NEW MICROBIOLOGICA, 35, 345-348, 2012 Pseudomonas aeruginosa septic arthritis of knee after intra-articular ozone injection Derya Seyman 1 , Nevgun Sepin Ozen 2 , Dilara Inan 3 , Gozde Ongut 4 , Dilara Ogunc 4 1 Antalya Training and Research Hospital, Department of Infectious Diseases and Clinical Microbiology, Antalya, Turkey; 2 Antalya Hıfzıssıhha Institute,Department of Clinical Microbiology,Antalya, Turkey; 3 Akdeniz University Medical Faculty, Department of Infectious Diseases and Clinical Microbiology, Antalya, Turkey; 4 Akdeniz University Medical Faculty, Department of Medical Microbiology, Antalya, Turkey INTRODUCTION Septic arthritis (SA) is serious disease affecting joint spaces, synovial fluid, and articular carti- lage, and carries a high potential for permanent joint damage and considerable loss of the joint function (Gallucci et al., 2007; Geirsson et al., 2008). The main risk factors for SA are age older than 60 years, recent bacteremia, rheumatoid arthri- tis, osteoarthritis, immunosupressive therapies and diabetes mellitus (Matteson et al., 1990). The most common etiologic agent of SA is Staphylococcus aureus and gram negative bacil- li account for approximately 10 to 20% of cases. Among the gram negative bacilli, coliform bac- teria, particularly Escherichia coli, are the most commonly isolated microorganisms. Pseudomonas aeruginosa an important patho- gen in intravenous drug users and has a parti- Corresponding author Dilara Inan, M.D Akdeniz University Medical Faculty Department of Infectious Diseases and Clinical Microbiology, Antalya-Turkey E-mail: inan@akdeniz.edu.tr cular affinity for fibrocartiloginous articular structures. There are several possible routes of joint invasi- on by microorganisms, including hematogeno- us spread, direct inoculation with a penetrating injury or iatrogenic causes like theraupetic jo- int aspirations or injections. Therapeutic joint injections such as intrafora- minal or intraarticular applications of ozone, steroids or joint viscous supplements may in- crease the risk of joint infections. Ozone therapy is a common procedure that is cost-effective and simple and it is widely used in outpatient clinics for acute and chronic pa- inful diseases of joints. It has been shown to ha- ve satisfactory clinical results with minimal complication rates. Ozone theraphy is preferred method as it pro- vides a rapid decrease in pain with reduced in- flammation and early mobilization (Bocci et al., 2004; Gallucci et al., 2007). Despite these beneficial effects, it should be kept in mind that local complications such as septic arthritis can occur. This report is of a unique case of P. aeruginosa- septic arthritis following intra-articular ozone injection that occurred in an immunocompetent patient with no risk factors. We describe a case of septic arthritis caused by Pseudomonas aeruginosa in an immunocompetent patient following intra-articular ozone injection into the knee. To the best of our knowledge, and after considering the current literatu- re, we believe this case is unique as no other reports of septic arthritis caused by P. aeruginosa following intra-articu- lar ozone injection has been made. Key words: Ozone theraphy, Pseudomonas aeruginosa, Septic arthritis. SUMMARY Received August 4, 2011 Accepted March 09, 2012