Abstract: Microbial risk assessment is one of the most important scientific tools to ensure food safety. It is crucial for the development of food safety policies, regulations and standards. Strain heterogeneity is the inherent characteristic of microorganisms, and is prevalent in various pathogens, affecting the accuracy and uncertainty of microbiological risk assessment. This review summarizes the current studies on strain heterogeneity. Meanwhile, the conception of strain heterogeneity is proposed and its main types are also elaborated, including growth and death heterogeneity, biofilm heterogeneity, virulence heterogeneity and antibiotic resistance heterogeneity. Furthermore, the manifestation of heterogeneity is analyzed and the influence of heterogeneity of microorganisms on microbiological risk assessment is discussed. This review proposes four solutions to decrease the impacts of strain heterogeneity and puts forward the concept of meta-model, which will hopefully help improve the accuracy and reliability of microbiological risk assessment.

Key words: food-borne pathogen, growth and death heterogeneity, biofilm heterogeneity, virulence heterogeneity, antibiotic resistance heterogeneity, risk assessment, meta-model