Analysis on the Biological Characteristics of Four Strains of Pasteurella multocida Derived from Chicken
Avian hemorrhagic septicemia,also known as avian pasteurellosis or avian cholera,is caused by Pasteurella multocida,with rapid occurrence and high mortality. In order to support future researches on the pathogenic mechanism of the bacteria as well as prevention and control of the disease in practice,relevant biological characteristics of four strains of Pasteurella multocida(Pm01,Pm03,1801 and 1803)were analyzed through PCR identification,drug resistance analysis,biofilm formation ability test and median lethal dose(LD50)determination. It was showed that,by PCR identification,all the four strains were capsular serotype A and contained 9 virulence genes including pfhA,exBDtonB,nanB,oma87,ompH,hgbB,hgbA,sodC and sodA,except toxA,nanH and ptfA;by drug resistance analysis,the four strains were fully or partially resistant to 7 antibiotics including clindamycin,erythromycin,tetracycline,kanamycin,amoxicillin,cefotaxime and ampicillin;by biofilm formation ability test,a very strong biofilm was formed by Pm01 strain,but failed by Pm03,1801 and 1803;and by the LD50 determination test,the LD50 values of the four strains were 1.33×101,2.74×102,4.22 and 4.22 CFU,respectively. In conclusion,all the four strains contained a variety of virulence genes that were with strong pathogenicity,for which the virulence was not completely related to the biofilm formation ability,and resistant to a variety of antibiotics. A technical support and reference data were provided for future prevention and control of avian pasteurellosis.