Lay ong nghiem ra, gan ni/dc tren di, do can vao dia petri tim au trung dudi kinh hien

- Khong co dap Un gm iln djch di truyen

7 Lay ong nghiem ra, gan ni/dc tren di, do can vao dia petri tim au trung dudi kinh hien

petri tim au trung dudi kinh hien vi

Hinh 41. Cacli tien hanh phuong phap phan ly du triing Baerman

Dung pheu co dudng kinh 5 - 1 0 cm, cudi pheu lap mot dng cao su dai 1 0 - 1 5 cm. cudi dng cao su lap dng nghiem. Dat ludi thep hoac vai man len mieng phdu. cho dav

nuoc aim 37 - 38°C, tren ludi thep dat 1 0 - 1 5 gam phan (neu la phan vien cua de, ciru thi 8 - 1 2 vien). De yen 30 phut - 1 gio, roi la'y can a ong nghiem quan sat dudi kinh hien vi de tim aiu trung.

Cdn chu y rang, d nhiet do 20 - 30°C, sau 1 8 - 2 4 gid, trung mot so giun tron thuoc bo Strongylata (nhu Oesophagostomum) se no ra a'u trung, kho phan biet voi au trung

Dictyocaulus. Vi vay, tot nhat la xet nghiem ngay, khong de phan qua dem.

Hien nay, d Viet Nam co the thay the phuang phap Baerman bang phuang phap cua Essen va Donalson co cai tien - phuang phap Thanh - Chau, dua theo nguyen tac cua phuang phap Baerman, nhung phuang phap nay dan gian, nhanh han va co hieu qua cao (Nguydn Vu Thanh va Nguydn Ngoc Chau, 1993).

- Phuang phap Vaida

Phuang phap Vaida dan gian han so vdi phuang phap Baerman, thudng dung de tim au trung trong phan gia sue co dang vien nhu phan dd, cuu. Dat 4 - 5 vien phan vao dTa petri va cho vao mot ft nude am. Sau 1 5 - 3 0 phut vdt cac vien phan bo di, con nude d hop long dem quan sat dudi kinh lup hoac kinh hidn vi tim au trung. Phuang phap nay ap dung dd han doi vdi dd, cuu nhung hieu qua tha'p han phuang phap Baerman.

Trong dudng tieu hoa cua gia sue nhai lai co nhidu loai giun trdn thuoc bo

Strongylida ky sinh, trufng cua chung co hinh thai gan gidng nhau, khi nd thanh a'u trung cung kho phan biet loai nay vdi loai khac. Tuy nhidn, cac dang au trung cam nhidm thuoc bo Strongylida khac nhau bdi sd lugng va hinh dang te bao ruot, kfch thudc cua au trung va phan mut dudi cua chung.

Vf du, cd the’ phan biet mot so au trung cam nhidm thuoc bo Strongylida nhu sau (hinh 42)

A7 v

. Au trung giun tron Dictyocaulus: mut duoi hinh non, ruot chua day cac hat mau sang.

/s'

. Au trung giun tron Haemonchus: mut duoi khong co gai, thuc quan dai khoang 1/5 chidu dai ca the.

. Au trung giun tron Tricliostrongylus: mut duoi co gai. thuc quan dai khoang 1/4 chidu dai co the.

. Au trung giun trdn Oesophagostomum: co 20 - 32 te bao ruot, mut duoi vuot dai.

A/

. Au trung giun tron Bunostomum: ruot la mot dng dai khong phan chia thanh nhung te bao rieng biet.

Hinh 42. Cac dang du trung cam nhiim cua bo Strongylida

1 - Haemonchus contortus; 2 - Cooperia; 3 - Trichostrongylus; 4 - Ostertagia; 5 - Chabertia;6 - Oesophagostomum columbianum\ 7 - 0. venulosum\ 6 - Oesophagostomum columbianum\ 7 - 0. venulosum\