The murein hydrolase LytF of Streptococcus sanguinis and the ecological consequences of competence development.

The murein hydrolase LytF of Streptococcus sanguinis and the ecological consequences of competence development. Appl Environ Microbiol. 2017 Oct 06;: Authors: Cullin N, Redanz S, Lampi KJ, Merritt J, Kreth J Abstract The overall health of the oral cavity is dependent upon a proper homeostasis between health-associated bacterial colonizers and bacteria known to promote dental caries. Streptococcus sanguinis is a health-associated commensal, a known early colonizer of the acquired tooth pellicle, and is naturally competent. We have shown that LytF, a competence-controlled murein hydrolase, is capable of inducing the release of extracellular DNA (eDNA) from oral bacteria. Precipitated and purified LytF were used as treatments against planktonic cultures and biofilms. Higher amounts of eDNA were released from cultures treated with protein samples containing LytF. Additionally, LytF can affect biofilm formation and cellular morphology. Biofilm formation was significantly decreased in the lytF complemented strain where increased amounts of LytF are present. This same strain also exhibits cell morphology defects in both planktonic cultures and biofilms. Furthermore, the LytF cell morphology phenotype was reproducible in wild type cells using purified LytF protein. In sum, our findings demonstrate that LytF can induce the release of eDNA from oral bacteria and suggest that without proper regulation of LytF, cells display morphological abnorm...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research