BACTERIOPATHOLOGICAL STUDY OF SALMONELLA INFECTION IN LAYER BIRDS OF SELECTED FARMS IN TANGAIL DISTRICT

Abstract

A bacterio-pathological study of Avian Salmonellosis was conducted in some selected layer farms at Sadar Upazila of Tangail district, Bangladesh during January-June 2014 to identify and isolate Salmonella organisms by using 39 liver sample and other visceral organs (lung, spleen, egg follicles and intestine) from dead birds of 15 layer farms and 75 laid eggs (5 eggs/farm) from respective 15 Salmonella suspected farms. Samples were subjected to isolation and identification of the causal agent followed by necropsy and histopathological study of the affected visceral organs. The used methods were culture in different media, Gram’s staining, different biochemical tests. Out of 39 liver samples 17 (43.59%) were found Salmonella positive. Whereas, Salmonella gallinarum, Salmonella pullorum and paratyphoid causing Salmonella sp were 70.58%, 17.64% & 11.77% respectively. During necropsy, the variable lesions were found in Salmonella affected organs of all 17 birds. About 64.70% livers of Salmonella affected birds were found enlarged, congested, friable and bronze coloured with white necrotic foci. Around 52.94% egg follicles were congested, hemorrhagic, discoloured with stalk formation and 70.58% intestines showed hemorrhagic to catarrhal enteritis. At histopathology, 82.35% livers were congested with formation of multifocal nodules characterized by huge infiltration of leukocyte. Infiltration of heterophils in intestinal mucosa was found in 52.94% cases. Four Salmonella isolates were found from 15 laid egg samples (5 eggs content comprised as 1 sample) and isolation rate was 26.66% reporting transovarian transmission in poultry Salmonellosis.