HiMedia – M1468 HiCrome™ Aureus Agar Base

Principle and Interpretation
HiCrome™ Aureus Agar Base is recommended for isolation and enumeration of coagulase positive Staphylococcus aureus from environment samples. Coagulase positive S. aureus gives brown black colonies with clear zone around the colony whereas S. epidermidis gives slightly brownish colonies. Other organisms give either colourless colonies or bluish coloured colonies due to the presence of chromogen. Listeria monocytogenes colonies are bluish in colour whereas Bacillus, E. coli and Micrococcus give colourless colonies. Tryptone, gelatin peptone,HM peptone B and yeast extract provide nitrogenous, carbonaceous compounds, long chain amino acids, vitamin B complex and other essential growth nutrients. Sodium pyruvate protects injured cells, helps recovery and enhances growth of Staphylococcus. Lithium chloride and potassium tellurite inhibit most of the contaminating microflora except Staphylococcus aureus(1). Due to addition of egg yolk, proteolytic bacteria produce a clear zone around colony (1).

原理與解釋
建議將HiCrome™Aureus瓊脂基質用於從環境樣品中分離和計數凝固酶陽性金黃色葡萄球菌。凝固酶陽性金黃色葡萄球菌給出棕色黑色菌落，在菌落周圍具有透明區域，而表皮葡萄球菌產生略帶褐色的菌落。由於色原的存在，其他生物產生無色菌落或帶藍色的菌落。 單核細胞增生李斯特菌菌落顏色為藍色，而芽孢桿菌，大腸桿菌和微球菌產生無色菌落。 胰蛋白腖，明膠蛋白腖，HM蛋白腖B和酵母提取物提供含氮，含碳化合物，長鏈氨基酸，維生素B複合物和其他必需的生長營養素。丙酮酸鈉可保護受損細胞，幫助恢復並促進葡萄球菌的生長。氯化鋰和亞碲酸鉀抑制 大多數污染微生物菌除金黃色葡萄球菌外（1）。由於添加了蛋黃，蛋白水解細菌在菌落周圍產生清晰的區域（1）。