by Typhoid-Paratyphoid Test (TPTest) was done and results compared with that of blood culture. For diarrheal samples, ETEC isolates were tested for specific toxins using multiplex PCR. Antibiotic susceptibility tests were performed according to the Clinical and Laboratory Standard Institute (CLSI) guidelines. Of 100 ARI samples analyzed, 30 bacteria of different species were isolated, of which S. pneumoniae (50%) and K. pneumoniae (26.7%) were the most prevalent. The overall antibiotic sensitivity test of the isolates showed Meropenem, Impenem, Ceftriaxone, Ciprofloxacin, Penicillin and Ampicillin as the most potent antibiotic against respiratory isolates. Of 47 samples tested for enteric fever, 1 (2.1%) was culture positive for Salmonella Typhi, while 23 (49%) were TPTest positive. The S. Typhi isolate was only resistant to Nalidixic acid. 5 of 17 (29.4%) diarrheal samples were culture positive, 3 of which were identified as ETEC and the other two V. cholerae, and Shigella dysenteriae respectively. The findings from this study elucidate the major aetiologies causing infection in under-five children in Dhaka. The antimicrobial sensitivity pattern of the relevant pathogens unraveled will help guide physicians to prescribe appropriate antibiotics in settings where diagnostic facilities are limited or not available.