Relationship between Tolerance and Persistence Mechanisms in Acinetobacter baumannii Strains with AbkAB Toxin-Antitoxin System

The molecular mechanisms of tolerance and persistence associated with several compounds in Acinetobacter baumannii clinical isolates are unknown. Using transcriptomic and phenotypic studies, we found a link between mechanisms of bacterial tolerance to chlorhexidine and the development of persistence in the presence of imipenem in an A. baumannii strain belonging to clinical clone ST-2 (OXA-24 β-lactamase and AbkAB toxin-antitoxin [TA] system carried in a plasmid). Interestingly, the strain A. baumannii ATCC 17978 (AbkAB TA system from plasmid) showed persistence in the presence of imipenem and chlorhexidine.This study was funded by grants PI13/02390 and PI16/01163, awarded to M.T., and by grant PI11-02046, awarded to F.F.-C., within the State Plan for R+D+I 2013–2016 (National Plan for Scientific Research, Technological Development and Innovation 2008–2011) and cofinanced by the ISCIII-Deputy General Directorate of Evaluation and Promotion of Research—European Regional Development Fund “A Way of Making Europe” and the Instituto de Salud Carlos III FEDER, Spanish Network for the Research in Infectious Diseases (REIPI, grants RD12/0015/0010 and RD16/0016/0001), as well as by the Study Group on Mechanisms of Action and Resistance to Antimicrobials, GEMARA (SEIMC). M.T. was financially supported by the Miguel Servet Research Programme (SERGAS and ISCIII). L.F.-G. was financially supported by a predoctoral fellowship from the Xunta de Galicia (GAIN, Axencia de Innovación).Peer reviewe