AUTHOR=Ng Say Yong , Ong Kai Xun , Surendran Smitha Thamarath , Sinha Ameya , Lai Joey Jia Hui , Chen Jacqueline , Liang Jiaqi , Tay Leona Kwan Sing , Cui Liang , Loo Hooi Linn , Ho Peiying , Han Jongyoon , Moreira Wilfried 

TITLE=Hydrogen Sulfide Sensitizes Acinetobacter baumannii to Killing by Antibiotics

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.01875

DOI=10.3389/fmicb.2020.01875

ISSN=1664-302X

ABSTRACT=<p>The production of endogenous hydrogen sulfide (H<sub>2</sub>S) has been shown to confer antibiotic tolerance in all bacteria studied to date. Therefore, this mediator has been speculated to be a universal defense mechanism against antibiotics in bacteria. This is assuming that all bacteria produce endogenous H<sub>2</sub>S. In this study, we established that the pathogenic bacteria <italic>Acinetobacter baumannii</italic> does not produce endogenous H<sub>2</sub>S, giving us the opportunity to test the effect of exogenous H<sub>2</sub>S on antibiotic tolerance in a bacterium that does not produce it. By using a H<sub>2</sub>S-releasing compound to modulate the sulfide content in <italic>A. baumannii</italic>, we demonstrated that instead of conferring antibiotic tolerance, exogenous H<sub>2</sub>S sensitized <italic>A. baumannii</italic> to multiple antibiotic classes, and was able to revert acquired resistance to gentamicin. Exogenous H<sub>2</sub>S triggered a perturbation of redox and energy homeostasis that translated into hypersensitivity to antibiotic killing. We propose that H<sub>2</sub>S could be used as an antibiotic-potentiator and resistance-reversion agent in bacteria that do not produce it.</p>