食品和动物饲料的微生物学-推定大肠杆菌检测与计数的水平方法-最可能数法-修正案1:增加培养基和试剂的性能验证Microbiology of food and animal feeding stuffs - Horizontal method for the detection and enumeration of presumptive Escherichia coli - Most probable number technique - Amendment 1: Inclusion of performance testing of culture media and reagents