Reduction of microbiology TAT for diagnosis of osteoarticular infection

Osteoarticular infections represent a critical diagnostic and clinical challenge. Microbiological diagnosis involves the collection of biopsy samples and joint fluid, as well as, in the case of periprosthetic infection, the orthopedic device. Long incubation times, ranging from 5 to 15 days, delay laboratory response. Rapid technologies and protocols are required to reduce response time. To this end, this paper conducted a retrospective analysis of the clinical impact of a syndromic molecular panel (JI-Biofire) and evaluated a bacteriological protocol to reduce the time required to determine the microbial species and drug susceptibility.In cases with clinical suspicion and negative bacteriological tests (n=70 patients), the etiological agent was identified using molecular technology. Data on current antibiotic therapy were available for n=51 patients. The study population was divided into adult and pediatric patients. Pediatric patients had a higher rate of positive results (36%) than adult patients (20%). In the pediatric population, a statistically significant (p<0.05) change in therapy was observed following a positive result (87.5%) compared to a negative result. This result was not observed in the adult population.The use of rapid methods for the identification of the microbial species directly from broth culture (n=169 samples) demonstrated an accuracy of 90% for monomicrobial cultures. The method currently in use (MALDI-ToF) does not detect polymicrobial cultures, but correctly identifies the most abundant species. In 26% of the samples, a sufficient amount of protein was recovered to determine the species.The direct susceptibility test, performed only for S. aureus and S. epidermidis species, demonstrated good reliability for all antibiotics except erythromycin and clindamycin, for which very major error values exceeding the acceptable percentage were reported.In conclusion, the use of the molecular panel has a greater impact on the pediatric population than on the adult population. The use of identification and the direct susceptibility test from broth culture demonstrates good reliability and accuracy.