Hegde Veena, Leon-Velarde Carlos G, Stam Christina M, Jaykus Lee-Ann, Odumeru Joseph A
Laboratory Services Division, University of Guelph, 95 stone Rd. West, Guelph, ON, Canada N1H 8J7.
J Microbiol Methods. 2007 Jan;68(1):82-7. doi: 10.1016/j.mimet.2006.06.011. Epub 2006 Aug 23.
The performance of BBL CHROMagar Listeria chromogenic agar for the detection of Listeria monocytogenes was evaluated for its ability to isolate and identify L. monocytogenes from food and environmental samples. The medium was compared to non-chromogenic selective agars commonly used for Listeria isolation: Oxford, Modified Oxford, and PALCAM. BBL CHROMagar Listeria had a sensitivity of 99% and 100% for the detection of L. monocytogenes from 200 natural and artificially inoculated food samples, respectively, with a colony confirmation rate of 100%. The sensitivity of non-chromogenic selective media for the detection of L. monocytogenes from these same samples was 97-99% with colony confirmation rates of 65-67.5%. From 93 environmental samples, BBL CHROMagar Listeria agar results correlated 100% with a Listeria spp. visual immunoassay (TECRA) performed on these same samples and the USDA-FSIS standard culture method for the isolation of L. monocytogenes. From environmental samples, the L. monocytogenes confirmation rate was 100% for BBL CHROMagar Listeria as compared to 50% for conventional agars tested. On BBL CHROMagar Listeria, L. monocytogenes forms a translucent white precipitation zone (halo) surrounding blue-pigmented colonies of 2-3 mm in diameter, with an entire border. BBL CHROMagar Listeria offers a high degree of specificity for the confirmation of suspect L. monocytogenes colonies, whereas non-chromogenic selective agars evaluated were not differential for L. monocytogenes from other Listeria species.
对BBL CHROMagar李斯特菌显色琼脂用于从食品和环境样本中分离和鉴定单核细胞增生李斯特菌的性能进行了评估。将该培养基与常用于分离李斯特菌的非显色选择性琼脂进行了比较：牛津琼脂、改良牛津琼脂和PALCAM琼脂。BBL CHROMagar李斯特菌琼脂从200份天然和人工接种的食品样本中检测单核细胞增生李斯特菌的灵敏度分别为99%和100%，菌落确认率为100%。从这些相同样本中检测单核细胞增生李斯特菌时，非显色选择性培养基的灵敏度为97 - 99%，菌落确认率为65 - 67.5%。在93份环境样本中，BBL CHROMagar李斯特菌琼脂的结果与对这些相同样本进行的李斯特菌属视觉免疫测定（TECRA）以及美国农业部食品安全检验局（USDA - FSIS）分离单核细胞增生李斯特菌的标准培养方法的结果100%相关。对于环境样本，BBL CHROMagar李斯特菌琼脂对单核细胞增生李斯特菌的确认率为100%，而测试的传统琼脂为50%。在BBL CHROMagar李斯特菌琼脂上，单核细胞增生李斯特菌在直径2 - 3毫米、边缘整齐的蓝色菌落周围形成半透明白色沉淀区（晕圈）。BBL CHROMagar李斯特菌琼脂对可疑单核细胞增生李斯特菌菌落的确认具有高度特异性，而所评估的非显色选择性琼脂对单核细胞增生李斯特菌与其他李斯特菌属无法进行区分。
