Joint Bone Spine 2002 ; 69 : 499-501 © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved S1297319X02004372/SCO
CASE REPORT
Septic arthritis due to Actinomyces naeslundii: report of a case Thierry Lequerré1, Michèle Nouvellon2, Kataryna Kraznowska1, Marie-Claire Bruno1, Olivier Vittecoq1, Othmane Mejjad1, Alain Daragon1*, Xavier Le Loët1 1 Rheumatology Department, Rouen University Hospital Charles-Nicolle, Unit INSERM 519, IFR 23, 76000 Rouen cedex 76031, France; 2 Bacteriology Department, Rouen University Hospital Charles-Nicolle, 76000 Rouen cedex 76031, France
(Submitted for publication March 21, 2001; accepted in revised form September 19, 2001)
Summary – In a man with osteoarthritis of the knee, Actinomyces naeslundii septic arthritis developed after intra-articular injection of hyaluronate. Actinomyces is an anaerobic Gram-positive rod. The outcome was favorable after treatment with two antibiotics and arthroscopy. The nature of the organism and its location to a joint are unusual features of this case, which illustrates the need to search for a septic complication before accepting a diagnosis of inflammation related to hyaluronate injection. Joint Bone Spine 2002 ; 69 : 499-501. © 2002 Éditions scientifiques et médicales Elsevier SAS Actinomyces naeslundii / hyaluronate / knee / septic arthritis
CASE REPORT A 70-year-old man with a 10-year history of bilateral knee osteoarthritis underwent several needle aspirations of the right knee for effusion. The fluid was noninflammatory. Arthroscopic drainage was done in November 1997. The effusion recurred a few months later, with a popliteal cyst. On December 14, 1999, hyaluronate (Synvisct) was injected into the right knee after cleansing of the skin with an iodinated antiseptic. The operator did not use gloves or a mask. Two days later, inflammation of the knee with a large effusion and a fever of 38.5 °C led to admission for suspected septic arthritis. The knee was red and hot with a large effusion filling the suprapatellar * Correspondence and reprints: Service de Rhumatologie, Hôpital de Boisguillaume, Centre Hospitalier Universitaire de Rouen, 76031 Rouen cedex, France. E-mail address:
[email protected] (A. Daragon).
recess. Range of motion was restricted; in particular, the knee could not be extended beyond 20° of flexion. The erythrocyte sedimentation rate was 90 mm/h and the C-reactive protein was 219 mg/L (N < 5 mg/L). Fluid aspirated from the joint on December 18 was cloudy and viscid, with 100,000 leukocytes/mm3 and a predominance of neutrophils (96%). Microscopic examination of joint fluid smears showed no bacteria or microcrystals. Aerobic and anaerobic cultures on a Hemolinet vial (bioMerieux, France) inoculated at the patient’s bedside were negative. Two other joint aspirations (December 20 and 22, 1999) recovered purulent fluid containing more than 100,000 leukocytes/ mm3 with a predominance of neutrophils (91%). Findings were negative from microscopic examination, tests for microcrystals, and aerobic cultures. However, anaerobic cultures of two specimens grew Actinomyces naeslundii, in 2 days and 3 days, respectively. As expected with this organism, antibiotic susceptibility
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testing showed resistance to aminoglycosides and fluoroquinolones. Blood cultures were negative and transesophageal echocardiography was normal. Roentgenograms of the right knee taken on 21 December 1999 X-ray revealed marked progression of femorotibial joint space loss as compared to February 18, 1999; subchondral sclerosis and osteophytes were visible also. The knee was immobilized in a heat-molded splint at admission. On December 24, 1999, combination antibiotic therapy with amoxicillin (9 g IV) and rifampin (1.2 g IV) was started. Daily joint drainage and lavage with saline through a trocar was not effective because the effusion was compartmentalized. Arthroscopic joint drainage was performed on December 29 when worsening of the roentgenographic damage was noted. Propionibacterium acnes and Actinomyces naeslundii were found in the synovial membrane biopsy specimens. Histology disclosed a fibrinous leukocytic exudate with a cluster of neutrophils around blood vessels suggesting infectious exudative synovitis. Roentgenograms taken on January 7, 2000, showed worsening of the joint space loss, demineralization of the trochlear groove and condyles, and an erosion in the right femur. After three weeks of antibiotic therapy, the body temperature was 37.5 °C, the knee inflammation was less marked, the erythrocyte sedimentation rate was down to 50 mm/h, and the C-reactive protein level was below 5 mg/L. The patient was discharged home with oral amoxicillin (4.5 g/d) and pristinamycin (3 g/d), immobilization of the knee in a splint, and protection from weight bearing. The erythrocyte sedimentation rate and C-reactive protein level returned to normal. The treatment was stopped after 3 months. The synovial fluid returned to normal. At last follow-up 1 year later (17 July, 2001), the patient had no disability or effusion. Flexion was 110° and extension was -5°. Laboratory tests were normal. DISCUSSION Anaerobic organisms are often underestimated as causes of osteoarticular infection because they are not looked for routinely and are difficult to detect. An anaerobic infection should be suspected when there is purulent fluid with air bubbles, although these signs are no longer present after antibiotic therapy initiation [1]. The anaerobic bacteria most often found in osteoarticular infections are Propionibacterium acnes and Peptostreptococcus. With these organisms, osteoarticular
infection often occurs after arthroplasty or in a patient with hematogenous discitis or with osteomyelitis complicating treatment for a disc herniation [1]. To detect these bacteria, samples must be quickly placed in adequate transport media such as Portagermt (bioMerieux, Marcy-l’Etoile, France) or TGVt (Pasteur, Marne la Coquette, France). Actinomyces naeslundii is a microaerophil, anaerobic, Gram-positive, and nonacid-fast rod. The most common species are A. israelii, A. bovis, A. naeslundii, and A. meyeri. Infections due to these bacteria are rare and occur more commonly in rural areas. Actinomyces are saprophytes of the gingiva, gastrointestinal tract, and tonsil crypts. The mains targets of Actinomyces infection are the brain, the head and neck, the chest, the abdomen, and the vertebras [2]. Bacteriologic and histological studies usually show PAS-positive, Gram-positive, Grocott-positive white granules. The organism causes acute or chronic suppuration with neutrophilic infiltrates and poor vascularization. This infection spreads slowly and is walled off by sclerosis, which promotes survival of the organism by protecting it from oxygen and antibiotics. Our patient had compartmentalized arthritis that made joint drainage difficult. Two other cases of septic arthritis due to Actinomyces pyogenes have been reported. In one, arthritis of the knee developed in an immunocompromised host. The other patient was an insulin-dependent diabetic who had subtalar joint arthritis with joint effusion and lytic changes in the talus and calcaneus [3]. This patient was treated by benzylpenicillin IV for 6 weeks followed by oral amoxicillin and rifampin for 6 additional weeks. There have been two other cases of osteoarticular infections due to Actinomyces naeslundii, one on a hip prosthesis and the other in the foot [4, 5]. Actinomyces is a commensal of the oral cavity. Joints are normally sterile, and Actinomyces should not considered saprophytic in joints. An orthopantomogram confirmed that our patient had no oral cavity infection. Contamination did not occur during diagnostic synovial fluid aspiration, since the organism was found on three occasions, twice in joint aspiration specimens and once in a synovectomy sample. However, Propionibacterium acnes found in the synovial tissue was considered a contaminant because it grew at a slow rate in 4 days and on a single occasion. Cultures of the hyaluronate bottle were negative. The most likely source of contamination is occult bacteremia from a dental or gastrointestinal focus of Actinomyces. However, contamination with saliva droplets during preparation
Septic arthritis due to A. naeslundii
or injection of the hyaluronate cannot be excluded. The inflammatory reaction triggered by the hyaluronate injection may have created conditions propitious to growth of the organism in the joint. Many rheumatologists are aware that intraarticular hyaluronate injection can cause joint inflammation. In a study of 88 injections in 28 knees, ten inflammatory reactions occurred. Aspiration, which was done in four patients, showed a predominance of neutrophils and lymphocytes in the joint fluid [6]. In addition, six cases of septic arthritis have been reported in Canada with Synvisct and four cases in Italy with Hyalgant [7]. In a patient with joint inflammation following an intraarticular injection, physicians must be alert to the possibility of septic arthritis. Septic arthritis due to Actinomyces naeslundii is rare. In our patient, a specimen inoculated at the bedside into a Hemolinet bottle (which is appropriate for anaerobic organisms) showed the presence of bacteria. Cultures for anaerobic bacteria should be done routinely in patients with suspected osteoarticular infection. Several specimens should be obtained then transported and inoculated into appropriate media (e.g., Portagermt or TGVt and Hemolinet, respectively).
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Following these rules should improve the management of osteoarticular infection. ACKNOWLEDGMENTS We thank Richard Medeiros for his valuable advice in editing the manuscript. REFERENCES 1 Desplaces N. Les bactéries anaérobies en pathologie osseuse. Méd Mal Infect 2000 ; 30 : 97-101. 2 Voisin L, Mejjad O, Vittecoq O, Krzanowska K, Defives T, Cambon-Michot C, et al. Spinal abscess and spondylitis due to actinomycosis. Spine 1998 ; 23 : 487-90. 3 Nicholson P, Kiely P, Street J, Mahalingum K. Septic arthritis due to Actinomyces pyogenes. Injury 1998 ; 29 : 640-2. 4 Wüst J, Steiger U, Vuong H, Zbinden R. Infection of a hip prosthesis by Actinomyces naeslundii. J Clin Microbiol 2000 ; 387 : 929-30. 5 Vandevelde AG, Jenkis SG, Hardy PR. Sclerosing osteomyelitis and Actinomyces naeslundii infection of surrounding tissues. Clin Infect Dis 1995 ; 20 : 1037-9. 6 Puttick M, Wade JP, Chalmers A, Connell D, Rangno K. Acute local reaction after intraarticular Hylan for osteoarthritis of the knee. J Rheumatol 1995 ; 22 : 1311-4. 7 Chazerain P, Rolland D, Cordonnier C, Ziza JM. Septic hip arthritis after multiple injections into the joint of Hyaluronate and glucocorticoid. Rev Rhum[Engl Ed] 1999 ; 66 : 436 p.
