Fig. 3

Comparative analysis of tet(X)-mediated eravacycline degradation. a Microbiological degradation for eravacycline. Five pBAD24-tet(X) constructs as well as their parental strains, including Clade_U6 10FS3-1 [tet(X3)-positive], A. indicus Q278-1 [tet(X4)-positive], Clade_U1 YH12138 [tet(X3)- and tet(X5.2)-positive], and A. piscicola YH12207 [tet(X3)- and tet(X5.3)-positive], are used. The presence of Tet(X) degrades eravacycline, and consequently, the degraded eravacycline loses its antimicrobial activity against a susceptible indicator strain. By contrast, the absence of Tet(X) yields a clear inhibition zone, with a diameter of > 18 mm. The groups with the addition of untreated eravacycline or with the addition of eravacycline treated with E. coli JM109 carrying the empty vector pBAD24 serve as negative controls. b LC-MS/MS quantification of eravacycline degradation by tet(X) clones. Individual values of four biological replicates are shown as dots, while the means and standard deviations are displayed as error bars. Vector (−), the control group with the addition of eravacycline treated with pBAD24-carrying E. coli JM109