Inactivation of ahpC renders Stenotrophomonas maltophilia resistant to the disinfectant hydrogen peroxide
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Inactivation of ahpC, encoding alkyl hydroperoxide reductase, rendered Stenotrophomonas maltophilia more resistant to H2O2; the phenotype was directly correlated with enhanced total catalase activity, resulting from an increased level of KatA catalase. Plasmid-borne expression of ahpC from pAhpCsm could complement all of the mutant phenotypes. Mutagenesis of the proposed AhpC peroxidactic and resolving cysteine residues to alanine (C47A and C166A) on the pAhpCsm 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 H2O2.
KeywordsAhpC Catalase Disinfectant H2O2 Stenotrohomonas maltophilia
This study was funded by a Research Career Development Grant (RSA6080063) from the Thailand Research Fund to NC.
NC and PV made a contribution to designing the study. NC, LJ, JC and NT were responsible for completing the experiments and data analysis. NC, SM and PV made a contribution to writing the manuscript. All authors read and approved the final manuscript.
Conflict of interest
The authors declare that they have no conflict of interest.
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