The c ‐di‐AMP signaling system influences stress tolerance and biofilm formation of Streptococcus mitis

In this study, we utilizedS.  mitis deletion mutants ofcdaA,pde1, andpde2 to analyze the role of c-di-AMP signaling in various stress responses, biofilm formation, and adhesion to eukaryotic cells. Here, we demonstrate that the Δpde1 mutant displayed a tendency toward increased susceptibility to acetic acid at pH 4.0. Deletion ofcdaA increases auto-aggregation ofS.  mitis but reduces biofilm formation on an abiotic surface. These phenotypes are more pronounced under acidic extracellular conditions. Inactivation ofpde1 orpde2 reduced the tolerance to ciprofloxacin, and UV radiation and the Δpde1 mutant was more susceptible to Triton X-100, indicating a role for c-di-AMP signaling in responses to DNA damage and cell membrane perturbation. Finally, the Δpde2 mutant displayed a tendency toward a reduced ability to adhere to oral keratinocytes. Taken together, our results indicate an important role for c-di-AMP signaling in cellular processes important for colonization of the mouth.

Source: MicrobiologyOpen - July 19, 2021 Category: Microbiology Authors: Gro Herredsvela R ørvik, Ali‐Oddin Naemi, Per Kristian Thorén Edvardsen, Roger Simm Tags: ORIGINAL ARTICLE Source Type: research