Preparation of test bacteria tablets for moisture resistance microbial penetrati
The wet microbial penetration tester is suitable for evaluating the performance of materials in resisting the penetration of bacteria in liquids when subjected to mechanical friction. It is mainly used for medical surgical sheets, surgical gowns, and clean clothes.
Applicable standards:
YY/T 0506.6, ENISO 22610
Main parameters:
1. Turntable speed: 60rpm±1rpm;
2. Test pressure: 3N±0.02N;
3. Outward wheel speed: 5~6rpm;
4. Timer setting range: 0~99.99min;
5. Total weight of inner and outer ring weights: 800g±1g.
Bacteria sheet preparation:
Staphylococcus aureus ATCC29213 was cultured on tryptic soy agar at 36℃±1℃ for 18-24 hours, and 2-3 colonies were inoculated into 3ml tryptic soy broth and cultured at 36℃±1℃ for 18-24 hours. Dilute with peptone water 1:10 to a concentration of 1×104CFU/mL~4×104CFU/mL, and count the final bacterial suspension.
Open the sterile bag take out the polyurethane film still attached to Zhenan, and place the wettable polyurethane film of the bacterial material sheet facing up on the cleanliness plate. For ease of operation, fix the four corners of the bacterial material sheet to the plate with double-sided tape. Use the culture dish cover as a template to cut out a corresponding area on the bacterial film, apply 1.0ml of Staphylococcus aureus suspension on the area, and then dry the bacterial sheet at 56℃ for about 30 minutes. During the drying period, use a sterilized glass applicator to continuously apply the bacterial suspension on the bacterial film to evenly distribute the bacterial liquid.
Test principle:
Put the test piece on the agar culture dish, put a bacterial sheet of the same specifications on the test piece, and then cover it with a high-density polyethylene film about 10 microns thick. Use a conical steel ring to clamp the three layers of materials (test material at the bottom, bacterial sheet in the middle, and high-density polyethylene film at the top) together. Place this ring set on the agar culture dish on the turntable. The test finger acts on the material in a way that it can move on the entire surface of the culture dish, so that the material is subjected to the combined effects of pressure and friction, thereby simulating the stress conditions that may occur in the barrier material during actual application and the penetration of microorganisms under wet conditions. After penetrating the test material, the microorganisms on the bacterial sheet will migrate to the surface of the agar culture medium. By culturing the agar culture dish and counting the colonies, the penetration performance of the test material can be quantitatively evaluated