Antibiotic resistance and adhesion properties of oral Enterococci associated to dental caries

In this study, 17 E. faecalis (27.5%) and 4 E. faecium (6.5%) were detected. The identified strains showed resistance to commonly used antibiotics. Among the 17 isolated E. faecalis, 12 strains (71%) were slime producers and 5 strains were non-producers. Among the 4 E. faecium, 2 strains were slime producers. All the tested strains were able to adhere to at least one of the two tested cell lines. Our result showed that 11 E. faecalis and 2 E. faecium strains adhered strongly to Hep-2 as well as to A549 cells.Drugs resistance and strong biofilm production abilities together with a high phenotypic adhesion to host cells are important equipment in E. faecalis and E. faecium which lead to their oral cavity colonization and focal infections.Enterococci are normal commensals Gram-positive cocci that inhabit the gastrointestinal tract and the human oral cavity [1]. The increasing interest to Enterococci in clinical microbiology is linked to their high level intrinsic resistance to currently available antibiotics [2]. Enterococcus faecalis is responsible for up to 90% of human enterococcal infections [3]. However, Enterococcus faecium accounts for the remainder of infections caused by Enterococci spp. [1]. Data on oral prevalence of E. faecalis vary widely in different studies [4] which ranged from 0 to 50% depending on the oral source of the tested specimens (saliva, root canals, plaque) and the studied populations [5]. Sedgley et al., [4] reported the presence of E. faecalis in 29% of oral rinse samples and 22% in gingival sulcus samples collected from 41 endodontic subjects. Recently, drugs resistance in E. faecalis and E. faecium and their possible contribution to horizontal gene transfer underline the growing attention being paid to Enterococci in the oral cavity [6].To date, E. faecalis, are not considered to be part of the normal oral microbiota [7]. However it has been considered as the most common species recovered from teeth with failed endodontic treatment [8] an