The Survey Of Bacterial Co-infection And Establishment Of Multiple PCR Detection For Mycoplasma Bovis Pneumonia

Mycoplasma bovis pneumonia is a serious disease to harm global beef cattle industry. The pathogenic factors of this disease are complicated and are generally though to be related to Mycoplasma bovis causing mainly respiratory disease symptoms.As early as1961, the American scientist isolated M. bovis from the cattle with mastitis. From that on, most of the countries in the world have reported the outbreak of M. bovis related disease. However, so far, scientists did not develop good drugs and vaccines for the treatment and prevention of this disease. China reported outbreak of M.bovis’ pneumoniafor the first time in2008, and confirmed a countrywide prevalence. This disease is related to the distance transportation of beef cattle and M.bovis infection is closely related to transportation stress and has caused tremendous economic loss. This study was aimed to elucidate the bacterial profile of this disease beside M.bovis and therefore provide evidence to take proper treatment strategy and develop specific vaccine. Meanwhile, this study aimed to provide a rapid detection method to diagnose this disease.The main content was as follows:1. The epidemiology survey of bacterialological mixture co-infection for Mycoplasma bovisThis paper’s study is to isolate and indentify the bacteria associated with M. bovis pneumonia,123clinical samples were collected from35cattle or dairy farms in the last three years. Results show that M. bovis infection is in a dominating position, and co-infections are mainly caused by M. bovis with Pasteurella multocida type A or M. bovis with Arcanobacterium pyogenes. These results are of vital importance for the clinical treatment, prevention and control of M. bovis pneumonia.2. Establishment of the triple PCR detection method of Mycoplasma bovis, Pasteurella multocida type A and Arcanobacterium pyogenesA triple-PCR method were developed to detected M. bovis, P. multocida type A and A. pyogenes. Primers were designed for the amplification of hyaC—hyaD gene segment of P. multocida type A, conservative section of16S rRNA gene of A. pyogenes and the UvrC gene of M. bovis. Specificity tests show that the PCR method amplified all three genes from these three pathogens without amplifying any other genes from other pathogens. Sensitivity tests show that the PCR sensitivity for P. multocida type A and A. pyogenes is8×105CFU/mL, and4×106CFU/mL for M.bovis. The detection sensitivity for this triple-PCR is10-100times lower than that of simple PCR. Examine reports show this triple-PCR method has a good consistency with cultural identification when screening the artificial clinical samples and clinical samples, the rate is above80%.