Pasteurella multocida can infect a variety of animals,causing pneumonia or systemic sepsis,resulting in serious economic losses.To identify the pathogen of a large number of cattle deaths in a beef cattle farm in Changli County of Hebei province,a strain of suspected Pm was isolated from the lungs of diseased cattle in this study,and was subjected to Gram staining and PCR amplification and sequence analysis of 16S rDNA gene.PCR amplification was further used for typing of the capsules and lipopolysaccharides.The 7 house keeping genes were amplified by PCR and uploaded to MLST network database for multi-locus sequence typing.The results showed that the isolated strain was Gram-negative with 99.87%homology to the 16S rDNA gene sequence of Pm,indicating that a strain of Pm was obtained.The results of PCR typing showed that it was serotype B and lipopolysaccharide L2,and MLST typing was type 44.The Pm isolate was named PmB-1.The isolate was intraperitoneally injected into mice at a dose of 4.88 cfu/mouse for pathogenicity test,and the results showed that PmB-1 could cause visceral hemorrhage in mice.The whole genome sequencing and bioinformatics analysis of PmB-1 were carried out by IlluminaHiseq second generation combined with PacBio third generation sequencing platform,and it showed that the PmB-1 genome contained 1 chromatin,2331836bp in length,2141 coding genes,19 rRNA,58 tRNA and 42 sRNA.It contains three prophages,five genomic islands,five acquired immunity(CRISPR-Cas)systems,three insertion sequences,and one transposon element.The results of pathogenicity prediction analysis showed that PmB-1 contained 244 virulence related genes;224 drug resistance genes;495 genes involved in pathogen and host interaction,including 14 genes encoding secretory system protein,535 genes encoding transporter protein,190 genes encoding secretory protein,499 genes encoding transmembrane protein,and 17 genes encoding two-component regulatory system.In conclusion,a strain of Pasteurella multocida was isolated,and its pathogenicity was tested in mice,and whole genome sequencing and bioinformatics analysis were performed in this study,providing a reference for preventing Pm epidemic and exploring its pathogenic mechanism.
Pasteurella multocidaisolation and identificationwhole genome sequencingbioinformatics analysis
维普
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