Guangxi Slugs Infected With Guangzhou Angiostrongylus Situation Analysis And Exploration Of Three Places Of Angiostrongylus Cantonensis Genetic Relationship

Objective:To investigate the Angiostrongylus cantonensis infection in slug that is the intermediate host of Angiostrongylus cantonensis, and to explore the genetic types of Angiostrongylus cantonensis isolated from three counties in Guangxi.Methods:We random investigated the Angiostrongylus cantonensis infection in slug in17counties/5regions in Guangxi. The slug was handed by enzyme-digestion method, and their third-stage larvaes were collected and infected in SD rats. The DNA of Angiostrongylus cantonensis isolated from Jingxi, Qinzhou and Tengxian County was extracted, PCR amplified and sequenced. For comparison the phylogenetic relationship of Angiostrongylus cantonensis among those isolated from Jingxi, Qinzhou and Tengxian in Guangxi, we calculated the genetic distance and similarity of Angiostrongylus cantonensis and then made the phylogenetic tree.Results:2455slug were collected from17counties with a positive rate of27.09%(664/2455). The infection rates of slug were different among the five regions. The highest and the lowest infection rate were in the West and the Middle of Guangxi with43.37%and21.91%, respectively. The Angiostrongylus cantonensis infection in slug also is varied in different types of environment; the residential areas have the highest infection rate (42.01%) and the wild areas have the lowest one (16.50%). Different infection rates also were observed in slug with different weights. The ITS2gene homology of Angiostrongylus cantonensis isolated from Jingxi were97%,99%and99%compared with those isolated from Qinzhou, Tengxian and the Spain standard strains, respectively. The ITS2gene homology of Angiostrongylus cantonensis isolated from Qinzhou were98%and99%in comparison with those isolated from Tengxian and the Spain standard strains. The ITS2gene homology of Angiostrongylus cantonensis isolated from Tengxian was98%compared with the Spain standard strains.Conclusions:Different infection rate in slug were observed in different regions and different types of environment. The total infection rate in slug was relative high, additionally the residents close contact with slug, leading to a potential transmission of Angiostrongylus cantonensis to human. The ITS2gene homologies of Angiostrongylus cantonensis isolated from three regions in Guangxi are high, and they have a close phylogenetic relationship with the Spanish standard strain, which indicated that they are belong to the same species.