Objective: to explore the clinical and microbiological characteristics of Rhizobium radiobacter infection, and therefore to provide information for the prevention and treatment of the disease.
Methods: the clinical and microbiological data were analyzed for patients proved to have Rhizobium radiobacter infection by blood culture obtained from May 2008 to July 2009 in the Second Affiliated Hospital of Fujian Medical University. Related literature were reviewed.
Results: there were 4 males and 2 females aging 5 - 88 years old. All the patients suffered from fever and chillsor malaise, and had increased peripheral WBC or neutrophil count. The majority (5/6) of the infections was pneumonia, characterized by mild cough and expectoration, lung rales, patchy infiltrates on chest X-ray. All the patients had underlying diseases or were immunocompromised. Five of the 6 patients had close soil exposure. Four of the 6 patients received broad-spectrum antibiotics or immunosuppressive therapy. Antibacterial susceptibility testing showed that, all the isolates of Rhizobium radiobacter were susceptible to the third generation cephalosporins, cephamycins, Carbapenems, fluoroquinolones, tetracycline, nitrofurantoin and some of the aminoglycosides, but resistant to penicillins, penicillins/enzyme inhibitors, first and fourth generation cephalosporins, and helices beta-lactamase antibiotics. There were no complications, and all patients recovered uneventfully after treatment with antibiotics according to the susceptibility testing.
Conclusions: rhizobium radiobacter infections often occur in patients with underlying risk factors. The clinical manifestations of Rhizobium radiobacter infection are nonspecific. The organism is sensitive to most antibiotics, and the clinical outcome is favorable.