Phenotypic Detection of Virulence Traits and Antibiotic Susceptibility of Endodontic <i>Enterococcus </i><i>f</i><i>aecalis</i> Isolates

Abstract

Enterococcus faecalis is a Gram-positive member of human gastrointestinal flora that is in recent years emerging as an important cause of endodontic infections. In this study, we have investigated the occurrence of virulence determinants and antibiotic susceptibility pattern of E. faecalis isolates, originating from root canals of apical periodontitis. Among 52 E. faecalis isolates, 32 (61.5%) isolates produced hemolysin on blood agar while all (100%) isolates showed hemolysin production on BHI-GA ((BHI medium supplemented with 1% glucose and 0.03% L-arginine), 18 (34.6%) produced gelatinase, 38 (73%) produced caseinase, no hemagglutination was observed in E. faecalis isolates, whereas all 52 (100%) resistant to serum and formed biofilm. Antibiotic susceptibility results showed that all (100%) E. faecalis isolates were susceptible to amoxicillin, amoxicillin/clavulanate, and vancomycin. Whereas, 32 (61.5%) E. faecalis isolates were resistant to chloramphenicol, 30 (57.6%) isolates were resistant to ciprofloxacin, 39 (75%) isolates were resistant to erythromycin, and 34 (65.3%) isolates were resistant to tetracycline. Multi-drug resistance was observed in 16 (30.7%) isolates of E. faecalis to chloramphenicol, ciprofloxacin, erythromycin and tetracycline antibiotics. These findings demonstrate the presence of putative virulence determinants in E. faecalis isolates originating from root canal and suggest amoxicillin, amoxicillin/clavulanate, and vancomycin as more effective than other antibiotics tested.

Prevalence of Virulence Factors and Drug Resistance in Clinical Isolates of Enterococci: A Study from North India

“…It is of interest to know that these adhesins are often transferable in the form of plasmids to other strains [ 21 ]. Property of haemagglutination as a virulence factor of enterococci has been studied less frequently, and total absence of this factor has been reported in one of the above-mentioned studies on endodontic isolates [ 22 ].…”

“…Indwelling urinary catheters, use of intravascular devices, and prolonged hospitalization have been studied to be significant risk factors for enterococcal infections [ 25 ]. Even higher rates of biofilm formation (86.6%) have been reported from India among the urinary isolates of enterococci [ 16 ], whereas another study has reported biofilm formation by all the endodontic enterococcal isolates [ 22 ].…”

Histopathological changes induced in an animal model by potentially pathogenic Enterococcus faecalis strains recovered from ready-to-eat food outlets in Osun State, Nigeria

“…The gelatin-hydrolyzing activity has been suggested to be different from that of caseinase activity. 34 , 35 Sedgley et al 36 reported that the gelatinase gene ( gelE ) was detected in all endodontic isolates of E. faecalis and that two thirds of the isolates expressed gelatinase activity. David et al 33 reported similar findings when investigating clinical isolates.…”

Association of Enterococcus faecalis with Different Forms of Dental Diseases among Patients Visiting a Tertiary Hospital in Ekiti State, Nigeria

“…The inoculum used was standardized by adjusting its density to equal the turbidity of barium sulphate (BaSO 4 ) solution (0.5 McFarland turbidity standard), and incubated at 35ºC for 18hrs. The isolates were tested against the following antibiotic disks (Abtek Biologicals, UK) with their concentrations (in µg): amoxicillin (25), augmentin (30), chloramphenicol (30), cloxacillin (5), cotrimoxazole (25), erythromycin (5), gentamicin (10), vancomycin (5), tetracycline (10), levofloxacin (5), ofloxacin (30), perfloxacin (5), sparfloxacin (10) and ciprofloxacin (10). The diameter of the zone of inhibition was measured and interpreted using the CLSI Guidelines [18].…”

“…Enterococcus faecalis is a Gram-positive coccus and facultative anaerobic bacterium that inhabits the oral cavity and other human parts such as the gastrointestinal tract as well as the vagina [8]. Enterococcus faecalis accounted for 90% of human enterococcal infections which increased substantially since the 1980s [9,10].…”