Corynebacterium diphtheriae
, the aetiologic agent of diphtheria, also represents a global medical challenge because of the existence of invasive strains as causative agents of systemic infections. Although tellurite (TeO
32−) is toxic to most microorganisms, TeO
32−-resistant bacteria, including
C. diphtheriae, exist in nature. The presence of TeO
32−-resistance (Te
R) determinants in pathogenic bacteria might provide selective advantages in the natural environment. In the present study, we investigated the role of the putative Te
R determinant (CDCE8392_813 gene) in the virulence attributes of diphtheria bacilli. The disruption of CDCE8392_0813 gene expression in the LDCIC_L1 mutant increased susceptibility to TeO
32− and reactive oxygen species (hydrogen peroxide), but not to other antimicrobial agents. The LDCIC-L1 mutant also showed a decrease in both the lethality of
Caenorhabditis elegans
and the survival inside of human epithelial cells compared to wild-type strain. Conversely, the haemagglutinating activity and adherence to and formation of biofilms on different abiotic surfaces were not regulated through the CDCE8392_0813 gene. In conclusion, the CDCE8392_813 gene contributes to the Te
R and pathogenic potential of
C. diphtheriae.
