Comparative study between culture media employed in sterility test

The sterility test aims at the contact of a product with a culture medium, as a way of detecting the possible presence of viable microorganisms in products which have been submitted to a sterilization process and/or to aseptic processing. Since the official introduction of the methodology, in 1932, several culture media have been proposed and adopted, in a constant attempt to offer conditions which support the growth of as many contaminants as possible. This work aimed at a comparative evaluation of the efficiency of microbial contaminants detection in the different types of culture media employed in sterility tests. The study led to the conclusion that the culture media recommended by the pharmacopoeia compendia, soybean casein digest and fluid thioglycollate, present the best results in microorganisms detection. Besides, the microbial strains, as well as microbial suspension density, recommended by the main pharmacopoeias to verify culture media growth promoting capacity, have also proved suitable for use.