Virulence Factors of Enterococcus faecalis and Enterococcus faecium Blood Culture Isolates

Elsner, Holger-Andreas; Sobottka, Ingo; Mack, Dietrich; Laufs, Rainer; Claußen, Maike; Wirth, Reinhard

doi:10.1007/s100960050007

Cited by 132 publications

(100 citation statements)

References 18 publications

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“…Even though some studies failed to detect these genes in Enterococcus faecium (Duprè et al, 2003;Mannu et al, 2003), in our study, 13 Enterococcus faecium (5 %) carried asp and two (1 %) the ace determinants. Our results are in agreement with the literature concerning higher incidence of virulence genes (esp, asp, ace) among Enterococcus faecalis (Abriouel et al, 2008;Duprè et al, 2003;Elsner et al, 2000). Abriouel et al (2008) reported lower incidence of ace gene in enterococci from water samples as compared with clinical isolates, a finding contradicting our results, since 39 (56 %) water isolates were ace-positive, while only 15 (8 %) clinical isolates carried the gene.…”

Section: Discussionsupporting

confidence: 78%

“…The Enterococcus surface protein (Esp), encoded by the esp gene, acts as an adhesin and is involved in the formation of biofilms (Upadhyaya et al, 2011), although this association has not been not confirmed by other investigators (Comerlato et al, 2013). Many proteins have been implicated in enterococcal virulence (Elsner et al, 2000). The most commonly implicated are the aggregation substance (asp gene) enhancing the adherence to matrix proteins and the collagen-binding protein encoded by the ace gene (Duprè et al, 2003;Vankerckhoven et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

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Biofilm synthesis and presence of virulence factors among enterococci isolated from patients and water samples

Papadimitriou-Olivgeris

Filippidou

Δρούγκα

et al. 2015

Journal of Medical Microbiology

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The goal of this study was to compare biofilm synthesis among enterococci recovered from clinical samples (infection or colonization) of patients as well as environmental samples in order to determine possible virulence factors and clonal relationship. During a two-year period, clinical samples (blood, catheter tips, bronchial secretions, wounds, peritoneal fluid, urine) and rectal swabs collected from hospitalized patients as well as environmental water samples were tested for the presence of Enterococcus faecalis and Enterococcus faecium. Antibiotic susceptibility testing was performed by the disc diffusion method and Etest. Strains were tested for the presence of vanA, vanB, esp, ace and asp genes by PCR. Clones were identified by PFGE (Sma I). From infected patients, 48 strains were identified: 24 Enterococcus faecium (10 vanApositive, 14 vancomycin-susceptible) and 24 Enterococcus faecalis (one vanA-positive, 23 vancomycin-susceptible). Among 143 colonizing isolates, 134 were Enterococcus faecium (58 vanA-positive, 11 vanB-positive, 65 vancomycin-susceptible) and nine Enterococcus faecalis (three vanA-positive, two vanB-positive, four vancomycin-susceptible). Among 167 environmental water samples, 51 Enterococcus faecalis and 19 Enterococcus faecium isolates, all glycopeptide-susceptible, were recovered. In total, 64 strains produced biofilm, whereas 34 were esp-positive, 64 asp-positive and 54 ace-positive. Biofilm production was associated with the presence of esp (P,0.001) and ace genes (P50.021), being higher in infecting (P,0.001) and water (P 0.005) isolates as compared with colonizing ones. Clones of environmental waterstrains were different than the patients' clones. The differences found in the incidence of antibiotic resistance, virulence factors and clones suggest that hospital and water enterococci are of different origin.

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Section: Discussionsupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Biofilm synthesis and presence of virulence factors among enterococci isolated from patients and water samples

Papadimitriou-Olivgeris

Filippidou

Δρούγκα

et al. 2015

Journal of Medical Microbiology

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“…Virulence factors of E. faecalis, such as hemolysin, gelatinase, and enterococcal aggregation substance (EAS) play an important role in the bacterium's pathogenesis (4). However, the mechanism through which E. faecalis persists in the root canal is not well understood.…”

mentioning

confidence: 99%

Biofilm Formation in Medicated Root Canals

Distel¹,

Hatton²,

Gillespie³

2002

Journal of Endodontics

318

224

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The hypothesis that Enterococcus faecalis resists common intracanal medications by forming biofilms was tested. E. faecalis colonization of 46 extracted, medicated roots was observed with scanning electron microscopy (SEM) and scanning confocal laser microscopy. SEM detected colonization of root canals medicated with calcium hydroxide points and the positive control within 2 days. SEM detected biofilms in canals medicated with calcium hydroxide paste in an average of 77 days. Scanning confocal laser microscopy analysis of two calcium hydroxide paste medicated roots showed viable colonies forming in a root canal infected for 86 days, whereas in a canal infected for 160 days, a mushroom-shape typical of a biofilm was observed.Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis showed no differences between the protein profiles of bacteria in freefloating (planktonic) and inoculum cultures. Analysis of biofilm bacteria was inconclusive.These observations support potential E. faecalis biofilm formation in vivo in medicated root canals.The most common reasons for failures in conservative root canal therapy are related to problems in instrumentation. However, occasionally, bacteria resistant to conservative therapy may also be involved (1). "Bacteria-associated endodontic failures together with pulp-periapical infections refractory to conventional treatment represent the unresolved bacteriological problems in endodontics" (2). Numerous studies have shown that persistent endodontic infections are often caused by Enterococcus faecalis (1, 3).Virulence factors of E. faecalis, such as hemolysin, gelatinase, and enterococcal aggregation substance (EAS) play an important role in the bacterium's pathogenesis (4). However, the mechanism through which E. faecalis persists in the root canal is not well understood. E. faecalis seems to be highly resistant to the medications used during treatment and is one of the few organisms that has been shown to resist the antibacterial effect of calcium hydroxide (5, 6). There is little research to explain why E. faecalis is resistant to root canal therapy. It is easily destroyed when grown in vitro, but it becomes resistant when present in the environment of the root canal system (7). Therefore, E. faecalis must undergo some type of change while in the root canal system, possibly activating some virulence factor that makes it more resistant. Alternatively, it may form a biofilm.Biofilms, also known as plaque, are complex communities of bacteria embedded in a polysaccharide matrix (8). Suspended, i.e. planktonic, bacteria that are either leaving or joining the biofilm surround the biofilm. The growth conditions vary between biofilm and planktonic environments. For this reason, proteins expressed by biofilm bacteria may differ from those expressed by their planktonic counter parts, and both the biofilm bacteria and the planktonic bacteria may differ from bacteria maintained in the laboratory.The purpose of this study was to test the hypothesis that E. faecalis forms a biofi...

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“…The only virulence factors that were established in the strain were haemolytic activity and biofilm formation. It should be noted that significance of haemolysin as a virulence factor of enterococci has not been proved, as it has been shown that only 0-16 % of blood culture enterococcal isolates display haemolytic activity (Elsner et al, 2000). Moreover, haemolytic activity was more common in non-endocarditis clinical isolates and in hospital faecal isolates than among endocarditis isolates (Coque et al, 1995) and there was no significant association between 14-day mortality and the presence of haemolysin in enterococci (Vergis et al, 2002).…”

Section: Discussionmentioning

confidence: 99%

Enterococcus durans endocarditis in a patient with transposition of the great vessels

Stepanović¹,

Jovanović²,

Lavadinović³

et al. 2004

Journal of Medical Microbiology

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Virulence Factors of Enterococcus faecalis and Enterococcus faecium Blood Culture Isolates

Cited by 132 publications

References 18 publications

Biofilm synthesis and presence of virulence factors among enterococci isolated from patients and water samples

Biofilm synthesis and presence of virulence factors among enterococci isolated from patients and water samples

Biofilm Formation in Medicated Root Canals

Enterococcus durans endocarditis in a patient with transposition of the great vessels

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