Enterococcus faecalis with capsule polysaccharides type 2 and biofilm-forming capacity in Indonesians requiring endodontic treatment

Aim: The aim of the present study was to evaluate the genetic diversity of Enterococcus faecalis (E. faecalis) strains isolated from saliva and infected root canal samples from Indonesians requiring endodontic treatment. Methods: A total of 50 isolates were genotyped using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) and analyzed for locus polymorphisms of their capsule polysaccharides (CPS) and for biofilm-forming capabilities. Results: It was shown that all E. faecalis isolates shared >60% similarity. A higher degree of diversity of E. faecalis was observed in cluster 1 (C1, 28%) and cluster 2 (C2, 22%) from samples isolated from infected root canals. CPS type 2 was the dominant form observed in five clusters (C1-C5), but there was no relationship between the origins of these isolates. In contrast, all isolates in cluster C5 were of root canal origin, and 50% were associated with a strong biofilm phenotype. Five unclustered strains were saliva isolates (<60% similarity). Most of these strains showed weak biofilm capability. Conclusions: E. faecalis CPS type 2 is relatively common in Indonesians requiring endodontic treatment, and there are differences in the biofilm-forming abilities produced by CPS type 2 strains in all isolates depending on the source. In addition, there is no relationship between the ERIC-PCR profile and biofilm formation.