Molecular detection of bacterial indicators in cosmetic pharmaceuticals and raw materials

PCR assays were compared with standard microbiological methods for rapid de tection of the United States Pharmacopoeia (USP) bacterial indicators in ar tificially contaminated samples of raw materials and cosmetic/pharmaceutica l products. DNA primers containing the specific sequences of the uidA gene of the beta-glucuronidase enzyme for Escherichia coli, the membrane lipopro tein gene oprL for Pseudomonas aeruginosa, and the 16S ribosomal gene for S taphylococcus aureus were used for detection in the PCR reaction. Contamina ted samples were incubated for 24 h at 35 degrees C. After incubation in br oth media with and without 4% Tween 20, samples were streaked on selective growth media. After 5-6 days, all microbial indicators were morphologically and biochemically identified using standard methods while detection and id entification by the PCR-based assays was completed within 27-30 h. Rapid PC R detection of E. coli, S. aureus, and P. aeruginosa will allow a faster qu ality evaluation and release of raw materials and cosmetic/pharmaceutical p roducts sensitive to microbial contamination.