A STUDY ON ISOLATION, IDENTIFICATION AND PREVALENCE OF SALMONELLOSIS IN BROILER CHICKEN AT SYLHET SADAR

Abstract

Salmonellosis is a leading cause of food borne illness worldwide with an estimated millions cases each year in the world. Transmission of this organism occur through horizontally and vertically. The source of the infection is usually difficult to determine, although carrier animals introduced into the flock are considered the most common source. A point of time study was conducted from July 2015 to November 2015 to isolate and identify the Salmonella spp from the broiler chicken and calculate the prevalence among the broiler birds in Sylhet sadar. The commercial broiler farms are located in various locations of the Sylhet sadar and 4 major commercial broiler markets of Sylhet sadar were taken into the count for the collection of the sample. Different chemicals and reagents were used for conducting the biochemical tests: Grams stain, Methyl red solution, Methyl-red VogesProskauer

(MR-VP) broth, Kovacs reagent, Potassium hydroxide solution, Phosphate buffered saline (PBS) solution, phenol red Dextrose, Maltose, Lactose, Mannitol and Sucrose. Other chemicals used for the experiment were 20% glycerin, liquid paraffin, wax, Alcohol, spirit etc. The isolates of Salmonella spp. showed positive result in Catalase test. In Grams staining under microscope, the Salmonella revealed Gram-negative, pink color, small rod shaped and arranged in single or paired. Motility test was fundamental basis for the detection of motile and non motile Salmonella organisms. The prevalence of salmonellosis at different farm level were 38.89%, 30.76%, 16.67%, 37.5%, 20.0%, 20.0%, 22.22%, 45.45% respectively. The overall farm level prevalence was obtained 31.25%. The prevalence in different commercial broiler markets were 66.67%, 64.28%, 37.50%, 33.33% respectively. The overall prevalence in commercial broiler markets was 55%.Age wise prevalence found 14.28% for 0-10 days, 40.62% for 11-20 days and 45.45% for 21 to above day’s birds. Retail chicken seller should be conscious about the problems of overcrowding and unhygienic management. They should be aware of proper sanitary management, handling transportation and litter management of broiler chicken in market. Feed should be supplied in hygienic condition.