A pathological and bacteriological report of systemic Salmonella infections in a dairy farm in the Mazandaran province

Salmonellas are geram negative, facultative anaerobic bacilli from of the family enterobacteriaceae that spread widely in the environment. They cause human and animal infectious diseases in a wide range as enteric pathogens and deadly in cases of septicemia. Salmonellas transfer by direct contact, contaminated food and water and asymptomatic carriers.
In this study, patiant calves were examined in a dairy farm following refer of fifteen under one month year old dead calves. High fever, weakness, dehydration, white to gray smelly mucus diarrhea and neurological symptoms in two cases were observed.
Mucofibrinous enteritis, bowel wall thickening, swollen mesenteric lymph nodes, petechiae on serous surfaces, liver and spleen congestion, petechiae and thickening of the meningeal membranes were observed in autopsy examinatin. Microbiological and histopathological samplings were performed. Histopathological examination showed congestion, edema, presence of mononuclear inflammatory cells in lung, congestion, mass of lymphocytes and macrophages in liver, congestion, epithelial mucus removal and presence of a pseudo- membrane in intestine, meningeal thickening, hyperemia and presence of inflammatory cells with perivascular cuffing in brain. After differentiating cultures Salmonella spp. were isolated, as Salmonella species. Antibiotic therapy was performed after antibiogram test with prescription of Enrofloxacin.
Salmonellosis may incur significant social and economic costs as a result of lost productivity, and impacts on industry and agriculture. The centers for disease control and prevention has ways to prevent salmonellosis.