Correlation between enterococcal biofilm formation in vitro and medical-device-related infection potential in vivo

Abstract

Hospital-acquired infections caused by enterococci have increased dramatically since the 1970s. Many nosocomial enterococcal bloodstream infections are associated with medical devices such as central venous catheters. The ability to form biofilm on medical devices is a potential virulence trait that may allow enterococci to cause infections in the expanding population of patients managed with such devices. In this study, the hypothesis that increased ability to form biofilm in vitro is associated with medical-device-related infection in vivo was tested. A microplate assay was employed to assess biofilm-forming characteristics of enterococci in 0·9 % (w/v) sodium chloride, an oligotrophic environment, and BHI, a nutrient-rich environment. Results were compared in isolates from different sources of infection. One hundred and nine enterococcal bloodstream isolates were assayed. Biofilm formation on microplates was demonstrated by all Enterococcus faecalis isolates and 16/38 (42 %) Enterococcus faecium isolates. E. faecalis isolates produced significantly more biofilm than E. faecium isolates in both media (P , 0·0001, Mann-Whitney U test). E. faecalis isolates from intravascular-catheter-related bloodstream infections (CRBSIs) produced significantly more biofilm than non-CRBSI isolates (P , 0·0001), or isolates of uncertain clinical significance (P , 0·0001). Biofilm formed by E. faecium isolates was not significantly affected by culture medium and did not differ between isolates from the different clinical categories. In conclusion, there was significantly more biofilm formed by E. faecalis isolates causing CRBSI compared with isolates from other types of infection or from isolates of uncertain clinical significance. The ability of E. faecalis isolates to form biofilm in vitro appears to be a marker of a virulence trait that enhances the ability of isolates to cause CRBSI.

Influence of the fsr locus on biofilm formation by Enterococcus faecalis lacking gelE

“…The binding of Enterococcus faecalis to heart valves and to various biomaterials (Joyanes et al, 1999;Toledo-Arana et al, 2001;Mohamed et al, 2004;Seno et al, 2005) and medical devices (Keane et al, 1994;Dautle et al, 2003;Sandoe et al, 2003) is the presumed initiating factor that then allows subsequent formation of a biofilm. Biofilm formation in E. faecalis has been reported to be influenced by various genes such as esp, initially reported by Toledo-Arana et al (2001).…”

A Time Course Study of Production of Virulence Factors by Biofilms of Pseudomonas aeruginosa

“…In order to understand biofilm formation and pathogenicity of MRSA infection in the urinary tract, it was highlighted that during cell to cell interactions in biofilm formation, the level of hemolysin correlated with the level of biofilm formation [46]. Similarly, ability of Enterococcus faecalis isolates to form biofilms in vitro was considered as a marker of virulence trait that enhanced the ability of this pathogen to cause catheter related infections [47]. Potential relationship between biofilm formation and genes encoding virulence factors like hemolysin, enterococcal surface protein and gelatinase in E. faecalis isolates from catheter-related UTIs was also highlighted by Seno et al, [48].…”

Evaluation Of Antimicrobial Effect Of Mineral Trioxide Aggregate On Various Microorganisms

“…5 Enterococcus faecium ve Enterococcus faecalis, hastane enfeksiyonlarında sıkça karşılaşılan, birçok antibiyotiğe karşı dirençli ve hızlıca biyofilm oluşturan patojenlerdir. 7 E. faecalis, endodontik tedaviden sonra başarısızlığa uğramış vakalardan en çok izole edilen mikroorganizmalardandır. [8][9][10][11][12] Enterokokların yanı sıra streptokoklar da birçok antimikrobiyal ajana yüksek direnç geliştirmiş ve hastane enfeksiyonlarında sıkça rastlanılan bakterilerdir.…”