Coexistence and characterization of Tet(X5) and NDM-3 in the MDR-Acinetobacter indicus of duck origin.

Tigecycline and carbapenem are last-resort antibiotics for serious infections caused by pathogens with multi-drug resistance (MDR). Whereas, bacterial pathogens with co-resistance to tigecycline and carbapenem are poorly addressed. Here we report a tigecycline- and carbapenem-resistant Acinetobacter indicus strain HY20 of duck origin, which co-produces Tet(X5) and NDM-3. Tet(X5) is harbored by a novel plasmid pAI01 (116,992 bp long), which carries 10 antimicrobial resistance genes (AMRs), and heavy metal resistance system cobalt-zinc-cadmium (czc) gene cluster. Unlike that tet(X5) is located in the res-tet(X5)-xerD segment of plasmid, the chromosomal blaNDM-3 is flanked by insertion ISAba125. Collectively, our result represents an example of co-carriage of tet(X5) and blaNDM-3, heightening the importance of AMR surveillance needed in poultry production.