HiMedia – M1577andM1641 HiCrome™ Enterobacter sakazakii Agar / Modified

Principle and Interpretation
Enterobacter species are widely distributed in nature occurring in fresh water, soil, sewage, plants, vegetables, animal and human feaces.*Cronobacter sakazakii has been closely associated with neonatal meningitis and sepsis (3). The chromogenic substrate in HiCrome™ Enterobacter sakazakii Agar (M1577) is cleaved specifically (2) by the glucosidase enzyme possessed by Enterobacter species resulting in formation of blue-green colonies. Other organisms, which do not cleave this substrate, produce yellow coloured colonies. Incorporation of the chromogenic mixture in the media renders an intense blue colour to *C.sakazakii colonies and light blue green colour to other Enterobacter species. HiCrome™ Enterobacter sakazakii Agar, Modified is recommended by ISO Committee for the isolation and identification of *C.sakazakii (1). The chromogenic substrate is cleaved specifically (2) by *C.sakazakii resulting in the formation of blue green colonies. Other organisms, which do not cleave this substrate, produce colorless to slightly violet coloured colonies. Tryptone, soya peptone and yeast extract provide the essential growth nutrients along with nitrogenous and carbonaceous compounds, long chain amino acids and vitamins. Sodium chloride helps in maintaining the osmotic equilibrium of the medium. Sodium deoxycholate and crystal violet (in M1641) inhibits the accompanying gram-positive flora.

原理與解釋
腸桿菌屬在自然界中廣泛分佈於淡水，土壤，污水，植物，蔬菜，動物和人類糞便中。*阪崎腸桿菌與新生兒腦膜炎和敗血症密切相關（3）。 HiCrome™阪崎腸桿菌瓊脂（M1577）中的顯色底物被腸桿菌屬物種所具有的葡糖苷酶特異性切割（2），導致 形成藍綠色的殖民地。其他不切割該底物的生物會產生黃色的菌落。將顯色混合物摻入培養基中使得* C.sakazakii菌落呈現強烈的藍色，而對其他腸桿菌屬物種呈現淺藍綠色。 HiCrome™Enterobacter sakazakii Agar，Modified被ISO委員會推薦用於分離和鑑定 * C.sakazakii（1）。顯色底物被* C.sakazakii特異性切割（2），導致藍綠色菌落的形成。 不切割該底物的其他生物產生無色至淺紫色的菌落。 胰蛋白腖，大豆蛋白腖和酵母提取物提供必需的生長營養素以及含氮和含碳化合物，長鏈氨基酸和維生素。氯化鈉有助於維持培養基的滲透平衡。脫氧膽酸鈉和結晶紫（在M1641中）抑制伴隨的革蘭氏陽性菌群。