MOT SO DAC DIEM DjCH TE HOC BENH
S U Y I NLON VA LJfNG DUNG KY THUAT SEMI-NESTED PCR XAC DINH MYCOPLASMA HYOPNEUMONIAE
U Vin Lanh', Huynh ThfMjiLf', Trinh Dinh Thau', B0ng HO-u Anh'. DSNgpc Thiiy^ vd Nguyin Bd Hiin'
T6M TAT
Nghien ciru dupc tiln hanh t^i 4 tinh/thanh pho la Hd Npi, Bdc Ninh, Hung Yf n vd Hdi Duong nhdm dilu tra mpt so ddc dilm djch tl hpc ciia bfnh suyIn Ipn. Kit qud cho thiy: tren dja ban cd 4 tinh dilu tra diu luu hanh bfnh suyIn lpn vdi ty If mdc dao dpng tir 19,92 - 21,16%. Ve liira tuoi mdc bfnh: giai doan Ipn tir 9 - <14 tuan tuoi mdc cao nhit (36,57%). Ipn ndi va lpn con theo m? cd ty If mdc thip (0.24 - 2,73%); Tuy nhien. Ipn con mdc bfnh thudng cd ty If tiir vong cao, Ipn ndi mdc bfnh thudng d thi man tinh va khdng cd tOr vong. Ddc bift khdng phdt hifn dupc bfnh d Ipn dye giong. Bfnh suyIn cd tinh chat raiia vy. xdy ra nhilu vao thdng 2, 3. 4 vd thdng 10. 11 trong ndm. Phuong thiirc chdn nudi khdng dnh hudng tdi ty If mdc bfnh. Cfng dyng ky thudt semi-nested PCR dd budc diu xdc djnh Mycoplamsa hyopneumoniae trong 10/16 mdu bfnh pham.
TCr khoa: Bfnh suyIn Ipn, Ddc diem djch tl, Ky thuat semi-nested PCR. Mycoplasma hyopneumoniae.
Some epidemiological characteristics of the enzootic pneumonia of pigs and application of the semi-nested PCR for detecting Mycoplasma hyopneumoniae
Le Van Lanh, Huynh Thi My Le. Trinh Dinh Thau, Dang Huu Anh, Do Ngoc Thuy and Nguyen Ba Hien
SUMMARY
A study was conducted in 4 provinces (Ha Noi, Bac Ninh, Hung Yen and Hai Duong) aiming at identifying epidemiological characteristics of the enzootic pneumonia of pigs. As a result, the prevalence of the disease was found high in all the 4 studied provinces varying from 19.92 to 21.16%. Conceming the age of the infected pigs, the highest prevalence (36.57%) was found in the pigs from 9 to 14 month old, a lower prevalence (0.24 - 2.73%) was found in other pig categories. However, the acute disease and high mortality was found in the younger pigs. The disease was not observed in the boars. The disease beard the seasonal character and occurred mainly in February, March, April. October and December. The relation between the prevalence and the husbandry methods was not found. The application of the semi-nested PCR has preliminarily identified M. hyopneumoniae in 10 of 16 pathological samples.
Key words: Enzootic pneumonia. Epidemiology, semi-nested PCR, M. hyopneumoniae.
' Khoa thu y, Dai hoc Nong nghiep Ha Npi.
'^ Vi$n thu y qudc gia.
KHOA HQC KY THUAT THU Y TAP XIX S 6 2 - 2012
I. DAT VAN D ^
Bfnh suyIn Ipn {Enzootic pneumonia) hay cdn gpi Id djch viem ph6i dja phuong ciia Ipn Id mOt bfnh truyen nhilm thudng d thi m?in tinh vd luu hanh d m^t dja phuang do Mycoplasma hyopneumoniae (MH) gay ra. Ddy Id mOt thu|it ngQ- dupc su dyng nhilu nhit do nd dupc md td theo ddc dilm djch tl hpc cua bfnh. Theo Thacker (2006). djch viem ph6i dja phuong Id kit qud ciia sy nhilm M. hyopneumoniae vd nhChig vi khuin cpng phdt khde nhu Pasteurella multocida.
Streptococcus suis. Haemophilus parasuis hay Actinobacillus pleuropneumoniae. Bfnh do M.
hyopneumoniae gay ra dupc coi Id nguyen nhdn tien phdt gay bfnh dudng hd hip phirc hpp d Ipn (Porcine respiratory disease complex - PRDC), gdy thift h^i ndng nl cho ngdnh chdn nudi Ipn. Lpn bj bfnh chdm Idn, tieu t6n thirc dn cao, thdi gian v6 beo k^o dai (ngudi ta dd xdc djnh dupc: so vdi lpn khoe. lpn bfnh tdng trpng hdng ngdy kfm it nhit 16% vd tieu ton thiirc dn cho 1kg tdng trpng tdng trfn 25%). Vifc phdng vd trj bfnh cung rit tdn kem. Bfnh cd the dupc chin dodn so bp cdn cOr vao mpt sd trifu chiimg vd bfnh tich ddc trung nhu: Lpn khd thd, thd thi byng, ngoi thd nhu ehd ngoi, ho nhilu vao sang sdm hodc chilu mu^n, benh tich viem ddi xiimg d cdc thiiy phoi. Mdc dii vay, chin doan trong phdng thi nghifm dl xdc djnh Mycoplasma mdi thyc sy cd y nghTa trong gidm sat djch bfnh.
Bdi bdo ndy nhdm cung cip thdng tin vl mOt sd ddc dilm djch tl bfnh suyIn lpn t^i m^t s6 tinh miln Bdc Vif t Nam; ciing vdi ky thu^t semi- nested PCR giiip chin dodn bfnh, gdp phin h^in chl thift h^i do bfnh gdy ra.
n. VAT LI$:U VA PHUONG PHAP NGHlfcN ClJu 2.1.V|tlifu
Bdng so lifu dilu tra tinh hinh djch bfnh t^i cac trai
- Philu dilu tra tinh hinh djch bfnh
- Mau xft nghifm gom phoi, h^ich lam ba, dich ngoay mui hodc djch ngody hiu hpng.
Nguyen vat I ifu va thilt bj trong phdng thi nghifm diing cho phdn img PCR.
2.2. Phirong phdp nghiSn cihi
Phuorng phdp diiu tra dich ti hgc hSi cAu vd diiu tra dich ti hgc md td: sOr dyng philu dieu tra vd phdn tich s6 I ifu djch tl theo Toma vd cs (1999) Djnh hudng dilu tra t^i cdc hO chdn nu6i nhd If (chdn nudi 1 lpn ndi hodc dudi 5 Ipn thjt) vd chdn nudi bdn cdng nghif p cd tong dan tir 5 din 50 con.
Phu ffng phdp ihy mSu: theo quy trinh ciia FAO (Alton vd cs. 1994).
Phuang phdp semi-nested PCR xdc dinh M. hyopneumoniae (theo quy trinh cQa Phdng thi nghifm virut hpc, Trudng d^ii hpc thii y, Dai hpc qu6c gia Seoul) nhu sau:
Bfnh phim dupc d6ng nhit bdng coi chay sir vd pha vdi nudc sinh ly thdnh huyIn djch bfnh pham 10%. Ly tdm huyIn djch d 4000 vdng/phiit trong 5 phut. Thu djch ndi.
* Tdch chiit ADN
Liy 200^1 cho vdo 6ng Eppendorf s^ch.
Them vdo SOOfil dung djch ly giai miu va 8^1 Proteinase K.
U 56°C trong 90 phiit.
Cho vao ong Eppendorf dyng miu da dugc dung gidi (ndi tren) 200^1 dung djch PCI (Phenol Chloroform Isoamyl).
Vortex trpn mau.
Ly tam 12000 vdng^hiit trong 15 phiit d4"C.
Liy 450^1 djch n6l phia tren.
- Them vdo 450nl isopropanol (ly I?
isopropanol: m5u= 1:1).
Tua ADN d nhift dO phdng (25T) trong vdng 15 phiii.
Thu c ^ ADN bdng cdch iy tam 12000 vdng/phiit trong 15 phut d 4''C.
D 6 bd dung djch phia tren, giO' cdn sau ly tam.
Rua ADN bdng chn 70%: Iml/mlu.
Ly tam thu cdn d 12000 vdng/phiit trong 15 phutd4*'C.
- Lo^i bd hodn todn c^n, giOrcdn ADN.
De khd ttf nhien is nhift dO phdng/15 phiiL Hda tan ADN thu dupc bdng 30fil TE buffer.
* Thirc hi^n phdn vmg PCR
Thanh phin phdn img semi-nested PCR:
Phdn img PCR vdng ngoai:
Sinh phim/hda chat i-Star master mix solution MHP950-1L(10pmol/nl) MHP950-1R(10pmol/nl) Spi khudn ADN
Tdng th^ tich
Th4 tich (pi) 17
1 1 1 20
Phdn umg PCR vdng trong:
Sinh phim/hda chit i-Star master mix solution MHP950-1L(10pmol/ul) MHP950-2R (lOpmol/ul) San phim PCR vdng ngodi
Tong t h i tich
T h i tich (pi) 17
1 1 1 20
Chu trinh nhift phdn iimg PCR vdng ngoai, PCR vdng trong
Giai doan Bien tinh PCR Keo dai cudi cung GiQ-
Budc
Bien tinh B i t moi Keo ddi
Nhi^t dp
rc)
94 94 52 72 72 4
Thdi gian (gidy)
300 30 30 90 600 Cho d i n khi dirng
So vdng phan U'ng
1 35
1
* Kiem tra kit qua phdn img
Sdn phim phdn umg PCR (vdng ngodi vd vdng trong) dupc difn di tren th?ich agarose 1% (pha trong dung djch TBE IX), trong vdng 30 phiit d hifu difn thi lOOV. Xdc djnh v^ch d$c hifu tren hOp den tiir ngoai (dya vdo kich thudc v?ich dupc nhan len so vdi kich thudc thilt kl).
Phuong phdp xir Iy s6 lifu: phuang phdp thing kf sinh hpc, siir dyng phin mem Excel 2007. WinEpiscope 2.0 vd Minitab 14.
2.3. Dja dilm nghien curu
Dilu tra tinh hinh djch tl bfnh suyIn Ipn tai mpt s6 trai Ipn thuOc dia ban 4 tinh/thdnh ph6 ding bdng sdng Hong Id Ha Npi, Bdc Ninh.
Hung Yen va Hdi Duong.
MIU xft nghifm dupc thyc hien tai Bp mdn vi sinh v$t - truyf n nhilm, Khoa thu y, Trudng dai hpc Ndng nghif p Ha Npi.
i n . K I T QUA VA THAO L U i ^
3.1. Mpt so d|c diem djch te bfnh suyen Ipn
^h nghien curu ddc difm djch te bfnh suyIn d dan lpn, chiing tdi tiln hdnh dilu tra bang cdc philu dieu tra va chin doan bfnh suyIn Ipn dua vdo trifu chung lam sang, bfnh tich ddc trimg.
Kit qua dupc thi hifn d hinh 1.
Hinh 1. Tri^u chirng va bfnh tich ddc trung cua Ip'n nghi mdc suyIn Ip'n
KHOA HQC KY THUAT THU Y TAP XIX S6 2 - 2012
Trifu chimg lam sdng ciia Ipn nghi mdc suyen Ipn bao gdm: (1) Hdt hoi, ho khan, hay ho khi vdn dOng, thudng ho vdo buoi sdng sdm vd chieu tdi hay khi trdi l^inh; (2) Thd khd, thd khd khf vd thd thi byng; (3) Sot. kf m dn, Idng xii.
Bfnh tich djc trung tdp trung d bO mdy hd hap vd h^ch phii: Vifm phoi thiiy, tir thiiy tim sang thiiy nhpn, tir thiiy dinh sang thiiy sau, thudng viem d phdn ria thip ciia phii, vifm dii ximg cdc thiiy vdi nhau d hai Id phii. Phii xuit hifn nh&ng chim dd hodc xdm bdng h^t ddu xanh. to din rli tdp trung thdnh tirng viing rpng. ChS phoi cd thi viem ciimg l^i, mdu xdm nh^t hay dd nhu mdu mdn chin, mdt phoi bdng
Idng, ben trong cd chira chit keo nen gpi la vifm phii kfnh. Khi bj viem ndng, phoi eirng, d$c l^i nhu bj gan hda, Iiic nay khi cdt phoi chi cdn mpt (t djch trdng xdm lin bpt. Phoi bj nhyc hda, dye mdu tro, ehdc khi bilu hifn gan hda, liic ndy cdt milng phii thd xuing nudc thiy milng phii chim.
3.1.1. Ty l^ mdc h^nh suySn ldn tren dia bdn nghien ciru
Kit qud xem bdng 1.
Bdng 1. Kit qud diiu tra ty 1$ Ip'n nghi mdc b^nh suyin theo dja phu'onig
Dia phuang Ha Ndi
Bdc Ninh Hung Yen Hai Duong
Tdng hpp
S6 Ipn dupc diiu tra
5326 4873 5044 4770 20013
S6 Ipn nghi mic bfnh
1127 978 1005
958 4068
Ty If mic (%) 21,16 20,07 19.92 20.08 20.33
S l l p n tu vong
144 103 114 126 487
Tylf i tu vong (%) !
12.78 ! 10.53 1 11.34
13.15 11,97
Bdng I cho thiy, qua dilu tra, theo ddi tong sd 20013 con lpn tai 4 tinh, thanh pho thi ty If nghi mdc suyfn lpn trung binh la 20,33%, ty If nay khdng cd sy chenh If ch ddng kl (P > 0,05) giCTa cdc tinh/thdnh phd do cdc tinh, thanh phi cd dilu kifn vl khi hdu, thdi tilt, ddc dilm vl chdn nudi thu y cd nhieu sy tuong dong:
Himg Yen cd ty If mdc thap nhit vdi 19,92%, trong khi dd thdnh pho Ha Npi cd ty If mdc cao nhit la 21,16%.
3.1.2. Ty 1^ Ifrn mdc bfnh suyin theo lira tuSi Bfnh suyIn Ipn thudng dien biln rat khac nhau d cdc liira tuoi, xuit phdt tir ddc diem djch tl dd, chung tdi cd tiln hdnh dilu tra ty if mdc bfnh d cdc giai doan tuli: 0 - <3 tuin tuli. 3 - <9 tuan tuoi, lpn choai tir 9 - <14 tuin tuli, Ipn thjt tir 14
<19 tuin tuoi, Ipn hdu bj, Ipn ndi sinh sdn va lpn dye giong.
Kit qud dilu tra dupc thi hifn d bdng 2.
Bdng 2. Kit qud diiu tra ty If l^n nghi mdc b^nh suyin theo li>a tu6i
I Lira tudi Ipn Lpn con theo me (0- <3 tuin) Lpn sau cai su'a (3- <9 tuin) Lpn choai (9- <14 tuin) Lpn thjt (14-19 tuin) Lpn hdu bi
Lpn ndi sinh san Lpn dye gilng
Tong hpp
S6 Ipn dupc diiu tra
4977 5648 3785 3236 1437 836
94 20013
S i l p n nghi mic bfnh
136 1108 1384 1140 298
2 0 4068
Ty If mic
(%) 2,73 19.62 36.57 35,23 20,74 0,24 0.00 20.33
S i l p n tu vong
35 187 196 57 12 0 0 487
Tylf tu vong (%)
25.74 16.88 14.16 5.00 4.03 0.00 0.00 11.97 J
Qua bdng 2 cho thiy, d giai do?in lpn choai vd lpn thjt (tir 9-19 tuan tuoi) cd ty If mdc cao, tir 35,23 - 36,57%, giai doan cd ty If mdc thip la lpn nai sinh san 0,24% va lpn con theo m? (0- <3 tudn tudi) 2,73%, rieng lpn dye giong khdng phdt hifn bj mdc bfnh suyln. Tuy nhien, ty If tiir vong d giai doan Ion con theo m? I^i chilm ty If cao nhit 25,74% va ty If nay gidm din theo lira tuoi:
lpn sau cai su:a (3- <9 tuin) ty If tiir vong 16.88%.
lpn choai (9- <14 tuin) 14,16%. Khdng phdt hifn d giai doan lpn ndi sinh sdn va lpn dye gidng cd hifn tupng tu vong do bj mdc bfnh suyln.
Theo nhan djnh cua chung tdi, ty If mdc vd ty If tir vong do bfnh suyln d cdc lua tuli nhu sau:
Giai do?ui Ipn con theo m? (0- <3 tuan) cd ty If mdc thap la do thdi gian ndy lpn con tilp xuc it vdi mdi trudng ben ngodi, khang thi do Ipn m? truyin sang lpn con vdn cd khd ndng chong l^i dupc vdi benh trong mpt khodng thdi gian xdc djnh. Tuy nhien. d giai do^n ndy lpn con gdp phdi rat nhieu dieu kifn bat lpi (thfch nghi vdi mdi trudng mdi, dinh dudng, khi hdu...) nen nhihig con lpn da bj mdc benh thi khd ndng tiir vong la rit Idn (25,74%).
Nhumg giai doan vl sau, tir 3 19 tudn, do Ipn dupc tilp xuc nhieu vdi mdi trudng ben ngodi, ddc
bift Id trong dilu kifn chuing tr^i mit vf sinh, dilu kifn chdm sdc khdng ddm bdo hodc do mdi trudng chuong nudi dd cd bfnh nen lpn rit dl man cdm vdi bfnh. Tuy nhifn, giai do^in ndy sire dl khdng cung dd dupc tfch Iiiy, thich nghi din vdi mdi trudng sing ben ngodi nf n ty If tir vong gidm tir 16,88% d giai do?in 3 - <9 tuin xuong cdn 5% d giai do?in 14 19 tuin tuli va cdng ve sau, giai doan Ipn ndi sinh sdn vd lpn dye giong, ty If nay gidm din, mOt sl con tao ra khdng thi ty nhien chIng l^i dupc bfnh. Kit qud dilu tra cua chung tdi cung phil hpp vdi kit qud nghien curu dd cdng bl cua Cii HQru Phu va cpng sy (2005).
3.1.3. Ty If mdc b^nh suyin theo th&i gian diiu tra
Trong qua trinh nghien cOru dl tai, chung tdi chia thdi gian theo ddi tinh hinh bfnh tir thdng 1 den thdng 12, tir dd cd thi ddnh gid dupc djch bfnh thudng xdy ra vdo thdi diem ndo trong ndm. Dya tren cdng thiirc tfnh chi sd mdc bfnh trung binh ngdy/thdng, chiing tdi xdc djnh dupc djch xay ra Ie te trong ndm hay djch xay ra dupc coi la thang djch hay thanh timg dpt djch khac nhau (miia djch). Ket qud dieu tra dupc thi hifn d bdng 3.
Bang 3. Kit qua xac djnh ty If l^n nghi mic bfnh suyln theo thdng diiu tra Thang
1 2 3 4 5
L ^ h 7
' 9
1 '
10 11 12 Tdng hpp
So Ipn dieu tra
1152 1880 1867 2015 1067 1589 1697 1735 1566 2034 1987 1424 20013
So Ipn nghi mic
308 588 557 584 120 162 298 237 191 375 367 281 4068
Tylf mic (%)
26.74 31.28 29.83 28,98 11.25 10,20 17.56 13,66 12.20 18,44 18.47 19.73 20.33
Sllpn to vong
45 93 98 91 7 6 13 14 13 34 38 35 487
Tylf tir vong
14,61 15.82 17.59 15.58 5.83 3,70 4.36 5,91 6,81 9.07 10,35 12.46 11.97
Hf so thdng dich
0.891458 1,884218 1,61215 1,74664 0.347321 0.484513 0.862515 0.68596 0.571247
1,085379 1,097632 0,813311
1 Ghi chu
1 1
Thdng dich Thdng dich Thdng dich
Thdng dich Thdng dich
Qua bdng 3 cho thiy, djch bfnh xdy ra nhilu nhit vdo thdi dilm thdng 2 vdi ty If mdc 31,28%, thdi dilm thang 3, 4, 10 vd thdng 11 cung mdc vdi ty If kha cao, lin lupt la 29,83%; 28,98%;
18,47% vd 19,73% vd cimg cd cac thang lien tilp
cd hf so thdng djch > 1, nhu vfy chung tdi coi day Id cdc miia djch trong ndm. Theo nhan dinh ciia chiing tdi, vao thdi dilm tir thdng 2 din thdng 4 dang Id miia ddng, thdi tilt lanh keo dai kem theo cdc dpt gid miia ddng bdc dl gay tin thuong
KHOA HQC KY THUAT THU Y TAP XIX S6 2 - 2012
cho phoi, t^o dieu kifn cho vi khuan gay viem, mdt khde thdi tilt lanh cung thfch hpp cho cdc loai virut. vi khuan ton tgi va phdt triln. ddc bift la Mycoplasma. Ngupc l^i vdi khodng thdi gian tren, djch bfnh xdy ra it nhit vdo thdi dilm thdng 6 vdi ty If mdc Id 10,20%, ty If tur vong 3,70% vd ciing vao khodng thdi gian tir thdng 5 9, djch bfnh .xay ra vdi ty If thip tir 10.20% din 17,56%, vdi ty If tOr vong tir 3.7% din 6.8%. Theo chung tdi. vao khodng thdi gian ndy, thdi tilt ndng ndng da tao dieu kifn bat loi cho sy lay Ian vd phdt trien ciia vi khuin. mdt khde sire de khdng ciia Ion tot do vdy Ipn it cam nhiem vdi bfnh. khodng
thdi gian ndy diu cd hf so thdng djch < I. chiinj tdi coi ddy Id cdc dpt dich 16 Xk. trong ndm.
3.1.4. Ty 1^ mic b^nh suyin theo phuffng thuc chdn nudi
Trfn CO sd djnh hudng quy md cua dl tai, chiing tdi t$p trung vdo dilu tra cdc hp chdn nu6i theo hai phuang thiirc Id chdn nudi nhd Ie vd chdn nudi bdn cdng nghif p, day Id hai phuang thirc chdn nudi dang tin tai phi biln d Vift Nam n6i chung vd tai cdc noi thuc hifn dl tdi ndi rieng.
Kit qud duoc thi hifn d bdng 4.
Bdng 4. K i t qud d i i u tra ty If Ipn nghi mdc b f n h suyin theo phinrng thi>c chdn nudi Phuong thu-c chdn nu6i
Chdn nu6i nho Id
Chin nuoi bdn cdng nghif p
s l Ipn dupc diiu tra
3578 16435
S l l p n nghi mic
558 3510 Tong hpp 20013 | 4068
Ty If mic (%) 15.60 21.36 20.33
S l l p n tu vong
79 408 487
Tylf tu vong (%)
14.16
1
11,62 11.97 1
1
Qua bang 4 cho thdy, doi vdi phuong thiirc chan nudi ban cdng nghifp, ty If mdc 21,36%, cao hon so vdi phuong thiirc chdn nudi nhd le (15,6%). Phuong thirc chdn nudi ban cdng nghif p cd ty If mdc cao Id do cd ehudng tr?i kfn, chdt, thap, mdi trudng tilu khf hau chuong nudi bj d nhiem. khdng cd sy luu thdng khdng khf nen lupng khf thai tdn tai nhieu trong ehudng, ddy la nguyen nhan ldn gay ton thuong phdi cung nhu dudng hd hip, tir dd t^o dieu kifn cho vi khuan Mycoplasma gay bfnh va mpt sl yi khuan khde xam nhap vdo co thi Ipn. gay nen hifn tupng viem phii. Ngupc I?ii, vdi phuong thiirc chdn nudi quy md nhd, Ie (quy md hp gia dinh chdn nudi I lpn ndi hodc 3 5 con Ipn thjt) do chuong trai thdng thoang, mdt dp nudi thudng thua hom nen cd ty If mdc thap. Ty If tir vong ciia phuang thirc chdn nudi nhd Ie Id 14,16% so vdi phuong thiirc chdn nudi ban cdng nghifp (11,62%). Tuy nhien, qua kit qud tfnh ty suit chenh giOra hai phuong thirc chdn nudi (OR = 0,68) chung tdi kit lu§n khdng cd sy sai khac vl ty If mdc bfnh gida phuong thuc chdn nudi nhd If vd phuang thuc chan nudi ban cdng nghif p vdi P < 0.001.
3.2. Ket qua xet nghifm PCR vdi mpt so mau bfnh pham nghi mdc bfnh suyln Ipn
Chung tdi lay mpt sd mau phdi Ipn cd bieu hifn bfnh tfch dai the ddc trung ciia Ipn bj mdc suyln va tien hdnh chin dodn xac djnh sy cd m$t ciia Mycoplasma hyopneumoniae bdng ky thudt semi-nested PCR. Kit qud thi hifn d hinh 2 cho thdy cd 10/16 miu duong tinh. chifm ty le 62,5%. Mdc dii phdn iimg PCR cd dp nhay va dp chfnh xac cao trong chin doan bfnh, vifc th\rc hifn phdn img PCR thdng thudng dl xdc dinh MH Id tuong doi khd khdn. Theo chiing toi nguyen nhan mpt phan do trong qua trinh lpn bj bfnh suyln dd dupc ngudi chdn nudi dieu trj vdi nhieu phdc do khde nhau. Qud trinh dilu trj nay dan den vifc gift chet mpt lupng Idn MH d ngoai bao. Hf qud Id lupng MH dirpc dua vdo phdn img PCR rit ft vd vdi mpt phdn img PCR thong thudng sg khd phdt hifn dupc MH. Quy trinh semi-nested PCR dupc thyc hifn vdi 2 vong chfnh la dl khde phye nhupc dilm nay. Theo quy trinh, ADN cua MH ban dau dupc nhan len bdng PCR vdng ngodi (PCR thdng thudng) nhimg chua thi quan sat dupc do cd ft bdn khudn. PCR vdng trong (semi-nested PCR) dupc thyc hifn
vdi ADN khudn chfnh la sdn phim ciia PCR vdng ngoai. Dp nh^y cua phan umg nested PCR da dirpc chung minh la gip hang ngdn lin so vdi
PCR thdng thudng va kit qud mang tfnh chfnh xac cao.
1 2 3 4 5 6 7 8 M M 9 10 I t f ? 1? t ^ fS I f
912bp:
I'PCR
1 2 3 4 5 6 7 8 M M 9 10 11 12 13 14 15 16
863bp:
y^pcR
Hinh 2. Ket qua xac djnh Mycoplasma hyopneumoniae d phoi l p n nghi suyen
Ghi chu: Hinh tr§n: PCR v6ng ngodi; Hinh di/6n: PCR vong trong (semi-nested) M: lOObp DNA marker 1: S I . 2: S2, 3: S3. 4: S4. 5: S5, 6: S6, 7: 87, 8: S8 9: S9,10: 810.11: 811,12: S12.13: S13,14: 814, 15: 815, 16: 816
IV.KfTLUAN
1. Mdt so ddc diem djch tf bfnh suyen Ipn Tren dja ban bin tinh/thanh phd dieu tra diu luu hdnh bfnh suyln lpn, ty If mdc dao dpng tir
19,92-21,16%.
- Trong cdc giai doan sinh trudng ciia lpn thi giai doan Ipn tir 9 <14 tuan tudi mdc cao nhit (36,57%), lpn ndi vd lpn con theo me cd ty If mic thip (0,24 2,73%). Tuy nhien. d Ipn con mdc bfnh thudng cd ty If tiir vong cao. Ion ndi mdc benh thudng d thi man tfnh va khdng cd tiir vong. Ddc bift khdng phdt hifn dupc bfnh d Ipn dye gidng.
- Bfnh suyln cd tinh chit miia vy, xdy ra nhilu vao thang 2,3,4 vd thdng 10, 11 trong ndm.
Phuang thuc chan nudi khdng dnh hudng tdi ty If mdc bfnh.
2. LTng dyng ky thuat semi-nested PCR da xdc djnh dupc sy cd mdt ciia MH trong bfnh phim
cua lpn, giiip chan doan khang djnh va de xuat bifn phdp phdng trj benh cd hifu qua.
TAI LlfU THAM KHAO
1. Cii Hihi Phu, Nguyin Ngpc Nhien, Nguyin Thu Hing, Au Xuan Tuin, Nguyin Bich Thiiy. Vu Ngoc Quy (2005). Xdc djnh nguyen nhan gay bfnh duong ho hap cua lpn nuoi tai mot so tinh phia Bic. Tap chi KHKT thu y 7(4).
2. Alton G.G, G.R. Carter, A.C. Kibor va L. Pesti (1994). Chin doin vi khuan hpc thii y: .so tay chan doan phong thi nghifm mpt sd bfnh chpn Ipc a vat nuoi (FAO Le Dinh Chi va Tran Minh Chau djch). Nha xuit bdn Nong nghif p, tr. 104-141.
3. Thacker E., 2006. Mycoplasmal diseases of swine (Eds: Straw B. E., Zimmerman J. J., D'Allaire S., and Taylor D.J.,) 9"' edition. Blacwell Publishing Ltd., Oxford, UK. pp 701-717.
4. Toma B., B.Dufour, M. Sanaa. J. J. Benct, F Moutou, A. Louza and P. Ellis (1999). Applied veterinary epidemiology and the control of disease in populations. Copyright by AEEMA, 7 avenue du General de Gaulle, 94704 Maisons- Alfort, France.