title: [Sterilization--the microbiology between claim and reality].
abstract: Sterilization means to free an object from all living and viable germs. To fulfill this claim, the microbiology is confronted with some fundamental problems. Under the action of a microbicidal agent the microorganisms do not die at the same time, even if there is a homogeneous population. The destruction of microorganisms follows a special destruction order. The number of dying organisms is always proportional to the number of viable organisms present. On theoretical grounds it is, therefore, impossible to free an object from all living and viable germs; there will ever be left a certain proportion of viable germs, even if this proportion may be very small. The aim of sterilization must be to keep that proportion very small. To reach this goal in a practical time without damaging the objects to be sterilized, microorganisms of high resistance should be excluded, i.e. the objects to be sterilized should not be contaminated by microorganisms of high resistance to the sterilizing agent(s). The assurance level that an object is free from all living and viable germs must be so high that it is practically impossible to proof this by a test for sterility. On the other hand, the absence of microorganisms of high resistance in the objects to be sterilized makes it feasible to use microorganisms of high resistance as test organisms for the manufacture of microbiologic indicators. Such indicators enable to record as an integral the action of all microbicidal parameters of the noxious agent(s) far beyond the region for which the application of a test for sterility is sensible. Nevertheless, bioindicators have a similar status as the physical and physico-chemical controlling instruments. Microbiological indicators make it possible to guarantee the application of a certain (minimal) efficacy of the microbicidal agent(s). Whether this efficacy is sufficient to reach the wanted sterility assurance level depends, last not least, on the microbiological contamination (bioburden) of the object to be sterilized. Each sterilization process has its own prerequisites.
authors.affiliation: Robert Koch-Institut des Bundesgesundheitsamtes, Berlin.
authors.forename: G
authors.initials: G
authors.lastname: Spicher
mesh_terms: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development*; D004352:Drug Resistance, Microbial; D005658:Fungi / Q000187:drug effects / Q000254:growth & development*; D011786:Quality Control; D013242:Sterilization / Q000592:standards*; D014780:Viruses / Q000187:drug effects / Q000254:growth & development*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents
vernacular_title: Sterilisation--Die Mikrobiologie zwischen Anspruch und Wirklichkeit.