Implant-infections remain one of the most devastating complications of prosthetic surgery. The most commonly cultured microorganisms are the coagulase-negative Staphylococci (CoNS). One of the resistance mechanisms of CoNS is the capacity to form biofilms. Biofilm formation turn some normal skin flora organisms considered “harmless” to pathogens.

The genes related to the biofilm formation are atlE, icaA, icaD, icaB and icaC, aap, fbe as well as the empb. Those genes are only expressed in CoNS strains which are forming biofilm and not in commensal organisms. The expression of biofilm-specific genes can be detected by feasible molecular methods like reverse transcriptase and quantitative polymerase chain reaction. Our research aim is to compare the expression of these genes in strains isolated from joint aspirates and skin from infected and non-infected patients.

Today, no diagnostic methods are able to inform if the infecting strains form a biofilm. Also, misdiagnosis involving contamination by skin commensal strains during the collection of samples is problematic and lead to higher morbidity and mortality rates of patients. The knowledge obtained with this project will help distinguishing infection caused by biofilm formation from skin contamination. This method can help avoid false positive diagnostics and also provide new insights on the future development of diagnostic methods and vaccines against coagulase-negative Staphylococci infection.