Kim Donghwa, Shin Woon-Seob, Lee Kyoung-Ho, Kim Kyunghoon, Young Park Joo, Koh Choon-Myung
Department of Microbiology, Yonsei University Wonju College of Medicine, Wonju, Korea.
Yeast. 2002 Aug;19(11):957-62. doi: 10.1002/yea.891.
In this study, we found that no Candida species other than C. albicans is able to form germ tubes at 39 degrees C in serum-free YEPD (1% (w/v) yeast extract, 2% (w/v) peptone and 2% (w/v) dextrose) media, which makes it easy to identify C. albicans from other Candida species. When cultivated in rabbit serum for at least 2 h at 37 degrees C, more than 60% of C. albicans cells generated germ tubes. In YEPD, however, germ tubes began to appear from C. albicans cells within 30 min at 39 degrees C, and more than 60% of C. albicans cells formed the germ tubes after 1 h at 39 degrees C. Standard Candida strains (ATCC, CBS), three C. albicans and two C. dubliniensis strains were cultured in serum at 37 degrees C for 2 h and in YEPD at 39 degrees C for 1 h. All of the three C. albicans formed germ tubes at 39 degrees C. The two C. dubliniensis strains formed germ tubes in serum at 37 degrees C, but grew as a yeast form in YEPD at 39 degrees C. All of the clinically isolated C. albicans strains in our laboratory formed germ tubes in YEPD at 39 degrees C for 1 h, and none of the clinically isolated Candida species other than C. albicans generated germ tubes in YEPD at 39 degrees C. Thus, the unique germ tube formation of C. albicans induced by high temperature (39 degrees C) in YEPD could be applied to a protocol for the rapid and convenient identification of C. albicans in clinical laboratories.
在本研究中,我们发现除白念珠菌外,没有其他念珠菌物种能够在无血清的YEPD(1%(w/v)酵母提取物、2%(w/v)蛋白胨和2%(w/v)葡萄糖)培养基中于39℃形成芽管,这使得从其他念珠菌物种中鉴定白念珠菌变得容易。当在兔血清中于37℃培养至少2小时时,超过60%的白念珠菌细胞产生芽管。然而,在YEPD中,白念珠菌细胞在39℃下30分钟内开始出现芽管,在39℃下1小时后超过60%的白念珠菌细胞形成芽管。标准念珠菌菌株(ATCC、CBS)、三株白念珠菌和两株都柏林念珠菌菌株分别在37℃的血清中培养2小时以及在39℃的YEPD中培养1小时。所有三株白念珠菌在39℃下都形成了芽管。两株都柏林念珠菌菌株在37℃的血清中形成芽管,但在39℃的YEPD中以酵母形式生长。我们实验室中所有临床分离的白念珠菌菌株在39℃的YEPD中培养1小时均形成芽管,而除白念珠菌外的其他临床分离念珠菌物种在39℃的YEPD中均未产生芽管。因此,高温(39℃)在YEPD中诱导白念珠菌独特的芽管形成可应用于临床实验室快速便捷鉴定白念珠菌的方案。