The use of PCR to monitor the population abundance of six human intestinal bacterial species in an in vitro semicontinuous culture system

Six PCR primer sets complementary to the 16S rDNAs (rRNA genes) were developed and shown to be specific for the following anaerobic bacteria: Clostridium clostridiiforme, C. perfringens, C. leptum, Bacteroides vulgatus, B. distasonis, and B. thetaiotaomicron, respectively. These primers were used for PCR to detect and monitor the bacteria in a semicontinuous culture system designed to mimic intestinal microflora in the human gastrointestinal tract. Except for C. perfringens, the five species of Bacteroides and Clostridia present in the in vitro culture system were detected by the PCR, and the titers varied from 10(-2) to 10(-6) dilutions. The role of azo dye reduction by these bacterial species in the system was examined and discussed.