Survey And Analysis On Bovine Anaplasmosis In HuNan

1.Surveying on Infection with Anaplasma in Cattle and Pathogen' s Route of Transmission in Part Districts of HuNanInfections with anaplasma in cattle during five different districts(Chang-sha Yong-an,Chang-sha Long-hua,Yi-yang An-hua,Lou-di Lian-yuan and Chang-de Shi-men) in Hunan were surveyed in this chapter via a series of methods,including blooding in vena cervicalis,blood smearing,Giemsa-Wrights dyeing and microscope detection,and mice inoculation.While pathogen' s route of transmission was studied via lab detection on infections with anaplasma in gadflies in the surroundings,mice inoculation with contents from infected gadflies and rabbits mixed feeding in a same layer.The results indicated that infections with anaplasma in cattle during that five different districts were 37.5%,54.5%,57.14%,33.33%and 63.64%respectively; Infections with anaplasma in gadflies in the surroundings was 71.6%in total;Mice inoculation with blood from infected cattle and contents from infected gadflies and rabbits infection with anaplasma via mixed feeding in a same layer both succeeded; Transmission of anaplasma can be effected mechanically by biting flies or blood-contaminated fomites.2.Establishing on Artificial Infection of Experimental animals with Bovine AnaplasmaTo set up anaplasma artificial infection model in experimental animals treated with dexamethasone,mice and rabbits were infected through abdominal cavity, subcutaneous way with the blood from infected cattle and suspension of viscera from infected animals,contagious infection with infected animals,respectively.Results indicated that a regularity of the anaplasma in experimental animals appeared.The time of appearance,peak and disappearance of anaplasma in experimental animals were 6th～8th days,16th～20th days,25th days,respectively after infection. Artificial infection model with anaplasma was established in experimental animals under immune suppression conditions.The ways of infection with anaplasma were found through abdominal cavity,subcutaneous way and contagion.3.Initially Studying on Molecular-biological Detection Method of Bovine Anaplasma Isolated in HuNanThe 16S rRNA gene sequence of anaplasma was amplificated form positive blood in cattle with anaplasma infection in five different districts of Hunan with the universal primers(fd₁ and rp₂) of protozoa。PCR products were partially sequenced and spliced,and the 16S rRNA gene partial sequence of anaplasma isolated from different districts in Hunan were analyzed or identified via molecular biological software.At last,a specific PCR diagnosis method on anaplasrna was researched with a pair of specific primers designed in the conservative interval of such acquired sequences in the study.Results indicated that a 1425 bp gene strap of anaplasma 16S rRNA can be got in all of the positive blood in cattle via PCR.Sequence homology of 16S rRNA among 5 isolated strains of anaplasma isolated from different districts of Hnan and other 10 isolated strains of anaplasma marginale on GeneBank were shown in 97%～98%.So such 5 anaplasma isolated strains were identified as anaplasma marginale,but attached to a different gene group with other 10 anaplasma marginale isolated strains abroad.At last,a specific PCR diagnosis method was established with the specific primers(Fp:5'-GGCCCGAGTTGGACCCTTGAC-3',109bp～129bp; Rp:5'-CCTGGCGACCGTTGTTTCCTATTC-3',634bp～611bp),which can amplify a 526 bp gene strap of anaplasma 16S rRNA from all of the positive blood in cattle.