engleski

Pathogenesis of Listeria monocytogenes infection following intra gastric inoculation in mice

Listeria monocytogenes is a gram positive, facultative intracellular pathogen that is, in its severest form, responsible for meningoencephalitis in both animal and man. Listeria was recognized as a food-borne pathogen since the 1980s when several outbreaks of listeriosis were identified in Europe and North America. In an attempt to obtain a model resembling natural listeriosis, we studied the course of infection in BALB/c mice challanged by gastric intubation. Animals received 10(8) CFU of L. monocytogenes directly into the stomach after overnight fasting. Systemic infection and dissemination of Listeria to the lungs, liver, spleen and kidney was observed. The repeated intra-gastric administration of L. monocytogenes for 3 consecutive days led to development of severe liver failure. All infected animals exhibited continously high numbers of Listeria in their livers, severe pathohistological changes and extreme metabolic dissfunction according to high levels of serum aminotransferases. In addition, L. monocytogenes was isolated from the brains of all infected mice, even though histological examinations revealed no lesions. The increased severty of infection in mice challanged intra-gastrically by repeated doses, appeared to result from listerial multiplication in the livers and other organs rather than from local proliferation in the intestinal tract. This model seems to be potentially useful for research of the pathogenesis, predisposing factors and therapy in naturally introduced listeriosis.

Listeria monocytogenes; intragastric

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