A quasi-universal medium to break the aerobic/anaerobic bacterial culture dichotomy in clinical microbiology.

In the mid-19th century, the dichotomy between aerobic and anaerobic bacteria was introduced. Nevertheless, the aerobic growth of strictly anaerobic bacterial species such as Ruminococcus gnavus and Fusobacterium necrophorum, in a culture medium containing antioxidants, was recently demonstrated. We tested aerobically the culture of 623 bacterial strains from 276 bacterial species including 82 strictly anaerobic, 154 facultative anaerobic, 31 aerobic and nine microaerophilic bacterial species as well as ten fungi. The basic culture medium was based on Schaedler agar supplemented with 1 g/L ascorbic acid and 0.1 g/L glutathione (R-medium). We successively optimized this media, adding 0.4 g/L uric acid, using separate autoclaving of the component, or adding haemin 0.1 g/L or α-ketoglutarate 2 g/L. In the basic medium, 237 bacterial species and ten fungal species grew but with no growth of 36 bacterial species, including 22 strict anaerobes. Adding uric acid allowed the growth of 14 further species including eight strict anaerobes, while separate autoclaving allowed the growth of all tested bacterial strains. To extend its potential use for fastidious bacteria, we added haemin for Haemophilus influenzae, Haemophilus parainfluenzae and Eikenella corrodens and α-ketoglutarate for Legionella pneumophila. This medium allowed the growth of all tested strains with the exception of Mycobacterium tuberculosis and Mycobacterium bovis. Testing primoculture and more fastidious species will constitute the main work to be done, but R-medium coupled with a rapid identification method (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) will facilitate the anaerobic culture in clinical microbiology laboratories.

Five cases of Kingella kingae skeletal infection in a French hospital.

Five cases of Kingella kingae skeletal infections were diagnosed in children admitted to La Timone Hospital between 1992 and 1997. Patients were between 6 and 31 months old and presented with septic spondylodiskitis, calcaneus osteomyelitis, and hip-joint arthritis. All displayed either an upper respiratory tract infection or eczema during the month prior to their admission. Laboratory findings included an elevated leukocyte count and an elevated erythrocyte sedimentation rate. Standard radiography was unrevealing, but 99mTc bone scans and magnetic resonance imaging showed significant abnormalities. Isolation of Kingella kingae was achieved in all cases by culture of fluid aspirates using the Bactec blood culture system. This bacterium was sensitive to the most common antibiotics tested, and the outcome was favourable in all cases.