Establishment of multiplex PCR detection for pathogens of chicken embryos

To establish a multiplex PCR assay for simultaneous detecation of Bordetella avium, Escherichia coli, Salmonella and Pseudomonas aeruginosa in infected embryos, four pairs of specific primers were designed and synthesized based on the genes of ompA in B. avium, invA in Salmonella, phoA in E. coli and toxR in P. aeruginosa for detection of these pathogenic bacteria by multiplex PCR. Test results indicated that the PCR products were 597 bp for B. avium, 724 bp for Salmonella, 372 bp for E. coli, and 278 bp for P. aeruginosa, and the limit detections were approximate 104 cfu/mL for B. avium, E. coli and P. aeruginosa and 103 cfu/mL for Salmonella, respectively, without any amplification from other related bacteria. The detection results from clinical embryos samples showed that the multiplex PCR were consistent with that of bacteria culture isolation. The multiplex PCR assay could be used for rapid detection of pathogenic bactera.