Neutralizers Of Disinfectants In Culture Media

By Regina Petrasch, Senior Application Development Manager BioMonitoring Merck KGaA Darmstadt | Germany and Dr. Anne-Grit Klees, Global Product Manager Environmental Monitoring, Merck KGaA Darmstadt | Germany

Most applications for monitoring microbial contamination are based on general-purpose, nonselective culture media, such as Tryptic Soy Agar. However, aseptic processing environments require the routine use of disinfectants, so during surface sampling the swab or contact plate is likely to take up disinfectant residues alongside the contaminants, which could suppress microbial growth and lead to false negative results. This is why the culture media for such purposes must be supplemented with substances known as neutralizers that inactivate the disinfectants being used. USP <1116>, the FDA Aseptic Guide (2004) and ISO 14698-1 specify this requirement.

This study tested the growth-promoting ability of a neutralizer-supplemented culture media in the presence of several commercially available disinfectants.