Use of an anaerobic culture jar in processing pediatric throat cultures

Two hundred consecutive throat cultures from a Pediatric Walk-in Clinic were processed, using both aerobic and anaerobic culture techniques. The 35 aerobic isolates of group A beta-hemolytic streptococci (BHS) were all confirmed anaerobically as well, and there were two additional isolates detected only by the anaerobic technique. Of these 37 bacitracin-sensitive isolates, only 24 (65%) could be identified at 24 hours using the aerobic technique, compared to 29 (78%) using the anaerobic technique. In contrast to this relatively small effect upon the isolation of group A BHS, the yield of BHS from groups B, C, F, and G was more than doubled by the anaerobic technique. The confusion engendered by the improved detection of these bacitracin-resistant BHS using the anaerobic technique offset the small advantage in thoroughness and speed of detection of group A organisms. On this account, until more is known about the possible significance of isolating nongroup A BHS in the pharynx, the advisability of using an anaerobic culture jar to process pediatric throat cultures remains uncertain.