Lee Yung-An, Yu Cheng-Pin
Department of Life Science, Fu Jen Catholic University, HsinChuang 24205, Taipei, Taiwan, Republic of China.
J Microbiol Methods. 2006 Feb;64(2):200-6. doi: 10.1016/j.mimet.2005.04.031. Epub 2005 May 31.
A medium was developed for the isolation and differentiation of Erwinia chrysanthemi from other Erwinia spp. based on the production of blue-pigmented indigoidine. The medium, named NGM, consists of nutrient agar supplemented with 1% glycerol, that induces pigment production, and 2 mM MnCl2*4H2O, that further enhances color development. More than fifty E. chrysanthemi strains from six different plant hosts were tested. All tested strains of E. chrysanthemi grew well on the NGM medium, developing dark brownish to blue colonies easily distinguishable from other Erwinia spp. The results indicate that pigment production on the NGM medium is a very stable property and can be used as a phenotypic property to differentiate E. chrysanthemi from other Erwinia spp. In addition, a specific oligonucleotide primer set was designed for the detection of indC, which is involved in indigoidine biosynthesis. All E. chrysanthemi strains tested contained indC as determined by PCR amplification. No amplification was observed with other Erwinia spp. Thus, pigment production of E. chrysanthemi on the NGM medium is consistent with the existence of indC. The NGM medium was used to isolate and identify the causal agent of soft rot lesions of diseased Phalaenopsis orchids from three orchid cultivation areas in Taiwan. The causal agents of Phalaenopsis soft rot were all identified as E. chrysanthemi. The results indicate that the NGM medium is efficient in isolation and identification of E. chrysanthemi from plants with soft rot symptoms and can also be used for epidemiological studies.
基于蓝色色素靛蓝素的产生，开发了一种用于从其他欧文氏菌属中分离和鉴别菊欧文氏菌的培养基。该培养基名为NGM，由添加了1%甘油（可诱导色素产生）和2 mM MnCl₂·4H₂O（可进一步增强颜色显现）的营养琼脂组成。对来自六种不同植物寄主的五十多株菊欧文氏菌菌株进行了测试。所有测试的菊欧文氏菌菌株在NGM培养基上生长良好，形成深褐色至蓝色菌落，易于与其他欧文氏菌属区分开来。结果表明，在NGM培养基上产生色素是一种非常稳定的特性，可作为一种表型特性来区分菊欧文氏菌与其他欧文氏菌属。此外，设计了一组特异性寡核苷酸引物用于检测参与靛蓝素生物合成的indC。通过PCR扩增确定，所有测试的菊欧文氏菌菌株都含有indC。其他欧文氏菌属未观察到扩增。因此，菊欧文氏菌在NGM培养基上产生色素与indC的存在一致。NGM培养基用于从台湾三个兰花种植区患病蝴蝶兰软腐病斑中分离和鉴定致病因子。蝴蝶兰软腐病的致病因子均被鉴定为菊欧文氏菌。结果表明，NGM培养基在从具有软腐症状的植物中分离和鉴定菊欧文氏菌方面是有效的，也可用于流行病学研究。
