HiMedia – M1418andM1505 HiCrome™ UTI Agar, Modified / HiCrome™ UTI Selective Agar

Principle and Interpretation
HiCrome™ UTI Agar, Modified/ HiCrome™ UTI Selective Agar is formulated on the basis of work carried out by Pezzlo (4), Wilkie etal (6), Friedman et al (1), Murray et al (3), Soriano and Ponte (5) and Merlino et al (2). These media are the modifications of HiCrome™ UTI Agar (M1353), which can be used in place of MacConkey Agar for isolation, and confirmation of various microorganisms. It facilitates and expedites the identification of some gram-negative bacteria and some gram-positive bacteria on the basis of different contrasted colony colours produced by reactions of genus or species specific enzymes with two chromogenic substrates. Enzymes produced by Enterococcus species, Escherichia coli and coliforms cleave the chromogenic substrates incorporated in the medium. Presence of rich source of phenylalanine and tryptophan from peptone and tryptone provides an indication of tryptophan deaminase activity, revealed with TDA Reagent (R036) indicating the presence of Proteus species, Morganella species and Providencia species, which appear brown. One chromogenic substrate is cleaved by b-glucosidase possessed by enterococci resulting in formation of blue colonies. E. coli produce purple to magenta colonies due to the enzyme b-D-galactosidase which cleaves the other chromogenic substrate.Further confirmation of E. coli can be done by performing indole test using DMACA Reagent (R035). Also, some strains of Enterobacter cloacae lacking b-glucosidase show pink colonies indistinguishable from E.coli. The DMACA reagent for indole test (should be performed on filter paper) distinguishes between E. coli and Enterobacter and TDA reagent between Proteus mirabilis and other species. Coliforms produce purple coloured colonies due to cleavage of both the chromogenic substrates. Peptone, HM peptone B and Tryptone provides nitrogenous and carbonaceous compounds, long chain amino acids and other essential growth nutrients. HiCrome™ UTI Selective Agar is made selective by the addition of bile salts, which selectively inhibits gram-positive bacteria.

原理與解釋
HiCrome™UTI瓊脂，改良/ HiCrome™UTI選擇性瓊脂是根據Pezzlo（4），Wilkie等（6），Friedman等（1），Murray等（3），Soriano和Ponte進行的工作配製而成。 （5）和Merlino等人（2）。這些培養基是HiCrome™UTI瓊脂（M1353）的修飾，可用於代替MacConkey Agar進行分離和確認各種微生物。它基於由屬或物種特異性酶與兩種生色底物的反應產生的不同對比菌落顏色，促進和加速鑑定一些革蘭氏陰性細菌和一些革蘭氏陽性細菌。 由腸球菌屬物種，大腸桿菌和大腸桿菌產生的酶切割摻入培養基中的生色底物。來自蛋白腖和胰蛋白腖的富含苯丙氨酸和色氨酸的來源提供了色氨酸脫氨酶活性的指示，用TDA試劑（R036）顯示表明存在變形棕色的變形蟲屬物種，摩根氏菌屬和普羅威登斯菌種。一種生色底物被腸球菌所具有的β-葡糖苷酶切割，導致藍色菌落的形成。 由於酶b-D-半乳糖苷酶切割其他生色底物，大腸桿菌產生紫色至品紅色菌落。通過使用DMACA試劑（R035）進行吲哚試驗，可以進一步確認大腸桿菌。此外，一些缺乏β-葡萄糖苷酶的陰溝腸桿菌菌株顯示出與大腸桿菌無法區分的粉紅色菌落。用於吲哚試驗的DMACA試劑（應在濾紙上進行）區分奇異變形桿菌和其他物種之間的大腸桿菌和腸桿菌和TDA試劑。由於顯色底物的裂解，大腸桿菌產生紫色的菌落。 蛋白腖，HM蛋白腖B和胰蛋白腖提供含氮和含碳化合物，長鏈氨基酸和其他必需的生長營養素。 HiCrome™UTI選擇性瓊脂通過添加膽汁鹽而具有選擇性，膽汁鹽選擇性地抑制革蘭氏陽性細菌。