title: Factors affecting infectivity of Tyzzer's organism in cultured mouse hepatocytes.
abstract: Factors affecting the infectivity of Tyzzer's organism, an obligate intracellular bacterium, were examined in cultured mouse hepatocytes. The organisms were subjected to physical and chemical impairments and the infectivity was estimated by immunofluorescence that discriminated adhesion and entry of the organisms to host cells and by the plaque assay. Pretreatment of the organisms with either mild heat or formalin abolished adhesion. UV irradiation completely removed the plaque forming ability, while adhering and entering capacity were more resistant in this order. Entry of the organism into host cells was suppressed in the presence of erythromycin, gentamicin or oxytetracycline, while it was relatively little susceptible to ampicillin, kanamycin or rifampicin. Plaquing efficiencies were increased by centrifugation during the infection. These results suggest that not only a structural but also a functional integrity of the organisms was requisite for establishment of the infection at the initial stage.
authors.affiliation: Department of Biomedical Science, Faculty of Agriculture, University of Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kawamura
authors.forename: T
authors.initials: T
authors.lastname: Mitsuoka
authors.forename: K
authors.initials: K
authors.lastname: Fujiwara
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D001407:Bacillus / Q000187:drug effects / Q000472:pathogenicity* / Q000528:radiation effects; D001422:Bacterial Adhesion / Q000187:drug effects; D002478:Cells, Cultured; D002498:Centrifugation; D005260:Female; D005455:Fluorescent Antibody Technique; D005557:Formaldehyde / Q000494:pharmacology; D006358:Hot Temperature; D008099:Liver / Q000166:cytology; D051379:Mice; D008826:Microbial Sensitivity Tests; D009336:Necrosis; D014466:Ultraviolet Rays
chemical_list: D000942:Antigens, Bacterial; D005557:Formaldehyde