Prevalence Of Coccidia, Life Cycle And Molecular Biological Identification Of Small Isospora-like Oocysts From Dogs And Cats In Kunming Area

Faecal samples of dogs and cats collected in Kunming area between May 2008 andOctober 2009 were examined microscopically. In 400 faecal samples of dog, 141samples (35.2%) were found coccidia. Four species coccidia oocysts found in caninefaeces and prevalence were: I. canis(9.7%), I. ohioensis(29.2%), Sarcocystis sp.oocyst(5.5%), Hammondia/Neospora-like oocysts(0.5%). In 85 feline faeces, coccidianparasites were found of 39 cats, with an overall prevalence of 45.8%. The followingspecies of coccidia and their respective prevalence were detected in feline faeces: I.felis(17.6%), I. rivolta(33%), Sarcocystis sp. (3.5%), Toxoplasma/Hammondia-likeoocysts (4.7%).To elucidate the life cycle of Hammondia/Neospora-like oocysts in canine faecesand Toxoplasma/Hammondia-like oocysts in feline faeces, these oocysts were infectedto experimental animal. Sporulated Hammondia/Neospora-like oocysts wereadministered to dog, gerbils, guinea pigs and KM mice, and tissues from theseinoculated animals were fed to coccidia-free dogs to determine species susceptibility toHammondia/Neospora-like oocysts. The results showed that gerbils, guinea pigs couldserve as experimental intermediate hosts, dogs and KM mouse were not. In addition, itwas found that the tissue cysts were unable to transmission between guinea pigs, whichwas interpreted as obligate heteroxenous life cycle. Sporulated Toxoplasma/Hammondia-like oocysts were administered to KM mice and cats, tissues from these inoculatedanimals were fed to coccidia-free cats. The results showed that cats and KM mice couldserve as experimental intermediate hosts. In addition, it was found out that tissue cystswere transmitted between KM mice, which was interpreted as facultative homoxenouslife cycle. Hammondia/Neospora-like oocysts in canine faeces were identified as H.heydorni and there were T. gondii oocysts contained in feline faeces.H. heydorni, N. caninum, T. gondii and H. hammondi PCR specific primersJS4/JS5, Np6/ Np21,Tox4/Tox5,CT1/HhammITS and Hham3R/Hham34F were used todifferentiate the oocysts. H. heydorni specific primers JS4/JS5 amplified a single bandgene fragment size 267bp from H. heydorni oocysts in canine feces, and the T. gondiispecific primers Tox4/Tox5 amplified a single band gene fragment size 529bp from T.gondii oocysts in feline feces. PCR amplification confirmed the result in animalexperiment.