Wiegand Irith, Hilpert Kai, Hancock Robert E W
Centre for Microbial Diseases and Immunity Research, University of British Columbia, 2259 Lower Mall Research Station, Vancouver, British Columbia, V6T 1Z4, Canada.
Nat Protoc. 2008;3(2):163-75. doi: 10.1038/nprot.2007.521.
The aim of broth and agar dilution methods is to determine the lowest concentration of the assayed antimicrobial agent (minimal inhibitory concentration, MIC) that, under defined test conditions, inhibits the visible growth of the bacterium being investigated. MIC values are used to determine susceptibilities of bacteria to drugs and also to evaluate the activity of new antimicrobial agents. Agar dilution involves the incorporation of different concentrations of the antimicrobial substance into a nutrient agar medium followed by the application of a standardized number of cells to the surface of the agar plate. For broth dilution, often determined in 96-well microtiter plate format, bacteria are inoculated into a liquid growth medium in the presence of different concentrations of an antimicrobial agent. Growth is assessed after incubation for a defined period of time (16-20 h) and the MIC value is read. This protocol applies only to aerobic bacteria and can be completed in 3 d.
肉汤稀释法和琼脂稀释法的目的是确定被测抗菌剂的最低浓度（最低抑菌浓度，MIC），即在规定的测试条件下抑制所研究细菌可见生长的浓度。MIC值用于确定细菌对药物的敏感性，也用于评估新型抗菌剂的活性。琼脂稀释法是将不同浓度的抗菌物质加入到营养琼脂培养基中，然后将标准化数量的细胞接种到琼脂平板表面。对于肉汤稀释法，通常采用96孔微量滴定板形式进行测定，将细菌接种到含有不同浓度抗菌剂的液体生长培养基中。在孵育规定时间（16 - 20小时）后评估生长情况并读取MIC值。本方案仅适用于需氧菌，且可在3天内完成。
