Streptococcus bovis endocarditis and vertebral osteomyelitis

Streptococcus bovis septic arthritis and osteomyelitis: A report of 21 cases and a literature review

BACKGROUND

The Streptococcus bovis group (SBG) is a well-known cause of endocarditis, but its role in osteoarticular infections (OAIs) has not been well described.

METHODS

We analyzed all patients with OAIs by SBG diagnosed in our hospital (1988-2014). We selected those cases with septic arthritis and osteomyelitis, as defined according to clinical, microbiological, and imaging studies. Identification of the strains was performed by using the API 20 Strep and the GP card of the Vitek 2 system, and confirmed the identification by molecular methods. In addition, we reviewed the literature to select all cases of OAI by SBG during the period 1980-2015.

RESULTS

From the 83 cases of OAI included in the analysis (21 from our center and 62 from the literature review), 59 were osteomyelitis (57 of them spondylodiscitis) and 24 were arthritis (2 with associated spondylodiscitis). The mean age was 66.9 years, and 79.2% of the patients were men. Endocarditis (IE) was associated with 59% of the cases and this association was greater for osteomyelitis than for arthritis (78.9% vs. 13.6%; P = 0.001). OAI was a presenting symptom in 63% of the cases of IE. Colonoscopy was performed in 64 cases, which detected colorectal neoplasm (CRN) in 46 patients (71.8%), almost all asymptomatic. Some 69.5% of these neoplasm were carcinomas or advanced adenomas. The blood cultures were positive in 78.3% cases. In 45 cases, the S. bovis species was identified; in 82.2% of the cases the cause was Streptococcus gallolyticus subsp. gallolyticus. The mortality was 7.2%, which in no case was attributable to the OAI.

CONCLUSIONS

OAIs are frequently the initial manifestation of IE caused by SBG. S. gallolyticus causes most of these infections. Echocardiogram and colonoscopy are therefore mandatory, given the species' close association with IE and CRN.

Late infection of a total knee arthroplasty with Streptococcus bovis in association with carcinoma of the large intestine

Infection of a total knee arthroplasty with Streptococcus bovis in a 76-year-old man that led to the diagnosis of a bowel carcinoma is reported. Investigation revealed a malignancy in the ascending colon with extension into the adrenal gland. S bovis in conjunction with colonic neoplasia has been reported in several orthopedic conditions: vertebral osteomyelitis, discitis, lateral neck abscess, and osteomyelitis of the ileum. The relationship of S bovis to endocarditis, meningitis, brain abscesses, and peritonitis has also been well described. However, S bovis is a rare pathogen infecting joint prostheses and should raise the possibility of a gastrointestinal lesion.

Osteoarticular infection complicating enterococcal endocarditis

Despite the common occurrence of musculoskeletal complaints in patients with infective endocarditis, infectious osteoarticular complications are diagnosed infrequently. Moreover, although enterococcal infection is the third most common cause of infective endocarditis, infectious osteoarticular complications are rare. We report a case of disk space infection in a patient with enterococcal endocarditis. Blood cultures and an L3-4 aspirate grew Enterococcus faecalis, and transthoracic echocardiography revealed a large vegetation on the posterior mitral valve leaflet. The osteoarticular infection resolved with antimicrobial treatment, but worsening heart failure necessitated valve replacement surgery. The patient had an uneventful recovery with no evidence of recurrence or complications. A review of the medical literature from 1966 through 1998 identified 13 additional cases, only 8 of which provided clinical and treatment data. We present the clinical and laboratory findings reported in these cases, along with data from our patient. This report highlights the rare occurrence of osteoarticular infection in the setting of enterococcal endocarditis and emphasizes early recognition and treatment.

Streptococcus viridans vertebral osteomyelitis

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