Revista de bioanálisis y biomedicina

How to Recovery of Damaged Microorganisms by Supplying Several Sorts of Nutrients

Abstract

Hideharu Shintani

Final sterilization was conducted to health care products immediately prior to shipping and sterility assurance OF 10-6 of SAL (sterility assurance level) must be confirmed from the result of Biological indicators (BIs). The survived microorganisms after sterilization may be mostly damaged and injured microorganisms. The auxotrophic characteristics of injured microorganisms are different from those of healthy microorganisms. In that sense, the cultivation conditions and culture medium constituent of injured microorganisms must be used for confirming reproducible sterilization validation study, otherwise it may result in false negative at shipping test. This is indispensable to attain safety assurance of health care products. The evaluation of several sorts of nutrients must be studied to recover injured microorganisms and support growth reproducibly. It is also important to study for diminishing variation of culture medium performance among culture medium suppliers and that lot to lot or batch to batch variation to attain reproducible sterility assurance. These were studied by adding several sorts of agents to the culture medium inoculating injured microorganisms exposed by moist heating, dry heating, ethylene oxide gas exposure gamma-ray and electron beam irradiation. Even though sterilizing method may differ, when amino acids mixture, gucose and calcium were added to the culture medium, cultivation performance of injured spores was significantly improved and reproducible sterilization validation can be attained in success.