Sequence analysis of inlb and acta gene of listeria monocytogenes of different sources and virulence evaluation of gene deletion strains

The specific primers were designed based on internalin B(inlB) and actin A(actA) genes of Listeria monocytogenes published in the GeneBank.Then inlB and actA genes were amplified from 5 Listeria monocytogenes strains isolated from clinically healthy sheep and one strain from diseased sheep.In addition,two Listeria monocytogenes strains with partial gene deletion were inoculated into mice to examine their virulence.The result showed that 5 strains from healthy sheep shared high homology with that strain from clinical case.The virulence of partial gene deletion strains were reduced but not significant.