Rapid visual detection of Pasteurella multocida through recombinase polymerase amplification combined with lateral flow dipsticks

Pasteurella multocida (Pm) is a zoonotic pathogen that can cause severe diseases in humans. It is easily confused with swine fever and swine erysipelas in clinical diagnosis because of mixed infections. The aim was to develop a highly sensitive and specific clinical rapid method for the detection of Pm in swine. A specific recombinant enzyme polymerase amplification (RPA) primer was designed according to the kmt1 gene sequence of Pm. By optimizing the reaction temperature and time of RPA, a Pm detection method based on RPA-LFD was developed. The sensitivity, specificity, and clinical application of the method were evaluated. The results showed that the rapid RPA-LFD for the detection of Pm in swine could be completed within 40 min at 39 degrees C, with the lowest detection limit of 1 x 10-6 copies <middle dot> mu L-1 and no cross-reactivity with enteropathogenic Escherichia coli, Staphylococcus aureus, Glaesserella parvoviridis,Aeromonas hydrophilus, Listeria monocytogenes,Actinobacillus pleuopneumoniae, or Streptocuccus suis. The detection rate of the RPA-LFD method for 50 clinical samples was higher than that of the conventional PCR method and bacterial isolation. The RPA-LFD assay for Pm in swine developed in this study has the advantages of high specificity, high sensitivity, rapid detection, and ease of operation, which provides a new technical means for the field detection of Pm.