The advancement in culture identification methods has made possible the culture and identification of slow-growing anaerobic bacteria in clinical samples. Here, we describe a case of polymicrobial bloodstream infection (BSI) caused by Eggerthella lenta and Desulfovibrio desulfuricans, identified by API 20A and Vitek 2 systems and by 16S rRNA sequencing.
CASE REPORTThe patient was an 86-year-old woman, living alone though provided with community home care assistance. In spring of 2009, the patient was admitted to hospital twice. The first time, she presented with dyspnea, an obstructive breathing pattern, confusion, and a high fever. She was admitted to a geriatric hospital where she stayed for 2 weeks and was initially treated with trimethoprim-sulfamethoxazole. Treatment was switched to cefuroxime after 3 days due to treatment failure, and the course was finished with amoxicillin. One week after getting discharged from the geriatric hospital, she was admitted to Stockholm South General Hospital. She presented with a fever, dyspnea, and this time with diarrhea as well. Upon examination, a decubital wound, not described earlier, which was 4 by 3 cm wide and 1 cm deep, was found in the sacrum area. She had a temperature of 39.3°C, a heart rate of 104 beats/minute, a blood pressure of 106/54 mm Hg, and a breathing frequency of 35 breaths/minute. Her white cell count at admission was 20 ϫ 10 9 /liter, and her C-reactive protein level was 104 mg/liter. Initially, the clinical picture together with the laboratory results was interpreted as a bloodstream infection (BSI) derived from an airway infection. However, the wound found in the sacrum, which appeared infected, was considered an alternative source for the infection. Cultures were taken from the blood, the nasopharynx, and the decubital wound. Growth was reported to occur in one blood culture vial on day 3. The nasopharynx culture showed no pathogenic bacteria, and the wound culture showed mixed bacterial flora containing several different types of Enterobacteriaceae. The antibiotic treatment was started with cefuroxime and then switched to amoxicillin after 2 days. The patient was discharged when both the clinical and the laboratory parameters, including C-reactive protein level and white cell count, were normalized after antibiotic treatment.Blood samples were cultured in a BacT/Alert 3D (bioMérieux, Inc., Durham, NC) automated blood culture system. After 52 h of incubation, one of two anaerobic blood culture vials signaled positive. Gram staining revealed Gram-positive bacilli. Broth from the anaerobic bottle was subcultured onto blood agar plates incubated in air, chocolate agar plates were incubated in 5% CO 2 , and blood agar plates were incubated in an anaerobic jar. After 48 h of incubation at 37°C, no growth was seen on the plates incubated in air and in those incubated in CO 2 . A tiny growth was seen in the plates incubated in the anaerobic jar, which was inhibited by a metronidazole disc (Oxoid, Ltd., Basingstoke, Hampshire, United Kingdom). The plate ...
