Application of non-radioactive BACTEC system to sterility testing and hygiene

The applicability of the non-radioactive BACTEC NR 660 system for the detection of low viable counts of aerobic and anaerobic bacteria (including non-fermenters and aerobic spore-forming bacteria) and fungi was investigated. The BACTEC system together with the usual BACTEC NR 6A and NR 7A media was able to detect most of the organisms without supplementation of the media; for growth of lactobacilli and other acidophilic organisms, sterile orange juice was used as a supplement. Microbial growth was detected from pure cultures and also from artificially contaminated beverages and ointment bases. Detection times varied according to the types of metabolism of the respective strains and their initial viable counts, but usually they were detected after 20 to 42 h of incubation. The BACTEC NR 660 system seems to be applicable not only for blood cultures in medical microbiology but also in pharmaceutical and food industry.