Comparison of Copan Amies Agar Swab and BBL Port-a-cul Swab for Recovery of Anaerobic Bacteria

Specialized transport devices have been utilized for collection of clinical specimens for anaerobic culture. We compared the Copan Amies swab transport system and the BBL Port-a-cul swab transport system for recovery of 30 anaerobic bacteria. Swabs were inoculated with 100-ml of a 107 CFU/ml organism suspension, incubated at room temperature for 0, 4, 24, 48h, and the swabs used to prepare three 10-fold serial dilutions in 0.9-ml saline. A 100-ml aliquot of each dilution was inoculated to reduce anaerobic brucella blood agar and incubated in an anaerobic atmosphere for 48-96h. Colony counts were obtained and the data analyzed as percent recovery compared to the 0h (initial inoculum) growth results. The Copan swab maintained viability after 48h for 24/30 (80%) and the BBL swab for 25/30 (83%) of the anaerobes tested. Two C. difficile and one F. nucleatum were not recovered after 48h in both Copan and BBL swab systems. One P. melaninogenica, B. ureolyticus, and P. bivia in the Copan swab and one P. asaccharolyticus and A. odontolyticus in the BBL swab were also not recovered after 48h. After 24h, 29/30 (97%, one C. difficile) in the Copan swab system and 28/30 (93%, P. asaccharolyticus and C. difficile) in the BBL swab system were recovered. The Copan Amies agar swab system is comparable to the BBL Port-a-cul swab system for maintenance of viability of anaerobic bacteria.