Evaluation of Escherichia coli hydrogenases in persistence

Abstract

Persistence enables a subpopulation of tolerant bacteria to survive in the presence of a bactericidal antibiotic. Reports indicate the non-inherited nature of persistence; however, it also seems to be a genetically influenced phenomenon that has evolved to allow the organisms to survive in sudden environmental insults. In contrary to some reports, lowered available pool of ATP, NAD, and ROS leads to increased survival via slowing down the metabolism and resulting in an increased persister fraction. In this study, the hydrogenases of Escherichia coli were analyzed for their role in persistence, where four hydrogenase operon deletion mutants were evaluated before and after antibiotic treatment. As result, the expressions of hydrogenases and cellular viability (specifically hyd-1, 2, 3) were found elevated in antibiotic-treated cells, indicating their influential roles in persistence. Further work elucidated the affected ATP, NAD, and metabolism in the antibiotic-treated mutant cells. The transcriptomic analysis further revealed a wide genomic connectivity of hydrogenases to influence persistence in E. coli. Hydrogenases were mainly reported for their essential roles in bacterial hydrogen metabolism, this study further demonstrates their probable role in bacterial survival against antibiotic stress.