HiMedia – M1831 HiCrome™ KPC Agar Base

Principle and Interpretation
HiCrome™ KPC Agar Base is a chromogenic medium designed for the detection and differentiation of KPC producing gram negative bacterial species without selective pre-enrichment. Carbapenems are the last line of defense against invasive or serious infections and are used to treat these life threatening infections that are caused by gram negative, drug resistant pathogens (2). Production of carbapenemase enzyme results in resistance to penicillins, cephalosporins (i.e. cefepime, ceftriaxone), carbapenems (i.e. meropenem, ertapenem) and aztreonam there by making these pathogens multi drug resistant. Most carbapenemase producing bacteria are included in the family Enterobacteriaceae and are thus termed as carbapenem resistant Enterobacteriaceae (CRE). Besides the Enterobacteriaceae family, rare strains of Pseudomonas aeruginosa and Acinetobacter baumannii have also found to produce carbapenemase (1, 2, 3). Peptone provides nitrogenous and carbonaceous compounds long chain amino acids and other essential growth nutrients. This medium can be made selective by supplementation with antibiotics for detecting microorganisms associated with hospital borne infections. Selective supplement have been added to inhibit the growth of yeast, gram positive organisms and gram negative organisms that do not produce carbapenemase. This medium is intended to be used as a screening medium. Isolates should be tested further for carbapenem susceptibility following CLSI guidelines. Indole test may be perform for the confirmation of carbapenem resistant E. coli because some rare strains of C. freundii may produce small pink to magenta coloured colonies similar to E. coli. Carbapenem resistant strains of Klebsiella, Enterobacter and Serratia species produce bluish green colonies. Acinetobacter and Salmonella species produce smooth, colourless colonies. Pseudomonas species produce colourless to light yellowish green, translucent colonies with wrinkled edges. Further biochemical tests may be needed for complete identification.

原理與解釋
HiCrome™KPC瓊脂基質是一種顯色培養基，設計用於檢測和分化產生KPC的革蘭氏陰性菌種，無需選擇性預富集。碳青黴烯類是防禦侵襲性或嚴重感染的最後一道防線，用於治療由革蘭氏陰性，耐藥病原體引起的這些危及生命的感染（2）。碳青黴烯酶的產生導致對青黴素，頭孢菌素（即頭孢吡肟，頭孢曲松）的抗性， 碳青黴烯（即美羅培南，厄他培南）和氨曲安在那裡使這些病原體具有多重耐藥性。 大多數產生碳青黴烯酶的細菌包括在腸桿菌科中，因此被稱為耐碳青黴烯的腸桿菌科（CRE）。除腸桿菌科外，罕見的銅綠假單胞菌和鮑曼不動桿菌也發現產生碳青黴烯酶（1,2,3）。 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。通過補充抗生素可以使該培養基具有選擇性，用於檢測與醫院感染相關的微生物。已經添加了選擇性補充劑以抑制酵母，革蘭氏陽性生物和不產生的革蘭氏陰性生物的生長 碳青黴烯酶。 該培養基旨在用作篩選培養基。應根據CLSI指南進一步測試分離株的碳青黴烯敏感性。吲哚試驗可用於確認耐碳青黴烯的大腸桿菌，因為一些罕見的弗氏檸檬酸菌株可產生與大腸桿菌相似的小粉紅色至品紅色的菌落。 耐受碳青黴烯的克雷伯氏菌，腸桿菌和沙雷氏菌菌株產生藍綠色菌落。不動桿菌和沙門氏菌產生光滑無色的菌落。假單胞菌種類產生無色至淺黃綠色，半透明的菌落，邊緣皺褶。可能需要進一步的生化測試以進行完全識別。