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
NHI£M
DOC
THUC
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

chid'm tdi
30% thanh
phSn
phan tu lectin. Trong khi do, cac axit amin
chiia luu huynh nhu cysteine, methionine chi chiem mpt ti le thap hoac hau nhu
khong
CO
trong thanh
phSn
lectin.
Trong phan
tir
lectin con co cac ion kim loai, thudng gap nhat la
Mn^"^
va
Ca^"*".
Cac ion nay khong
true
tiep tham gia vao lien ket lectin-dudng, nhung lai
rat cin cho su tuong tac nay
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

lectin. Vf du ConA
d pH trung tfnh co cau tnic tetramer vdi khdi lugng phan
tir
khoang 102 000 Da,
nhung d pH < 6 cau tnic tetramer bi phan ly thanh cac dimer cd khdi lugng phan
tula 51 000
Da [21].
1.2.3. Tinh tan cua lectin
Lectin co kha nang hoa tan trong nudc, dac biet lectin ra't
dt
tan trong
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 trong 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

dung de tinh che lectin. Nhieu glycoprotein cd chiic nang sinh
hpc da dugc tinh che bang phuang phap sac ky ai 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 ai luc hoa hpc, gia tri pH cd y nghia dac biet trong su tuang tac dd.
Ngoai ra, do lectin cd ban cha't la protein, hai gia tri pH can dugc luu y nhieu
nha't trong 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

gin
vao mang te bao hdng
cSu
dl dang han, do
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, do 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

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), do 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 khi bi lectin gin vao se bi mit tac dung, do dd lam tang
kha nang phan chia te bao. Tuy nhien gia thiet nay cling chua that thuye't
phue,
do nhilu lectin tuy 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 trong
y hpc va miln dich hpc de nghien
ciiu

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 trong ket dinh
cac te bao npi md thanh 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 nay 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 ra 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 trong viec
chdng lai cac tac nhan tac dpng tu ben ngoai, ke't dfnh te bao va

qua nhanh, chinh xac ma khdng cin diing huyet thanh miu. Tuy nhien phuang
phap nay 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 trong qua trinh biet hoa benh ly,
thdng qua su thay doi thanh 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 ai luc manh
vdi AFP, lectin
tir
dau lang va
tir

cu
hiru
ich trong
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 trong sinh- y hpc
[16,20,40].
Hiu het viec
sir
dung lectin trong 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

Viec nghien
ciiu
lua chpn lectin tuong tac dac hieu vdi cac loai vi khuan
cd the giiip ich trong viec dinh danh cac vi sinh vat nay ]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 tuy tien. Da sd cac
vi khuin nay phat trien trong khoang nhiet dp
tir
5-12"
C, cd the ton tai rat lau
trong mdi trudng va nhay cam vdi viec thanh
triing,
ngoai ra 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 thanh te bao. He thdng
mang bao gdm mang ngoai va mang trong. Mang trong dugc cau tao gdm mpt
ldp lipid kep day khoang 8 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 3 thanh phin: lipid A, mpt chudi dudng phan
nhanh va khang nguyen O. Thanh phin cdn lai
ciia
mang ngoai la cac protein

cac bien ddi thanh 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 trong 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 thanh 100 typ huyet
thanh khac nhau. 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

sic td huynh quang, phat miu xanh khi 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 khi 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 do 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
].
1.5.4 Samonella
Samonella la vi khudn Gram (-)
hinh
que cd nhieu long, kich thudc trung
binh 3 x 0,5
j^m,

Hien nay ti
16
Samonella khang thudc ngay cang gia tang, da cd tdi 40%
chiing dugc phan lap (nam 1998) khang lai ampicillin va 62% khang lai
chloramphenicol
[1,7].
1.5.5
Shigella
Shigella la
true
khuin gram am, manh, dai tir 1-3
^im,
khi mdi nudi ciy cd
dang
true
ciu khuin. Shigella khdng cd long, khdng cd vd va khdng sinh nha
bao,
la vi khuan hieu khi tuy tien nhung phat trien tdt trong dilu kien hieu khf
[1].
Thanh te bao Shigella cung bao gdm cac thanh phin gidng nhu
Samonella: peptidoglycan chi chiem mpt ti le nhd (5-10%), cac tetrapeptide tren
mdi chudi peptidoglycan lien ke't cheo vdi cac tetrapeptide khac, ngoai ra cdn
lien ket vdi techoic acid [27].
Mang ngoai ciia vi khuin la ldp lipid kep cau tao tii ba thanh phan chfnh:
khang nguyen O, lipid A va protein ca chat. Trong dd thanh phdn khang nguyen
O chfnh la cac polysacharide (la vi tri lien ket lectin tilm nang trong phan
iing
ngung ket vi khuan) [27].
Tit ca cac Shigella
diu

khdng nha bao va khdng vd. Cac
loai
thudc chi Staphylococci
diu
la vi khuin
yim
khf tuy tien.
Tu ciu vang cd kha nang dl khang vdi nhiet dp va hoa chat cao han cac vi
khuin khdng nha bao khac, bi diet d nhiet dp
80"C
trong mdt gid, tuy nhien kha
nang dl khang vdi nhiet dp thudng phu thudc vao kha nang thich
iing
vdi nhiet
dd tdi da ma vi khuin cd the phat trien
[1,6].
Ciu tnic thanh te bao ciia vi khuin cd cac nhdm chit nhu polysaccharide
va glycoprotein (cac nhdm chit mang gdc dudng cd
thi la
vi tri lien ket vdi
lectin trong phan
iing
ngung ket) [27].
Nhilm vao ngudi khi an phai thuc phim khdng dugc bao quan tdt, loai vi
khudn nay gay ndn
mira
nhilu va dau co thit viing bung, cd the gay tieu chay
hay dau diu [1]. Da sd tu ciu vang khang lai penicillin G, mdt sd cdn khang
dugc methicillin
[1,4],

iing
tilm nang
ciia
cac lectin [34]. Tren ca
sd dd, cd
thi
sir dung cac miu lectin tach tir sinh vat trong thien nhien nhu
16
nhihig cdng cu trong viec dinh dang cac chiing vi sinh vat, hay phan biet cac loai
cd type
huyl^t
thanh khac nhau nhu: sir dung lectin WGA (agglutinin mim
liia
mi) phat hien cac chiing vi khuin thudc chi Neisseriaceae gay ra cac benh viem
mang nao, tiet nieu, sinh
due
[24], gay ngung ket va xac dinh dugc cac chung
cua nhdm Campylobacter jejuni vd Campylobacter coli [44], sir dung mdt sd
ddi tugng lectin trong viec xac dinh tu ciu vang va tu ciu trang[9,
18,
22]
17
t^A'HOC
QUOC GIA HA
NOl
TRUNG TA^-HONG
TIN
THl.r
v/iPN
P/

Vien ve sinh dich tl Trung uang va cac chung vi sinh chuin qudc te
do Trung tam bao tdn gidng vi sinh vat cung cip.
2.
7. 2 Hod chdt vd thiei bi
Cac hda chit, dung dich dem sinh phim sii dung trong nghien
ciiu
dugc mua tir
cac hang Sigma, LKB, Merk
diu
cd dp tinh khiet cao.
Cac thiet bi chinh diing trong thuc nghiem bao gdm:
- May ly tam MR 18, Jouan - Phap.
- May ly tam lanh eppendorf
5417R
-
Diic
- May do quang pho Shimazu UV-200 - Nhat ban,
- May do pH ATI- ORION - Bekman-My.
2.2 Phuomg phap nghien cuu
2.2.7 Tdch chiei cdc mdu lectin tho
Lectin
tir
cac miu thi nghiem dugc chiet xuat bing dung dich dem PBS pH
7,4 (hoac Tris -
HCI
(TBS) 20 mM pH 8,3) vdi ti le 1/10
(kl/tt)
(vdi nguyen lieu
tuai) va 1/20 (kl/tt) (vdi nguyen lieu d dang bdt khd), khuay ttr 30 phiit, ly tam
8000v/phut trong 15 phiit d nhiet dp

thii
hai,
trpn
diu,
lam tuang tu vdi cac gie'ng tie'p theo cho de'n het, bd di
50|il
trong
gilng cudi cung sau khi trpn.
Cho vao mdi gie'ng 50
\i\
hdng ciu da hda loang, de ban nhua d
37"
C,
sau
30 phiit dpc ket qua.
2.23 Tuong tdc
giira
lectin vd
tebdo
vi khudn [30].
Cac vi khuan thir nghiem dugc ciy truyln tir dng gidng qua mdi trudng
thach thudng, de qua dem trong dilu kien thudng.
Tir
dng thach cho 5 ml dung
dich mudi sinh ly, diing que cay thu sinh khdi, dich vi khuan dugc bat hoat bing
dung dich formaldehide 0,5%. Tiep den, tien hanh
rira
te bao bdng mudi sinh ly,
ly tam thu tua, hoa tan tua trong dung dich dem PBS pH 7,4, chinh dp due cua
dich huyin phu d budc sdng 540 nm den OD = 1 (tuang

ngung ket yeu, - : khdng cd ngung ket). Vdi
19
kSt
qua
am
tinh, cac
i€
bao vi khuin vin d dang huyin phii hoac ldng
diu
d giira
giiing
thiir.
Trong nghien cuu cdn sii dung cac phuang phap tinh sach lectin bdng sdc
ky tren cdt trao doi ion DEAE 52 va cpt Ipc gel Sephadex G-75; xac dinh ham
lugng protein bing phuang phap do quang pho va ky thuat Bradford; xac dinh
dd sach ciia che phim lectin bing
di6n
di bien tfnh tren gel polyacrylamide
(SDS-PAGE); nghien curu anh hudng
ciia
cac ye'u td: nhiet dp, pH va tac dung irc
ch^
cua cac hgp chit dudng
ien
hoat dp cua lectin.
2.2.4 Cdc quy trinh
chiei
xudt vd tinh che lectin
20
Mdu hat

Mdu hat dao bien
Nghien hat dao bien thanh bpt min.
Ngam va khuiy tii trong dem PBS pH 7,4
trong 3 gid.
Ly tam 8000
v/phiit
6
4*'C
vdi thdi gian
20*
Nap dich chiet thd len cot sdc ky trao d6i ion
DEAE Sephadex A-50, tao gradient nong dp
NaQ
de day cac protein gdn tren cpt. Thu
cac phan doan cd hoat do lectin cao nhat.
Dinh cd hoat tfnh
DBl
Nap dinh DBl len cot sdc ky lpc gel
Sephadex G-75
Thu che pham (CP)
i
Dien di bien tfnh tren gel polyacryamide
(SDS-PAGE) 12,5
%.
Kilm tra dp tinh sach
cua che pham
So
do 2 - Quy trinh chiet xuat va tinh che lectin hat dao bien
22
Dich chiet

sir dung gradient nong dp NaCl de day protein
lectin khdi cdt
Che
pham lectin (CP)
So do
3 - Quy trinh chiet xuat va tinh che lectin hemocyte sam bien
23
Chuang
3-
Ket qua va ban luan
3.1 Khao sat hoat tinh gay ngung ket hong cau
ngucri
cua mot sd loai thuc
vat Viet Nam
Chung tdi da tien hanh khao sat hoat tinh gay ngung ket hdng ciu ciia han 100
miu thuc vat thudc 50 loai d 28 hp khac nhau.
Trong tong sd 50
loai
khao sat (bang 1), 32 loai cd hoat tinh ngung ket
hdng ciu vdi
miic
dd khac nhau, tap trung d cac hp; Arecaceae, Brassicaceae,
Cucurbitaceae, Fabaceae, Dliciuacea,
Lecythidaceae,
Liliaceae, Meliaceae,
Millettia,
Momordica, Moraceae,
Papihonoidea,
Sapindaceae, Solanaceae,
chi^m

cay
[32].
Ke't qua dilu tra cho thay mpt sd loai cd hoat tinh gay ngung ket hdng ciu
rit cao nhu ldc
vtmg
{Barringtonia acutagula
L.),
dao bien {Canavalia
maritima),
cam thao day {Abrus precatorius
L)
Nhixng
miu nay da dugc
chiing tdi tap trung nghien ciru sau han.
24
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ra
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muirindus indica
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ed-
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m
chom
Cho
ephclirum lappaceum
^
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rj
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—
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duac
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aromaticum
1)
u
o
^-
ci:
Zin
o
W-,
3*2 Phat hidn va phan
I$p
mot so
loai
vi khuan gay nhilm doc thuc pham
Benh
ph^m
tur cac
b^nh
nh^n
bi
ng6 dpc
thuc pham, cac nguon thuc pham hay
gia Stic
gay
b^nh
da duac thu thap va bao quan.
Tijr
do. cac
miu
vi

gay
d6c
thuc phdm; 1-03
tiT
thjt gia
siic
gay benh, con 5-02 va 12-
04 phan lap
tilr thtic
an).
+ 5 chung
E.
coli
(3-04,13-04,
24-04 duac phan lap tir phan cua ngucri benh,
25922 la chung
chu^
cua tap doan giong quoc te).
+ 3 chung Salmonella (ca ba mSu A, B, D
diu
duac phan lap tir phan cua
ngucri
b6nh).
+ 3 chung Shigella (213, 474 phan lap tir phan, con 259 phan lap tir mau
ngucri benh).
Ngoai ra con co sau chung chuan cua cac tap doan giong qudc te do trung
tam bao tang gidng chuan vi sinh vat - Trung tam cong nghe Sinh hoc cung cap
bao gom: Pseudomonas
aeruginosa,
Proteus,

6
7
8
9
10
11
12
13
14
15
16
17
18
19
20(
Miu
Hoa hoi
Lac
Dau ngu
Dau
dai
Cam thao
day
CP lectin CTD
Qu6
Bura
Roi
Qua
lau
Mudp

2+
+
-
+
+
-
2+
+
-
+/-
55
3+
+
-
+
-
+
2+
2+
+
2+
2+
-
-
+
-
-
50
25
3+

- 2+
-
-
50 55
143
3+
3+
-
-
+
+
2+
2+
2+
2+
-
-
2+
-
-
-
45
150
3+
2+
-
-
+
-
+

-1-
-
-
2-1-
3-1-
-t-
-
-
-
+
-
40
Staph,
epidermidis
5-02
2-1-
2+
-
-
+
-
-
-
-
3-1-
-
-1-
-
-
3+

-
2+
-
-
-
25
1-04
12-0^
2-1-
-»-
5-1-
-
-
-
-1-
-»-
+
+
+
-
+
+
-
2+
-1-
_
-
-
-
35 25

tong the, sd luang cac chung tu clu vang bi ngung ket duai tac dung cua lectin
la cao han (45- 55%) so vdi cac chiing tu clu trlng (25- 35%).
Ddng thdi, mot sd lectin cdn cd kha nang phan biet cac vi khuan trong ciing
mot loai. Vi du, lectin tir hoa hoe cd
miic
do gay ngung ket khac nhau tuy thuoc
26
ttog
chung tu clu trlng (manh nhit vdi 5-02,
y^u
han vdi 1-03, sau dd vdi 1-
04),
tuang tu nhu vay la lectin tii qua ca chua (sd 16). Trudng hop lectin tir hat
lac (sd 2) tuy cung tac ddng len
hiu h6't
cac loai vi khuan thu nghiem, nhung vdi
su chtnh
Itch
ra't ldn ve
miic
dd:
Staph,
epidermidis 1-04 bi ngung ke't dac biet
manh so vdi cac chung khac,
vi
vay cd the duac sir dung de nhan bie't chung tu
clu trlng gay doc thuc
phim
nay.
Thdng thudng, da sd cac phdng thi nghiem sir dung catalase va xet

khong tac dung
Itn
cac vi khuin G(-) la E.
coli.
Salmonella hay Shigella
(miu
khoai tay (18) va che
phim
lectin cam thao day (6)
cQng
cd tac dung
gin
tuang
tu).
Dieu nay cho tha'y nhung lectin nay khong cd cac vi tri lien ket vdi
phin
carbohydrate ciia cac lipopolysaccharide (LPS) cd tren thanh te bao vi khuin G
(-) va cd the
diing
de nhan biet loai vi khuan nay.
Lectin cd trong hat mudp
ding (11)
cd tac dung r5 ret len E. coli (vdi
miic
do manh ye'u khac nhau tuy thupc timg chiing) ma
hiu
nhu khong cd (hoac neu
cd chi la phan
iing
ye'u) vdi mot vai chiing thuoc cac loai khac. Trong khi dd,