HiMedia – M1829 HiCrome™ ESBL Agar Base

Principle and Interpretation
Extended-spectrum b-lactamase (ESBL)-producing organisms are an increasing challenge for healthcare practitioners fighting healthcare-associated infections (HAIs). Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca are the most common ESBL- producing pathogens (1). ESBL-producing organisms are generally resistant to many classes of antibiotics, including aminoglycosides and fluoroquinolones; ESBL-producing organisms are able to attack newer cephems and monobactams as well as narrow-spectrum cephalosporins and anti gram-negative penicillins (1). They are associated with increased mortality and are difficult to detect and treat. The widespread use of extended-spectrum, third-generation cephalosporins, introduced in the 1980s to treat antibiotic-resistant bacteria, is believed to be a major contributor to the emergence of ESBL-producing organisms. HiCrome™ ESBL Agar Base is chromogenic screening medium for the selective isolation of ESBL producing organisms. It contains peptone mix which serves as the carbon and nitrogen sources, long chain amino acids, vitamins and other growth nutrients. Chromogenic mixture is used to differentiate the ESBL producing organisms on the basis of colour. HiCrome™ ESBL Agar Supplement (FD278) helps in inhibition of other contaminating organisms. ESBL producing E.coli grow as pink to purple colonies. ESBL producing members of the KESC group produce bluish green colonies; Proteus, Morganella and Providencia do not utilize any chromogen resulting in colourless to light brown colonies. This medium can be inoculated with liquid suspension equivalent to 0.5 McFarland turbidity, prepared from rectal screening swabs, faecal samples or from isolated colony. Isolated colonies should not be directly plated on to this medium, because the high level inoculum may cause false positive results. Further confirmation using biochemical identification tests is recommended.

原理與解釋
產生超廣譜β-內酰胺酶（ESBL）的生物體對於針對醫療相關感染（HAI）的醫療保健從業者來說是一個越來越大的挑戰。 大腸埃希氏菌，肺炎克雷伯菌和產酸克雷伯菌是最常見的產ESBL病原體（1）。產ESBL的生物通常對許多類抗生素有抗性，包括氨基糖苷類和氟喹諾酮類;產ESBL的生物能夠攻擊新的頭孢菌素和單核苷酸以及窄譜頭孢菌素和抗革蘭陰性青黴素（1）。它們與死亡率增加有關，難以檢測和治療。在20世紀80年代引入的用於治療抗生素抗性細菌的超廣譜第三代頭孢菌素的廣泛使用被認為是產生ESBL的生物的主要貢獻者。 HiCrome™ESBL瓊脂基質是用於選擇性分離產ESBL菌的生色篩選培養基。它含有蛋白腖混合物，可作為碳源和氮源，長鏈氨基酸，維生素和其他生長營養素。顯色混合物用於基於顏色區分產生ESBL的生物。 HiCrome™ESBL瓊脂補充劑（FD278）有助於抑制其他污染生物。產ESBL的大腸桿菌生長為粉紅色 紫色的殖民地。生產ESBL的KESC組成員產生藍綠色菌落; Proteus，Morganella和Providencia不使用任何色原體，產生無色至淺棕色菌落。 該培養基可以接種相當於0.5McFarland濁度的液體懸浮液，由直腸篩選拭子，糞便樣品或分離的菌落製備。不應將分離的菌落直接接種到該培養基上，因為高水平的接種物可能導致假陽性結果。建議使用生化鑑定試驗進一步確認。