Loading...
Publication
Biofilm Formation by ST17 and ST19 Strains of Streptococcus agalactiae
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 557.81 KB | Adobe PDF |
Advisor(s)
Abstract(s)
Bacterial biofilms are an important virulence factor with a vital role in evasion from the host immune
system, colonization and infection. The aim of the present study was to evaluate in vitro the effects of
three environmental factors (H+ , glucose and human plasma) in biofilm formation, by carrier and
invasive S. agalactiae strains of ST17 and ST19 sequence types, including DNase producers and nonproducers.
Bacteria ability to assemble biofilms was classified based on crystal violet assay. Biofilm
formation was also monitored by scanning electron microscopy. Depending on the growth medium
used, each bacterial isolate could fit in different biofilm production categories. Our data showed that
optimal conditions for S. agalactiae biofilm assembly were reached after 48 h incubation at pH 7.6 in
the presence of glucose and inactivated human plasma. In the presence of inactivated human plasma,
the biofilm biomass of ST19 strains experienced a higher increase than ST17 strains. The composition
of the extracellular polymeric matrix of the three strongest biofilm producers (all from ST17) was
accessed by enzymatic digestion of mature biofilms and proteins were shown to be the predominant
component. The detailed identification of the extracellular protein components should contribute to
the development of new therapeutic strategies to fight S. agalactiae infections.
Description
Keywords
Streptococcus agalactiae Biofilms Extracellular Polymeric Substance Matrix DNases Microscopy