Analysis of different genetic traits and their association with biofilm formation in Staphylococcus epidermidis isolates from central venous catheter infections
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The aim of the present study was to characterize clinical isolates of Staphylococcus epidermidis, one of the bacterial species most often implicated in foreign-body-associated infections, for their ability to form biofilms and for the presence of mecA and IS256 element. Sixty-seven Staphylococcus epidermidis clinical isolates, obtained from implantable medical devices, were investigated. Overall, 70% of the strains were positive for ica operon genes, 85% possessed atlE, and 46% contained aap. In 89% of the population, the Congo red agar test confirmed the correlation between the presence of ica genes and slime expression. Almost all of the strains could be classified as biofilm producers by both the crystal violet assay and microscopy. The bacterial population studied showed a very high frequency of strains positive for mecA as well as for the IS256 element. Although well-structured biofilms have been previously observed only in those strains possessing genes belonging to the ica operon, this study demonstrates that strains lacking specific biofilm-formation determinants can be isolated from catheters and can form a biofilm in vitro. Hence, different and yet-to-be identified factors may work together in the formation and organization of complex staphylococcal microbial communities and sustain infections associated with implanted medical devices.
KeywordsCrystal Violet IS256 Element Polysaccharide Intercellular Adhesin Oxacillin Resistance atlE Gene
This work was supported in part by grants from the Italian MIUR (FIRB 2001 and PRIN 2003).
We are also grateful to Dr. D. Mack for the generous gift of S. epidermidis strains 1457 and 1457-M11.
- 9.Rohde H, Burdelski C, Bartscht K, Hussain M, Buck F, Horstkotte MA, Knobloch JK, Heilmann C, Herrmann M, Mack D (2005) Induction of Staphylococcus epidermidis biofilm formation via proteolytic processing of the accumulation-associated protein by staphylococcal and host proteases. Mol Microbiol 55:1883–1895PubMedCrossRefGoogle Scholar
- 11.Karchmer AW, Gibbons GW (1994) Infections of prosthetic heart valves and vascular grafts. In: Waldvogel FA, Bisno AL (eds) Infections associated with indwelling medical devices, 2nd edn. American Society for Microbiology, Washington DC, pp 213–249Google Scholar
- 13.Rupp ME, Ulphani JS, Fey PD, Bartscht K, Mack D (1999) Characterization of the importance of polysaccharide intercellular adhesin/hemagglutinin of Staphylococcus epidermidis in the pathogenesis of biomaterial-based infection in a mouse foreign body infection model. Infect Immun 67:2627–2632PubMedGoogle Scholar
- 14.Cafiso V, Bertuccio T, Santagati M, Campanile F, Amicosante G, Perilli MG, Selan L, Artini M, Nicoletti G, Stefani S (2004) Presence of the ica operon in clinical isolates of Staphylococcus epidermidis and its role in biofilm production. Clin Microbiol Infect 10:1081–1088PubMedCrossRefGoogle Scholar
- 16.Yao Y, Sturdevant DE, Otto M (2005) Genomewide analysis of gene expression in Staphylococcus epidermidis biofilms: insights into the pathophysiology of Staphylococcus epidermidis biofilms and the role of phenol-soluble modulins in formation of biofilms. J Infect Dis 191:289–298PubMedCrossRefGoogle Scholar
- 21.Vandecasteele SJ, Peetermans WE, Merckx R, Rijnders BJ, Van Eldere J (2003) Reliability of the ica, aap and atlE genes in the discrimination between invasive, colonizing and contaminant Staphylococcus epidermidis isolates in the diagnosis of catheter-related infections. Clin Microbiol Infect 9:114–119PubMedCrossRefGoogle Scholar
- 22.Bradford R, Abdul Manan R, Daley AJ, Pearce C, Ramalingam A, D’Mello D, Mueller Y, Uahwatanasakul W, Qu Y, Grando D, Garland S, Deighton M (2006) Coagulase-negative staphylococci in very-low-birth-weight infants: inability of genetic markers to distinguish invasive strains from blood culture contaminants. Eur J Clin Microbiol Infect Dis 5:283–291CrossRefGoogle Scholar
- 24.Mack D, Nedelmann M, Krokotsch A, Schwarzkopf A, Heesemann J, Laufs R (1994) Characterization of transposon mutants of biofilm-producing Staphylococcus epidermidis impaired in the accumulative phase of biofilm production: genetic identification of a hexosamine-containing polysaccharide intercellular adhesin. Infect Immun 62:3244–3253PubMedGoogle Scholar
- 25.Clinical and Laboratory Standards Institute (2005) Performance Standards For Antimicrobial Susceptibility Testing. M100-S15. CLSI. Wayne, PA, USAGoogle Scholar
- 26.Chung M, de Lencastre H, Matthews P, Tomasz A, Adamsson I, Aires de Sousa M, Camou T, Cocuzza C, Multilaboratory Project Collaborators et al (2000) Molecular typing of methicillin-resistant Staphylococcus aureus by pulsed-field gel electrophoresis: comparison of results obtained in a multilaboratory effort using identical protocols and MRSA strains. Microb Drug Resist 6:189–198PubMedCrossRefGoogle Scholar
- 27.Arciola CR, Campoccia D, Gamberini S, Cervellati M, Donati E, Montanaro L (2002) Detection of slime production by means of an optimised Congo red agar plate test based on a colorimetric scale in Staphylococcus epidermidis clinical isolates genotyped for ica locus. Biomaterials 23:4233–4239PubMedCrossRefGoogle Scholar
- 31.Carrico JA, Pinto FR, Simas C, Nunes S, Sousa NG, Frazao N, de Lencastre H, Almeida JS (2005) Assessment of band-based similarity coefficients for automatic type and subtype classification of microbial isolates analyzed by pulsed-field gel electrophoresis. J Clin Microbiol 43:5483–5490PubMedCrossRefGoogle Scholar
- 32.Ziebuhr W, Krimmer V, Rachid S, Lossner I, Gotz F, Hacker J (1999) A novel mechanism of phase variation of virulence in Staphylococcus epidermidis: evidence for control of the polysaccharide intercellular adhesin synthesis by alternating insertion and excision of the insertion sequence element IS256. Mol Microbiol 32:345–356PubMedCrossRefGoogle Scholar
- 35.Martineau F, Picard FJ, Grenier L, Roy PH, Ouellette M, Bergeron MG (2000) Multiplex PCR assays for the detection of clinically relevant antibiotic resistance genes in staphylococci isolated from patients infected after cardiac surgery. The ESPRIT Trial. J Antimicrob Chemother 46:527–534PubMedCrossRefGoogle Scholar
- 36.Martineau F, Picard FJ, Lansac N, Menard C, Roy PH, Ouellette M, Bergeron MG (2000) Correlation between the resistance genotype determined by multiplex PCR assays and the antibiotic susceptibility patterns of Staphylococcus aureus and Staphylococcus epidermidis. Antimicrob Agents Chemother 44:231–238PubMedCrossRefGoogle Scholar
- 40.Kozitskaya S, Cho SH, Dietrich K, Marre R, Naber K, Ziebuhr W (2004) The bacterial insertion sequence element IS256 occurs preferentially in nosocomial Staphylococcus epidermidis isolates: association with biofilm formation and resistance to aminoglycosides. Infect Immun 72:1210–1215PubMedCrossRefGoogle Scholar
- 41.Rohde H, Kalitzky M, Kroger N, Scherpe S, Horstkotte MA, Knobloch JK, Zander AR, Mack D (2004) Detection of virulence-associated genes is not useful for discriminating between invasive and commensal Staphylococcus epidermidis strains from a bone marrow transplant unit. J Clin Microbiol 42:5614–5619PubMedCrossRefGoogle Scholar
- 42.Mack D, Becker P, Chatterjee I, Dobinsky S, Knobloch JK, Peters G, Rohde H, Herrmann M (2004) Mechanisms of biofilm formation in Staphylococcus epidermidis and Staphylococcus aureus: functional molecules, regulatory circuits, and adaptive responses. Int J Med Microbiol 294:203–212PubMedCrossRefGoogle Scholar