ISOLATION, IDENTIFICATION, BIOCHEMICAL AND ANTIBIOTIC SUSCEPTIBILITY OF SALMONELLA FROM THE RIVER, TAP WATER AND SEWAGE SAMPLE OF DHARAN, ITAHARI AND BIRATNAGAR

Abstract

Salmonella is a genus of rod -shaped (bacillus) gram negative bacteria of Enterobacteriaceae. Salmonella is one of the leading causes of intestinal illness all over the world. as well as the etiological agent of more severe systemic diseases such as typhoid and paratyphoid fevers. Salmonellae are mainly known as water and food borne pathogens to humans, and animals. Salmonella is commonly reported in water-borne outbreaks despite it being frequently detected in surface waters including recreational waters and waters used for irrigation or as a drinking water source the main sample to isolate salmonella is water, which is the main component of environment. In our research work we focused on collection, transportation, culture, gram staining, biochemical and antibiotic susceptibility The water samples were from different places of Dharan, Itahari and Biratnagar. Water was collected aseptically in the pre-sterilized bottle, and transported to the laboratory, following standard methods with APHA, American Public Health Association, 1995. The collected water samples were analyzed on the same day immediately after its delivery and always within 6 hours of collection. Salmonella detection was done by enrichment of water sample in Selenite Cysteine broth then spread plate on Salmonella Shigella Agar (SSA) and identified by biochemical tests according to Bergey's Manual of Determinative Bacteriology and antibiotic susceptibility was done. Total 100 samples were collected 76 (76%) of the samples shows the presence of Salmonella. Based on place, Dharan (81.30%) showed highest prevalence followed by Itahari (73.68%) and Biratnagar (63.63%). Similarly, the prevalence rate of sewage is 81.81% whereas the prevalence of river and tap water are 74.07% and 68.62% respectively. After isolation and identification Salmonella were tested against different antibiotics among them Ampicillin was found to be highly resistant whereas azithromycin was found to be highly sensitive.