Prevalence Investigation And Molecular Biological Identification Of Kalicephalus Isolated From Snakes In Hunan

In order to provide valuable references to prophylaxis and treatment of snake nematodosis, Prevalence of Kalicephalus which parasitize snakes was investigated in Hunan province and isolated Kalicephalus were identified by means of morphology as well as molecular biology.In the first part,prevalence survey of Kalicephalus was conducted in10areas in Hunan.The average infection intensity is15.66/unit(11.22-19.33/unit),indicating Kalicephalus are preponderance parasite in snakes. The general infection rate is39.36%with digestive tract symptom and lesion turned up in infected snakes.The,refore,,Kalicephalus are prodigiously harmful to health of snakes.In the second part,morphology method was applied in species identification of Kalicephalus,with the conclusion that there are3species K.indicus,K.bungari and K.brachycephalus distributed in Hunan.In the third part,ITS genes of21Kalicephalus belonging to3species were cloned and sequence analyzed.These ITS gene sequences are750bp-797bp in length. Intraspecific similitude percent completely exceeds98.4%while interspecific similitude percent is80%-89%in comparison. Phylogenetic tree reconstructed by NJ reveals that congener Kalicephalus form a same branch,which are far apart from other branches composed of other nematodes.It is in agreement with morphology result, showing that phylad analytical method based on ITS gene is relatively accurate.ITS gene is provided to be a reliable molecular genetic marker for identification of Kalicephalus.It is the first time that prevalence of Kalicephalus is comprehensively and systematicly inquired and molecular biology of Kalicephalus is studied,which laies the foundation for classification,identification,diagnostics,molecular epidemiology and phylogenetics of Kalicephalus.