Two Multiplex PCR Methods for Detecting Several Pathogens Associated with Feline Respiratory and Intestinal Tracts

SIMPLE SUMMARY: Coinfection with multiple pathogens is common among feline respiratory tract and intestinal diseases. In clinical cases, cats may exhibit similar symptoms between respiratory and intestinal disease, making it difficult to accurately identify and distinguish pathogens. This study aimed to establish two novel multiplex polymerase chain reactions (mPCRs) for simultaneous detection of pathogens associated with the feline respiratory and intestinal tracts. Regrading sensitivity, the detection limits for FeKoV, FPV, FeAstV, FCoV, IAV, C. felis, FeLV, FHV-1 and FCV were 10(3), 10(4), 10(3), 10(3), 10(3), 10(4), 10(4), 10(5) and 10(5) copies/µL, respectively. Moreover, the specificity of the two mPCRs was high. In summary, the two newly mPCR methods provide available, specific, sensitive and inexpensive tools for detecting pathogens. ABSTRACT: Respiratory tract and intestinal diseases are common threats to feline health. Coinfection with multiple pathogens is not rare among clinical infectious cases. Rapid diagnosis of these coinfections is of great significance for timely and effective clinical treatment. In this study, two novel multiplex polymerase chain reactions (mPCRs) were established for simultaneous detection of four pathogens associated with the feline intestinal tract (feline coronavirus (FCoV), feline astrovirus (FeAstV), feline panleukopenia virus (FPV) and feline kobuvirus (FeKoV)) and five pathogens associated with the respiratory tract (feline calicivirus (FCV), feline herpesvirus 1 (FHV-1), feline leukemia virus (FeLV), Chlamydia felis (C. felis) and influenza A virus (IAV)). The results of sensitivity analysis revealed that the detection limits for FeKoV, FPV, FeAstV, FCoV, IAV, C. felis, FeLV, FHV-1 and FCV were 10(3), 10(4), 10(3), 10(3), 10(3), 10(4), 10(4), 10(5) and 10(5) copies/µL, respectively. Moreover, the specificity of the two mPCRs was high. When the two mPCRs were applied to clinical samples, the assay worked well. In conclusion, we established two mPCR methods that provide an excellent tool for the diagnosis and monitoring of pathogens associated with the feline respiratory and intestinal tracts.