Avian Salmonella Infection: Isolation and Identification of Organisms and Histopathological Study

Abstract

The Present study was performed in the Department of Pathology, BAU, Mymensingh during the period from January to December 2004. The study was conducted to determine the occurrence and pathology of pullorum disease, fowl typhoid and salmonellosis (paratyphoid infection) in dead chickens at necropsy in Mymensingh district of Bangladesh. A total of 70 samples (liver, ovary and intestine) were collected for isolation of bacteria in different media, and identification was performed based on the staining, cultural and biochemical properties of Salmonella spp. Routine histopathological method was used for the detection of tissue level alterations in Salmonella infected cases. Grossly, in all the infected cases the liver was enlarged and congested and in few cases, liver discoloration with focal necrosis. Old raised hemorrhages in the caecal tonsil and congested deformed ova were other important findings. There was catarrhal inflammation in the intestine. Microscopically, the section of livers showed congestion, hemorrhages, focal necrosis with infiltration of mononuclear cells. The pulmonary lesions consisted of sero-fibrinous exudation with mononuclear cell infiltration. The intestinal mucosa exhibited congestion, hemorrhages and infiltration of plasma cells, heterophils and macrophages. Out of 70 samples, 8 isolates were identified as Salmonella (11.42 %). Of them, five isolates were identified as Salmonella gallinarum, causative agent of fowl typhoid, one isolate was characterized as Salmonella pullorum, causative agent of pullorum disease and other two motile salmonella were identified as paratyphoid infection. Keywords: Fowl typhoid, pullorum disease, paratyphoid, histopathology, isolation, identification doi:10.3329/bjvm.v4i1.1518 Bangl. J. Vet. Med. (2006). 4 (1): 07-12