Detection of Bacteria Bearing Resistant Biofilm Forms, by Using the Universal and Specific PCR is Still Unhelpful in the Diagnosis of Periprosthetic Joint Infections

Abstract

Intraoperative conventional bacteriological cultures were compared with different polymerase chain reaction (PCR) methods in patients with total joint arthroplasties. The isolated bacteria were investigated for biofilm formation, and the biofilm forming strains, in their planktonic and biofilm forms, were further tested for their antimicrobial resistance against several clinically important antimicrobials. Forty four bone and joint samples were included and classified as infected or non-infected according to standard criteria for periprosthetic hip and knee infections. For the bacteriological diagnosis, conventional culture, two types of universal PCR and species specific PCR for three selected pathogens (Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa) were applied. Biofilm formation determination was performed by the tissue culture plate method. Antimicrobial susceptibility of the planktonic bacteria was performed by the minimal inhibitory concentration determination and, of the biofilm forms, by the minimal inhibitory concentration for bacterial regrowth from the biofilm. Twenty samples were culture positive, with S. epidermidis, S. aureus, or P. aeruginosa. All PCR methods were very ineffective in detecting only one pathogen. All isolates were biofilm positive and their biofilm forms, were highly resistant. In this study, compared to PCR, culture remains the “gold standard.” The biofilm formation by the causative bacteria and the concomitant manifold increased antimicrobial resistance may explain the clinical failure of treatment in some cases and should be considered in the future for therapeutic planning.

Evaluation of a Genus- and Group-Specific Rapid PCR Assay Panel on Synovial Fluid for Diagnosis of Prosthetic Knee Infection

“…Most studies, albeit heterogeneous in their methodology, have yielded variable results, and overall, molecular diagnostics have not been shown to be consistently better than culture, the current gold standard (38). Our study has shown that synovial fluid PCR has lower sensitivity than culture; however, it did detect two S. aureus PJI cases that were negative by synovial fluid culture.…”

Intraosseous concentration and inhibitory effect of different intravenous cefazolin doses used in preoperative prophylaxis of total knee arthroplasty

“…The protective effect of the higher dose (2 g) of cefazolin may be more beneficial than that of the lower dose (1 g) due to the longer persistence of the inhibitory effect, particularly in the final period of the operation. A previous study found that biofilm formation could develop for up to 1–2 days [ 12 ]; therefore, hypothetically, the higher dose (2 g) of cefazolin might be more beneficial than the lower dose of 1 g. Second, the recommendations for surgeons from the results of the present study might appear to be weak because of the lack of evidence concerning relationships between the intraosseous concentration of cefazolin, its inhibitory effect and the related infection. This issue relates to the previous limitation mentioned, as there was no clarification of those relationships during the final period of the operation.…”

The use of polymerase chain reaction in the diagnosis and management of prosthetic joint infections: a debatable issues at this time

“…Both methods detected 16s rRNA. 32 They found that the specific PCR had better results than universal, but both had issues when compared to culture. They state that PCR may not replace the gold standard of cultural because of its interpretative problems and that perhaps could be used if small amount of sample were available or when there was a negative culture after 24h of incubation.…”

“…They state that PCR may not replace the gold standard of cultural because of its interpretative problems and that perhaps could be used if small amount of sample were available or when there was a negative culture after 24h of incubation. 32 The issue with broad range PCR is that while it has a high specificity, there is often a poor sensitivity in diagnosing infections. 33 However when the PCR and bacterial cultural were considered together, the sensitivity of PCR increased to 67%.…”