Detection of Cutibacterium acnes in Tissue Samples from Clean Primary Shoulder Surgeries – Part II

Objective Research and identification of Cutibacterium acnes ( C. acnes ) and other microorganisms in deep tissue samples collected in clean shoulder surgeries of patients who did not undergo any previous invasive joint procedure and who had no clinical history of infection. Methods We analyzed the results of cultures of intraoperative deep tissue samples from 84 patients submitted to primary clean shoulder surgery. Tubes containing culture medium were used for storage and transport of anaerobic agents, prolonged incubation time, and mass spectrometer for diagnosis of bacterial agents. Results Bacteria growth was evidenced in 34 patients (40.4%) of the 84 included in the study. Of these, 23 had growth of C. acnes in at least one sample of deep tissue collected, corresponding to 27.3% of the total patients. The second most common agent was Staphylococcus epidermidis , present in 7.2% of the total individuals included. We showed a higher relationship between sample positivity and males, a lower mean age, absence of diabetes mellitus, ASA I score, and antibiotic prophylaxis in anesthetic induction with cefuroxime. Conclusions A high percentage of isolates of different bacteria was found in shoulder tissue samples of patients undergoing clean and primary surgeries, who had no history of previous infection. Identification of C. acnes was high (27.6%), and Staphylococcus epidermidis was the second most frequent agent (7.2%).