Studies on Bacteria1 Contamination of Cloth (Part.3) Survival test of bacteria in dean and undean cloth

Survival test of bacteria in the cloth was done by using five sorts of bacteria and three kinds of textiles, clean and unclean cloth with fruit juice(orange),egg-yolk,milk and sebum.Bacterial suspension was dropped into the sample cloth. After certain period of time,the number of survived cells of bacteria were estimated by the colony count method. The results and discussion､are as follows : 1. Different sorts of bacteria showed different grades of survival in the cloth. 2. Gram-positive Staphylococcus aureus 209P was stronger in both clean and unclean cloth than Gram-negative bacteria, such as Proteus vulgaris 209P,Escherichia coil B and Pseudomonas aeruginosa Kitasato. In genera1, the survival grade of each species was higher in the unclean cloth than in the clean one. Candida albicans showed the medium grade between Gram一positive and Gram-negative bacteria. 3. The cloth stained with fruit juice had the highest survival grade of bacteria. 4. The weak bacteria increase their survival grade in exact proportion to the rate of increase of stained materials. But,it was saturated at the some higher grade of staining. 5. The different kinds of textiles showed different results, that is､ the cloth with higher moisture content, such as woolen muslin showed the highest grade of surviva1. 0n the other hand, the polyester taffeta with lower moisture content showed the lowest grade.