Η κλινική εφαρμογή των μοριακών τεχνικών στη διάγνωση της ορθοπαιδικής λοίμωξης

Abstract

Intraoperative conventional bacteriological cultures were compared with different polymerasechain reaction (PCR) methods in patients with total joint arthroplasties. The isolated bacteria wereinvestigated for biofilm formation, and the biofilm forming strains, in their planktonic and biofilmforms, were further tested for their antimicrobial resistance against several clinically importantantimicrobials. Forty four bone and joint samples were included and classified as infected or noninfectedaccording to standard criteria for periprosthetic hip and knee infections. For thebacteriological diagnosis, conventional culture, two types of universal PCR and species specificPCR for three selected pathogens (S. aureus, S. epidermidis, and P. aeruginosa) were applied.Biofilm formation determination was performed by the tissue culture plate method. Antimicrobialsusceptibility of the planktonic bacteria was performed by the minimal inhibitory concentrationdetermination and, of the biofilm forms, by the minimal inhibitory concentration for bacterial regrowthfrom the biofilm. Twenty samples were culture positive, with S. epidermidis, S. aureus orP. aeruginosa. All PCR methods were very ineffective in detecting only one pathogen. All isolateswere biofilm positive and their biofilm forms were highly resistant. In this study, compared toPCR, culture remains the “gold standard”. The biofilm formation by the causative bacteria and theconcomitant manifold increased antimicrobial resistance may explain the clinical failure oftreatment in some cases and should be considered in the future for therapeutic planning.