Survival of bacteroides species in Amies transport medium stored at different temperatures.

The viability of four Bacteroides species in Amies medium at different temperatures was evaluated by a series of quantitative and qualitative experiments using B. bivius, B. disiens, B. fragilis and B. melaninogenicus. In the quantitative assessment, the Bacteroides spp. were recovered from Amies transport medium stored at -20 degrees C up to the six weeks of storage. At -10 degrees C no Bacteroides spp. was recovered after two weeks. At both storage temperatures, B. fragilis showed the highest survival rate. In the qualitative assessment, the test strains were recovered after four months of storage at -20 degrees C in Amies medium with noticeable decline in number of surviving bacteria towards the end of that period. The effect of thawing and refreezing was also assessed and was found to affect survival rate considerably. Our results provide an alternative, convenient and cheaper method of preserving anaerobes.