Ap4A modulated quorum sensing in treated bacteria to resistant kanamycin

Abstract

Abstract Background Dinucleotide alarmone, diadenosine tetraphosphate (Ap4A) that increased in cellular has been shown to affect bacteria survival under stress. Results Here, we labeled Ap4A with biotin and incubated the labeled Ap4A with the total proteins extracted from the kanamycin treatment E. coli to screen the Ap4A binding protein in bacteria under kanamycin treatment. Liquid chromatography-mass spectrometry (LCMS) uncovered novel Ap4A interaction proteins that involved biofilm formation, quorum sensing, and lipopolysaccharide biosynthesis pathways. Furthermore, we used apaH knockout strain of E. coli K12-MG1655 which increased intracellular Ap4A to demonstrate that Ap4A affected the expression of biofilm formation related genes including csrB、csrC、rpoS, quorum sensing related genes sdiA、ribA, and lipopolysaccharide biosynthesis related genes lpxA、lpxC、lpxP、waaC、gmhB. The biofilm formation of apaH mutant strain and wild-type strain has no difference, but under the kanamycin treatment, the biofilm formation of the mutant strain decreased compared with the wild-type strain. We also observed that apaH mutant reduced the swarming motility of bacteria. Conclusions These results showed that Ap4A can regulate the quorum sensing (QS) mechanism to impact bacteria swarming motility reducing the bacteria’s survival under kanamycin stress. According to these, we could enlarge kanamycin in combination compound to use in the treatment of multidrug-resistant bacteria.