Yang Y, Merriam J J, Mueller J P, Isberg R R
Department of Microbiology and Molecular Biology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
Infect Immun. 1996 Jul;64(7):2483-9. doi: 10.1128/iai.64.7.2483-2489.1996.
Yersinia pseudotuberculosis inv mutant strains cured of the virulence plasmid exhibit thermoinducible adhesion to cultured mammalian cells. To identify the genes responsible for this phenotype, Y. pseudotuberculosis homologs of the Y. enterocolitica ail and the Y. pestis psa loci were identified. Mutations in the Y. pseudotuberculosis ail and psa loci were constructed and tested for thermoinducible binding. Results of cellular binding assays indicated that only mutations in psa, not in ail, resulted in defects for thermoinducible binding, with inv yadA psa strains showing no detectable cell adhesion. In addition, an inv psa strain was defective for hemagglutination of sheep erythrocytes, in contrast to an inv psa+ strain which was fully competent for hemagglutination. The introduction of a plasmid containing a 6.7-kb KpnI-ClaI fragment of Y. pseudotuberculosis encompassing the psa locus was sufficient to complement both the cell adhesion and hemagglutination defects of the psa mutant. Results from subcloning and transposon mutagenesis indicated that the complete 6.7-kb region was required for thermoinducible binding and hemagglutination.
治愈了毒力质粒的耶尔森氏假结核杆菌inv突变株对培养的哺乳动物细胞表现出热诱导黏附。为了鉴定导致这种表型的基因，确定了小肠结肠炎耶尔森氏菌ail和鼠疫耶尔森氏菌psa位点在耶尔森氏假结核杆菌中的同源物。构建了耶尔森氏假结核杆菌ail和psa位点的突变体，并对其热诱导结合进行了测试。细胞结合试验结果表明，只有psa位点的突变，而不是ail位点的突变，导致热诱导结合缺陷，inv yadA psa菌株未检测到细胞黏附。此外，与完全具备血凝能力的inv psa+菌株相比，inv psa菌株对绵羊红细胞的血凝作用存在缺陷。导入一个含有耶尔森氏假结核杆菌6.7 kb KpnI-ClaI片段（包含psa位点）的质粒足以弥补psa突变体的细胞黏附和血凝缺陷。亚克隆和转座子诱变结果表明，完整的6.7 kb区域是热诱导结合和血凝所必需的。
