First the primers that were designed from ctx A were used to detect specimens,then the other primers were used to differentiate CVC,EVC and O 139 .48 EVC,2 CVC,6 O 139 and 33 non O1 non O 139 strains were detected,the results were all correct.

• 对48株EVC，2株CVC，6株O139群和33株非O1非O139群进行检测，扩增结果与设计均一致。