负压屏障设施动物饲养笼具的选择及其感染风险的识别

Selection of laboratory animal cages and recognition of infection risk in the negative-pressure barrier facility

目的生物安全实验室的感染性动物实验大部分经空气传播的致病因子可利用安全隔离装置有效控制,啮齿类动物饲养笼具作为一种常用设备对其要求仍不明确。本研究将测试本实验室(负压屏障设施)模拟感染动物实验在使用开放和密闭2种啮齿类动物笼具的病原暴露风险,并评价本设施的硬件条件和管理措施对于风险控制的水平。方法使用具有卡那霉素抗性的大肠杆菌(Kan^+,E.coli,DH5α)作为指示微生物,测试开放笼盒饲养、密闭笼盒(与外界无压力梯度)饲养、生物安全柜动物换笼等操作的暴露风险,并对负压设施内外的指示微生物进行监测。结果动物在负压屏障设施中使用开放笼具饲养存在病原暴露风险,负压屏障设施一定程度上可以控制病原的播散;动物在无压力梯度的密闭笼盒的饲养环节未能检测到指示菌;密闭笼盒使用生物安全柜设备进行换笼操作可有效控制病原暴露风险。结论在负压屏障设施内使用密闭笼盒,在笼盒与外界无压力梯度的情况下亦可保障生物安全风险的有效控制。

Objective Most of the airborne pathogens of infectious animal experiments in biosafety laboratories can be effectively controlled by barrier apparatus. However,the requirements for biosafety parameters of the rodent cages, which are commonly-used devices, are not clear yet. The purpose of this study is to estimate the risk of pathogen exposure by mimicking infectious animal experiments using open cage or sealed cage for rodents in barrier facility under negative pressure in our laboratory, and to evaluate the risk-controlling level of the hardware conditions and management measures of our facility. Methods E. coli （ DH5α, with the kanamycin-resistance gene, Kan＋） was used as the indicator microor-ganism. The risk of pathogen exposure of the following operations were tested： mice raised in open cage or sealed cage （ without pressure gradient inside and outside） , and sealed-cage changing of mice in biosafety cabinet. The quantities of in-dicator microorganisms inside and outside the facility with negative pressure were monitored to estimate the efficiency of bio- safety-control over the facility. Results There was a risk of pathogen exposure when open cage was used in the barrier fa-cility under negative pressure, and the spread of pathogens could be controlled in barrier facility under negative pressure to some extent. There was no indicator microorganism detected when animals were raised in sealed cage without pressure gra-dient inside and outside, and the risk of pathogen exposure during the procedure of sealed-cage changing in the biosafety cabinet could be effectively controlled. Conclusions The biosafety of animal experiments can be ensured using sealed cage in barrier facility under negative pressure, even without pressure gradient inside and outside of the cage.