Standards of the in vitro mutation frequency study and the antimicrobial activity study in gut

In view of the recent rapid increase in incidence of infection with antimicrobial resistant bacteria in human medicine, there is international controversy as to the medical risk that is created by transfer of antimicrobial resistant bacteria and antimicrobial resistant genes, which may be produced through the processes of administration of antimicrobials to food-producing animals, via the food chain. Accordingly, International Cooperation on Harmonization of Technical Requirements for Registration of Veterinary Medicinal Products (VICH) provides the comprehensive guidelines for characterizing selection of antimicrobial resistance by bacteria which may adversely affect human health in order to establish the system of registry of antimicrobial drugs to be administered to food-producing animals.Currently, Japanese Society of Antimicrobials for Animals recognizes the lack of technical test standards in compliance with VICH guidelines in the world and has established the test standards for "in vitro mutation frequency studies" to evaluate the appearance frequency and resistant level of resistant bacteria and those for studies on the "antimicrobial activity in gut" to estimate the effects on intestinal flora from professional aspects.