title: Genetic loci of Mycoplasma agalactiae involved in systemic spreading during experimental intramammary infection of sheep.
abstract: Mycoplasmas are amongst the most successful pathogens of both humans and animals yet the molecular basis of mycoplasma pathogenesis is poorly understood. This is partly due to the lack of classical virulence factors and little similarity to common bacterial pathogenic determinants. Using Mycoplasma agalactiae as a model we initiated research in this direction by screening a transposon mutant library in the natural sheep host using a negative selection method. Having successfully identified putative factors involved in the colonization of local infection and lymphogenic sites, the current study assessed mutants unable to spread systemically in sheep after experimental intramammary infection. Analysis of distant body sites for complete absence of mutants via SSM PCR revealed that additional set of genes, such as pdhB, oppC, oppB, gtsB, MAG1890, MAG5520 and MAG3650 are required for systemic spreading apart from those that were necessary for initial colonization. Additional in vitro studies with the mutants absent at these systemic sites confirmed the potential role of some of the respective gene products concerning their interaction with host cells. Mutants of pdhB, oppC and MAG4460 exhibited significantly slower growth in the presence of HeLa cells in MEM medium. This first attempt to identify genes exclusively required for systemic spreading provides a basis for further in-depth research to understand the exact mechanism of chronicity and persistence of M. agalactiae.
authors.affiliation: Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.|Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
authors.forename: Shivanand
authors.initials: S
authors.lastname: Hegde
authors.affiliation: Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Zimmermann
authors.affiliation: Clinic for Ruminants, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
authors.forename: Martina
authors.initials: M
authors.lastname: Flöck
authors.affiliation: Institute of Pathology and Forensic Veterinary Medicine, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
authors.forename: Rene
authors.initials: R
authors.lastname: Brunthaler
authors.affiliation: Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
authors.forename: Joachim
authors.initials: J
authors.lastname: Spergser
authors.affiliation: Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria.
authors.forename: Renate
authors.initials: R
authors.lastname: Rosengarten
authors.affiliation: Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210, Vienna, Austria. Rohini.Chopra-Dewasthaly@vetmeduni.ac.at.
authors.forename: Rohini
authors.initials: R
authors.lastname: Chopra-Dewasthaly
mesh_terms: D000818:Animals; D004251:DNA Transposable Elements / Q000235:genetics; D005260:Female; D056426:Genetic Loci / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D008413:Mastitis / Q000382:microbiology / Q000662:veterinary*; D009175:Mycoplasma Infections / Q000382:microbiology / Q000662:veterinary*; D045644:Mycoplasma agalactiae / Q000235:genetics* / Q000472:pathogenicity; D010641:Phenotype; D012756:Sheep; D012757:Sheep Diseases / Q000382:microbiology*
chemical_list: D004251:DNA Transposable Elements