First Case of Osteomyelitis Due to Shewanella algae

Abstract

Shewanella spp. are infrequently recovered from clinical specimens. We report here on the first case of osteomyelitis due to Shewanella algae. This bacterium, at first misidentified by phenotypic tests as Shewanella putrefaciens, was subsequently identified correctly as S. algae by 16S rRNA gene sequence analysis. CASE REPORTA 45-year-old woman who lived in Turkey and who had a history of depression tried to commit suicide in June 2003 by throwing herself into an open well. She broke her right tibia, resulting in an open fracture. Treatment of the fracture included osteosynthesis. No information about the initial prophylactic antibacterial therapy was available for this report. Following treatment, the initial outcome was favorable and the patient was capable of walking within the expected time frame. Ten months later, however, she presented with severe pain and limited use of her leg. She had a low-grade fever (temperature, 38°C). Her right leg was inflamed, but no fistula was present. Biochemical tests showed that her C-reactive protein level was elevated (47 mg/liter; normal range, Ͻ10 mg/liter) and her erythrocyte sedimentation rate was elevated (72 mm; normal range, Ͻ10 mm) at presentation. Radiographs of the affected leg revealed delayed consolidation of the bone with pseudarthrosis. An osteotomy and intramedullary pinning of the tibia were performed, and specimens of the removed bone and intramedullary tissue were cultured. A direct Gram stain was performed on this material but did not reveal any bacteria. Samples were inoculated onto chocolate agar plates (bioMerieux Inc., Marcy l'Etoile, France) and incubated at 37°C in a 5% CO 2 atmosphere. The samples were also inoculated onto 5% sheep blood agar (bioMerieux Inc.) and incubated under anaerobic conditions at 37°C, although prereduced medium was not used for anaerobic cultures. Fungal and mycobacterial cultures were performed but showed no growth. After 2 days, small brown mucoid colonies were observed on both agar plates (approximately 10 4 CFU per plate) and exhibited beta-hemolysis on the sheep blood agar. On a Gram stain, the isolate was found to be a gram-negative rod. The bacteria were isolated from the osteomyelitis tissue in pure culture and were identified as Shewanella putrefaciens, to which they had 99% similarity, by using the API 20NE system (bioMerieux Inc.). To further characterize the isolate, we extracted the nucleic acids from harvested colonies using a MagNA Pure kit (LC Roche,

Human soft tissue infection by the emerging pathogen Shewanella algae

“…algae have been implicated in more infections in human beings than S. putrefaciens possibly because of the production of bacterial hemolysin by S. algae [10]. In a recent publication, M.S.…”

“…However, rapid development of resistance to imipenem and piperacillin-tazobactam has been reported [1]. Thus the treatment options available are β-lactams (provided that the strain is susceptible), aminoglycosides, and quinolones [1,3,10]. Previous reports have shown that Shewanella infections should be treated aggressively with a combination of surgical therapy/debridement and appropriate antibiotics.…”

The Phantom Menace for Patients with Hepatobiliary Diseases: <i>Shewanella haliotis</i>, Often Misidentified as <i>Shewanella algae</i> in Biochemical Tests and MALDI-TOF Analysis

“…Since S. algae was added to the database of commercial identification systems a decade ago, this species has been easily differentiated from S. putrefaciens. S. algae causes a wide range of infections, including otitis media, cholecystitis, cholangitis, liver abscess, bacteremia, nonhealing ulcer, gastroenteritis, osteomyelitis, cellulitis, pneumonia, peritonitis, and septicemia, similar to V. vulnificus (9)(10)(11)(12)(13)(14). In 2007, S. haliotis was first isolated from the gut microflora of abalone by Kim et al (6).…”

Skin and Soft Tissue Infections (Patera Foot) in Immigrants, Spain

“…S. algae is considered a rare opportunistic pathogen for humans, frequently involving immunocompromised hosts (6,8,9), and are usually part of a polymicrobial infection (6,10,11), which may mask its clinical importance. The presence of chronic leg ulcers in the context of peripheral vascular disease occurs commonly in adults with S. algae SSTI (6,10,12,13), and the affi nity of S. algae for necrotic or ischemic tissues has been well described (12,14,15).…”