There are current ISO horizontal methods for the detection and enumeration of L. monocytogenes in food and animal feed. ISO 11290-1:1996 is a method for the detection of L. monocytogenes, while ISO 11290-2:1998 is a method for enumeration. Both methods were amended in 2004 to include modified media. Similar standard methods have been published elsewhere by other bodies, notably in the USFDA Bacteriological Analytical Manual (BAM).