为探明小型屠宰场生产牛肉中产气荚膜梭菌的消费风险及其生产链中的关键风险防控点，以北京市某小型肉牛屠宰场不同样品的产气荚膜梭菌污染监测数据和调研数据为基础，构建了牛肉中产气荚膜梭菌定量风险评估模型，并通过@Risk软件模拟运行分析。通过模型模拟的屠宰后单头牛胴体表面产气荚膜梭菌污染量90%的可能分布在102.00~563.00 CFU，平均值为280.84 CFU，而实际监测数据拟合为291.17 CFU，说明模型可信。根据屠宰过程中各环节的模拟数据，构建了牛胴体表面携带产气荚膜梭菌消长变化图，发现产气荚膜梭菌携带量从剥皮后的122.31 CFU/头上升至屠宰后的280.00 CFU/头，屠宰环节携带量为0.11 CFU/100 g，而销售环节升至4.95 CFU/100 g。通过模型对各变量参数进行敏感性分析，发现胴体表面产气荚膜梭菌污染对牛肉产气荚膜梭菌污染的风险贡献最大（R=0.69），其次是空气中的带菌量，而销售环节100 g牛肉携带产气荚膜梭菌的风险主要与从屠宰到销售过程中牛肉带菌量变化有关（R=0.96）。可见，屠宰过程中肉牛的本底携带、空气中带菌量以及储运销售过程中的交叉污染是牛肉中产气荚膜梭菌污染的关键控制点。结合剂量-反应关系和膳食数据，模型评估的本屠宰场生产牛肉中产气荚膜梭菌引发的感染风险每年不足1例，风险极低。本研究构建了小型肉牛屠宰场屠宰过程中产气荚膜梭菌定量风险评估模型，可为牛屠宰场产气荚膜梭菌污染的风险管理提供参考。
In order to identify the consumption risk brought by Clostridium perfringens（C. perfringens）produced during beef production in small slaughterhouses and key risk control points along production chain，a quantitative risk assessment model of C. perfringens in beef was constructed based on the monitoring and investigation data for C. perfringens in different samples in a small slaughterhouse in Beijing City，and operational analysis was simulated by @Risk software. 90% of simulated C. perfringens contamination on individual carcass surface was likely to be distributed at 102.00 to 563.00 CFU，with the mean of 280.84 CFU，while the actual monitoring data was fitted to 291.17 CFU，which indicated that the model was reliable. The change chart of C. perfringens carried on carcass surface was constructed based on the simulation data collected from each process of slaughtering. It was found that the bacteria load increased to 280.00 CFU/head after slaughtering from 122.31 CFU/head after peeling，which was 0.11 CFU/100 g during the process of slaughtering and increased to 4.95 CFU/100 g during selling. It was found that，by sensitivity analysis for various variable parameters through the model，the contamination with C. perfringens on carcass surface played the most important role in the risk of contamination in beef（R=0.69），followed by the amount of bacteria in air；the risk of C. perfringens carried in 100 g beef was mainly related to the change of bacteria amount during the process from slaughtering to selling（R=0.96）. It could be observed that the key control points of contamination with C. perfringens in beef included background carrying of beef cattle during the process of slaughtering，the load of bacteria in air and cross-contamination during the processes of storage，transportation and selling. Based on dose-response relationship and dietary data，as evaluated by the model，the risk of infection caused by C. perfringens in beef in the slaughterhouse was less than one case every year，with extremely low level of risk. Therefore，some reference was provided for risk management of contamination with C. perfringens in slaughterhouses by the established model in the study.