Can antimicrobial blue light contribute to resistance development? Genome-wide analysis revealed aBL-protective genes in Escherichia coli

Antimicrobial blue light (aBL) is a promising non-antibiotic approach to fighting multidrug-resistant bacteria. However, the complete mechanism of aBL action is not fully understood yet. This study contributes to a better understanding that the response to aBL depends on many factors and that it is hardly possible to identify a predominant mechanism underlying microbial sensitivity to photoinactivation. The results of this study provide insights into genetic changes that may lead to bacterial survival at higher aBL doses, giving rise to aBL-resistant strains. To our best knowledge, this is the first study concerning genome-wide mutant testing of aBL. We managed to identify 64 single-gene mutants that lacked certain protective genes expressing aBL-increased sensitivity.