Rapid Automated System for the Detection of Objectionable Microorganisms in Nutraceutical and Dietary Supplements

Abstract

Background: The U.S. Pharmacopeia (USP) established microbiological procedures to evaluate nonsterile products and nutritional and dietary supplements for objectionable microorganisms of concern in the industry. A rapid method has been developed to detect the presence of microorganisms based on real-time photometric monitoring of pH, carbon dioxide, or fluorescence indicators within a novel broth/agar combination vial and accompanying reader.

Objective: To validate the performance of the Neogen Rapid Microbiology System (NRMS) method against the USP reference method for the ability to detect presence or the absence of Escherichia coli, Salmonella, Staphylococcus aureus, and Pseudomonas aeruginosa in nutraceutical and dietary supplements.

Methods: Over 200 samples were evaluated for the presence of objectionable microorganisms. For each specified microorganism, a minimum of 23 matrices were tested uninoculated and with a low-level inoculum of <1-27.4 CFU/g, as paired samples, by NRMS and USP methods.

Results: In the four objectionable microorganism categories evaluated, 100% inclusivity, 97-100% exclusivity, 97-100% positive predictivity, 100% negative predictivity, and Kappa Indices of 0.97-1.0 were achieved following ISO 5725-6:1994 standards.

Conclusions: The validation study demonstrates that NRMS is a rapid and effective method to detect objectionable microorganisms in a variety of nutraceutical and dietary supplements.

Highlights: A novel method was validated against the relevant USP reference method for the detection of Escherichia coli, Salmonella, Staphylococcus aureus, and Pseudomonas aeruginosa in nutraceutical and dietary supplements. NRMS provided results statistically comparable to the USP reference method within 22 h following primary enrichment compared with 5-7 days by the reference method.