Single-step multiplex reverse transcription-polymerase chain reaction for the detection and differentiation of QX-like infectious bronchitis virus from the Thai variant and vaccine strains H120, Ma5, and 4/91

Background and Aim: QX-like infectious bronchitis virus (IBV) is a highly avian coronavirus that causes respiratory kidney disease. It linked to increased mortality loss of performance in infected chickens worldwide, including Thailand. Thus, simple rapid diagnostic method for the diagnosis IBV needed. This study aimed develop single-step multiplex reverse transcription-polymerase chain reaction (mRT–PCR) assay detect differentiate from Thai vaccine strains used poultry industry (H120, Ma5, 4/91). Materials Methods: Primer sets specific were designed target S1 gene. The specificity technique was verified using nine isolates IBV, four other viral pathogens. detection limit evaluated serial ten-fold dilution IBV. Results: results showed mRT–PCR could it H120, 4/91. developed 102.2 embryo dose (EID)50/mL 101.8 EID50/mL Interestingly, identify mixed infection by both IBVs single sample. Conclusion: this can potentially discriminate 4/91 reaction. also suitable use all laboratories with access conventional PCR equipment. Keywords: detection, virus, reaction, specificity.