*دراسة امكانية الانتقال العرضي Cross transmission لبعض انواع طفيلي الابواغ الخبيئة المعزولة من الطيور الى الانسان من خلال الاصابة التجريبية في الفئران المختبرية

Abstract

The present study aimed to investigate of host specificity and know how incidence ofcross transmission of Cryptosporidiosis which infected birds to human through testedincidence of experimental infection with Cryptosporidium spp. which isolated from birdsin white mice balb/c .To attainment this purpose a laboratory mice were dosage with difference species ofcryptosporidium which isolated from wild and domestic birds and then we determinate ofsusceptible of age group to infection and histological changes in experimentally infectedmice. Laboratory mice divided into two age's group: Immature and mature mice ,experimentally groups were gave a limited infection dose orally for each species ofparasite (1X103oocyst / mouse).Result showed that cross transmission could happened for three species ofCryptosporidium that infected birds to lab. mice which are: C.parvum,C.meleagridis andC.baileyi with total ratio 30% and showed a significant difference compared with controlgroup , and the results record a mortality ratio in infected mice (7.5%).The probability of mammalian infection by Cryptosporidium species which isolated frombirds in our study represent the first record in Iraq. C.parvum and C.meleagridis showedloss of host specificity whereas C.baileyi was opportunist in his ability to infect anotherhost beside their ordinary host (birds), while C.galli showed a high specificity for its host.The results showed a distinction of immature mice on mature mice with a significantdifference (35% vs 25%).The histological sections of intestine from infected miceshowed : one of parasite's phase was adhere to epithelial cells and noted a histologicalchanges which included: cohesion of neighboring villi , dwarf of villus , necrosis of theirtop and infiltration of inflammation cells nearby infection regions