Evaluation of Bacterial Colonization Following Aesthetic Thread Implantation in Guinea Pigs Using Mannitol Salt Agar Culture

Background: Infections following aesthetic thread implantation may cause abscesses, tissue damage, and the need for thread removal. Microbiological evaluation under standardized implantation conditions may complement clinical complication reports and inform assessments of procedural safety. Objective: To assess bacterial growth on mannitol salt agar (MSA) in tissue swab samples collected around thread implantation sites in guinea pigs. Methods: This descriptive microbiological analysis presents three thread implantation groups from a parent laboratory experiment, comprising nine female guinea pigs receiving polydioxanone (PDO), polycaprolactone (PCL), or APTOS NAMICA. All study thread products held marketing authorization from the Indonesian Ministry of Health and were implanted aseptically. Each group comprised three animals, with one animal euthanized on each of days 3, 7, and 21. Four sites per animal yielded 36 subcutaneous tissue swab samples. MSA cultures were incubated at 37°C for 24–48 hours. Findings were summarized as the number of samples showing growth relative to the number examined. Results: No colonies grew in any of the 36 samples obtained from nine animals. At each sampling time, all 12 samples from three animals were culture-negative. The same finding was observed in all three groups. Conclusion: No bacterial growth was detected on MSA in tissue swab samples collected around implantation sites through day 21 under the study conditions. These findings provide culture data following aseptic implantation of authorized thread products, with interpretation limited to the sampling sites, observation period, and methods used. Selection of authorized thread products and consistent aseptic technique remain important considerations for procedural safety.