A multiplex polymerase chain reaction assay was developed for the detection of Pasteurella multocida,Haemophilus paragallinarum,and Escherichia coli.According to the genome sequence of P.multocida,H.paragallinarum,and Escherichia coli in GenBank,three pairs of primers were synthetized.The multiplex PCR reaction condition was optimized and the multiplex PCR for simultaneously detecting P.multocida,H.paragallinarum,and Escherichia coli was established.The specificity test showed that target fragments were obt...