Inactivation of ahpC renders Stenotrophomonas maltophilia resistant to the disinfectant hydrogen peroxide

Abstract

© 2018, Springer Nature Switzerland AG. Inactivation of ahpC, encoding alkyl hydroperoxide reductase, rendered Stenotrophomonas maltophilia more resistant to H 2 O 2 ; the phenotype was directly correlated with enhanced total catalase activity, resulting from an increased level of KatA catalase. Plasmid-borne expression of ahpC from pAhpC sm could complement all of the mutant phenotypes. Mutagenesis of the proposed AhpC peroxidactic and resolving cysteine residues to alanine (C47A and C166A) on the pAhpC sm plasmid diminished its ability to complement the ahpC mutant phenotypes, suggesting that the mutagenized ahpC was non-functional. As mutations commonly occur in bacteria living in hostile environment, our data suggest that point mutations in ahpC at codons required for the enzyme function (such as C47 and C166), the AhpC will be non-functional, leading to high resistance to the disinfectant H 2 O 2 .