KHOAHQCKfTHUjiTTHOYTjPXXStS 1-2013
PHAN TiCH Dl TRUYEN VIRUT G A V H O I CHffNG COl CQG TR^N HEO SAU CAI SJJA TAI T I N H OdlUG NAI VA T H A N H PHO Hd CHJ MINH
Nguyh Nggc Hii', Yd Khdnh Hung' va Nguyin Thj Kim Hing'
T6M TAT
HOi chiing c6i cpc tr6n heo sau cai slla (PMWS) do Porcine circovirus typ 2 (PCV2) l i mOt trong nhihig b^nh mdi, gSy thi^t hji nghiSm trpng tr6n din heo Vijt Nam. D^ g6p ph4n xie djnh tinh hinh nhiSm PCV2 tai Vi^t Nam, mOt phiin 0RF2, gen quy djnh capsid protein ciia 2 chiing PCV2 thu nhin tai thinh ph6 H 6 Chi Minh v i 11 chiing PCV2 thu nh?n t?i tinh Ding Nai dupe giii trinh Ur vi phSn tich ciy di truyin vtti cac chiing PCV2 tham chi^u trSn th^ gi6i. Ket qui nghita ciiu cho thiy, cfc chiing PCV2 thu nhfin t»i tinh D6ng Nai vi thinh ph6 H 6 Chi Minh chu ylu li 2 genotype PCV2b v i PCV2d. Trong d6, 1 chiing PCV2 thu nhjn tji thinh ph6 HA Chi Minh v i 4 chiing thu nh$n l?ii tinh D6ng Nai thu0c PCV2b; Cic chiing c6n I»i thuOc PCV2d vAi dO tirong d^ng khi cao so vdi cic chiing phin ISp t?i Trung Qu6c trong nim 2010 (99,1-99,3%).
n khda: Heo sau cai stta, H^i chiing c6i cpc, PCV2, ORF2, Genotype, D^ng Nai, TP Hh Chf Minh
Genetic analysis of porcine circovirus type 2 (PCV2) In post-weaning pigiets In Dong Nai province and Ho Clii IMInh city
Nguyen Ngoc Hal, Vo Khanh Hung and Nguyen Thi Kim Hang SUIVIIUIARY
Post-weaning muitisystemic wasting syndrome (PMWS) due to the PCV2 is one of the emerging diseases caused the important lost for swine industry in Viet Nam. To determine Ihe PCV2 infection in Vietnam, a part of 0RF2 - gene encoding capsid protein of two and eleven PCV2 strains obtained from Ho Chi Minh city and Dong Nai province respectively was sequenced and analysed to build a phylogenetic tree with the PCV2 strains referred from genebani<. The studied result showed that all of the PCV2 strains isolated from Ho Chi Minh city and Dong Nai province mainly belonged to genotypes PCV2b and PCV2d. Of which, one strain isolated from Ho Chi Minh city and four strains isolated from Dong Nai province belonged to PCV2b. The rest of strains belonged to PCV2d with high similarity (99.1- 99.3%) compared to the PCV2 strains isolated from China in 2010.
Key words: Piglet, Post-weaning muitisystemic wasting syndrome, PCV2, 0RF2, Dong N^
province. Ho Chi Minh city
I. B ^ i T V A N Bt gSy nSn hOi chiing niy. BO gen cila PCV2 g6m HOi chiing c6i c,c tren heo sau cai sOa (Post ^ " ^ ^ ^ ''"= " * ^°^ '='''°^-
- Weaning Muitisystemic Wasting Syndrome - - ORF I ma hda cho protein tham gia vdo PMWS) dupe ghi nhdn lan ddu tidn tren mdt svr nhdn len ciia virut (replication associated dan heo d Canada vdo ndm 1991. Porcine proteins),
circoviruts type 2 (PCV2) dupe xem Id tdc nhfin
' Khoa Chan nuoi Thu y - DH N6ng Lam Tp.HCM
= B9 mfin Cong ngh? Sinh hgc - Dai hgc Nong Lam Tp.HCM
KHOA HQC KY THUAT THO Y TAP XX S(3 1 - 2013
- 0RF2 md hda protein vd capsid cila virut.
Protein nay gill vai trd quan trpng trong ddp ling miin dich ddi vdi PCV2.
- ORF3 mS hoa cho protein giQ- vai trd gdy ndn hipn tu^ng apoptosis (apoptotic protein) cua td bdo bi nhilm virut (Mankertz et al., 1998).
Trong sd 3 ORF, 0RF2 cd nhieu bidn d6i nhdt. Id thdnh phan chinh quyet djnh si^ da dgng di truydn ciia PCV2, vi th^ trinh tv nucleotide ciia 0RF2 thudng dupe sii dyng d^ xdc djnh kidu di truyen ciia PCV2 (Olvera A. eM/.,2007).
Hpi chiing PMWS dd dupe ghi nh§n d Vi^t Nam tu nhidu nfim nay. Nguyin Thj Thu Hdng vd ctv., 2008, da cdng b6 k^t qud so sdnh s\t hiong ddng cua chiing PCV2 phan lap d Vi^t Nam vdi edc chiing PC V2 cdng bo fren Genbank.
Chiing PCV2 phan l|p d Vt$t Nam tuong ddng khoang tir 99,26 - 99,66% vdi mlu PCV2 phan Idp tii heo bi b?nh PMWS d Trung Qudc (chiing AY035820), d Hd Lan (chung AY484414), d Ue (chiing AY424405), hay d Phdp (chiing AY322000). PCV2 dupe chia thdnh nhidu kidu gen khac nhau d\ra theo bp gen ciia vuut. Hi$n tai PCV2 duQfc bidt ddn gdm 5 kidu gen PCV2a, b, c, d vd e. PCV2a vd b dudng nhu phan bd rpng khdp thd gidi, trong khi PCV2 c, d va e ehi phdt hien thdy tgi Dan Mach, Trung Qudc vd Thai Lan (Baekbo R et al.. 2011). Tuy nhien van chua CO nghien ciiu lidn quan ddn kieu gen cua PCV2 d Viet Nam. Kidu gen ciia PCV2 khdng chi CO y nghia vd mdt djch tl md cdn lidn quan ddn viec kidm sodt b$nh do PCV2 gdy ra. Yoichi Takahagi et al., (2010) qua kdt qud nghien ciiu vacxin phdng b§nh do PCV2 dd cho rdng kidu gen ciia PCV2 cd thd dnh hudng ddn hieu qua ciia vacxin phong b?nh do PCV2. Khac vdi
trudc ddy, HOi chiing PMWS do PCV2 gdy ndn khdng cdn d dgng tiim an niia md dd trd thdnh mOt trong nh£hig yeu t6 gdy thi$t hgi kinh tl hdng ddu cho ngdnh chdn nudi heo cdng nghiep d Vi§t Nam. Dl d6i phd vdi b?nh PMWS, nhieu trgi dd dp dyng tidm phdng vacxin ngiia b?nh.
D I tdi dupe thyc hidn nhdm xdc djnh cdc kieu gen PCV2 hi^n di?n d Vi§t Nam, 1dm ca sd cho cdc nghidn ciiu ddnh gid hi§u qud ciia vacxin trong phdng ehong b§nh PMWS.
II. Vi^TUfUVAPHirONGPHAP
2.L MSU vd primer
13 mlu duofng tinh vdi PCV2 bdng phucmg phdp PCR chpn tii 5 trgi khdc nhau (3 trgi tgi Ddng Nai ky hi?u trai idn lupl Id DNTBY, DNTBH, DNTB vd 2 trai tai TRHCM ky hi?u Idn lu(7t Id SGCC) dupe gidi trinh ty. Sdn phdm PCR dupe phdn tich tren gel agarose vd dupic tinh sach bdng QIAquick PCR Purification kit (Qiagen, Germany) va dupe gidi frinh ty nucleotide theo phucmg phap gidi tryc tiip.
Primer dupe thiit k l theo quy trinh ciia Kwang vd cs (2008).
2.2. Phdn tich trinh t^ vd xay dyng cdy di truyin Trinh tu nucleotide cua cdc chiing PCV2 thu dugc dugc xdy dung cay di truyen va so sdnh vdi 20 chiing virut PCV tham chilu fren thd gidi tii ngdn hdng gen (Bdng 1) theo Grau-Roma L.
vd ctv., 2008 va Long va etv., 2010. Cdc trinh tu phan l§p vd tham khdo dupe sdp gidng hang cOt de so sdnh phan tich bdng phdn mlm Lasergen (DNASTAR Inc., Madison, WI) vd xdy dyng cay di truyin theo chuong frinh MEGA 4 vdi h#
so bootsfrap 1000.
Bdng 1. Cac ch6ng PCV tham chieu tr§n th^ gfdl (tii ngfin hdng gene NCBI)
STT 1 2 3
"
ChQng Aust4 so-5 WB-H-8
SO-10
Qu6c gia Australia Guangdong - China
Hungary Guangdong - China
Ndm phin i$p 2005 2006 2006 2006
Ki^u gen PCV1 PCV1 PCV1 PCV1
set hi$u Genbank AY764016 DQ472016 DQ648032 DQ669164
KHOA HQC KY THUAT THtl Y TAP XX S(3 1 - 2013
Bing 1. Cic chOng PCV tham chitfu trin th< gidi (tir ng«n hilng gene NCBI)
STT 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
ChOng No.35 GER1 SPA1 26607 34464 KSY-1 S2 Fcl3 NL_Conlrol_3
JF JMS
SH BDH
AH MDJ DK1990PMWS DK19B7PMVI/S
Qutfc gia Japan Germany
Spain Iowa. USA
Canada South Korea
China France United Kingdom
Jlliin, China Heiiongiiang Shanghai. China
Heiiongiiang Anhui, China Heiiongiiang
Denmarlf Denmari<
Nim phin l(p 2009 2000 2000 2000 2000 2002 2003 2003 2003 2008 2007 2006 2008 2008 2007 1990 1987
Ki^u gen PCV2a PCV2a PCV2a PCV2a PCV2a PCV2a PCV2b PCV2b PCV2b PCV2b PCV2b PCV2b PCV2d PCV2d PCV2d PCV2C PCV2C
Stf hi4u Genbank AB072303 AF201305 AF201308 AF264039 AF264043 AF454546 Y288133 AY3219e4 AY484409 HM038022 HM038023 HM038D27 HM038017 HM038030 HM038031 EU148505 EU14B504
III. KET QUA VA THAO LUAN 3.1. Phdn dch sdn ph4m PCR
Dya theo vj tri primer FORF2 vd RORF2 tren genome ciia PCV, sdn pham ciia phdn ling PCR xdc djnh PCV2 dy dodn Id 568 bp (hinh
I). Theo kit qud phdn ling PCR ndt fren, dl tii dd thu dupe 13 mau ducmg tinh vdi PCV2 co ngu6n goc tii S trgi khdc nhau. Nhihig mau ADN ndy dugc gidi trinh ty vd phdn lo^i genotype, kit qud dugc trinh bdy qua Bang 2.
Hinh 1. Kit qui PCR vdi primer FORF2 vi R0RF2 trin cic miu b$nh phim nhiSm
Kit qud thu dugc frong Bang 2 cho th4>
PCV2 hi?n di?n frong mlu thu nhdn dugc tCr heo d 2 khu vyc Tp. Hd Chi Minh vd D6ng Nai bao gdm genotype PCV2b (5 chiing) vd PCV2d (8 chung). 0 cd 2 khu vyc Tp. Hd Cht Minh vd Ddng Nai deu phdt hi^n dugc kilu genotype PCV2b vd PCV2d. Cdc nghidn ciiu vl PCV2
irC'n hco deu thdng nhat nhan djnh la cac chiing P(_V2 thupc genotype PCV2b va PCV2d c6 doc lyc cao hoTi PCV2a va duoc phat hien chu yen d cac trai cd benh lam sang cua hgi chimg PMWS. 13 chung PCV2 trong nghien ciru nay Cling thu dugc tir cdc mau tren heo cd bieu hien lam sang ciia hpi chimg PMWS.
KHOA HOC Ki THU^T THp Y TAP XX S6 1 - 2013
Nhu vdy, du cdn nhilu franh cdi vd khd ndng cua PCV2 gdy hpi chtimg edi cpc fren heo sau cai siia, PCV2 phdn lap tit heo cd biiu hi§n
lam sang ciia hpi chiing PMWS hdu het khdng thupc genotype PCV2a.
Bdng 2. Genotype cOa cdc chiing PCV2 du^c gidi trinh ti/
STT 1 2 3 4 5 6 7 8 9 10 11 12 13
Ten m i u SGCC2M SGCCPL2 DNTBY5 DNTBY13 DMTBH21 DNTBH22 DNTBH28 DNTBH34 DNTBHA2 DNTBHT2P DNTB43 DNTB44 DNTB47
0|a dl^m TP.HCM TP.HCM D6ng Nai D6ng Mar D6ng Nai 06ng Nai D6ng Nai Ddng Nai D6ng Nai Ddng Nai Ddng Nai D6ng Nai D6ng Nai
N i m 2010 2010 2010 2010 2010 2010 2010 2010 2010 2010 2010 2010 2010
Genotype PCV2d PCV2b PCV2d PCV21) PCV2b PCV2d PCV2d PCV2d PCV2d PCV2d PCV2b PCV2b PCV2d
Theo cdch phan logi ciia Hpi nghi ve PCV2 d chdu Au 2008 (htq3://www.pcvd.net), PCV2 dugc chia thdnh 3 kilu gen: PCV2a, PCV2b vd PCV2c. Tuy nhien, 19 chiing PCV2 phdn lap tir nam 2004 - 2008, trong nghien ciru ciia Long et al., 2010, dupe xdc dinh la PCV2a, PCV2b vd PCV2d. PCV2d dugc cho Id genotype mdi, xuat hien do sy tdi td hgp cua PCV2a vd PCV2b. Ciing theo nghidn ciru ndi fren, PCV2d Id kilu geno^pe chidm da sd trong cac chimg PCV2 phan lap dugc d Trung Qudc. Jantafong et ai, 20II, nghien ciru fren 10 chiing PCV2 phdn lap d Thai Lan td nam 2007 - 2008 dd xdc dinh dugc 7 chung la PCV2b, 3 chiing cdn Igi Id PCV2e. Nhu vdy so vdi kit qua phdn tich di truydn, xdc dinh kieu gen cac chiing PCV2 phan lap dugc d 2 nude Idng gieng cd sy mua bdn heo vdi Viet Nam Id Thai Lan vd Trung Qudc, genotype ciia cdc chung PCV2 xac dinh dugc d Tp. Hd Chi Minh vd Ddng Nai ciing nhdm genotype ciia PCV2 phdn Idp d Trung Qudc (PCV2b va PCV2d). Kilu gen PCV2d
cung chiem da sd (8/13 chung PCV2 nghidn ciiu), tuong ty nhu nghien eihi eiia Long et al., 2010, fren cdc chiing PCV2 phdn Igp d Tnmg Qudc. Tuy nhien 6% cd thi khdng dinh dugc ngudn gdc Idy nhidm, cdn phdi phan tich vd so sdnh frinh ty gen vdi cac chiing tham ehieu cua Trung Qudc.
3.2. Phan tich di truyin PCV trdn viing gen ORF2
Trinh ty nucleotide cua 13 chiing PC V2 (bang 2) gdm 11 chung thu dugc tir Ddng Nai dugc ky hi?u theo trgi: DNTBY (chiing Id DNTBY5, DNTBY 13); DNTBH (6 chiing Id DNTBH21, DNTBH22, DNTBH28, DNTBH34, DNTBHA2, DNTBHT2P) vd DNTB (3 chung Id DNTB43, DNTB44, DNTB47) vd 2 chiing phdn Idp tiir 2 frai tai TRHCM vdi ky hidu Id SGCC2M vd SGCCPL2 dupe xay dyng cdy di truyen vdi cdc chiing tham chieu fren the gidi (Bdng 1).
KHOA HOC K ? T H U A T T H O Y T ^ P XX S 6 1 - 2013
n M F H n SCCCPL;
i ) M H i i : i
Fd3 M._CDrtnil D M I ' H I : P I)N I Fn 5 s r ; c c n ; DM U I I : ; r)\Ti)n:8 nvTHH-v:
, DMBH-^l
|6| GDH W J A t 26007
5 T i J c _ _
wnil l_iaui(Hcn2
9>A1 9 9|— DKIOOIPW
— CK1W7PW
as— Aisr
t
Hinh 2. CSy dl truyjn PCV2 xty d^fng dtfa trin viing trinh t^ ciJa 0RF2 b^ng cdng CM Megalign (DNAstar)
Cay di truyen cho thay r6 PCV chia th&nh 2 genotype PCVl v4 PCV2 (hinh 2).
Genotype PCV2 chia thinh 4 subgenotype PCV2a, PCV2b, PCV2c va PCV2d. PCV2d mdi dugc phat hi?n gSn dSy tai m0t s6 tinh Trung Qu6c (Long va civ., 2010).
Cic chiing phan i^p tgi Dong Nai va Tp.HCM trong nghien cijni thuoc ve 2 subgenotype PCV2b va PCV2d nim cung nhanh vdi cdc chung PCV2b va PCV2d phan Ijp t?i Trung Qu6c vao nam 2006 den 2008 (BDH, MDJ, AH, Long v4 ctv., 2010).
Cac chung thupc subgenotype PCV2b gom 4 chiing thu dinyc tvr Ddng Nai (DNTB43,
DNTB44, DNTBYI3. DNTBH21) v4 1 chiing phSn l$p tir Tp.HCM (SGCCPL2) vdi d* tirong dong khi cao 99,7 - 100 %, va tuong dong so vdi 3 chiing PCV2b (JMS, SH, JF) tir Trang Qu6c la 98,8 - 99,5 %. Tim chiing PCV2 con l!ii gom 7 chung phan l(lp tii Ddng Nai va 1 chiing phan IJp tit Tp.HCM thuQC PCV2d. Bo tuang dong gifta cic chiing trSn khi cao tit 99,5 d^n 100%. Trong dd cic chiing DNTBHT2F, DNTBY5, SGCCTT2, DNTBH22, DNTBH28 v4 DNTBHA2 giong nhau 100%, 2 chOng DNTBH34 v4 DNTB47 tucmg ddng so vdi 6 chiing tren l i 99,7%. dd tuong ddng ciia 2 chung DNTBH34 v4 DNTB47 14 99,5%. DO tuong d6ng ciia cdc chung PCV2d phan lip tji D6ng
KHOA HQC KY THUJLT T H O Y TAP XX S 6 1 - 2013
Nai vd TP.HCM so vdi cdc chiing phan Tnmg Qudc frong ndm 2008 (AH, BDH, MDJ) kha cao tir 99,1 din 99,3 %. Dp tuong ddng di fruyin rdt cao gifta cdc chung PCV2b vd PCV2d thu dupe d Vi^t Nam so vdi cdc chiing phdn Idp tgi Trung Qu6c cho thdy ngu6n goc di truyin ciia chiing rat gan nhau. D§c bi?t sy tuong ding di truyin 100% ciia edc chiing DNTBHT2P, DNTBY5, SGCCTT2, DNTBH22, DNTBH28 vd DNTBHA2 thu dupe tir cdc frgi khdc nhau vd d 2 viing dja ly khdc nhau (Tp. Hd Chi Minh, ehiing SGCCTT2, vd D6ng Nai, cdc chiing edn Igi) cho thdy sy mua bdn, frao ddi heo Id mdt frong nhftng nguydn nhdn quan frpng frong phdt tdn, Idy nhiem mam b?nh, frong dd cd PCV2.
Mdt khdc, tai ciing mpt trgi cd sy hi$n di?n ciia 2 subgenotype PCV2b vd PCV2d. DO tuong ddng di truydn giiia 2 subgenotype PCV2b vd PCV2d eiia cdc ehiing vao khoang 94,4% - 94,8%, frong khi dd sy tuong ddng di truyen frong Cling subgenotype tii 99,5 - 100%. Dieu nay cho thay cd sy bien ddi di truyen quan frpng ciia PCV2 nhiem fren heo. Neu nhu tai Hpi nghi vl PCV2 d chau Au nam 2008, PCV2 chi dugc phdn chia thdnh 3 subgenotype PCV2a, PCV2b vd PCV2c thi frong nghien ciiu ciia Long vd ctv, 2010, PCV2 dd dupe chia thdnh 4 subgenotype PCV2a, PCV2b, PCV2c va PCV2d. Ngay sau do, tai Thdi Lan, Jantafong T. vd ctv., 2011, da xdc dinh them mgt subgenotype mdi PCV2e.
Dogn ADN dugc gidi trinh tu ndm frong ORF2 mang gen quy djnh tdng hgp ndn protein Cap ciia PCV2. Cap protein la thdnh phan protein edu tnic chinh cua PCV2 va Id khdng nguydn gay ddp ling mien dich bdo hO ddi vdi virut PCV2. Su biln ddi di truyin ciia 0RF2 cd thi dan din su thay ddi ddc dilm protem Cap, ddc dilm khdng nguyen cua PCV2. Guo et ai, 2011 bdng ky thuat ELISA, vdi khang thi trung hda don ddng, da ghi nhgn sy khac biet vl khang nguydn giiia cac chung PCV2 thupe cdc genotype khdc nhau. Dieu ndy cd thd la mpt thdch thurc cho chiln lupc kiem soat bdnh do PCV2 bdng vacxin. Vd tinh hinh sd cang phiic tgp hon khi frong ciing mot frai c6 sy hien didn nhilu genotype c ^ PCV2.
tgi IV. KET LUAN
PCV2 hi$n di^n trdn ddn heo cua Vi$t Nam cd it nhat Id 2 kilu genotype PCV2b vd PCV2d, trong dd PCV2d chilm da so trong cdc mau khdo sdt (8/13 mSu, tuong duang 61,34%). Cdc chiing PCV2b vd PCV2d trong nghidn cim diu cd tinh tuong ding di truyin cao vdi edc chiing PCV2b vd PCV2d phan Igp tgi Trung Qu6c tii ndm 2004 - 2008. Sy da dgng kieu genotype ciia PCV2 nhilm d cdc frgi chdn nudi heo eiia Vi^t Nam Id m^t thyc tl, cd thi dnh hudng din hi?u qud cua vi^c kilm sodt b?nh do PCV2 bdng vacxin. Vi thi cdn cd nhthig nghien eim di^n rgng vd sau hon ca ve khia canh dich te, di truyen va mien dich cua PCV2 tren cdc frgi chdn nudi heo d Vidt Nam de cd thi xdy dyng bi§n phdp kilm sodt hidu qud b§nh do PCV2 gay ra.
T A I L I E U T H A M K H A O 1. Baekbo P., Kristensen C, S., Larsen L.
E., 2011. Epidemiology and confrol of porcine circovirus diseases with focus on postweaning muitisystemic wasting syndrome. 6-th International Symposium on Emerging and Re-emerging Pig Diseases, Barcelona 12-15 June, 2011.
2. Grau R. L., Crisei E., Sibila M., Lopez S. S., Nofrarias M., Cortey M., Fraile L., Olvera A., Segales J., 2008. A proposal on porcine circovirus type 2 (PCV2) genotype definition and their relation with postweaning muitisystemic wasting syndrome (PMWS) occurrence. Vet. Microbiol., 128:23-35.
3. Kwang Soo Lyoo, Hyeun Bum Kim and Han Soo Joo, 2008. Evaluation of a nested polymerase chain reaction assay to differentiate between two genotypes of Porcine cireovirus-2. Journal of Veterinary Diagnostic Investigation Vol. 20, Issue 3, 283-288.
4. Long J. Guo, Yue H. Lu, Yan W. Wei, Li R Huang, Chang M. Liu. Porcine circovirus type 2 (PCV2), 2010. Genetic variation
KHOA H Q C KY T H U A T T H O Y TJiP XX S 6 1 - 2013
and newly emerging genotypes in China.
Virology Journal. 7:273=
5. Long J. Guo, Yue H. Lu, Li R Huang, Yan W.
Wei, Hong L. Wu and Chang M. Liu. 2011.
First construction of infectious clone for newly emerging mutation porcine circovinis type 2 (PCV2) followed by comparison with PCV2a and PCV2b genotypes in biological characteristics in vitro. Virology Journaly 8:
291.
6. Mankertz A., Mankertz J., Wolf K. and Buhk H. J.. 1998. Identification of a protein essential for replication of porcine circovims.
Journal of General Virology, 79. 381-384.
8. Nguyen Thj Thu Hdng, Le Thj Thu Phuong, Ddng Hiuig, Nguyen Tiln Hd, Nguyen Ngpc Hdi. Chris. J. Morrissy, Darren Schafer, 2008. Phdn tich di truyen porcine circovirus
type 2 trdn heo d Nam Vi§t Nam. Tgp chi Khoa hQC vd kp thugt thti y, XV, 2.
9. Olvera A, Cortey M, Segales J., 2007.
Molecular evolution of porcine circovirus type 2 genomes: phylogeny and clonality../
^7ra/., 357: 175-185.
lO.TIppawan Jantafong, Alongkot BOOD- soongnern, Pariwat Poolperm, Kitcha Urairong, Chalermpol Lekcharoensuk, Porntippa Lekcharoensuk, 2011. Genetic characterization of porcine circovirus type 2 in piglets from PMWS-affected and-negative farms in Thailand, l^rology Journal, 8:88.
Nh§n ngdy: 6-11-2012 Phdn bi^n ngdy: 12-11-2012
Lfe T R A O B A N C T i t N Sl C U A V l f N T H t l Y NAM 2012
Ngay 19/11/2012, CCT s6 dio t^oVi^n Thiiy da t6chCrc iS trao bfimg, h^c Vj tidn si cho cac nghi&i cuu sinh di hoan thanh vi?c bao v^ luan ^ tien sT clp Vi^n nam 2012 PGS.TS Phumg Quoc Chuong - Vi^n tnrong dS neu 1^
thinh tich 20 nam ve dio tao hpc vj tien si ciia M^n Thii y, m$t co sd dio t^o ehuyen ng&nh dly uy tin. Cho din nay Vi?n Thii y da dio t?o dugc 72 tien sT. nhilu nguin Irong s i d6 dS phit huy tflt kiln thirc da dugc dio t?o trong nghien cmi ichoa hpc. trong phyc vy th\tc tien sin xuit, mpt s l ngain iucjc p h ^ c6ng giO vj tri lanh d^o quan irpng trong nginh Nhin chung nhihig ngufri sau khi n h ^ hpc vi tien sT t^i co s6 dio t?o ciia V i ^ da dong g6p hit siic hi?u qua cho sir nghiep phit tiien kinh te. xa h^i lim dn djnh vi phtit trien nginh thu y, chin nuoi noi neng vi dit nuoc n6i chung.
PGS TS Phiing Qudc Chu&ng dgc dien vdn
Cdc tdn lien sT vd dgi bieu chyp dnh luu nifin
Quyet dfnh cua BO tnrdng B$ Giio dye vi Dio t^o da dugrc trao cho 3 t&i tiln sT: TS. Nguyen Nhto Limg (Chi eye thu y Bic Ninh). TS. V6 Thinh Thin (Ph^in vi^n thii y Miln Tnmg) vi TS. U Vin Son (Tning tSm ki6m nghi?m thuoc thii y tning uong 2).
D91 dien nh6m tfln tien sT, TS. U Yin Scm phit bilu cim on co sd dio t ^ , cic th^y, c6 giio hirdng din vi cim on ^ t ci cac don vi, th chuc, T^p chf KHKT thii y.... dS giup dd nghifin ciJru sinh thyc hi|n thinh cdng lu|n in tien st de c6 vinh danh ngiy hdm nay.
