摘要
目的建立快速、高效、特异的定量水体中尾蚴的数量和检测水体中日本血吸虫尾蚴残余基因组DNA的方法,来评估水体受日本血吸虫尾蚴污染的程度。方法根据日本血吸虫基因组DNA中的3个多拷贝序列Sjrh1.0(序列号:U92488.1)、18S小亚基单位核糖体核酸基因(18SrRNA)序列(序列号:AY157226.1)和逆转录转座子SjR2的G55A序列(G55A)(序列号:AF412221.1),设计常规PCR引物和实时定量PCR引物,选取较好的靶序列建立SYBR GreenI实时定量PCR方法,绘制尾蚴数的对数与Ct值的标准曲线,并对疫水中日本血吸虫尾蚴残余的基因组DNA进行检测。结果尾蚴数的对数与Ct值的标准曲线有良好的线性关系,相关系数r2为0.918 6,重复性良好。结论本方法特异性高,灵敏,可定量水体中尾蚴数,对疫水检测有一定的预警作用。
The objective was to establish a rapid,sensitive and specific method to detect the number of cercariea in water and evaluate level of water stained by Schistosoma japonicum cercariea.Convenience PCR primer sequences were designed targeting pSjrH1.0（U92488.1）,Sj18SrRNA（AY157226.1） and the clone G55A of the highly repetitive retrotransposon SjR2（AF412221.1） in S.japonicum genome,and sequence the PCR product.Based on conserved sequence of pSjrH1.0,Sj18SrRNA and clone G55A of highly repetitive retrotransposon SjR2（G55A）,design primers and the quantitative real-time PCR essays were established,by which,the amplifying products were 150 to 170 bp.The sequence in S.japonicum genome and the best annealing temperature were selected by comparing their threshold cycle（Ct value）.Then the quantitative real-time PCR essays were established under the better annealing temperature,generate standard curve between the logarithms of gradient diluted DNA templates and Ct value.Five DNA samples extracted from 1,5,10,20 and 80 cercariae were used as quantitative template to generate standard curve between the logarithm for the number of S.japonicum cercariea and Ct value.Using the modified ROSE method,extract genome DNA from 200uL water samples containing cercariea and establish flourescent quantitative real-time PCR essays to detect the residue cercariae genome DNA in water containing S.japonicum cercariae after 24 hours.The results of the essays showed that pSjrH1.0 had higher sensitivity and lower Ct,in the same template concentration condition,comparing with Sj18SrRNA and G55A,and could quantitatively detect as low as 2 fg S.japonicum genome DNA in the study.The standard curve showed a fine linear relationship between the logarithms of gradient diluted DNA template and Ct value,and the correlation coefficient r2 was 0.997 7.The standard curve showed a fine linear relationship between the logarithm of the number of S.japonicum cercariae and Ct value,and the correlation coefficient r2 was 0.918 6.Repeated experiments prove that the method of quantitative detection of S.japonicum cercariea has high repetitiveness,which is a rapid,highly sensitive and highly repetitive method for evaluation of the water containing S.japonicum cercariae.
出处
《中国人兽共患病学报》
CAS
CSCD
北大核心
2011年第12期1075-1081,共7页
Chinese Journal of Zoonoses
基金
江苏省自然科学基金(BK2009076)资助
关键词
日本血吸虫
尾蚴
荧光实时定量PCR
预警
Schistosoma japonicum
cercariae
fluorescence real-time quantitative PCR
precaution
