HOI NGH! KHOA HOC C O N G N G H E SINH HOC Ta.-r ^
NGHIEN CLTU BUOC D A U V ^ 0OC TiNH CLIA CAC C H O N G K H U A N T A W S R / Q . CHOLERAE P H A N LAP TAI VlET NAM G A N DAY
Le Thj Thanh Thao\ Le Trin Hfing Ngoc\ Pham Himg Van^ Nguyin Thj Thu Hoai^
' Tnrdng Dai hgc qudc ti, D^l hgc quoc gia Tp. Hd Chi Minh ' Cong ty Nam khoa Biotek. Tp. H6 Chi Minh
T 6 M TAT
Nam cbunK v, khu4n ta Vibno cholerae phan lap va tuySn chon tir nhimg benh nhan tieu chay cfip o mien nam Viet Nam vao nhuogs 2010 v S z d T p b l b c b k h . ning sLxuitproteaT.^^^
th^ch chua CO ch4t tuong ung d6ng flioi b i m tra su hi^n hien ciia gene dgc lo ta bang phumg phap PCR^ HoJ tmh e n ^ e cac d^
duoc danh gia dvra tren vong phan buy cua mSi chung trSn dia thach tuang iing. Vong phan hiy protein dao dpng rir 2,67±0 57 mn, (»
2 S ^ ) d t 3 6 7 X l 5 m m ( 2 « % 1 2 r v 6 n g a « . huyit tu 2mm (242-2012) ta,3mm(104-2012)^pangng,cn
lipase khong ph^l h.en iU a chung 42-2010 song c6 6 tit ca 4 chung con 1^ vm vong phan giai^tbay doi hr 2mm (1O4-201?, 3 5±0.71min (41-2010 v4 VCrC-2012). Kfit qua PCR cung cho tiiay rang, trong 5 mau v?t pham, 3 mau chua c^ ha. gene cttA vi«, (VCTC-2012 41-2010 vi 242-2012). Chung ta s6 42-2010 chi chua duy nhat gene cttA va an mgng la chuiig ta 104-2012 khong*
gene ma h6a doc l6 la. Nhihig kit qua neu tren chi ra rSng dpc linh ta khong cbi phu thugc vao gene ma hoa doc to ta ma con phy Ihi vio cic yeu lo khic cin phai dupe nghien cuu sfiu hon.
Tir kh6a: Vibrio cholerae, protease, hemolysin, lipase. Ope l6 li, lac nhan dfic.
MdeAu
B^nh ta Id b§nh ti§u chdy cSp nguy hiem din din vi§c m^t niroc v^ nhanh chong d i n den b> von^ n4u khonj dui^c chiia B§nh do phly khuin Vibno cholera (V. cholerae) gky ra. lan buyen qua du-crng thuc kr\. naae uong hogc tiep xCic vdt ph cua ngi/&i b$nh B^nh cd thi gay ra nhimg dich trfin quy m6 I6n khi cke dilu ki^n ve sinh khong 6km b i o vk chu ylu l^i ra d cke nadc dang phat biln. HSng nkm c6 khoang 3 din 5 bieu ca bfinh ta va 100 den 130 ngan n^ain chet do 13 p 2010] TO t h i ki thi> 19 din nay, nhan loai da trki qua bay dgi djch VD'I quy mo ngu'6'i mac, so vung, so nu'd'c mac nhiluti vk tic d$ tay lan cung nhanh ho'n.
06 khoing 200 nh6m huylt thanh O du'p'c biit din, tuy nhien chi hai nh6m huylt thanh 01 va 0139 ia dac biet nguy hiln c6 dOc tinh cao vk c6 khS nang tgo ra djch tren di§n rong, Ngutyc tai nhOng nhom V. cholerae Mike Oagc gop chung Nl nhdm V. cholerae kh6ng-01, kh6ng-0139 kh6ng gSy dich hoac dgi dich. Cac chung 01 du-gc chia ra lam 2 typ smh hgc typ c i diln vk typ Et Tor, va 3 kieu huylt thanh (Ogawa, Inaba hoac Hikojima) di,Fa theo s y phkn biet cac kieu hinh vi?
dSy Ik dga theo sa khac bi?t v l cac gen dpc to bao gom gen ma hoa nai (toxin-coregulated piius-tcp) tap tnang vko alen Id viing dilu h6a cua C7X phage (phage mang di^c t l ta) rstR (regutatory region for phage lysogeny) va kieu dpc t l la {ctK*|
toxin, CT, gen ctxA, ctxB) Ouqc sin smh. 95% cac chung thuoc nhom 01 va 0139 deu co kha nang sinh dpc to t i CT!- khi 95% Miic thuOc cic nhom kh6ng-01, kh6ng-0139 con tgi khong co kha nang n i y [Karaotis va cs. 1998]. TT\r(K\
1992. nhfim 01 t i nh6m huylt thanh duy nhat gay ra d|ch. Nam 1992. mpt nhom huylt thanh khic, l i 0139 giy ra ck biing phit tgi An Dp v i Bangladesh. Sif hign dign cua nh6m huylt thanh nay du-pc cho t i sy chuyin gen ngang giiia nhfim chung 01 va kh6ng-01 [Bik v i cs. 1995]. Nhu vgy c6 thi thay, sy biln dot v§ dpc tinh cua cac chung khuan tki ik nguy ca tilm ting giy nSn cic dich Ifin.
B|nh ta chu y l u Oagc gky ra do d^c t l ta ma hoa boi gen cfxAB. Mac du hai gen ctxA v i ctxB nam tren cung m$t vdng operon, lh|m chi mOt phin cua hai dogn gen nim ching ifin nhau tgi khung dpc mo (Open reading frame] nhiing tiSupl A v i biu phin B lai duvc ma hoa mgt cich ri§ng bifit [Lockman va cs, 1983; Mekalanos 1983]. Sau khi xam nh$p,pl khuin ta ca bu trong duong tieu hoi v i gay hgi cho nguoi theo mpt co c h l phCrc tap. Trong dul'ng rupt cua ngu^,t^
khuin bim vio cic Ifing nhung thanh nipt va tilt dOc to bao gim hai tieu phiin A v i B. Ty te v l tu-gng du'VC tilt ra cua!
tiiu thinh phin l i 1:5. Tiiu phin B kit hgp va dfing hoa tieu phan A tgo thinh beu phin A l . Dang biln dli A l xiic tfcl binh h6a hpc lim tang cirfrng tong hgp AMP vong (cAMP) khiln bieu mo ruot giai phfing "6 at" djch t h i va chit dien gSl tieu chiy. Ngoii dpc t l t i van con nh&ng doc t l khac gop phin gay nfin benh ta nhu- zot (zonula occludens toxin), (accessory chotera toxin), sto/sbi (none-01-heat stable enterotoxin), tcpA (toxin coregutated pilus). hlyA (hemolysin) vi enzyme ngogi bio.
Tgi Vigt Nam. b§nh ta da difgc ghi nh|n xuit hien tir giQa thi ky 19. Nam 1964 d miln Nam biing ten 1 vu dich tk I*
hing bim ngin ca, lan ra 35/ 45 tinh vol ty te ti> vong la 4,1 % [Hiln 2011]. Vao cac nam 2007-2010, dich t i da quayld nuoc ta v i xuit hien 6 nhieu tinh thanh bong c i nu^c. Cho din nay, nu-oc ta v i n phii dot mgt voi cac dich ta te t6 vSl CO bung phit thanh dich Ifin de dpa sue khoe cong dfing Cac ca benh ta xuat hign a Viet Nam chu y l u do nhfim 01,1 Tor vd'i cic duoi typ khac nhau gay ra (Tran HD va cs. 2012], Tuy nhien d i n nam 2010 da phit hien nhfim 0139 tronH
"Vf? " . ^ ^ '^' ^^"^ °'"^. " ^ " " ^ ^°'^ ' ' " ^ ^^ ^^^ "^"9 9^y ^^^^ ^="3 '^^ Ph^y ^ nay v^n chua dugc l i m ro [NguyenM cs. 2012). Cho tfin thoi diem hien tgi, c6 rat it nghien cuu ve dpc tinh cua khuan ta cung nha sy bien d l i cua cicilj khuan t i tgi Vi§t Nam, Do vgy, myc tieu cOa bii nghifin cuu cua chiing toi la nghien cuu buoc dau ve doc tinh ciM Chung khuan ta V. cholerae phin Igp tai Vigt Nam vao nam 2010 v i 2012
HQI NGH! KHOA HQC C O N G N G H ^ SiNH HOC TOAN QUOC 2013
NGUYEN L i f u VA PHUWNG P H A P NGHIDN COU Nguy&n l i f u
Nim Chung khuan t i (41-2010, 42-2010, 104-2012, 242-2012, VCTC-2012) dugc phan l$p tir nhu'ng b$nh nhin thupc miln nam Vigt Nam v i dtpgc chpn Ipc Kr bO smj tap cua TS Pham Hiing Van thupc cong ty Nam Khoa Biotek (qugn 7, tp HCM).
Phipomg phap nghien ci>u
Phin irng sinh hoa cho c i c enzyme ngoai bao
n o pl djch nuoi cly qua dem (khoing 7,5 xlO^ te bio) cua moi chung V. cholerae biang mdi birfi'ng LB (Luria- Bertani Broth) [dugc nhfi I6n giua dia thgch LB co b l sung 1,5 % bpt sira chi>a casein dugc diing nhif eg chat cho enzyme protease. Cic : dTa nay dugc Q fi' nhigt dp SS^C trong vong 24 gio, sau do dirge phin tich vong phan giai casein nhim dinh g i i hogt tfnh
^protease dya theo c i d i tinh cCia Alane va cOng sy [Alane v i cs. 1996].
.Hemolysin
••^10 pl djch nufii cay qua dem (khoing 7,5 xlO^ t l bao) cOa mfii chiing V. cholerae trong m6i trucrng LB dugc nho ten gi&a dia
^thgch mau. Cac dfa niy dugc iJ d nhi§t dp 35°C frong vong 72 gio', sau dfi dirge phin tfch vong tan huylt nham dinh gia tinh chit v i hoat tinh hemolysin.
Lipase
10 pl dich nufli cay qua dem (khoang 7,5 x10* te bao) cQa m i l chung V. cholerae frong mfli bir&ng LB dugc nho Ifin giira dTa .^mfli frifcrng bibutyrin chO-a 20 g/L of tributyrin agar (Fluka No. 91015) v i 10 ml/L dau fributyrin (Fluka No. 91010). Cic dTa
"niy dugc 0 g nhi#t dfl SS^C trong vong 48 gifi", sau do dugc phan tfch vong phin giai fributyrin nham dinh g i i hogt tinh lipase.
iPhin tich PCR
AON t6ng s6 cua khuan V. cholerae dugc tich chiet theo phi/ang phip sic nhi$L O i u bin, mgt khuan Igc cua V. cholerae Oirgc hoa tan frong 300 pl ciia chat dgm TE (Tris- EDTA) va dugc dun nfing tgi lOO^C trong vong 10 phut. Sau do, h6n hgp Itfiiy dugc dgt vao d i 10 philt tilp theo va sau cung dugc li tam vcri vgn t i c 13.000 vong frong 10 phut. 100 pl cua dung dich ijnli tren m i l chi>a ADN dugc diing lim khufin mau cho phan i>ng PCR
'' Phan tich PCR dugc thyc hi^n bing ba cgp moi dac hi^u trong do bao gim hai cgp moi dgc hi§u cho gen ctxA v i mpt cgp
~ noi dac hi$u cho gen cfxB v i dugc mi§u t i d Bang 1. Thanh phan PCR (trong 20 pl) bao gom 10 pl ciia hfln hgp Taq PCR 'Tiaster mix (Quiagen No. 201443); 0,1 pl ciia moi mfli logi v i 5 pl cua ADN khudn mau. Khuich dgi PCR theo phuang thirc.
I'db'^CI 5 phut; 30 chu ky; 95°C/1 phiiL SO^C/I phiit, 72''C/ 1 phOt; va cuii ciing 72°C/ 7 phut. Sin pham PCR dugc ^en di .^I'jen gel aganase 2 % v i nhuflm bang Gelred (Biotium).
aBing 1: Cip mdi dimg trong phin tfch PCR
MuctiSu
CtxA cbtA
cb(B C $ p m o i
F, Rl Fz R I F R
ChuSi Nucleotide AAAGAArrCAAGCAGTCAGGTGGTCTTATGC AAAGGATCCTCGATGATCTTGGAGCATTCCC CTCAGACGGGATITGTTAGGCACG TCTATCTCTGTAGCCCCTATTACG AAAATTCTTTGACGAATACC TTGCTTCTCATCATCGAACC
\ f i b 1 b e n c b t opemn"
609-639 1131-1161
712-735 990-1013 1193-1212 1698-1717
kfch thucrc b i n sao (bp) 553
302
525
Tham k h i o
[Salles vk cs 1993]
[Shirai vS cs.
1991]
[Karaolis v i cs. 1999]
ii
* 'Chuli nucleotide cOa clx operon duo^ tircrng thugt bcri Mekatonos v i c6ng sy [Mekalonos va cs. 1983]
K ^ QUA VA T H A O LUAN
^'iCic djnh s y hien dien cua c i c enzyme ngogi bao trong c i c chung V. cholerae J* Protease
If Sau khi nufli cay 24 gia, sy sin xuat enzyme pnDtease cua V. cholerae Oagc xie djnh bang sy xuit hifin cua vong phin giii Jibrotein xung quanh khuan Igc. Kha nang phan huy cua protease diroc do v i phin cap dya theo kich thufl'c cCia vfing phan p^iii protein [Alane v i cs. 1996]: (++) > 2 mm; (+) 1- 2 mm; (-) khong co vfing phin giii. Theo do kich thufl'c cua vflng phan (i^iai protein phin bo tir 2.67± 0,57 mm ( chung 104-2012) din 3,67± 1,15 mm (chung 42-2012). Phin tfeh dya v i o tren ket
•i^uk nay cho thay ring khong co sy khic bfet ro ret v l kha nang phan giii protein cua eac chung V. cholerae giua nam 2010 ik nim 2012. Tuy nhifln, c i n cfl so \agng m i u Ifi-n hgn d l khing dinh ket qua nay.
HOI NGH! KHOA HQC CONG NGHE SINH HQC I U A I N U U ^ - <
41-2010 42-2010 104-2012 242-2012 VCTC-2012
H,„h ,: Khi „ s n , phSn 0i, protein « p «a ,h,.h c h * . oas.l. d ^ dOng nh„ co. ch3, cho enz,n,. protease o u , S ch»
cholerae giira nam 2010 va 2012.
Bang 2: Kich thu*c v i d p d$ phan huy protein ciia nam chiing V- cholerae Oagc si> dung trong nghiSn cur.
j^IE»i;;f'Jj^S!Ei,,.,;^ . S^m l^ saumm
'&n chuna
Kich thu*c v6ng phin gidl protein (mm) 3.00± 0.00 C^p<l$
Hemolysin M Sv san mil hemolysin cua V. choleroe ( J w thS hien bSng vdng tiSu huyit cua V. ctoterae tren dia thach mju ( H l n h ^
qua cho thSy, tit c l nSm chung V. cholerao 6l,u \i chung lieu huylt p (san smh p- hemolysin g i y tan mau hoin M n j ^
°a ,6ng ti6u huySt v*i kich thj^c t£r 2,00* 0,00 mm (chung 242-2012) din 3,00± 0,00 mni (chung 104-2012) (Bang s f l ao tiSu huyit cua nSm chung a w e aanh gia vS ghi nh»n trong Bang 3 Theo phan tich thSng kS cho thSy rang k h 6 n g « khac bi« ra ret nio v i khi nang hoat aOng ciia hemolysin cua nam chung V. cholerae giira nam 2010 va nam 2012. T u i lv, mOt phan Uch IrSn s6 Iwng mSu ion ho'n la can Ihlll a l khang ajnh ket qua nay.
41-2010 42-2010 104-2012 242-2012 VCTC-2012 Hlnh 2: Kha ndng san xuSt hemolysin cua nam chung khuin V. cholerae giira nim 2010 va 201Z
Bang 3; Kich thviVc vdng tiiu huy^t cua nam chang t^. cfioferae du'crc si> dung trong nghien c
Kich thu'^c v6ng tifiu huy^t (mm) 2,67± 0,57
C5p ap ++
g^K'Hi] a^Sffi' 2,67± 0,57 ++
.[lilSTiTO 3,00± 0,00 ++
• -SCpKilR 2,00+ 0,00 +
• TIHTi^hW 2.67± 0,57 f
**
Lipase
Cung gilng nhu protease va hemolysin, k h i ning sin xuat lipase cua nam chung V. cholerae Oaac xac djnh dya tr§nvi phin giii lipid (Hinh 3). Tuy nhiin, trong nam chung V. cholerae duyc nghifln CLPU, chi co bin chiing cfi kha nang sans lipase (chung VCTC-2012. 41-2010. 104-2012, 242-2012) v i tao ra vong phan giai lipid co kich thuoc tu 2,00± 0,001- (chung 104-2012) din 3,50± 0,71 mm (chiing 41-2010 v i VCTC-2012). Rieng chung V. cholerae 42-2010 khflng sann enzyme lipase nao duoc xac iflnh trang thu- nghigm nay (Bang 4).Gi6ng nhu protease v i hemolysin, d p dfl phin gi^ii'' cua cic Chung V. cho/erae ducrc danh gii va I h l hi§n 6' Bing 4. Ogc biet, neu phin tich nhom theo nam thi co su- khact rfl r§t v l khi ning phin giai lipid cua cic Chung V. c/jo/erae giQ-a nam 2010 va 2012. Tuy nhien, giong nhu doi vm phan.:
cho pRjtease v i hemolysin, kit luan niy can duyc kilm chung VD'I S6 luang mau Idn han. l Xie djnh s y hign dign ciia gen ctxA trong cac chiing V. cholerae
Sg hi§n dign cua gen cfxA trong V. cholerae Oaac xie djnh bing PCR vai cgp mfli dgc hieu. Kit qua dien di treo agarose gel cho thiy khfing xuat hiin bing ADN d chung V. cholerae 104-2012 va xuat hign bang ADN co kfch thuo-cg kich thufi'c mong dyi (553 bp v i 302 bp) 6 nhung chCing V. cholerae con lai (VCTC-2012, 41-2010, 42-2010, 242-2(
Dieu niy gyi y gen c(xA khdng ton tgi trong hg gen cua chung V. cholerae 104-2012. (Hinh 4a va 4b) Xac djnh gen cllrB trong nam chiing V. cholerae
Kit qui phin tfch PCR duyc trinh bay a hinh 5 eho thay cfi 3 bang ADN xuat hien d cae ehung V. cholerae VCTC-2011 2010, 242-2012 v i kich thudc cua bing ADN khoang 525 bp phii hap vai kfch thudc mong dyi. Tuy nhien, bang cO^
.^ , CONG NGHE SINH HOC TOAN QU6C 2013
;hurig 242-2012 ma hem h i n hai chiing c6n Igi, rh co t h i lien quan d i n s6 lugng ban sao gen ctxB tnang chung 242-2012 Jo hien tugng so liremg sai khic vk s6 lugrng ban sao cie gen doc to noi chung va ctxB noi ridng fi* cae chiing V. cholerse Ik
•kt pha Win [Mekalanos 1983]. Bgn canh d6, khong c6 bang ADN nao xuit hign d hai chting V. cholerae 104-2012 v i 42- 2010. Kit q u i n i y khang djnh gen cbtB khing ton tgi o- hai chiing V. cholerae 104-2012 v i 42-2010. Vigc khong xuat hign gen ddc to t i , cfteA v i ctxB d m^t s6 thiing V. cholerae l i hi$n tuang da dup'c ghi nhan, do hai gen n i y nam tren phage Karaolis v i cs. 1998]. Tuy nhidn, viec phit hi|n sij- bien mit cua c(xB don le, va c(xA-B dong thdi trin cac chCing V.
zholerae l i m sang tgi Vi^t nam l i mpt diim mdi, c i n phii dugrc nghiin ctru thim.
41-2010 42-2010 104-2012 242-2012 VCTC-2012
•flnh 3: Khi ning san xuit lipase cua nim chDng V. cholerae glQa nam 2010 v i 2012 3ang 4: Kfch thadc vong phin giil lipid ciia nam chOng V. citolerae augc sd dvng trong nghien cuu fTen c h d n g ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ B
Kich thadc vdng phan giii lipid (mm)
< Cap do
• 4 ^ 0 1 0 H ^ I 3,50± 0,71 ++
^Ht^oio^l
0,00± 0,00
| l 0 4 ^ 0 1 ^ H 2,00± 0,00 +
^ E 4 2 - 2 0 l 3 i l 3,00± 0,00 ++
BK?^^c^oi2lH
3,50± 0,71 [
1
553 bp
Hinh 4: Di#n di sin pham PCR sii' dgng c|p m&i ctxAl (a) v^ cfxA2 (b). L: thang chuSn kich thudc ADN (100 bp), 1- 5 chOng V. cholerae /CTC-2012,41-2010.104-2012,42-2010,242-2012, (-) thSnh ph^n PCR khdng c6 ADN mau.
ffinh 5: Dign dJ san pham PCR su di^ng cap moi ctxB. L: thang chuan kich thu'dc ADN (100 bp), 1-5 chung V. cholerae VCTC-2012, 11-2010,104-2012, 42-2010, 242-2012, (-) thanh phin PCR khdng cd ADN miu.
<eTLUAN
aua q u i trinh nghiin cuu, chiing toi nhin thiy ring ddc tinh ciia cac chiing V. cholerae cfi sy khac biit nhit djnh va k h i
•ling gay b§nh t i ciia c i c chiing l i m sang n i y khong ch! phy thuOc duy nhit vao sy hign dien cua dgc to ta. Sy thay do! eiia enzyme ngogi b i o eung chua dup'c thay ro trong nghien cuu cOa chung t l i do bj gidi han ve so luang mau v^t. Do vay d l
HQI NGH! KHOA HOC CONG NGHE SINH HOC TOAN Uuu<^ ^u iJ
n h i n duiTc k i t q u i c 6 # nghTa h e n , d n t h i l t p h i i m d r g n g s l l u p n g cac c h u n g c h p n l p c s y d y n g c h o n g h i i n c u u c Q n ^ p h i n « c h t h i m c i c d&c l l k h i c c f i l i i n q u a n d i n d | c tinh c u a k h u i n ta n h u z o t , a c e . t c p , c a c e n z y m e n g o g . b i o k h i c , v.v.
T A I u e u T H A M K H A O
Atar« B. v., M N L. M.. Andrea L . Simooe D G. P, Andre A. C . Marta H. B (1996) Detectkm of extracellular proteases (n, nvcroorganisms on agar plates. Mem inst Osvraldo Cruz. Rk> de Janeiro 91 (6): 755-760
Bik EM. Bunschoten AE, Gouw RD, Hooi FR (1995) Genesis of the novel epidermc Vibrm t^olerae 0139 strain: evidence for horizaia transfer of genes involved in polysaccharide synthesis EmbroL 14:209-216
Hi^n ND (2011) Bgnh ta. Thif vi$n Y hoc Vi$t Nam
Karaolirs DK, Johson JA, Bailey CC, Boedeker EC, Kaper JB, Reeves PR (1998) A Vibrio choleraepalliogenkity island associated tm epidainc and pandemk: strains. Proc HaOficad Sci USA 95.3134-3139
Karaoiis, D K R . . Somara. S., Manev^ Jr.. D.R., Johnson, J A and Kaper, J.B. (1999) A bacteriophage encoding a pathogenicity islanit type-IVpaus and a phage receptor in cholera baclena. Nature 399, 375-379
Lockman, H. A. and Kaper, J B (1983) Nucleotide sequence analysis of the A2 and B subunits of Vibrio cholerae enterotoxin. JounMs|
BiokigKcal chemistry. 258, 13722-13726
Mekalanos, J J. (\9S^). DuplicaScn and amplification of toxin genes in Vibrio cholerae. Cell, 35:253-263
Nguyen DT. Ngo TC, Tran HH, Le m , Nguyen HT. Nguyen BM, Tran ND. Yamashiro T. Ehara M (2012). Characterization of Vibno c/iota Ol39 of an Aquatic Isc^atkxi in Northern Vietnam. Open Microbiol J 6:14-21
Salles, C A . , Momen, H , Vicente. A.C.P. and Coelho, A (1993) Vibriot^olerae in South America, polymerase chain reacHon and ryram analysis. Trans R. Soc. Trop Med Hyg 87. 272
Shirai UN, Nishlbuchi M, RamaimBthy T (t99t) f^merase chain reaction hr delectmn of the cholera toxin opemn of Vibrio cholera. J Ch Microbiol.. 29.2517-2521
Tran HD. Alam M. Trung NV. Wnh NV. Nguyen HH, Pliam VC, Ansanjzzaman M, Rashed S M . Bhuiyan NA, Dao TT, Endtz HP, Wertf*
HF. Multi-drug resistant Wbno cholerae Ol variant El Torist^ated in Northern Vietnam between 2007 and 2010. J Med Miaobiol 61:4314 Worid Health Organization. Chotera vacdnes. A bnef summary ofthe Match 2010 position paper.
FIRST REPORT ON THE VIRULENCE OF SOME VIBRIO CHOLERAE STRAINS ISOLATED IN VIETNAM RECENTLY
Lft T h | T h a n h T h a o ' , L d T r i n H o n g N g 9 c \ P h a m H i i n g V W , N g u y i n T h j T h u H o a i ' ' 1. Khoe Cdng ngh^ sinh hpc, D^i hgc qudc t4, Dei hgc quoc gie tp HCM
2. C6ng ty Nam khoa Biotek, qu$n 7, tp HCM
Vtbno cholm,. c u s a t v e agcal o f severe watery dian-hea resaneijed i n 2007 in Vietnam and smcc then caused several laree ck oulbrealoi Ihranening public health. Clinical data indicated a change in the viralence o f V. cholerae strains associated with t h e i u l b . however evidence is s n l l l a c k n , ^ To fiilfill this gap, a n^resenUlive coUechon o f five V. clioleroe strains isolated from diarrheal pli in sonlhem Vietnam between 2010 and 2012 was investigated. They were examined f o r the ptodnction o f extracellular Z , hemolysin and lipase enzyme acn vines and presence o f cholera toxin gene by using PCR method. The enzymatic «itivities were U S 2 ? l t ' ~ t ' " s ™ r " ? . * = . " ™ ' » » ' " " S f » ' ' > ' » ' » ' •^' P""«^ activity and hemolysis a c t i > a W f Merce stiains M and 2012 were not significantly diHctent Proteolytic nng ranged from 2.67±0.57 m m (104-2012) to 3 67±1 15 m m r242.20m.
Z t l » ' l o ' l 4 ? 2 " l 2 T < ! S ' ™ ? ' ° . ' , r , i i r ° " ' - " • » " ' " " " • ^ ™ ^ * " • i ° « i " « Z O l f a i d p r e T n t ' „ 4 ~ S L ft! p c k ~ u 1 ? r f I ^ k " J i , ^ " ' " ' ™ « ' ° ^ '""" ' " ™ < " " ' - 2 ° ' 2 > "> 3 - 5 ± 0 ' l ™ n (41-2010 and VCTC-20B M l ^ ' d 242 ™ ^ H ^ t o f ' T t ° " ' . ! f " • • ' • " " " 8 "•=»= 5 clinical strains, 3 isolates had c a A and c t t B genes (VCTC-20I1|
20 " i raSBiiiSSSeSf r J " ' w ' " ^ " " ° ' ° ' " ^ i ^ ™ » v e l y . ' i - > l " e did „ o . c o n l i n a^y c « g e i « l
Key words. Vibrio cholera, pmtease, hemolysin, lipase, cholera toxin, vimlence fiictors
* Corresponding author ntthoai@haniu edu.vn
