Comparison of three anaerobic systems for the isolation of anaerobic bacteria from clinical specimens.

Abstract

An anaerobic glove box, the GASPAK jar system, and a roll-streak tube system with prereduced, anaerobically sterilized medium were compared for recovery of anaerobic bacteria from selected clinical specimens collected in anaerobic tubes. Both prereduced plating media held in an anaerobic glove box for a minimum of 48 hr. before use and fresh plating media exposed to atmospheric oxygen for no longer than 1 hr. were used in the glove box and GASPAK systems. In general, the recoveries of anaerobic bacteria with the three systems were comparable. Bacteroides melaninogenicus strains were recovered with the glove box and GASPAK systems and were not detected with roll-streak tubes, but the PRAS medium used in the roll-streak tube system did not contain hemin or menadione, whereas some of the media used in the other systems did. Only one organism, a peptostreptococcus, was recovered in the roll-streak tube system and not in the GASPAK or glove box systems. Of 29 anaerobes isolated from the 15 specimens examined, 28 were recovered in both the GASPAK and glove box systems and 23 were isolated with the roll-streak tube system. The advantages and disadvantages of each system are discussed.