BIfl PHl/ONG
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TRUNG ™ ONG DUNG C ONG NGHE 3NH H OC D ONG NAI:
THANHCONGBU1)1IDAUTIlilNGNGHrENCini,CHETIlOI(ITCHANDOAN^
ThS N G U Y I N THj HOANG, NGO QUANG HUdNG
S<5 KH&CN P^ng Nai
Vdi mong mud'n cha'n doan nhanh 2 djch benh chu ydu b heo la: hpi chdng rd'i loan sinh s i n , hO hdp va tigu chiy cap, gdp phln Icidm soat djch b@nh trong chdn nudi heo tren dja ban tinh Ddng Nai va cac dja phiTdng lan can, Trung tarn iJng dgng Cdng ngh^ Sinh hgc Ddng Nai
da thirc hign thanh cdng dd tai "XSy dUng kit phat hl^n virus PRRS (hdi chdng rd'l loan sinh s i n , hd hd'p), virus, vi Ichu^n trong b@nh ti@u chiy ca'p trgn heo nudi b^ng phuong phap PCR' vdi l(g't qui khi quan...
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hdng nam gan day, nganh chan nudi cCia Viet Nam ph&i dd'i mat vdi hang loat djch benh nguy hiem. Trong dd, benh tieu chay d p va hpi chdng r l i logn hd hip, sinh s^n tr§n heo khdng chi nguy hiem, gay ttf vong nhanh cho heo ma cdn d l bung phat thanh djch Idn. Ding Nai la tinh co dan heo Idn thd ba trong ck nddc (sau Ha Npi va Nghe An), nam 2009, tren dja ban tinh da xky ra dich tieu chay cap, ngay sau do la djch roi loan sinh san va ho hap tren heo, g§y thiet hgi nghi§m trpng cho ngddi chan nudi.Do dd, de nganh chan nudi phat trien on dinh, ben cgnh viec ap dung cac tien bp ky thuat trong chan nudi, can quan tam dgc biet tdi nhdng bien phap phdng ching djch benh.
Hpi chdng roi logn sinh skn va hd hap 6 heo, cdn gpi la benh "tai xanh" (PRRS - Porcine Reproductive and Respiratory Syndrome) ddpc ghi nhgn lan dau tien d My vao nkm 1987, do virus RNA thupc bp Nidovirales, hp Arteriviridae, giong Arterivirus. Gan dciy, mpt bien the cija genotype 2 co ddc lyc cao hdn da xult hien, gay nhieu tdn thit cho cac nudc ch^u A. B§nh lam g\km ty l§ sinh san, gay say thai, heo chet luc sinh d heo nai, gay roi logn hd hap d i n den td vong 6 heo con. Benh cd the lay lan nhanh trong dan heo trong 7-10 ngay. Ddi vdi benh nay, kho khan thd nhat la phan biet dddc chung dpc lyc cao va chung thddng de cd bien phap phdng ngda,
Chan tri hieu quk; kho khan thd hai \k each lay m§u benh pham hi§n nay thddng td cac md ndi quan se khdng t h i tiln hanh tren dan heo giong lam m§
nen phydng phap chin doan can thilt phki xac djnh dddc tac nh§n gky bdnh tr§n m l u huyet thanh. Dda vao cac nguydn ly hoat ddng ciia cac phddng ph^p chan doan sinh hpc ph§n tiS thi phddng phap RT- PCR hoan toan cd the phan biet nhd thiet k l primer dgc hieu cho moi chung va thf nghiem cung cd the tiln hanh tren mau huyet thanh hay cac loai mlu khac.
Doi vdi benh ti§u ch^y cap. cac tac nhan gky benh rat da dang, bao gom virus, vi khuIn va nguyen sinh dpng vat, trong do virus la tac nhan g^y hgi Idn nhat. Trong so cac virus, nhom Rotavirus va hai Coronavirus la PEDV (Porcine Epidemic Diarrhea Virus) va TGEV (Transmissible Gastroenteritis Virus) la nguy hilm nhat, vdi t^ IS gky chit den 100% dd'i vdi heo con dddi 7 ngay tuoi. Benh cd to'c dd lay lan rat nhanh, khi co tac nhan gSy binh xuat hien trong vung. Do do, van d l la phk\ tim ra mpt phypng phap chan doan nhanh, chfnh xac cac tac nh&n gay benh de kip thdi phong ngda dac biettd dan heo giong nhgp ve. Them vao do, benh do nhilu tac nh§n gay ra nhdng Igi cd trieu chdng tddng ty nhau trong khi m5i tac nhan doi hdi ph&i c6 nhdng bien phap phu hdp d l phdng ngda, chin tri.
D I g\k\ quyet v l n d l nay c i n phlii cd mpt phddng
I TopchKHOAHM ^ . , , „ ^^^^
CONGNCHEVIETNiftf ' ° ' ' " ^ " ' ° ^ '
BIfl PHl/ONG
phap chan doan nhanh dong thdi cac tac nhan tren va xac djnh ddpc mau benh pham nhilm tac nhan nao. Phddng phap multiplex PCR cho phep phat hien nhanh (trong vdng 4-5 gid td khi nhan mlu) va chi ra chinh xac mpt hoac dong thdi nhilu tac nhkn nen rat phu hdp vdi muc tieu nay.
Xac djnh ddpc cac van de tren, td nam 2010 Trung t£im Lfng dgng Cdng nghe Sinh hpc Dong Nai da thyc hi§n d l tai "Xay dyng kit phat hien virus PRRS (hpi chdng roi logn sinh san va hd hap), virus va vi khuIn trong benh tieu chay cap tren heo nudi bang phypng phap PCR" vdi muc tieu: giai quylt v l n d l chan doan nhanh tac nhan gay 2 dich benh Idn la hdi chdng rd'i logn sinh s^n va hd hap; tieu ch^y cap tren heo. Qua thyc hien d l tai, Trung tam da x§y dyng thanh cdng 04 bp kit PCR gom: 01 bp kit RT-PCR phat hien PRRSV gay hpi chdng roi logn sinh skn va hd hap; 01 bp kit multiplex RT- PCR phat hien nhdm Rotavirus, TGEV va PEDV trong benh ti§u chky cap; 01 bp kit multiplex PCR ph^t hien Salmonella Typhimurium, E. coli ETEC va Clostridium perfringens trong b§nh tieu chay cap; 01 bp kit real-time RT-PCR phat hien PRRSV.
Cac kit dddc thd nghiem tr§n mlu thdc dja va danh gia khi so sanh vdi kit thddng mgi (Labhoo) cho thay hieu qua phat hien tot, chfnh xac, tien dyng, khong phy thupc vao thdi gian van chuyen.
Kdt qui so sinh kit thuang m^i real-time RT-PCR (Labhoo) vi kit RT-PCR phit hien PRRSV gay hdi chdng rd'i loan
sinh sin va hd hi'p cda dS tii
Kdt qui so sinh kit thUOng mai real-time RT-PCR vi kit multiplex PCR phat hien vi khuan cua de tii
PRRSV RT-PCR
Kit RT-PCR (+)
(•)
Tdng
Kit real-time RT-PCR (Labhioo) (+)
8 4 12(80%)
( • )
0 3 3 (20%)
Tong
8 (53%) 7 (47%) 15 K& qui so sinh kit thUdng mai real-time RT-PCR (Labhoo)
vi kit real-time RT-PCR phit hien PRRSV cua de tii
Pliat hien PRRSV
Kit real-lime RT-PCR
(*)
( • )
Tong
Kit reai-time RTPCR (Labtioo) (+) 11 1 12 (80%)
( • )
0 3 3 (20%)
Tong
11(73%) 4(27%) 15
So sanh kit phat hi$n VI khuan
Kit multiple!
PCR (+) H To^ng
H I so kappa (6) K i t e
(*)
152
17 (94%)
(-)
0'
(B%) Tdng
15
|S3%]
3 (17%)
18
0,45 K I t E
(*) ^
0
9 (50%)
(-) ^
5
9 (50%)
Tong
13 (72%)
5 (2S%)
18
0,56 Kits
(*)
12
0
(67%)
( • )
°
6
e (33%)
T . . ,
12 (67%)
6 (33%)
IB
1,0
Trong dd. (C) - kit C. perfringens, (E) - kit E. coli ETEC, (S) - kit Salmonella spp. (Labhoo) Ket qua phit hien Rotavirus bing kit real-time RT-PCR thUdng mai (Labhoo) vi kit multiplex RT-PCR cda de tai
Kit multiplex RT-PCR
(*)
( • )
Tonq
Kit Rotavirus real-time RT-PCR (Labhoo) (+1
8 1 9 (50%)
(-)
0 9 9(50%)Tong B(44%) 10(56%) 18
Bd kit chin doin tic nhin
Ngoai cac du diem ndu tren, kit do d l tai nghien cdu che tao cd gia ca hdp ly va che dd hgu mai tot hdn so vdi cac kit nhgp ngoai. Cung vdi cac d l tai nghien cdu khac, k i t qua cua de tai "Xay dyng kit phat hien virus PRRS (hpi chdng rdi logn sinh san, hd hap), virus, vi khuan trong benh tieu chay cap tren heo nuoi bang phddng phap PCR" da trdc tiep phuc vy ldi I'ch cua ngddi 6kn trong vung va cac dia phddng lan can, giai quylt nhOng bai toan dat ra td ddi song san xuat; dong thdi gdp phan nang cao trinh dp nghien cdu cua cac bp trong Trung tam •