title: Mycoplasma gallisepticum invades chicken erythrocytes during infection.
abstract: Recently, it was demonstrated using in vitro assays that the avian pathogen Mycoplasma gallisepticum is able to invade nonphagocytic cells. It was also shown that this mycoplasma can survive and multiply intracellularly for at least 48 h and that this cell invasion capacity contributes to the systemic spread of M. gallisepticum from the respiratory tract to the inner organs. Using the gentamicin invasion assay and a differential immunofluorescence technique combined with confocal laser scanning microscopy, we were able to demonstrate in in vitro experiments that M. gallisepticum is also capable of invading sheep and chicken erythrocytes. The frequencies of invasion of three well-defined M. gallisepticum strains were examined over a period of 24 h, and a significant increase in invasiveness occurred after 8 h of infection. In addition, blood samples derived from chickens experimentally infected via the aerosol route with the virulent strain M. gallisepticum R(low) were analyzed. Surprisingly, M. gallisepticum R(low) was detected in the bloodstream of infected chickens by nested PCR, as well as by differential immunofluorescence and interference contrast microscopy that showed that mycoplasmas were not only on the surface but also inside chicken erythrocytes. This finding provides novel insight into the pathomechanism of M. gallisepticum and may have implications for the development of preventive strategies.
authors.affiliation: Institute of Bacteriology, Mycology and Hygiene, Department of Pathobiology, University of Veterinary Medicine of Vienna, Veterinaerplatz 1, A-1210 Vienna, Austria.
authors.forename: Gunther
authors.initials: G
authors.lastname: Vogl
authors.forename: Astrid
authors.initials: A
authors.lastname: Plaickner
authors.forename: Susan
authors.initials: S
authors.lastname: Szathmary
authors.forename: László
authors.initials: L
authors.lastname: Stipkovits
authors.forename: Renate
authors.initials: R
authors.lastname: Rosengarten
authors.forename: Michael P
authors.initials: MP
authors.lastname: Szostak
mesh_terms: D000818:Animals; D002645:Chickens / Q000382:microbiology*; D004912:Erythrocytes / Q000382:microbiology* / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D009175:Mycoplasma Infections / Q000382:microbiology / Q000662:veterinary*; D045686:Mycoplasma gallisepticum / Q000502:physiology* / Q000648:ultrastructure; D011201:Poultry Diseases / Q000382:microbiology*