[A simple and rapid confirmation method of the bacterial contamination using polymerase chain reaction]

We studied the method for detection of bacterial contamination. Polymerase chain reaction (PCR) was used to amplify the 888 base pair of 16S ribosomal RNA (rRNA) gene fragment of various strains of bacterial species. The supernatant of bacterial suspension after treatment for 10 min at 100 degrees C was used for a template DNA. A total of 151 strains of 16 genus of Gram-negative rod and of one genus of Gram-positive cocci were confirmed and were divided into five categories by comparing digestion patterns resulting from restriction endonuclease (MluI, Eco RI and Hind III) cleavage of target rDNA fragment. These five types, such as Shigella spp. and E. coli group (Group I), other nine genera of Enterobacteria excluding Group I and Aeromonas spp. (Group II), Vibrio spp. (Group III), Campylobacter spp. and P. aeruginosa (Group IV), and S. aureus (Group V), were recognized. The group I was digested by three enzymes used, group II was by Mlu I and Eco RI but not by Hind III, group III was only by MulI, and group IV was not digested with all enzymes. The group V was sensitive to Eco RI and Hind III but was resistant to Mlu I. This method is a widely applicable technique for detection of bacterial contamination.