Epidemiological Investigation Of Canine Ascarid And Molecular Biology Identification Of Canine Ascarid Eggs

Pollution investigation was carried out to the Canine Ascarid eggs in pet dogs and stray dog excrement samples. A total of572pet dogs and stray dog excrement samples were collected from7areas in Hunan Changsha and Huaihua. Including221domestic dog feces samples and351wild feces samples.76fecal samples containing Canine Ascarid eggs, the total infection rate of Canine Ascarid was13.28%.Toxocara canis infection rate was4.89%, Toxascaris leonine infection rate was8.39%. Puppy is the major infestor of Canine Ascarid, infection rates as high as40.7%.Recycling canine ascarid eggs from fecal samples.Using tissue grinding apparatus grinding canine ascarid eggs,and then extract DNA in canine ascarid eggs.PCR amplification were used to analysis of the sequence in cytochrome c oxidase subunit (coxl) among Canine Ascarid eggs. The pearl genes of canine ascarid eggs are429bp in length. The gene has obvious interspecific differences (10.5%-12.5%), can very good to distinguish the two kinds of canine ascarid eggs.Amplify ITS genes among Canine Ascarid eggs. The ITS-2gene fragment and base content exist significant differences. The length of ITS-2gene fragment of Toxocara canis eggs is323bp; the length of ITS-2gene fragmentof Toxascaris leonine eggs is282bp. The A+T base content of Toxocara canis eggs is53.87%to54.80%,the C+G base content is45.20%to46.13%. The A+T base content of Toxascaris leonine eggs is63.48%to64.54%,the C+G base content is35.11%to35.46%. Sequence alignment results show that interspecific differences from36.1%to37.7%, significantly higher than the intraspecific differences from1.0%to3.3%.This experiment is the first time using Molecular biology research on coxl and ITS gene of Toxocara canis eggs and Toxascaris leonine egg.The research testified that coxl and ITS provide appropriate genetic markers for molecular biology identification of Canine Ascarid eggs. The research results help to understand the life history, epidemiology of different Canine Ascarid eggs, and also help to the diagnostics,prevention and treatment for the related disease.