Identification of Early Colonizing Bacteria Involved in Formation of Dental Unit Waterlines Biofilm Using TA Cloning

Abstract

Background: Bacterial adhesion is the first and the most important step in biofilm formation in dental unit waterlines (DUWLs). Information on the initial adhesion and colonizing bacteria is needed to prevent biofilm formation in DUWLs. To identify the bacterial strains involved in the early adhesion step of DUWL biofilm formation, the thymine adenine (TA) cloning method was used to identify the constituent bacterial species in biofilms formed at different time points in DUWL biofilm models. Methods: DUWL biofilms were formed in the United States Centers for Disease Control and Prevention (CDC) biofilm reactor model, and the bacterial species in the DUWL biofilms obtained at different formation periods were identified using TA cloning. Results: Thirteen genera and 19 species were identified from 267 clones. For Rhizobium pusense and Pseudomonas parafulva, the detection was low in batch culture but high in the biofilm formed. Conclusion: R. pusense and P. parafulva may be involved in the early stages of DUWLs biofilm formation. The findings of this study may be helpful in developing methods for preventing DUWL biofilm formation in the future.

Keywords

• bacterial adhesion
• biofilms
• cloning
• dental unit waterlines
• water microbiology