实验动物垫料的微生物污染监测及影响因素研究

Monitoring of microbial contamination in the bedding of laboratory animals and analysis of its influencing factors

目的对实验动物垫料进行微生物指标监测,为管理机构制定垫料的卫生标准提供依据,为垫料生产企业在加工、灭菌、包装、运输、储存等环节及动物使用单位对动物实验结果影响因素分析方面提供参考依据。方法对来自不同实验动物生产和使用单位的垫料,参照GB4789-2010、2012检测方法进行菌落总数、霉菌及大肠杆菌计数、沙门菌的检测。结果 49份未灭菌的垫料存在不同程度的细菌、霉菌及大肠杆菌污染,未检出沙门菌;不同材质的垫料在不同条件下灭菌,在121℃30 min的条件下具有最佳灭菌效果,各项微生物指标均合格;已灭菌的21份垫料有19份存在不同程度的细菌及霉菌污染,未检出沙门菌及大肠杆菌;松软的混合型刨花垫料在灭菌后7 d检测到细菌;采用敞开编织袋储存5 d即检测到细菌污染;垫料使用1 d后的菌量可达104CFU/g,细菌及霉菌含菌量按天数逐步递增,但未检出沙门菌。结论垫料使用前必须消毒灭菌,采用合理的方式储存,及时更换可改善饲养环境,可减少微生物污染,保障实验动物的质量及实验结果的可靠。

Objective To monitor the indicators of microbial contamination in the bedding of laboratory animals, and to pro- vide a basis for the management agency to establish the hygienic standard regarding the manufacture enterprises＇ bedding process- ing, sterilization, packaging, transportation and storage and for analyzing the factors affecting the experimental results. Meth- ods According to the standard of GB4789 2010 and GB4789 - 2012, the aerobic bacterial count, fungus, Escherichia coli and Salmonella were detected in the bedding samples manufactured by different enterprises and used by different laboratories. Re- sults Aerobic bacteria, fungi and Escherichia coli were variably found in 49 non- sterilized bedding samples, but Salmonella was not detected. The sterilization at 121~C for 30 minutes showed the optimum disinfection efficacy for various texture bedding samples, with all microbiological indicators qualified. Aerobic bacteria and fungi were variably found in 19 sterilized bedding sam- pies, but Salmonella and Escherichia coli were not detected. The mixed - wood - shaving bedding samples were found to be con- taminated by bacteria 7 days after being sterilized. The bacteria could be detected in the 5th day when the bedding samples were stored in unsealed woven bags. The bacteria in the bedding samples used for 1 day could be up to 104 colony - forming units （CFU）/g, and the concentrations for bacteria and fungi both increased with the prolonged use, but no Salmonella was detected. Conclusions It is necessary to sterilize and store the bedding of laboratory animals appropriately before use. To change the bedding timely can improve the animals＇ feeding environment and decrease the risk of microbial contamination so as to ensure the qualities of laboratory animals and experimental results.