Possé Björn, De Zutter Lieven, Heyndrickx Marc, Herman Lieve
Department of Veterinary Public Health and Food Safety, Faculty of Veterinary Medicine, University of Ghent, Merelbeke, Belgium.
FEMS Microbiol Lett. 2008 May;282(1):124-31. doi: 10.1111/j.1574-6968.2008.01121.x. Epub 2008 Mar 18.
This study reports two novel selective differential media. A first differential medium can be applied in methods for the isolation of non-O157 Shiga toxin-producing Escherichia coli (STEC) serotypes (O26, O103, O111 and O145) from food or faeces. A second differential medium was designed for both sorbitol-positive and -negative O157 STEC strains. Selective differential media are based on a chromogenic compound to signal beta-galactosidase activity and one or more fermentative carbon sources. The chromogenic marker and carbohydrates were combined with a pH indicator and several inhibitory components, which resulted in highly specific differentiation media. Consecutive use of a serotype-dependent choice of confirmation media resulted in a very low incidence of false-positive isolates when comparing clinical STEC strains with a collection of commensal E. coli strains.
本研究报告了两种新型选择性鉴别培养基。第一种鉴别培养基可用于从食品或粪便中分离非O157产志贺毒素大肠杆菌（STEC）血清型（O26、O103、O111和O145）的方法。第二种鉴别培养基是为山梨醇阳性和阴性的O157 STEC菌株设计的。选择性鉴别培养基基于一种显色化合物来指示β-半乳糖苷酶活性以及一种或多种发酵性碳源。显色标记物和碳水化合物与pH指示剂及几种抑制成分相结合，从而产生了高度特异性的鉴别培养基。当将临床STEC菌株与一组共生大肠杆菌菌株进行比较时，连续使用依赖血清型选择的确认培养基导致假阳性分离株的发生率非常低。
