Phát hiện và sử dụng tính đặc hiệu của lectin để nhận dạng một số vi khuẩn gây nhiễm độc thực phẩm

DAI HOC QUOC GIA HA NOI TRI/CING DAI HOC KHOA HOC TI/NHIEN DETAI PHAT HlfiN VA Sir DUNG TINH DAC HIEU CUA LECTIN ¥)t NHAN DANG MOT SO VI KHUAN GAY N H I £ M D O C T H U C PHAM MA SO: QG 04.12 CHU TRI DE TAI: TS Bui Phuomg Thuan ^^^ HOC n(7?vV^~Tr t>'r/ozzi HA NOI - 2005 1.2 Tinh chat Iy hoa - sinh hoc cua lectin 1.2.1, Cdu tao phdn tvr cua lectin Da so lectin co ban chit la glycoprotein, chi mpt so rat ft la protein dan gian nhu ConA (chiet tir dau rua Canavalia ensiformis D.C) va lectin mam liia mi [21] Thanh phSn ducmg ciia lectin bao gom mannose, glucose, galactose, ngoai co sialic acid (la dSn xu^ft N- acyl ciia neuramic acid) thudng nam a phan cuoi chu5i oligosaccharide cua cac glycoprotein hoa tan Thanh phSn protein gom mot hay nhieu chu6i polypeptide ket hgp lai nhd lien ket cpng hoa tri Lectin ciia m5i loai chiia phan axit amin khac nhau, nhung ph6 bien nha't la aspartic acid, serine, arginine va threonine Cac axit amin chid'm tdi 30% phSn phan tu lectin Trong do, cac axit amin chiia luu huynh nhu cysteine, methionine chi chiem mpt ti le thap hoac hau nhu khong CO phSn lectin Trong phan tir lectin co cac ion kim loai, thudng gap nhat la Mn^"^ va Ca^"*" Cac ion khong true tiep tham gia vao lien ket lectin-dudng, nhung lai rat cin cho su tuong tac vi chiing anh hudng den ca'u hinh khong gian cua phan tir lectin va trung tam lien ket dudng 7.2.2 Khdi luang phdn tucua lectin Cac phirang phap sang lpc phan tu, dien di tren gel polyacrylamide, sieu ly tam cho thay khoi lugng phan tir cua letin dao dpng tir vai nghin Da (8.500 Da d lectin rl cay gai Uricaceat) den vai tram nghin Da (700.000 Da d lectin ciia sam bien chau A Tachypleus tridentatus) [21] Cho den nay, khoa hpc khong tim thay moi lien quan nao giua khoi lugng phan tu va hoat tfnh ciia letin Khdi Iugng phan tir ciia lectin khong mang tfnh dac trung va khong phu thupc vao miic dp tien hoa cua loai hay ca the Do phan tir lectin co the dugc ca'u tao tu nhieu tieu don vi, nen khoi lugng phan tii cua chiing phu thupc ra't nhieu vao ca'u tnic khong gian Cac yeu to lam thay ddi cau tnic khong gian cua lectin nhu: pH, dung dich ure nong dp cao, guanidin clorit ddu co the anh hudng de'n khdi lugng phan tir lectin Vf du ConA d pH trung tfnh co cau tnic tetramer vdi khdi lugng phan tir khoang 102 000 Da, nhung d pH < cau tnic tetramer bi phan ly cac dimer cd khdi lugng phan tula 51 000 Da [21] 1.2.3 Tinh tan cua lectin Lectin co kha nang hoa tan nudc, dac biet lectin ra't dt tan dung moi la mudi loang, vi vay cac nha khoa hpc thudng sii dung cac dung dich d6m chiia mudi d nong dd sinh ly lam dung moi chie't xuat Do ban chat la protein nen lectin dl ke't tiia vdi aceton, alcohol d nhiet dp thap, mot sd mudi trung tinh nong dp cao va mudi kim loai nang [26] 1.2.4 Khd ndng tucmg tdc vdi du&ng cua lectin Kha nang tuong tac vdi dudng la mpt nhung tinh chat dien hinh ciia lectin Lectin cd the lien ket vdi ca phan tu dudng dan lan ca gdc dudng nam tren be mat te bao Cac loai dudng nhu glucose va glucosamine, galactose va galactosamine, fucose, mannose tuong tac vdi nhieu loai lectin [21] Cd ra't nhieu gia thuyet ve ban cha't su tuang tac giua lectin vdi gdc dudng Tuy nhien, cac nha khoa hpc deu thdng nha't cho rang su bin vung cua phiic hgp lectin - dudng dugc tri nhd cac lien ket phan cue (lien ke't hydro giua cac nhdm -OH ciia dudng vdi cac dau phan cue cua cac gdc axit amin tren phan tir lectin) va lien ke't khdng phan cue hay lien ke't khong gian (lien ke't bang luc Van der- Walls) [21] Mankela da phat hien tha'y su khac biet ca'u tnic khong gian d vi tri C3, C4 cua cac loai dudng phan cac loai lectin la nguyen nhan chfnh dan den luc hoa hpc khac cua chiing vdi cac loai dudng [17] Kha nang tuang tac dac hieu cua lectin - dudng da dugc iing dung nhieu cac nghien ciiu te bao hpc, huyet hpc va miln dich hpc Dac biet gan day, nd cdn dugc iing dung de tinh che lectin Nhieu glycoprotein cd chiic nang sinh hpc da dugc tinh che bang phuang phap sac ky luc lectin 7.2.5 Cdc yeu tddnh hudng den hogt tinh lectin Nhung ye'u td cd anh hudng de'n hoat tfnh gay ngung ket te bao (dac tfnh sinh hpc quan trpng cua lectin) la pH, nhiet dp, cac loai dudng, enzyme - Anh hucmg cua pH: Do sir tuang tac cua lectin vdi cac hgp chat dudng (hoac cac thu the) la theo kieu tuang tac luc hoa hpc, gia tri pH cd y nghia dac biet su tuang tac dd Ngoai ra, lectin cd ban cha't la protein, hai gia tri pH can dugc luu y nhieu nha't qua trinh tinh che lectin la pH dang dien va pH tdi thfch - Anh hudns cua nhiet do: Nhi^t dd cung tac dong I6n ciu tnic khong gian bac bdn cua phan tir lectin, lam anh hudng dd'n luc li6n k^t vdi dudng ciia cac trung tam hoat dpng va lam thay doi hoat tfnh ciia lectin Da sd lectin hi ma't hoat tfnh d nhiet dp cao, lien ke't hoa tri cua phan tu hi diit gay khien ca'u tnic khdng gian ciia chiing khdng ihi phue hdi lai (bi bien tinh khong thuan nghich) O nhiet dp thap, hoat tfnh lectin bi giam, tang din nhiet dd thi hoat tinh lectin cung ciing tang din den mpt gia tri cue dai d nhiet dp tdi thich - Phdn img cua lectin vdi cdc logi dudng Khi cd (cac) loai dudng dac hieu, trung tam hen ke't vdi saccharide cua lectin bi phong be lam mit tac dung lien ke't vdi cac thu the tren bl mat te bao, lit dd lam mit kha nang gay ngimg ket ciia lectin - Tdc dung cua enzyme Cac enzyme cd kha nang lam bie'n doi tfnh chat ciia mang te bao va lam thay doi kha nang gay ngung ket te bao cua lectin Mpt sd enzyme nhu trypsin, papain cd tac dung lam tang hoat tfnh ciia lectin Khi hdng ciu dugc xii ly bang cac enzyme nay, mpt sd protein tren bl mat mang te bao hdng cau se bi thuy phan lam bpc Id ro cac thu the cd ban chat la glycoprotein, giiip cho lectin gin vao mang te bao hdng cSu dl dang han, vay se lam tang hoat tfnh ngung ket te bao hdng cau ciia lectin Ngugc lai mpt sd enzyme lai lam giam hoac mat hoat tfnh ciia lectin Khi xir ly hong ciu bang galactose oxidase hoac mot sd glycosidase, cac gdc dudng dac hieu vdi lectin bi phan huy, dd hoat tfnh ngung ke't se bi giam - Anh hudng cua cdc ion kim logi: Mot vai ion kim loai cung anh hudng den hoat tfnh ciia lectin Tac dpng ciia chiing kha phiic tap khdng tuan theo quy luat nao: cd the lam giam hoac tang hoat tfnh cua lectin 1.3 Dac tinh sinh hoc va miln dich ciia lectin 7.3.7 Khd ndng gdy ngimg kei tebdo Gay ngung ke't te bao la dac tfnh sinh hpc dien hinh ciia lectin, dua vao dd ma ngudi ta phat hien lectin d cac ddi tugng nghien ciiu, cung nhu de phan biet lectin vdi nhOng hgp chit sinh hoc khac cung cd kha nang tuang tac vdi dudng nhu glycosidase, glycotranferase [26] De cd the gay ngung ket i6 bao, lectin phai tao nhilu cau ndi giua cac t^ bao bi gin ket Tuy nhien kha nang gay ngung ket khdng chi phu thupc dan thuin vao sd lugng lectin, ma cdn phu thupc vao nhilu ye'u td nhu: dac tfnh phan tiJ ciia lectin, dac tinh mang tl bao (sd trung tam lien ket dudng, kfch thudc phan tii, sd lugng thu the, tfnh chit va tinh trang trao doi chit ciia mang), ndng dp te bao, pH, nhiet dp, chit kich thfch, chit kim ham, ion kim loai [41] Hiu het cac lectin cd kha nang ngimg ket te bao hong ciu ciia ngudi (trong dd sd lectin dac hieu vdi nhdm mau la rit ft), mpt sd cdn cd kha nang ngung ket hong ciu ciia cac dpng vat khac nhu: thd, cCai Ngoai ra, ngudi ta ciing phat hien thiy lectin cdn cd the gay ngung ket ca vi khuin, nim, sinh vat dan bao va cac bao quan (ty the) Chfnh vi vay lectin cd vai trd quan trpng nghien ciiu khoa hpc va y dugc hpc 7.3.2, Khd ndng kich thich vd kim hdm phdn bdo Kich thfch phan bao cung la mpt dac tfnh quan trpng mang lai nhilu iing dung thuc tiln cho lectin Lectin xam nhap vao ca the cd tac dung nhu nhung khang nguyen kich thich su phan chia cac te bao lympho (loai te bao dugc lectin kfch thfch manh nhit), dd giiip cho ca the tang cudng dap iing miln dich Ngoai ra, lectin cdn cd kha nang kfch thfch su phan chia cua nhilu loai te bao khac nhu tebao phdi ga , Cho tdi nay, ngudi ta vin chua biet ro ca che kfch thfch phan bao ciia lectin Cd y kie'n cho rang saccharide tren mang te bao la yeu td kim ham sir phan chia te bao, mpt bi lectin gin vao se bi mit tac dung, dd lam tang kha nang phan chia te bao Tuy nhien gia thiet cling chua that thuye't phue, nhilu lectin lien ket dugc vdi cac phan tu saccharide tren bl mat cua mang song lai khong cd kha nang kfch thfch phan bao Nhung phat hien ve glycoprotein mang te bao chi lien ket chpn lpc vdi nhirng lectin cd kha nang kfch thfch phan bao (Centerlind va cpng sir - 1980) da din den kha nang tdn tai cua nhirng thu the mang dac hieu vdi lectin kfch thfch phan bao [19] Kha nang kfch thfch phan bao cua lectin dugc sir dung cd hieu qua y hpc va miln dich hpc de nghien ciiu cac qua trinh bien doi sinh hoa cua te bao tu trang thai nghi sang trang thai hoat dpng (cd tac dung phan chia te bao tfch cue va gay dap iing miln dich), cung nhu dl nghien ciiu su bit thudng ciia cac nhilm sic the va cac htnh ly khac d ngudi Trong dd, mpt sd lectin lai cd kha nang lic che sir phan chia te bao, nhu kim ham su phat triln va di can ciia te bao ung thu Theo Brucke, dd la cac phan tu lectin da tac ddng den phan tu ADN khdi dpng cho su tong hgp interferon tir te bao chu xam nhap vao te bao ung thu, dd lie che su phat trien ciia khdi u [31] Tren thuc te, su tuang tac giua lectin va cac glycoprotein dugc bieu hien qua su tuang tac ciia cac globulin miln dich (IgG) vdi khang nguyen benh va mpt sd enzyme 7.3.3 Ddp img mien dich Trong nhung nam gin day, hang loat lectin dugc phat hien cd chiic nang sinh ly va dap ling miln dich tren bl mat te bao ddng vat bac cao va ngudi Selectin cd kha nang lien kl^t vdi nhilu chit ket hgp dudng, cd vai trd chii ye'u ket dinh cac te bao npi md mach, kiem soat hien tugng viem va di can ung thu [26] L3.4 Cdc quyei dinh khdng nguyen nhdn biei Lectin cd the tham gia vao viec nhan bie't cac vi sinh vat ciing nhu nhan biet cac te bao cua ca the Kha nang cho phep giai thfch hang loat sir tuang tac giiia cac te bao nhu sir ke't dfnh cua te bao vi khuan vao dpng vat, su lien ke't ciia vi khuan cd dinh dam d rl cua cay hp dau, su tiep can tinh triing vdi tning Nhilu nha nghien ciiu da chi ring, tac dpng cua lectin ngoai sinh len cac te bao dpng vat in vitro cd the gidng nhu tac dpng cua protein lien ket vdi dudng, thudng xuit hien d bl mat ciia nhung te bao lan can [12] Lectin cdn cd vai trd nhu la protein bao ve: bao ve thuc vat viec chdng lai cac tac nhan tac dpng tu ben ngoai, ke't dfnh te bao va gay dpc ddi vdi dpng vat [32] Gidng nhu enzyme, khang nguyen va khang the, lectin cung la nhung protein cd kha nang nhan bie't tinh vi cac hgp chit dudng tren bl mat te bao, vay Cling cd anh hudng de'n viec dilu chinh cac chiic nang sinh ly ciia te bao Lectin cdn cd thi ddng vai trd van chuyen chat du trii va lam nguyen lieu du tru, lam chit trung gian lien ke't giira vi khuin va thuc vat hien tugng cd dinh dam, vf du nhu lectin chiet tir cd ba la cd kha nang tuang tac vdi khang 10 nguyan bl mat te bao vi khuin Rhizobium trifollii, lam ke't dfnh vi khuan vdi t ^ b a o c u a r l c a y l l l , 19,33] 1.4 Mot sd umg dung cua lectin 7.4.7 Trong huyei hpc Six dung lectin de phan loai nhdm mau la iing dung sdm nhit, cho den vin cdn dugc ap dung rpng rai Phuang phap xac dinh nhdm mau bang lectin cho ket qua nhanh, chinh xac ma khdng cin diing huyet miu Tuy nhien phuang phap ddi hdi lectin phai cd dp tinh khiet va tfnh dac hieu cao 1.4.2 Trong te bdo hpc Lectin dugc sir dung nhu mpt cdng cu huu hieu de nghien cihi ciu tnic mang te bao va nhung bien doi tren bl mat mang te bao qua trinh biet hoa benh ly, thdng qua su thay doi phin cabonhydrat tren bl mat te bao 1.4.3 Trong y hpc Lectin dugc sii dung nhu mpt cdng cu chan doan cd hieu qua (dua vao kha nang tac dung dac hieu len mpt sd loai vi sinh vat), ket hgp vdi cac xet nghiem thdng thudng khac de nang cao gia tri chin doan benh True khuan than {Bacillus anthracis) dugc phat hien nhd xet nghiem ELLA vdi lectin dau tuang {Glycin max), hay benh nhan nhilm ki sinh triing san mang {Schistosoma mansoni) da dugc chan doan nhd sii dung lectin Dua vao kha nang luc manh vdi AFP, lectin tir dau lang va tir dau than dd da dugc sii dung de chain doan ung thu bieu md te bao gan [24, 25] Dua tren thuc te lectin thupc hp lan, hp thuy tien cd tac dung kim ham in vitro su phat triln ciia virut HIV nudi cay te bao lympho T- CD"*"" (do ke't hgp duac vdi glycoprotein tren bl mat te bao the chd ciia HIV), hay lectin tir hat mit {Artocarpus heterophyllus) cd the kim ham hien tugng nhilm HIV va han che kha nang mdc benh nhd tuang tac dac hieu vdi phan tu glycoprotein CD^^ d bl mat te bao T cua ngudi (la phan tu ke't hgp dac hieu vdi HIV pha dau cua qua trinh nhilm benh), cd the du doan lectin se trd mpt sinh phim cd gia tri dilu tri va chan doan benh L4.4 Trong vi sinh vgt hpc 11 Do bl mat cua vi khuin mang cac gdc dudng, lectin cd the ket hgp vdi cac vi tri lien kft tilm nang nay, th^m vao dd la tinh dac hieu khien chiing trd cong cu hiru ich vi6c nhan dang vi khuin [11] Do cd kha nang li^n ket vdi dudng va cac hgp chat chiia dudng (thanh phin ciu tao quan trpng lr€n bl mat te bao), lectin cd tilm nang iing dung rat ldn sinh- y hpc [16,20,40] Hiu het viec sir dung lectin nghien ciiu benh ly hen quan den vi sinh vat diu dua tren ca sd phan iing ngung ket chpn lpc Lectin WGA (agglutinin mim cay lua mi) cd the dugc sir dung phat hien cac loai ciia chi Neisseriaceae [32], hay sir dung WGA de phat hien Neisseriaceae gonorrhoeae Viec six dung lectin kit hgp vdi enzyme phii hgp da giiip giam thdi gian thu nghiem ddi vdi Neisseriaceae gonorrhoeae, N meningitidis, N lactamica vd Moraxell catarrhalis Mpt bang chiing khac vl tinh hiiu dung cua cac lectin dugc dua la kha nang gay ngung ket chiing Bacillus, dac biet Bacillus anthracis, bdi vi rat khd de phan biet vdi cac chiing B cereas, B mycoides vd B thuringiensis Phuang phap gay ngung ke't de nhan B anthracis la su dung cac lectin thu dugc tir dau nanh (SBA) va tii dc sen (HPA) Trong cac chung Bacillus, SBA chi ngung ket B anthracis va B mycoides, nhung khdng tac dung len ddi vdi B thuringiensis Han nQa, lectin cdn tac dpng len cac bao tu cua B anthracis Cac ket qua tuang tu cung thu dugc ddi vdi loai B thuringiensis [15, 31] Viec nghien ciiu lua chpn lectin tuong tac dac hieu vdi cac loai vi khuan cd the giiip ich viec dinh danh cac vi sinh vat ]14, 23] 1.5 Dai cuong ve mpt sd vi sinh vat gay ngo doc thuc pham 7.5.7 E.coli Escherichia coli la vi khuan Gram am, hinh que, cd kfch thudc (1,1-1,5) |im X (2-6) i^m thupc hp Enterobacteriaceae la loai yem khf tien Da sd cac vi khuin phat trien khoang nhiet dp tir 5-12" C, cd the ton tai rat lau mdi trudng va nhay cam vdi viec triing, ngoai cdn chiu dugc mdi trudng cd axit va nhiet dp thap tdt han cac vi khuan khac [2] Vi khuin dugc bao bpc bdi mpt he thdng mang va te bao He thdng mang bao gdm mang ngoai va mang Mang dugc cau tao gdm mpt ldp lipid kep day khoang nm cd chiia 40% phospholipide va 60% protein 12 Mang ngoai la ciu tnic Upid kep ciia lipopolysacharide (LPS) va phospholipid LPS dugc ciu tao tii phin: lipid A, mpt chudi dudng phan nhanh va khang nguyen O Thanh phin cdn lai ciia mang ngoai la cac protein [27] Bao bpc he thdng mang ngoai la te bao, dugc ciu tao nen tu peptidoglycan lien ket ddng hoa tri vdi mang ngoai (peptidoglycan la he thdng ciu tao ciia cac polymer lien ket dong hoa tri ciia cac gdc dudng va cac don vi peptide) [27] He thdng cac polymer nim tren mang va vach te bao cd mang cac gdc dudng la ca sd cho viec lien ket vdi cac loai lectin [11] E.coli dMqc phan loai theo tinh khang nguyen ciia chiing, chii ye'u la khang nguyen loai O va H Theo phan loai gin day ngudi ta chia E.coli nam nhdm (chii y^u dua irtn yeu td gay benh, trieu triing lam sang, dich tl hpc va cac typ huyet khac nhau): nhdm gay benh, nhdm sinh dpc td rupt, nhdm xam nhap, nhdm gay dpc td mau va nhdm xam nhap theo dam [27, 35] Do dugc truyln nhilm vao rupt chu yeu tir thuc phim, E coli la nguyen nhan quan trpng gay benh viem rupt, gay viem nhilm tao mu d nhilu nai [27] E coli cd kha nang khang lai cac loai khang sinh cd dien trudc day thudng hay dung de dilu tri benh nhan tieu chay Kha nang ciia chiing cd thi dugc hinh dot bien gen, di truyln qua cac the he, tie'p hgp hoac cac bien ddi va mang te bao [4] 7.5.2 Proteus Proteus la true khuin Gram am, cd long xung quanh than va cd kha nang di dpng, la vi sinh vat hieu khf nhung cd the phat trien mdi trudng ky khf, khdng len men lactose nhung cd kha nang len men mpt sd loai dudng khac, cd sinh hai Proteus gdm bdn loai: P vulgaris, P mirabillis, P morganii va P rettgeri Tuy nhien mpt sd tac gia xep P vulgaris, P mirabillis vao chung mpt loai P haiiseri va dai dien dien hinh ciia Proteus la P vulgaris [27] Dua vao khang nguyen O va H, Proteus dugc chia 100 typ huyet khac Dd la cac vi khuin ca hpi gay viem dudng tie't nieu, nhilm khuin huyet [l] 7.5.3 Pseudomonas aeruginosa 13 True khuin mii xanh la vi khuin gram am cd hinh thing hoac hai cong nhung khdng xoin, hai diu trdn cd kfch thudc tir (0,5 - 1) |im x (1,5 - 5) ^m, cd mgt ldng nhat d mpt cue, cac pili (dai khoang 6nm) la noi tie'p nhan nhilu loai phage va giiip cho vi khuin gin vao bl mat te bao chii [I] Day la vi khuin hieu tuyet ddi, cd the mpc tren mdi trudng thdng thudng khoang nhiet dp tir - 42°C, nhiet dp tdi uu la 3TC va pH tdi thich la 7,2 -7,5 Tfnh chit dac tnmg ciia true khuin mu xanh la sinh sic td va chit tham, vdi hai loai sic td chinh: - Biocyalin cd mau xanh la cay, tan nudc va cloroform, khuech tan tdt mdi trudng lam cho mdi trudng va khuan lac cd mau xanh - Bioverdins la loai sic td huynh quang, phat miu xanh chieu tia cue tfm cd budc sdng 400 nm Pseudomonas aeruginosa la loai vi khuin gay benh cd dilu kien, chiing xam nhap til mdi trudng ben ngoai vao ca the qua cac vet thuang hoac ca the bi suy giam miln dich hay bi mic benh man tfnh Nhiing ngudi diing corticoid keo dai, khang sinh hoac chit chdng ung thu thi dl mdc benh nhilm triing npi sinh hoac ngoai sinh true khuin mu xanh True khuan mu xanh khang lai nhilu loai khang sinh thdng dung (penixilin, ampixilin, cloramphenicol va tetracyclin), d nudc ta cd khoang 407o sd chiing true khuin mu xanh khang dugc gentamycin [ ] 1.5.4 Samonella Samonella la vi khudn Gram (-) hinh que cd nhieu long, kich thudc trung binh x 0,5 j^m, sdng hieu ki tien, phat trien tren mdi trudng thdng thudng Cho de'n da cd han 1800 chung typ huyet thupc loai Samonella [6, 28] Thanh te bao vi khuin Samonella dugc ciu tao tir peptidoglycan va techoic acid Peptidoglycan la loai polyme xdp, khdng tan, dugc tao nen tir aceiylglucosamine, N-acetymuramic acid va tetrapeptide Cac techoic acid la cac polyme lien ket vdi peptidoglycan va mang te bao chat Bao ngoai te bao la mpt ldp lipid kep day khoang 3-7 nm dugc cau tao tir photpholipid, lipoprotein, liposaccharide (LPS) va cac protein [27, 28] Samonella cd mat d khdp mpi nai tren ca the ngudi, tap trung chu yeu d dng tieu hoa va gay cac benh truyen nhilm nguy hilm nhu nhilm khuan dudng tieu hoa, viem dudng rupt, nhilm triing mau va thuang han [3, 28] 14 NHlfNG VAN DE NGHIEN CJfU CO BAN TRONG KHOA HOC Slf SONG 777 Bang T i r a n g tac lectin lpc vCrng-vi k h u a n Salmonella Loai khac W^u ATCC 9347 6/00 191 39 44 49 12-04 104-04 6-04 105-04 94-04 E Sh T DCT 3+ 3+ 4+ 2+ 4+ 3+ 2^ 1+ 2+ 3- 2+ - - - CP 3+ 3+ 4+ 2+ 4+ 3+ 2+ U 2+ 3- 2+ - - - (-) khdng cd phan ung ngung kit; (+) mice 66 gSy ngung kit; DCT: dich chilt the CP: c h i phIm; E: E.coli; Sh: Shigella; T: Staphyloccocus Nghien cii'u tuong tac lectin- vi khuan: Chung tdi da t i l n hanh thii' nghiem tac dung gay ngung k i t ciia cac m i u lectin vdi mpt sd vi khuan; Staphylo-eoceus, E coli Salmonella, Shigella Pseudomonas aeruginosa va Proteus vulgaris n h i m de dinh logi chung K i t qua thuc nghidm (bang 2) cho t h i y sd cac vi khuan nghien cu-u, cac phan dogn ciia lectin lpc vCi-ng (tu dich chiet thd d i n c h i pham) d i u chi t u o n g tac vdi mpt loai n h i t la Salmonella Han nua, mifC dp gay ngung k i t ciia c h i pham so voi m i u thd la khong doi; t u n g ehiing ed the dgt mu-e tif y l u (1+) d i n taing binh (2+), manh (3+) va r i t mgnh (4+) Dieu n^y chirng to dp nhgy rat cao cua lectin: ehi can mot ham iupng lectin r i t t h i p o mau thd da cd kha nang gay n g u n g ket vi khuan Nhu vgy, ed the sip dyng che pham lectin ldc vO-ng de phan biet Salmonella vd'i cae lo^i vi khuan khac (qua phan ipng n g u n g k i t dac hieu), hon nua cdn cd the phan biet cac chiing Salmonella vd'i (dya tren s y sai khac mu-c dp ngung k i t ) K i t qua nghien cicu da gdp p h i n k h i n g dinh kha nang sif dyng lectin, dac biet la cac che pham tach t u ngudn thue vat phong phii eiia Viet nam n h u mpt cdng cu huu ich de phat hi^n nhanh cae vi khuan cd t i m quan trpng sinh-y hpc, TAI LI$U THAM KHAO Bui Phuong Thuan, de la Barca A.M C , Burk G., Galsworthy S B and Doyle R.J- 2000 Interaction between listeriae and lectins Romanian archives of microbiology and immunology 59: 55-61 Etsler M.E Distribution and function of plant lectins, 1986 In: The lectins: properties, functions, and applications in biology and medecine {e6s Liener I E., Sharon N and Goldstein l.J.) Academic Press Orlando, USA: 371-435 Goldstein I.J.& Poretz R D.,1986 Isolation and chemical properties of lectins In: The lectins: properties, functions, and applications in biology and medecine (eds Liener I E Sharon N and Goldstein l.J.) Academic Press Orlando USA: 33-247 Khin M M.; Hua J S.; Han N C ; Wadstrom T and Ho B., 20CO, Agglutinaticn cf Helicobacter pylon coccoids by lectins World J Gastroenterol (2): 202- 209 Slifkin M 1994, Application of lectin in clinical bacteriology In: Lectin - microorganism interactions (eds Doyle R.J and Slifkin M M.) Publ Marcel Dekker Ink New York: 143 - 172 van Damme E J M., Peumans W J Pusztai A and Bardocz S 1998 Handbook of plant lectins: properties and biomedical applications Publ John Wiley & Sons LTD, Chichester, England: 1-22 ' Cdng trinh duac su hd tro ciia OHQG Ha npi (DT QG- 04-12) Cac tac gia xin cam an PGS.TS Nguyin V3n Mui da dpc va gdp y cho ban thao SUMMARY Purification and characterization of Barringtonia acutagula seed lectin Bui Phuong Thuan, Ngo Ba Binh University of Science, VNU, Hanoi Lectin from Barringtonia acutagula seed can be purified by a simple procedure (chromatography of the crude cell extract on DEAE 52 ion exchange column followed by a Sephadex G-75 colum) The 'ectjn preparation ,s highly purified and contains only one polypeptide band of 45 kDa in SDS-PAGE The lectin has the pH optimal around 6.8- 8.3 and is rather stable at room tempera-res Among the tested sugars the lectin activity is inhibited by galactose, fucose lactose at as low concentration as 3.15 mM The lectin fractions agglutinate selectively only Salmonella strains and can be used for l^e typing cf tnese :5c:ena N g u a i tham djnh; PGS.TS Nguy§n Van Mui, Trud'ng Dai hoc KHTN Dai hoc Quoc gia Ha Ndi f V A DAI HOC QUOC GIA HA NOI TRl/CJNGDAI HOC KHOA HOC TUNHIEN ^^ip"-"fc^ »"^* ^ * * !(C J|C JfC Sit 5(6 I-.,//••^.z i^.,/1^:^ Ngo Ba Binh NGHIEN CtJtJ VA SU DUNG LECTIN TRONG TlTONG TAC DAC HIEU VOl CAC VI KHUAN GAY N G O D O C THU'C PHAM Chuyen nganh: HOA SINH HOC Ma so: 05.10 LUAN VAN THAC S! KHOA HOC NGUdi HUdNG DAN KHOA HOC: TS BUI PHUONG THUAN Ha noi - 2005 DAI HOC QUOC GL\ HA NOI TRUONG DAI HOC KHOA HOC TLTNHIEN KHOA SINH HOC Ta Duy Hien TINH SACH VA NGHIEN O J t MOT so TINH CHAT CUA LECTIN Tl/DICH CHIET HEMOCYTES SAM BEEN (TACHYPLEUS TRIDENTATUS) KHOA LUAN TOT NGHIEP HE CHINH QUT Nghanh: Cong nghe Sinh hoc Can bo hirong dan: TS Bui Phuong Thuan Ha Noi - 2004 DAI HOC QUOC GIA HA NOI TRUQNG DAI HOC KHOA HOC TUNHIEN KHOA SINH HOC Vo Dinh Hoang PHAT HIEN VA NGHIEN ClJtJ CAC LECTIN CO KHA NANG NHAN BIET M O T SO CHUNG VI KHUAN GAY DOC TH0C PHAM KHOA LUAN TOT NGHIEP HE DAI HOC CHINH QUY Nganh: Cong nghe sinh hoc Can bo hudng d^n: TS Bui Phuang Thuan ThS Nguyin Thj Thanh Ha Ha Noi 2004 T R U O N G DAI HOC KHOA HOC TUNHIEN DAI HOC QUOC GIA H A NOI KHOA SINH HOC Nguyen Thuan Loi DIEU TRA HOAT TINH LECTIN M O T SO CAY THUOC VIET NAM VA M O T SO TINH CHAT CUA LECTIN TACH Tl/ HAT CAM THAO DAY (ABRUS PRECATORIUS L) KHOA LUAN TOT NGHIEP HE DAI HOC CHINH QUY N2anh: C6n2 nshe sinh hoc Can bo huong dan: TS Biii Phuong Thuan Ha Noi - 2004 DAI HOC QUOC GIA HA NOI TRL'dNG DAI HOC KHOA HOC TL'NHIEN KHOA SINH HOC -—oOo—- BUI THI KHANH sur DUNG LECTIN HAT CAY HO DAU DE DINH DANG VI KHUAN VA NGHIEN CUU M O T SO TINH CHAT CUA LECTIN TACH TlT HOA HOI (ILLISUM - PACVIFLORUM) • • • • > KHOA LUAN TOT NGHIEP HE D.AI HOC CHINH QUY Nganh: Sinh hoc Can bo huong din: TS Bui Phuong Thuan Ha Noi, 2004 TOM TAT CAC CONG TRINH NCKH CUA CA NHAN (1) Nganh: Sinh hoc; Chuyen nganh: Hoa sinh hoc Ho va ten cac tac gia cong trinh: Biii Phuang Thu$n Nam: 2004 Ten bai bao; Phat hien cac lectin co kha nang nhin bidt mot so chiing vi khuin g^y d6c thuc pham Ten tap chi: Bao cao Hoi nghi toan quoc 2004 "Nhiing vSh de nghien ciiu ca ban khoa hoc su s5'ng- Dinh huofng y duac hoc", Hoc vi6n Quan y, 28/10/2004, tr 165-168 Tom t^t cong trinh bling tieng Viet K^t qua thi nghiem tac dung g^y ngung k^t cua lectin vdi vi khu& da cho th^y kha nang cua m6t so lectin viec dinh dang vi khuin thdng qua phan ung gSy ngung ket dac hi6u Cac lectin ttr nhieu ngu6n d6ng- thuc v|t khac da dugc su dung di dinh dang 25 chung vi khudn thu6c cac loai Staphylococcus {Staph, aureus va Staph, epidermidis), E coli Salmonella va Shigella, ma da s6 la cac vi khufo gay dpc thuc phim va co hai cho ngudi Do lectin co the gay ngung ket chon loc cac loai vi khuin, tham chf la cac chung b^n loai (phu thuoc vao p h i i ducmg oligosaccharide va ca'u tnic glycoprotein trdn b^ mat ciia chiing), su ph^i hop cac lectin co cung dac tinh (hoac co dac tinh trai ngugc nhau) co the giiip phan loai vi khuin Cu the su dung lectin tir hat xoai, dau dai, dau ngu va khoai tay (chi gay ngung ket tu cau vang Staph, aureus) ket hgp vdi lectin tir te bao sam bien Tachipleus tridentatus (chi gay ngung ket tu c^u trdng Staph, epidermidis), co the phan bidt hai loai tu cdu mot thdi gian rat ngin la phut; lectin tiir hat mudp dang (Momordica charantia) va tit te bao sam bien giup nhan dang E coli; lectin tir hoa hoe (Sophora japonica) chi gay ngung ket manh chung SalmoneUa A, lectin tu hat dan (Amaranthus tricolor) chi gay ngung ket nhat cac chung ShigeUa Cac ket qua thu dugc da giup chon lua mot so lectin co tac dung dinh dang cac vi khuin nghien cihx Tom t^t cong trmh b^ng tieng Anh Bui Phuong Thuan (2004) Screening of lectins capable of recognition of foodpoisoning bacteria Issues of basic research in life sciences, Proceedings, The 2004^ National Conference on Life Sciences Military Medicine Institute Volume: October 28,2004, pp 165- 168 Lectins from various vegetal and animal sources were used to differentiate 25 bacterial strains belong to Staphylococcus species (Staph, aureus and Staph, epidermidis), E coli Salmonella and Shigella, most of which are food- poisonoing and harmful to human Based on the fact that lectins can agglutinate selectively bacteria species or even strains within one species (depending on the oligosaccharide components and glycoprotein structures on their surfaces), the combination of lectins having the same (or the opposite) characterizations can enable us to type these bacteria Namely lectins from mango seed, beans and potatoes combined with lectin from horseshoe crab ceUs can distinguish Staph, aureus from Staph, epidermidis, lectin from biuer pear melon (Momordica charantia) seed and crude extract from horshoe crabs cells can recognise E coli; lectin from pagoda tree flower (Sophora japonica) agglutinates strongly only strain A of SalmoneUa, lectin from tassel flower (Amaranthus tricolor) chooses to agglutinate uniquely ShigeUa strains These lectins can be used successfuUy for the identification of the study bacteria n ^_ _ i TOM TAT CAC CONG TRINH NCKH CUA CA NHAN (2) Nganh: Sinh hoc; Chuyen nganh: Hoa sinh hoc Ho va ten cac tac gia cong trinh: Biii Phuang Thuan, Ngo Ba Binh Nam: 2005 Ten bai bao: Tinh sach va nghidn curu cac dac tinh cua lectin hat lOc v&ng (Barringtonia acutagula L.) Ten tap chi: Bao cao Hei nghi toan quoc 2005 "Nhiing vSh d6 nghidn cuxi ca ban khoa hoc su sdng", Trucmg Dai hoc Y Ha noi, 03/11/2005, tr 775777 Tom tit cdng trinh b^ng tieng Viet Viae di^u tra khai thac va nghidn ciiu tfnh ch^t cua lectin- nhom hgp chat co ti^m nang iing dung r^t 16n sinh- y hoc dang dugc tien hanh manh me va thu dugc nhung k^t qua kha quan Trong s6 do, lectin hat I6c vimg Barringtonia acutagula L hiiu hi^n tac dung gay ngung ket dac hieu cac vi khuin Salmonella gay doc thuc phim da dugc lira chpn cho d6 tai nghian cuu Dich chi^t th6 hat I6c viimg da dugc sijr dung di tinh che lectin bang sic ky tr6n c6t trao d6i ion DEAE 52 va tiep theo la c6t loc gel Sephadex G-75 Viae kia'm tra bang SDSPAGE cho tha'y che phim thu dugc la hoan toan tinh sach vdi mot bang nha't co kh6'i lugng phan t i khoang 45 kDa Theo cac ke't qua thu dugc, nhiet tir 20° C den 4*" C la thich hgp cho viec bao quan va tinh ch^ lectin lgc vimg, pH co anh huong ldn den hoat tinh sinh hoc cua lectin nd chi hoat ddng manh d vung gin trung tinh va hoi kiem (nha't la 6,8 - 8,3), tinh dac hieu dudng cua lectin ldc vtog la kha rgng Tac dung gay ngung ket ciia cac mau lectin vdi mgt so vi khuin: Staphylococcus, E coli Salmonella, Shigella, Pseudomonas aeruginosa va Proteus vulgaris da dugc thu nghiem Ke't qua cho tha'y cac phan doan ciia lectin loc vung (tir dich chiet thd den che phim) d6u chi tuong tac vdi mdt loai nha't la Salmonella d mgt ham lugng lectin rat tha'p Nhu vay, CO tha' sir dung che phim lectin ldc vimg de phan biet Sahnonella vdi cac loai vi khuin khac, hon nua cdn cd the phan biet cac chung SalmoneUa vdi (dua Uen su sai khac mu:c dd ngung ket) Ket qua nghidn cuu da gdp phii khang dinh kha nang sir dung lectin, dac biet la cac ch^ phim tach tir ngudn thuc vat phong phii ciia Viet nam, nhu mot cdng cu huu ich de phat hidn nhanh cac vi khuin cd tSm quan trgng sinh-y hgc m Tom tdt cong trinh bling tieng Anh Bui Phuong Thuan, Ngo Ba Binh (2005) Purification and characterization of Barringtonia acutagula seed lectin Issues of basic research in life sciences, Proceedings, The 2005^ National Conference on Life Sciences Hanoi Medical University Volume November 03, 2005, pp 775- 777 Lectin from Barringtonia acutagula seed can be purified by a simple procedure (chromatography of the crude ceU extract on DEAE 52 ion exchange column followed by a Sephadex G-75 column) The lectin preparation is highly purified and contains only one polypeptide band of 45 kDa in SDS-PAGE The lectin has the pH optimal around 6,8- 8,3 and is rather stable at room temperatures Among the tested sugars, the lectin activity is inhibited by galactose, fucose, lactose at as low concentration as 3,15 mM The lectin fractions agglutinate selectively only SalmoneUa strains and can be used for the typing of these bacteria IV TOM TAT CAC CONG TRINH NCKH CUA CA NHAN (3) Nganh: Sinh hoc; Chuyen nganh: Hoa sinh hoc Ho va ten cac tac gia cong trinh: Ngo Ba Binh, Biii Phuang Thuan Nam: 2005 Ten bai bao: Mot s5 dac tinh va kha nang iing dung ciia che' pham lectin dao bi^n (Canavalia maritima), Ten tap chi: Bao cao Hoi nghi toan quoc 2005 "NhOng v& dd nghien cihi ca ban khoa hoc su song", Trudng Dai hoc Y Ha ndi, 03/11/2005, tr 401404, Tom tdt cong trinh bang tieng Viet Lectin hg dau chiem mdt so lugng r^t ldn sd cac lectin dugc quan tam nghian cuu Di tiajp tuc hudng di^u tra khai thac ngudn tai nguyan thuc vat phong phu cua Viat nam, chung tdi lua chgn mdt loai dau hoang dai cdn chua dugc gidi khoa hgc quan tam da'u la dao bien (Canavalia maritima) Lectin ciia loai dau da dugc tach, tinh ch^ va nghian cuu dac tinh dinh hudng su dung de dinh dang nhanh cac vi khuin cd tim quan trong sinh-y hgc Lectin hat dao bien da dugc tinh che bang sic ky tran cdt trao d6i ion DEAE 52 va tiap theo la sac ky tran cdt lgc gel Sephadex G-75 Che phim lectin cd hieu sua't hoat dd kha cao (khoang 15 %), tinh sach tang lan hon sau lln so vdi dich chie't tho ban diu vdi m6t bang dien di bien tinh nha't cd khdi lugng phan tu khoang 23 kDa Vi dac tinh hoa sinh hgc, che phim lectin dao bien hoat dong pH tuong ddi rdng tir den 8,3 (vdi pH tdi thich nam khoang 6,0 - 7,4), ban d 4°C va kha ben d nhiet dd phong, dong thdi cd phd dac hieu dudng kha rgng sd 12 loai dudng thu nghiem gay lie che hoat lectin dao bien, phin ldn vdi muc rat manh Tinh chat ciia lectin dao bien cho phep du doan nd cd the tuong tac vdi nhiau loai vi khuin vdi cac ca'u tnic dudng khac tren be mat te bao Vi kha nang urong tac vdi vi khuin, sd nam chung qudc te (thudc cac loai khac nhau) dugc nghian cihi, lectin dao bien chi gay ngung ke't dac hieu nha't chung Shigella ATCC 7896, dong thdi giup phan biet dugc cac vi khuin khac cung chi Salmonella dua tran muc gay ngung ket Do do, cd tha sir dung ket hgp lectin vdi cac lectin khac (vi du nhu lectin hat lgc vimg Barringtonia acutagula) he thdng dinh loai Salmonella Tham vao dd, nhay phan ung gay ngung ket la rat cao: chi mot ham lugng nhd lectin d miu dich chiet thd cung da cd tac dung Day chinh la mdt uu the cua viec six dung lectin dinh loai vi khuin Tom tdt c6ng trinh bang tieng Anh Ngo Ba Binh, Bui Phuong Thuan (2005) Some characteristics and application of Canavalia maritima lectin Issues of basic research in life sciences Proceedings, The 2005"^ National Conference on Life Sciences Hanoi Medical University November 03, 2005, pp 401- 404 Lectins from Leguminous family have been strongly studied for their precious biological activities Lectin from Canavalia maritima seed has been purified by chromatography on a DEAE 52 ion exchange column and a Sephadex G-75 column consecutively The only polypeptide band of 23 kDa in SDS-PAGE demonstrates the high purity of lectin preparation While the pH optimal for Canavalia maritima lectin activity is in the neutral and slighUy acid ranges (6,0-7,4), it is stiU active within pH values from - 8,3 The lectin is relatively stable at 4°C and room temperatures, and has a rather broad saccharide specificities All of 12 tested sugars but three have inhibited lectin activity, especially very strongly in the cases of glucose, marmose, maimosamine, fructose and lactose (at 3,15 mM concentration) This feature of the lectin suggests that it can form the complexes with different bacteria, as their surfaces bear many of the sugar residues In fact, Canavalia maritima lectin agglutinates only Shigella strain ATCC 7896 among the ATCC strains of different bacteria (E.coli, Salmonella, Staphyloccocus ,), and can distinguish beetwen various SalmoneUa isolates by distinct agglutinaion activities Thus, the lectin can be employed to selectively detect bacteria species, as well as can be used in combination with other lectins (like one from Barringtonia acutagula seed) for the typing of Salmonella Because the lectin is active at very low concentrations (as in the crude extraction), stable and easy to store, it is really a useful tool for identification of bacteria VI SCIENTIFIC PROJECT BRANCH: Biology; PROJECT CATEGORY: Vietnam National University level Title: Detection and use of lectin specificity in the idenrificalion of some food- poinsoning bacteria Code number: QG 04-12 Managing Institution: Vietnam National University, Hanoi Implementing Institution: Hanoi University of Science Colaborating Institutions: National Institute of Hygien and Epidermiology Coordinator: Dr Bui Phuong Thuan Key implementors: MSc Nguyen Thanh Ha, MSc Ngo Ba Binh, Ta Duy Hien, Vo Dinh Hoang, Nguyen Thuan Loi, Bui Thi Khanh Duration: from 6/ 2004 to 12/ 2005 Budget: 60,000,000 VND (sixty milHon dongs) 10 Main results: - Results in science and technology: • Detecting lectins from biological resources in Vietnam which are capable of identifying food- poinsoning bacteria • Producing a set of purified lectins (a bioactive kit) that can be used in typing bacteria harmful to human beings • Characterizing the purified lectin - Results in practical application: • Purified lectin preparations can be supplied at low cost to the laboratories and the epidermic survey etablishments as the effectif tool for the detecting and typing the food- poisoning bacteria - Results in training: one master student defended his thesis with highest scores and four undergraduate students finished successfully their graduation theses - Publications: three papers have been pubhshed 11 Evaluation grade VII [ • PfflEU DANG KY K^T QUA NGHIEN CtJtJ KH - CN Ten de tai: Phat hian va six dung tinh dac hieu ciia lecUn de nhan dang mpt so vi khuin gay nhiSm d6c thuc pham Ma so: QG 04-12 Ccr quan chu tri de tai: Tnrcmg Dai hoc Khoa hoc Tu nhien Dja chi: 334 Nguydn Trai, Thanh xu^n Ha n6i Tel: (04) 858 8579/5583001 Ca quan quan ly de tai: Dai hoc Qu6c gia Ha n6i Dia chi: 144 ducmg Xuan Thuy, Cfiu giefy Ha n6i, Tel: (04)754 8664 Tong kinh phi thuc chi: 60 000 OOOd (Sau mucd trieu d6ng) Trong do: - Tir ngan sach Nha nudc: 60 000 OOOd - Kinh phi cua Truomg: - Vay tin dung: - Von tuco: - Thu hoi: Thdi gian nghien curu: Thdi gian bat dau: 24 thang - 2004 ThM gian ket thuc: 12-2005 Ten cac can bo phoi hgp nghien cihi: ThS Nguydn Thanh Ha, ThS Ngo Ba Binh CN Ta Duy Hien, CN Vo Dinh Hoang, CN Nguydn Thu^n Lai, CN Biii Thi Khanh S6 dang ky dd tai So chung nh£Ln dang ky ket qua nghidn cuu: Ngay: Bao mat: a Pho bien rong rai: X b Ph6 bie'n han chd': c Bao mat: vni Tom tit ket qua ngfalen curu: Hem 100 miu dich chiet lectin th6 tit cac nguon (chii yeu la thao moc nhu hoa, qua, hat) da duac thu thap, xii ly, thi nghidm hoat tfnh qua phan ung gay ngung ket h6ng cfiu va nghidn cihi tinh dac hidu ducmg Dua trdn cac ket qua nay, cac mfiu phu hop vdi cac thii nghidm ti^p theo da duoc lua chon 28 chiing vi khufin thuoc cac loai Staphylococcus (gom ca tu cfiu vang va tu cfiu trfing), E coli, Salmonella va Shigell da dugc phan lap tiir cac mSu benh phim, dugc nu6i cfiy va xii ly Qua thtr nghidm tac dung vdi vi khufin de xac dinh phan iing gay ngung ke't, da thu dugc cac kd't qua bu6c dfiu ve kha nang dinh loai vi khuii ciia cac mfiu lectin, dua trdn sir khac bidt vi dac tinh cfiu tao b^ mat td" bao Cu ihi ket hgp lectin t^ hat xoai (Mangifera indica), dau (Phaseolus vulgaris) va khoai tay (Solanum tuberosum) vdi lectin hemocyte sam biln (Fachypleus tridentatus) da phan bidt dugc Staph, aureus va Staph, epidermidis; lectin tfir mudp dfing (Momordica charantia) va tir dich chid't hemocyte sam biln da nhan bid't dugc E coli; lectin ttr hoa hoe (Sophora japonica) gay ngung kd't manh chiing Salmonella A, lectin tir hat den (Amaranthus tricolor) chi gay ngimg k^t lua chon cac chiing ShigeUa Trong phfin tiep theo, hai lectin thuc vat (tiir hat loc vimg (Barringtonia acutagula L.) va tii hat dao biln (Canavalia maritima)) va lectin tir hemocyte ciia mau sam biln (Tachypleus tridentatus) dugc lua chon de tinh che va nghidn cihi dac tinh Nhiing kd't qua nghien cuu cho thfiy cd thi dinh loai cac vi khufin gay ddc thuc phfim bang each sii dung lectin mot quy trinh don gian va cho keft qua nhanh Vide tinh sach cac lectin dac hidu la nhfim muc dfch tao mot bo sinh phfim cac lectin CO kha nang phat hidn va dinh danh nhanh cac loai cac vi khufin gay hai thuc phim, lam ca sd cho vide dua cac bidn phap hieu qua dl loai trir tac hai cua chung Kien nghi ve quy mo va doi tugng ap dung nghien cuu: Nghidn ciiu cfin duac md rong vl quy mo nham phat hidn va tinh che dugc nhung ch^phfim lectin vdi dac tinh In djnh va hOu hieu, cho phep dinh loai cac vi khufin gay d6c thuc phfim bang m6t phuang phap tien lgi, nhanh chdng va ft ton kem Thu truong cof quan chu tri de tai Chu tich Hpi dong danh gia chinh thuc Ma/^ 7