genome-scale analysis of mycoplasma agalactiae loci involved in interaction with host cells公司分析,支原体agalactiae位点与宿主细胞的参与互动.pdfVIP

Genome-Scale Analysis of Mycoplasma agalactiae Loci Involved in Interaction with Host Cells ` 1,2 1,2 ´ 1,2 ´ 1,2¤ 1,2 Agnes Skapski , Marie-Claude Hygonenq , Eveline Sagne , Sebastien Guiral , Christine Citti , Eric Baranowski1,2* ´ 1 INRA, UMR1225, IHAP, Toulouse, France, 2 Universite de Toulouse, INP, ENVT, UMR1225, IHAP, Toulouse, France Abstract Mycoplasma agalactiae is an important pathogen of small ruminants, in which it causes contagious agalactia. It belongs to a large group of ‘‘minimal bacteria’’ with a small genome and reduced metabolic capacities that are dependent on their host for nutrients. Mycoplasma survival thus relies on intimate contact with host cells, but little is known about the factors involved in these interactions or in the more general infectious process. To address this issue, an assay based on goat epithelial and fibroblastic cells was used to screen a M. agalactiae knockout mutant library. Mutants with reduced growth capacities in cell culture were selected and 62 genomic loci were identified as contributing to this phenotype. As expected for minimal bacteria, ‘‘transport and metabolism’’ was the functional category most commonly implicated in this phenotype, but 50% of the selected mutants were disrupted in coding sequences (CDSs) with unknown functions, with surface lipoproteins being most commonly represented in this category. Since mycoplasmas lack a cell wall, lipoproteins are likely to be important in interactions with the host. A few intergenic regions were also identified that may act as regu