Listeriosis outbreak in sheep raised in feedlots in the Southern Region of Rio Grande do Sul state, Brazil
Ribeiro, Luiza SoaresScheid, Haide ValeskaMarques, Lucas dos SantosVenancio, Fabiano da RosaSilva, Elisa Rocha daLadeira, Silvia Regina LealSchild, Ana Lucia
Background: A listeriosis outbreak in a sheep fattening feedlot in the Southern Region of Rio Grande do Sul State, Brazilis described. This disease is caused by Listeria monocytogenes and represents a risk to public health since it affects notonly ruminants but also humans. This agent is widely spread in the environment, such as in the soil and water. It is alsofound in decaying vegetable matter and the feces and fluids of domestic animals. The aim of this study was to describe alisteriosis outbreak in sheep raised in feedlots, its epidemiology, and to establish the importance of this disease in this typeof sheep management system, evaluate the possible sources of infection, and suggest ways to control it.Cases: Sheep were kept in a 2-sector shed, one with east solar orientation and the other with west solar orientation, thelatter with free access to domestic birds. Sheep were fed silage and concentrate. Seven sheep were affected, 5 died and 2recovered. Clinically, the sheep displayed loss of balance, excessive drooling, and tremors; one exhibited circling, headdeviation, apathy, nystagmus, lateral recumbency, paddling, and labored breathing. At necropsy, macroscopic lesions werenot found, and histologically several micro-abscesses and perivascular cuffs with lymphocytes, macrophages, and neutrophils were present in the brain stem. Listeria monocytogenes suspected colonies were observed in the microbiologicalculture, and the bacteria was identified by biochemical analysis. The immunohistochemistry test in brain stem sectionswas positive for the antibody BD DifcoTM Listeria O Antiserum Poly Serotypes 1 and 4.Discussion: A listeriosis outbreak in a feedlot sheep was confirmed through epidemiological findings, histological lesions,bacterial culture, and immunohistochemistry analysis. This infection is frequent...(AU)
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