Multiple factors are involved in regulation of extracellular membrane vesicle biogenesis in Streptococcus mutans

This study showed that when added to the culture medium, MVs significantly enhancedS. mutans biofilm formation especially in the presence of sucrose and regardless of whether human saliva was also added. Multiple factors including 4 ’‐phosphopantetheinyl transferase (Sfp), di‐adenylyl cyclase (Dac) and phosphodiesterase (PdeA) were found to play significant roles in regulation of MV production. AbstractStreptococcus mutans, a major etiological agent of human dental caries, produces membrane vesicles (MVs) that contain protein and extracellular DNA. In this study, functional genomics, along with in vitro biofilm models, was used to identify factors that regulate MV biogenesis. Our results showed that when added to growth medium, MVs significantly enhanced biofilm formation byS. mutans, especially during growth in sucrose. This effect occurred in the presence and absence of added human saliva. Functional genomics revealed several genes, includingsfp, which have a major effect onS. mutans MVs. InBacillus sp.sfp encodes a 4 ′‐phosphopantetheinyl transferase that contributes to surfactin biosynthesis and impacts vesiculogenesis. InS. mutans, sfp resides within the TnSmu2 Genomic Island that supports pigment production associated with oxidative stress tolerance. Compared to the UA159 parent, theΔsfp mutant, TW406, demonstrated a 1.74 ‐fold (p  <  .05) higher MV yield as measured by BCA protein assay. This mutant also displayed increased susceptibility to low pH an...
Source: Molecular Oral Microbiology - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research