Isolation And Identification Of Mycoplasma Bovis And Molecular Epidemiology Of Vsp Gene In Xinjiang Area

Mycoplasma bovis is a pathogenic pathogen that can infect cattle,it can cause pneumonia,mastitis,arthritis,conjunctivitis and other diseases of cattle,and ofen mixed with a variety of pathogens infection,so it is difficult to completely cure it.In order to further determine the infection of Mycoplasma bovis in Xinjiang,the genetic composition of the representative strains and the genetic characteristics of virulence genes,in this study,41 samples of suspected mycoplasma infection,including the dead calf lung tissue,synovial fluid and nasal swab were collected from 9 large-scale cattle farms in 6 different regions of Xinjiang.The pathogen isolation and PCR identification of M.bovis,the genotyping of the variable surface lipoprotein Vsp E and the whole gene sequencing of the representative strains were carried out to provide the pathogen epidemiological basis for the prevention and treatment of M.Bovis and the development of new vaccines.The research contents and results are as follows:1.The mycoplasma culture medium was developed independently.The pathogen isolation,culture and PCR identification of 41 suspected Mycoplasma bovis were collected.Results showed that 24 strains of typical colonies with M.bovis were obtained from 41 samples,all the isolates were detected by PCR and were identified as Mycoplasma bovis,and the positive rate was 58.5%.The analysis showed that the homology of nucleotide and amino acid homology of 24 strains isolated from different regions of Xinjiang was higher,with the international standard strain PG45(CP002188.1)amino acid homology was 97.3%~100%.The results provide a theoretical basis for molecular epidemiology and immunoprophylaxis of M.bovis in Xinjiang.2.The complete genome size of this strains was 953,064 bp,the content of GC% was 29.97%,the genome contains 114 scaffolds after sequencing assembly,the number of andem repeats were 208,the total length were 16,559 bp,accounting for 1.74% of the total length of the genome.The number of t RNA and r RNA were 90 and 9.There was metabolism gene in the genome.3.For studies on genetic characteristics of different regions of Xinjiang cattle Mycoplasma isolates Vsp gene,Test choose 13 strains of isolates from different regions in Xinjiang,according to the Gen Bank log cattle Mycoplasma Vsp E sequence(Gen Bank accession number: AH008162.2),designed primer.Detected Vsp gene by PCR and analysed sequence.The results show that the nucleotide homology of 13 Xinjiang isolates and standard strains of PG45 was 64.1%~95.8%,it showed that the gene fragment was in the conserved region.The nucleotide homology of the 13 strains was 62.5%~100%,there are certain variation.