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

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. Species were identified by the MALDI-TOF MS analysis. The minimum inhibitory concentrations (MICs) of common antibiotis were determined by broth microdilution and interpreted according to the CLSI guidelines and EUCAST breakpoints. We totally covered 29 (2.26%, 29/1284) tet(X4)-positive E.coli, and 96.6% of them (28 isolates) exhibited resistance to tigecycline. In conclusion, the specific screening strategy for tet(X)-positive strains may be able to facilitate the advance and development of the tet(X).