A method for screening tigecycline-resistant gene tet(X) from human gut

Objectives: To develop an effective enrichment method for tet(X) detection, we performed PCR and Sanger sequencing to screen and confirm the presence of tet(X) gene. Methods: Species were identified by MALDI-TOF MS analysis. The minimum inhibitory concentrations (MICs) of common antibiotics were determined by broth microdilution and interpreted according to the CLSI guidelines and EUCAST breakpoints. Results: We obtained 29 (2.26%, 29/1284) tet(X4)-positive Escherichia coli, and 96.6% of those (28 isolates) exhibited resistance to tigecycline. Conclusion: This specific screening strategy for functional tet(X) mediating tigecycline resistance will be useful to facilitate development and advancement of our knowledge of tet(X). (c) 2020 The Authors. Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).

Automated summary

The study developed an effective enrichment method for tet(X) detection using PCR and Sanger sequencing. Results showed a 2.26% prevalence of tet(X4)-positive Escherichia coli, with 96.6% exhibiting resistance to tigecycline. This specific screening strategy will aid in advancing knowledge of tet(X) and tigecycline resistance mechanisms.