Cloning And Sequence Analysis Of Capsule And Virulence-related Gene Of Pasteurella Multocida From Bovine

With development of large-scale fanning and the increasing of raised density, the chance of mixed infection is becaming more greater, many bacterial play the role of Secondary infection. In 2007,The sick calf with age between one to nine weeks was characterized by fever, dyspnea and pathological changes in lung,part of which have diarrhea and about ninety calf died of pneumonia in six pastures of dairy cow in Xinjiang shihezi.Through clinical symptoms, and isolation and identification of pathogenic bacteria, Pasteurella multocida pneumonia was diagnosed.In order to trace the Pathogen and control the occurrence of the disease, cotton swab of was collected from healthy cattle nasal, through the separation of bacteria, biochemical identification, susceptibility testing, animal experiments and PCR methods of detection, two Pasteurella multocida were isolated. Cloning and Sequence Analysis of hasR, ompH, plpE, ptfA of Pasteurella Multocida from health Bovine and Pasteurella multocida caused pneumonia, which make a basis for calfing source of infection, study the pathogenesis of Pasteurella multocida, studying molecular characteristics and expression of this genes1,Two gram-negative bacteriacan were isolated from nasal swab, which have same result of biochemical-identification, cultural characteristics, morphological with Pasteurella multocida.In the Animal experiments,the mice died in 24 hours,showing highly pathogenic.2,Refering the Pasteurella multocida species-specific primers and serotype-specific gene primer Townsend published with the DNA of 2 isolations as a template, two bands 500bp and 1000bp can be amplified by multiplex PCR, the two bands were recovered and sepuenced then BLAST by the GenBank.The result showed that the sequence of two bands have 99% gene homologous with Pasteurella multocida species-specific genes and capsular serotype A gene.3,Susceptibility tests showed that the isolation of nasal swab from healthy cattle are highly sensitive to Neomycin, Gentamicin, Ciprofloxacin,Ofloxacin, Norfloxacin,tolerance to Ampicillin sodium, Cephradine, Kanamycin, Ceftiofur sodium, Amikacin.4,Cloning and sequence analysis of the capsule and virulence genes hasR, ompH, plpE, ptfA showed that Pm-BS-d, Pm-BS-a, Pml42-x-4, Pm142-x-3, Pm149-x, Pm149-xby have high homology 82.2%-100%.There is a high conservative in this genes of Pasteurella multocida from different Bovine.The high homology of gene between healthy calves isolation and calves with pneumonia isolation indicate that the Pasteurella multocida inducing pneumonia of calf mey be come from upper respiratory of their own or their parents.