title: Comparative histopathology of draining lymph node after infection with virulent or attenuated strains of Salmonella abortusovis in lambs.
abstract: Histological responses to the early phase of infection were compared in parotid lymph nodes of lambs infected by the subcutaneous route into the right eyelid with either a virulent or an attenuated strain of Salmonella abortusovis. The right parotid lymph nodes showed a massive PMN infiltration for the first days of infection for both strains. From day 6, the infected lymph nodes developed a lymphoid hyperplasia with prominent germinal centers independent of strain type. The virulent strain of S. abortusovis induced focal lesions in 2 out of 6 lambs necropsied on days 6 and 10, and provoked a systemic infection evidenced by the regular colonization of spleen on day 6. In contrast, no focal lesion and a restricted bacterial dissemination were observed in lambs infected with the vaccinal strain.
authors.affiliation: Ecole Nationale Vétérinaire d'Alfort, Laboratoire d'Anatomie Pathologique associé à l'INRA, Maisons-Alfort, France.
authors.forename: J J
authors.initials: JJ
authors.lastname: Fontaine
authors.forename: M
authors.initials: M
authors.lastname: Pépin
authors.forename: P
authors.initials: P
authors.lastname: Pardon
authors.forename: J
authors.initials: J
authors.lastname: Marly
authors.forename: A L
authors.initials: AL
authors.lastname: Parodi
mesh_terms: D000818:Animals; D001428:Bacterial Vaccines; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D012475:Salmonella / Q000472:pathogenicity*; D012481:Salmonella Infections, Animal / Q000382:microbiology / Q000473:pathology*; D012756:Sheep; D012757:Sheep Diseases / Q000382:microbiology / Q000473:pathology*; D014613:Vaccines, Attenuated; D014774:Virulence
chemical_list: D001428:Bacterial Vaccines; D014613:Vaccines, Attenuated