Experimental Mixed Infection of Rabbits with Yersinia enterocolitica and Listeria monocytogenes

Abstract

Experimental mixed infection was reproduced in rabbits after per os infection with Yersinia enterocolitica serotype 0:3 cells. Four days later some of animals were re-infected orally with Listeria monocytogenes serotype 4b cells. A third group of healthy rabbits was also infected per os with Listeria monocytogenes. The infectious process was followed dynamically from days 1-28. The experimental animals were examined for clinical, paraclinical and morphological findings. Augmentation of body temperature and alveolar macrophage number, a decreased number of peritoneal macrophages, leucopenia as well as purulent meningoencephalitis, catarrhal pneumonia, lienitis, lymphadenitis and enteritis were detected after experimental mixed infection. Both types of macrophages demonstrated a weak bactericidal activity against Yersinia enterocolitica and a highly expressed killing effect against Listeria monocytogenes. Yersinia and Listeria cells were isolated from the viscera and brain. Both species of bacteria were established intracellularly in the macrophages by electron-microscopic examination. The data received showed that mixed Yersinia enterocolitica 0:3 and Listeria monocytogenes 4b infection of rabbits runs with transitory hyperthermia as a generalized infection and is similar to the Listeria mono-infection. The immunosuppressive effect induced by oral Yersinia enterocolitica infection of rabbits promotes the expression of listerious agents.

Prevalence of Anti‐Yersinia Outer Protein Antibodies in Goats in Lower Saxony

“…The factors Ômicrobial infectionÕ and Ônematode parasitismÕ might be promoted by immunosuppression caused by underlying Yersinia-infection. Najdenski and Vesselinova (2002) showed that this connection for Yersinia and Listeria infection in rabbits. Pigs and cows are asymptomatic carriers of Yersinia.…”