Analysis of tellurite resistance level and resistance gene cluster in non-O157 Shiga toxin-producing Escherichia coli isolates

VernacularTitle:非O157产志贺毒素大肠杆菌分离株亚碲酸钾抗性水平及抗性基因簇分析
Author: Xiangning BAI ; Ailan ZHAO ; Qiong MENG ; Jianguo XU ; Yanwen XIONG
Publication Type:Journal Article
Keywords: Non-O157 Shiga toxin-producing Escherichia coli; Tellurite resistance; ter gene cluster
From: Chinese Journal of Microbiology and Immunology 2012;32(7):585-588
CountryChina
Language:Chinese
Abstract: Objective To investigate the tellurite resistance level,the presence of tellurite resistance (ter) gene cluster and their relationships in non-O157 Shiga toxin-producing Escherichia coli(STEC) isolates.Methods Tellurite resistance level was evaluated by plate dilution method and the ter gene cluster was tested by PCR.Results Only 5 of 39 non-O157 STEC isolates tested in this study were identified to have ter gene cluster,which showed relatively high levels of tellurite resistance ranging from 128 μg/ml to 512 μg/ml.In contrast,the other 34 isolates without ter gene cluster were sensitive to potassium tellurite and showed very low levels of tellurite resistance,the minimal inhibitory concentration (MIC) was ＜1 μg/ml for 29 isolates,8 μg/ml for 2 isolates and 2 μg/ml for 3 isolates.Conclusion Most non-O157 STEC isolates were sensitive to potassium tellurite.It could be concluded that much attention should be paid when screening the non-O157 STEC isolates using the selective medium supplemented with potassium tellurite.