Isolation and Characterization of Salmonella Serovars from Enteric Fever Suspected Patients Attending Birhospital

Abstract

Enteric fever is a multi-systemic illness caused primarily by Salmonella Typhi. A similar but less severe disease is caused by S. Paratyphi A,and less commonly by S. Paratyphi Band S. Paratyphi C. A study was conducted at Microbiology Unit, Bir Hospital,Kathmandu from June 2011 to September 2011 with the objective to isolate and characterize Salmonella serovars from enteric fever suspected patients. During the study period, 1542 blood samples were collected from patients suspected of enteric fever of which 126 (8.17%)showed positive culture result and among the culture positive, 87(69.05%) were Salmonella isolates and remaining were other bacterial species.The other bacterial species isolated were Acinetobacter spp. (15.87%), Enterobacter spp. (3.97%),Staphylococcus aureus(3.97%),Pseudomonas aeruginosa(3.17%),Escherichia coli(2.38%) and Klebsiellaspp. (1.59%). Among Salmonella isolates, 48 (38.10%) isolates were Salmonella Typhi and 39(30.95%) isolates were Salmonella Paratyphi A. Typhoid fever was more prevalent causative organism of enteric fever than paratyphoid fever.Prevalence of enteric fever was seen higher in male patients (58/87; 66.67%) than in female patients (29/87;33.33%) and it was statistically insignificant (χ²=0.2517, P>0.05). Salmonella Typhi was found to be 100% sensitive to Ofloxacin and Ceftriaxone, followed by Ciprofloxacin (95.83%), Chloramphenicol (95.83%), Amoxycillin (93.75%) and Cotrimoxazole (91.67%).Similarly,S. Paratyphi A was found to be 100% sensitive to Ofloxacin, Ceftriaxone and Chloramphenciol, followed by Ciprofloxacin (94.87%),Cotrimoxazole (94.87%) and Amoxycillin (92.31%). Out of 48S. Typhi isolates, two(4.17%) were found to be Multi Drug Resistant (MDR).No MDR strains of S. Paratyphi A were isolated. Out of 36 Nalidixic acid resistant Salmonella Typhi two isolates were intermediately sensitive to Ciprofloxacin and out of 29 Nalidixic acid resistant Salmonella Paratyphi A two isolates were intermediately sensitive to Ciprofloxacin. Keywords: Enteric fever, Salmonella serovars, Multidrug resistant(MDR), Nalidixic acid resistant