A TaqMan-based multiplex real-time PCR assay for the rapid detection of tigecycline resistance genes from bacteria, faeces and environmental samples

Abstract

Background: Tigecycline is a last-resort antibiotic used to treat severe infections caused by extensively drug-resistant bacteria. Recently, novel tigecycline resistance genes tet(X3) and tet(X4) have been reported, which pose a great challenge to human health and food security. The current study aimed to establish a TaqMan-based real-time PCR assay for the rapid detection of the tigecycline-resistant genes tet(X3) and tet(X4). Results: No false-positive result was found, and the results of the TaqMan-based real-time PCR assay showed 100% concordance with the results of the sequencing analyses. This proposed method can detect the two genes at the level of 1 × 102 copies/μL, and the whole process is completed within an hour, allowing rapid screening of tet(X3) and tet(X4) genes in cultured bacteria, faeces, and soil samples. Conclusion: Taken together, the TaqMan-based real-time PCR method established in this study is rapid, sensitive, specific, and is capable of detecting the two genes not only in bacteria, but also in environmental samples.