医疗废物储存温度和时间对细菌和真菌生存率影响的模拟研究

Effects of storage temperature and time on survival rates of bacteria and fungi in simulated medical waste

目的调查偏远地区医疗废物中细菌载量,并进行医疗废物模拟样本微生物生存测试,为偏远地区医疗废物暂时储存温度控制和储存时间提供科学依据。方法选择偏远地区医院为本次调查研究现场,采用现场调查与实验室结合的方法,获得自然储存条件下不同储存时间医疗废物中的细菌载量,采用大肠埃希菌、铜绿假单胞菌、金黄色葡萄球菌和白色念珠菌加标医疗废物模拟样本,测试不同温度不同储存时间下4种测试微生物的生存率。结果偏远地区医院医疗废物中的细菌载量范围为101.00~105.05CFU/g,平均载量为102.53CFU/g。在4℃储存条件下,四种测试微生物生存率出现下降,在20~30 d的储存期内表现出生长抑制的现象;在15和35℃储存条件下,4种测试微生物生存率先上升达到一定高值后随后下降,在20~30 d的储存期内表现出生长繁殖的现象。结论 15和35℃的储存温度会促进医疗废物中微生物的生长,4℃储存条件抑制医疗废物中微生物生长,可为医疗废物暂时储存温度的控制提供数据支持。

Objective To investigate the bacterial load in medical waste from the remote area and conduct the test of microbial survival rate in the simulated medical waste,so as to provide basis for modifying the temperature and stored period of temporary storage. Methods A hospital was selected as the investigated site,the bacteria load of medical waste in different storage time under natural environmental conditions was obtained by site investigation and experiment research,the microbial survival rate of four strains,including Escherichia coli,Pseudomonas aeruginosa,Staphylococcus aureus and Candida albicans,added into the simulated medical waste and cultivated at different temperature and stored time were determined. Results The bacteria loads of site samples from a hospital in remote area were 101.00-105.05 CFU/g with an average level of 102.53 CFU/g. During the storage period of 20-30 days,the four tested strains were inhibited with decreasing microbial survival rate at 4 ℃,and produced rapidly with increasing microbial survival rate at 15 ℃ and 35 ℃,which increased first and then decreased gradually.Conclusion The microorganism populations are strongly affected by the temperature,the growth of which is promoted at 15 ℃,35 ℃ and inhibited at 4 ℃ respectively.This study provides scientific basis for the control of storage temperature of temporary storage of medical waste.