Possible role of the adhesin ace and collagen adherence in conveying resistance to disinfectants on Enterococcus faecalis

Abstract

The presence of the ace gene confers resistance against IKI, NaOCl, and Ca(OH)(2) on E. faecalis. Exposure to collagen makes the wild-type bacterium more resistant against CHX and IKI; however, exposure to collagen apparently decreases resistance to Ca(OH)(2).

The Resistance of Collagen-associated, Planktonic Cells of Enterococcus faecalis to Calcium Hydroxide

“…In one of these studies, the susceptibility to calcium hydroxide of cells of E. faecalis that were either allowed to adhere to dentinal surfaces for 24 hours or prepared as planktonic suspensions was compared; cell recovery was found to be remarkably greater for the adhering bacteria at 10-and 100-minute challenge periods as assessed by culture (13). In a recent study, similar in design to the study presented here, we investigated whether Ace-mediated binding to collagen conferred resistance on E. faecalis to common endodontic disinfectants (14). It was found that collagen-associated bacteria were more resistant against chlorhexidine and iodine-potassium iodide but were surprisingly more susceptible to calcium hydroxide compared with bacteria not exposed to collagen (14).…”

“…In a recent study, similar in design to the study presented here, we investigated whether Ace-mediated binding to collagen conferred resistance on E. faecalis to common endodontic disinfectants (14). It was found that collagen-associated bacteria were more resistant against chlorhexidine and iodine-potassium iodide but were surprisingly more susceptible to calcium hydroxide compared with bacteria not exposed to collagen (14). This finding and the results of the study presented here regarding the susceptibility of collagenassociated cells to calcium hydroxide are in contrast.…”

“…E. faecalis adhering to dentinal surfaces is more resistant against calcium hydroxide compared with its free-floating counterparts (13). We have previously found that collagen-associated E. faecalis may be more resistant against chlorhexidine and iodine potassium iodide but more susceptible to calcium hydroxide compared with bacteria not exposed to collagen (14). Because increased susceptibility to calcium hydroxide was an unexpected finding, the latter study addressed the need for further studies on the effect of collagen association by E. faecalis to its resistance against calcium hydroxide.…”

Molecular characterization of vancomycin-resistant enterococci and extended-spectrum β-lactamase-containingEscherichia coliisolates in wild birds from the Azores Archipelago

“…The current study shows the presence of the ace virulence gene that encodes a protein which mediates the adherence to collagen (Kayaoglu et al, 2008). In a previous study, the ace virulence gene was found in E. faecalis isolated from partridges (Silva et al, 2011).…”

Evaluation of antimicrobial effectiveness of two endodontic irrigation solutions on the microbial reduction of Enterococcus faecalis in infected root canals (in vitro study)

“…[12] It is also able to invade the dentinal tubules. [13] This resistant is attributed to the ability to form a complex structure called biofi lm. [14] In addition to the diffi culty of removing this biofi lm and other bacterial structures that colonizing root canal, the presence of dentin residues and the debris from root canal preparation provide hiding places to previous structures like smear layer which make this more diffi cult to remove.…”