Add two Listeria monocytogenes dilutions into cod enrichment broth,when the addition number of Listeria monocytogenes was 55.5 per 100ml in cod enrichment broth,the detection result from the fish enrichment broth was 110 per 100 ml (MPN).

• 将两种稀释度(10-4和10-7)的单核细胞增生李氏菌液加入鳕鱼增菌液中；加入到鳕鱼增菌液的菌数为55.；5个/100 ml；按最可能数计数法(MPN)能检测到的菌数为110个/100 ml；增菌液DFB培养48 h后；能检测到的最低浓度为0