Objective: The isolation of microorganisms in joint fluid samples is one of the most important laboratory findings guiding the treatment. Knowing the distribution of the isolated microorganisms allows for the correct empirical approach to treatment. The frequency of MRSA isolation from joint fluid cultures is increasing, and MRSA infections are increasing in importance among infectious arthritis cases. This study aimed to determine the distribution of microorganisms that grew in joint fluid cultures and the antibiotic susceptibility patterns of staphylococci grown in these cultures.
Methods: Our study is retrospective and planned to cover the years between 2015 and 2019. Of the synovial fluid samples sent to the Microbiology Laboratory, 103 samples with growth in culture were included in the study. Bacteria isolated from the samples were identified with the MALDI-TOF MS device and were evaluated for antimicrobial susceptibility in the automated system.
Results: Samples of 103 patients were included in the study. While 19 of the patients included in the evaluation had a history of joint replacement, 84 patients had natural joint involvement. Generally, S. aureus ranked first in both group samples (41.7% and 42.2%). Coagulase-negative staphylococci and streptococci came second and third, respectively. Gram-negative bacilli were in fourth place (10.8%) in samples belonging to natural joints. In comparison, only one growth (5.3%) was detected in samples of patients with a prosthetic history. However, no statistically significant difference was found between the natural joint and prosthesis in terms of pathogen distribution (p> 0.05). All MRSA isolates were susceptible to vancomycin, teicoplanin, linezolid, daptomycin, and tigecycline. No MRCNS isolate was resistant to vancomycin, tigecycline, and trimethoprim/sulfamethoxazole.
Conclusion: We think that our study will contribute to the literature on the distribution of infectious arthritis agents, the evaluation of antimicrobial resistance profiles of these agents, and empirical antimicrobial selection.