关键词: 聚合酶链反应, 中华按蚊, 血源鉴定, 人血指数, 媒介调查

Abstract:

　　【Abstract】　Objective　To develop a molecular technology to assay human blood index of Anopheline mosquito which could substitute for the traditional immunological method. Methods　A pair of specific primer were designed according to the sequence of human rDNA, and the human blood in Anopheline mosquito was identified by polymerase chain reaction （PCR）. Meanwhile, the DNA extracted from the blood of pig, cattle, goat, mouse and the mosquito without bloodsucking were detected to verify the specificity  of  the  method.  And the DNA extracted from the mosquitoes after its bloodsucking for different time （such as 1 h, 6 h, 12 h, 18 h, 24 h, 27 h, 30 h, 33 h, 36 h, 40 h, 44 h, 48 h） were detected to determine the sensitivity of the method. Results　The specific PCR product （519 bp） was amplified from the DNA extracted from human blood.  No specific PCR product was found either from the blood of other animals or from the mosquitoes without bloodsucking. The specific bands were produced from all the mosquitoes within bloodsucking for 24 h. After bloodsucking for 27 h, 30 h, 33 h and 36 h, only 4, 4, 2, 1 mosquito could produce specific bands in the total of 5 tested mosquitoes, respectively. No specific PCR product was amplified after feeding for 40 h. Logistic regression analysis indicated there was a negative correlation between the bloodsucking time and the quantity of positive mosquitoes detected by PCR after bloodsucking for 24-40 h （P＜0.01）. Conclusion　The PCR method developed in this study could identify human blood in Anopheles sinensis within bloodsucking for 24 h accurately， which could replace the traditional immunological method.

Key words: Polymerase chain reaction, Anopheles sinensis, Blood meal identification, Human blood index, Vector survey