H VI SINH VT THC PHM

H vi sinh vt thc phmVi sinh vt c hiVi sinh vt c li

Yu cu:

K tn nhng vi sinh vt c li v ng dng ca chng. K tn nhng vi sinh vt c hi in hnh v ngun ly nhim. Cch ngn nga s ly nhim hoc hn ch tc hi ca VSV c hi?

Vi Sinh vt thng gy nhim thc phm1. Vi khunEscherichiaEnterococcusBacillus LactobacillusMicrococcus ListeriaStaphylococcusSamonellaClostridium Pseudomonas ShigelaVibrioYersiniacampylolacter

3. Nm menSaccharomycesCandida

2. Nm mc AspergillusFusariumPenicilliumRhizopus

8 ngun i tng gy nhimt v ncNg cc v rau quVt cha ng thc phmQua ng tiu haTay ngiThc n gia scC th ng vtBi khng kh

S H HNG THC PHM

I. VI SINH VT GY BNH THNG GP Coliform va coliform phan Hnh que, Gram (-), khng to bo t Ln men lactose v sinh hi t0 pht trin: (-) 2 500C pH: 4,4 9,0 Nhim nc hoc thc phm nhim phn Loi tiu biu: E.coli, Enterobacter aerogenes, ShigellaColiform phan

Escherichia coli Hnh que, khng to bo t Gram (-), catalase (+), oxidase (-), t0 pht trin: 7 500C, topt: 370C pHopt : 7,0-7,5 aw : 0.95 Nhim t phn Gy bnh ng rut, tiu chy nhiem khuan mau, viem mng nao, nhim khun ng tiuI. VI SINH VT GY BNH THNG GP

I. VI SINH VT GY BNH THNG GPEscherichia coli

VI KHUAN NG RUOT- E.coli

VI KHUAN NG RUOT Coliform

ColiformC E.Coli v cc dng coli khc: que ngn hoc di, khng sinh bo t, chuyn ng, gram m, k kh ty tin. Nhit ti thch 37oC, pht trin tt 44-45oC, ngng pht trin 5oC, sau 15-20 pht cht 60oC. Nu nhim mt lng ln s b ng c.

VI KHUN NG RUTTch cc: to thnh vitamin nhm B, c tnh i khng vi cc vi khun gy bnh, c bit vi khun l v thng hn Tiu cc: ngi mt v yu, m bnh c th xut hin tnh gy bnh ca vi khun ng rut.

- Staphylococcus Hnh cu, khng to bo t Gram (+), t0 opt: 370C, pHopt : 6 7 CNaCl: 9 10% Sng da ngi, ng h hp, tiu ha. To mn nht, lm ng huyt tng Gy bnh vim phi, vim mng no vim c tim, vim thn, ty xng Cht c ch: hexaclorophen, tm gential Cht tiu dit: clorit, neomycine, polymycine I. VI SINH VT GY BNH THNG GP

I. VI SINH VT GY BNH THNG GP-Ngun gy nhim: t nhng ngi b vim mi gy nn vim xoang, t cc ung nht, hoc cc vt thng b nhim trng, t da ngi tip xc vi ngi bnh. Staphylococci gy chng vim v b, lm nhim sa v cc sn phm t sa. Cc sn phm thc phm thng c Staphylococci : tht v cc sn phm t tht, c v cc sn phm t c, sa v cc sn phm t sa, salad, pudding, cream.

STAPHYLOCOCCUS AUREUS

Gi l t cu vng, sinh sc t vng kim, rt hay gp trong ng c do nhim khun. c trng nht l t v b sa b vim. Sinh ngoi c t (enterotoxin), bn vi nhit (ung si 2h or 30 pht 120oC), gi c hot tnh trong 2 thng nhit thp, chu c mi trng axit vi pH 5 v cn.c t ca Staphylococcus aureus khc nhau v tc vi c cht khc nhau, nhanh trong mi trng giu protein v cht bo.STAPHYLOCOCCUS AUREUS

Staphylococcus c hnh cu kt thnh chm, khng chuyn ng, khng to bo t, chu c kh hn, sinh sc t trn mi trng nui cy. Hiu kh ty tin. Nhit ti thch 37oC, trn 4oC to c c t. S. aureus chu c nhit 70oC, 80-85oC cht sau 20-25 pht. Chu c trong dd mui 12% v ng 50%.STAPHYLOCOCCUS

- Shigella Trc khun gram(-) Khng di ng, khng sinh bo t K kh ty tin Ch to acid t ng t0 opt: 10 40oC, pHopt : 6 8 - Nhim vo c, qu, rau, tht, t nc hoc phn ngi To c t, gy tiu chy, c ch hp thu ng v acid amin rut non, tiu ra mu c nim mc rut, mt nc, st cao c th gy t vong (bnh l trc khun).I. VI SINH VT GY BNH THNG GP

SHIGELLA

SHIGELLAVi khun lTrc khun, khng sinh bo t, khng chuyn ngiu kin ti thch: 370C, pH mi trng trung tnh 450C: Trc khun khng pht trin 600C: Cht sau 10 phtPhn ngi bnh hoc ng vt b bnh l ngun ca mm bnh

- Salmonella- Trc khun gram (-), khng to bo t- C tin mao (tr S. gallinarum)- Kch thc t bo: 0,5 3 m - Vo c th t phn (ngi, ng vt lng v); t ngi bnh - t0 opt: 37 oC, pHopt : 4 9- Gay tieu chay, oi ma, buon non, chng Sal. typhy, Sal. paratyphi gy st thng hnI. VI SINH VT GY BNH THNG GP

SALMONELLA

Salmonellac im chung: C hnh que (trc khun) un thnh cc vng trn, chuyn ng, khng sinh bo t, k kh ty tin. K ti thch 37oC, pH kim nh. Ngng pht trin 5oC, 70oC b cht sau 10 pht, nhy cm vi cc cht khng khun. Salmonella sng kh lu trong mi trng ngoi, c th tn ti vi thng trong thc phm ng lnh.VK Salmonella c th sinh trng TP nhng khng sinh c t, ch sinh c t trong rut hoc mu, gy vim nim mc rut. Khi nhim s c triu chng bnh thng hn v ph thng hn, km theo cc triu chng ng c.

SALMONELLA

SALMONELLAVa c tnh bnh truyn nhim, va l bnh nhim khun- c tS. typhosa (st thng hn)S. typhimurium (Ph thng hn)ng vt khe mnh vn c th mang mm bnhNhng loi khng gy bnh c kh nng ln men ng lactoseNhng loi gy bnh khng c kh nng nyTrc khun thng hn c kh nng ng ha cc ngun ng thp nht

- Yersinia Trc khun gram (-) C th chuyn ng. K kh ty tin Khng to bo t t0 opt: 25 32oC Nhim vo thc phm: tht, c, sa, phomt Khi mi nhim: nn ma, tiu chy; lu: ng mu, ni hch, h huyt p, ngi tr nn l , suy thn, suy timYersina pestisI. VI SINH VT GY BNH THNG GP

- Vibrio Phy khun. Phn ln thuc gram (-). Di ng nhanh Khng sinh nha bo Phn ng oxydase dng tnh. Hiu kh ty tin Thng c mt hi sn, cc sn phm hi sn C kh nng gy bnh dch t, nhim trng mu Vibrio cholerae tren moi trngTCBSVibrio choleraeI. VI SINH VT GY BNH THNG GPVibrio parahemolyticus

VIBRIO

VIBRIO

VIBRIOVi khun gy bnh tHai loi gy bnh: Vibrio cholera; V. comma Vibrio parahemoliticusPhy khun t

Vibrioc im chung: Trc khun c hnh ung cong nn gi l phy khun t, khng sinh bo t, c th chuyn ng, sinh ni v ngoi c t. c mt khp ni (tr khng kh) nhng tc nhn chnh vn l rui nhng. Vibrio bn vi mi trng ngoi (25 tun trong t, 40 ngy trong c cua ho s), b cht sau vi giy trong nc si, nhy cm vi cc cht st khun v mi trng axit.Tc ng lm ri lon trao i dch mui-nc, ri lon iu ha thn nhit v hot ng ca h tim mch, t l t vong kh ln.

- BacillusTrc khuan G(+), sinh bao t, k kh tuy ytang trng trong khoang nhiet o t 5-50oC, toi u 35-400C. Xam nhap vao sa, tht, rau qua, hon hp gia v, san pham kho Tiet hai loai oc to chnh: diarrhoeal toxin gay tieu chay va emetic toxin gay non ma. Bacillus cereusI. VI SINH VT GY BNH THNG GP

BACILLUS ANTHRACIS

Bacillus anthracisc im chung: L mm bnh than, nguy him vi ngi. c dng hnh que ln, sinh bo t, khng chuyn ng, t bo thng dnh nhau thnh chui v c bao nhy. ng vin mp khng bng phng v chng lin kt chng cho, xon li vi nhau. Nhit ti thch 30 - 37oC, to bo t 12-40oC (tt nht 30oC) trong k hiu kh. Di 12oC v trn 42oC vi khun ngng pht trin. Mm bnh t ng vt bnh. Th hin 3 dng: Rut: do n ung, t vong cao Phi: qua h hp Da: do tip xc, t da s vo mu pht bnh.

BACILLUS ANTHRACIS

BACILLUS ANTHRACISBo t cc k bn vng: - Sng hng chc nm trong iu kin kh - Khng b tiu dit trong nc si - Chu c mi trng cc oan: acid, kim, tanin, v mui khong

BRUCELLA

Brucellac im chung: C dng hnh cu hoc que ngn, khng tin mao, khng to bo t, k kh ty tin. Sinh trng t 4 - 45oC, nhit ti thch 37oC. Sng lu trong mi trng bn ngoi, chu c kh hn, chu lnh, nhng nhanh cht nhit cao, cht sau vi giy 100oC, km chu ng vi cc cht st khun.Brucella gy bnh sy thai non ng vt. d v cu l mm bnh nguy him nht i vi ngi l loi Brucella melitensis.

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- Clostridium Trc khun gram (+) Khng di ng Ym kh (k kh) To bo t. Bo t rt chu nhit. t0opt: 43 47oC, pH: 5 9 B c ch bi NaCl 5%, hoc NaNO3 2,5%Clostridium botulinumI. VI SINH VT GY BNH THNG GP

I. VI SINH VT GY BNH THNG GP- Clostridium perfringens: nhim vo tht gia cm. Gy au tht bng, tiu chy.

- Clostridium botulinum: nhim vo hp, rau qu, tht, c, cc sn phm thu sn. Tit c t botulin gy hi chng botulism (ng c tht): i ma, bun nn, ri lon thn kinh, th gic, t lit, c th dn n t vong

CLOSTRIDIUM BOTULINUM

T l t vong cao, Clostridium botulinum cn gi l vi khun c tht.Thuc dng k kh nghim ngt, sinh trng mnh 20 37oC , di 20oC t to c t, ln men c mt s ng v to axit, sinh hi, khng pht trin pH

L vi khun gy phng hp hp tht c. Trong iu kin ym kh s sinh ngoi c t gi l botulin, c c tnh mnh nht. c t khng b phn hy trong mi trng axit d dy v enzyme tiu ha, chu c nhit thp, mt hot tnh nhit cao v mi trng kim, b ph hy 50oC sau 30 pht.c t tc ng n h thn kinh no b, mch p nhanh, h tun hon v h hp b t lit.CLOSTRIDIUM BOTULINUM

H vi sinh vt tht: Ly nhim trong qu trnh git m, vn chuyn v bo qun: - Vi khun gy thi ra Cc bo t nm mc Cc t bo nm men II. VI SINH VT TRONG CH BIN V BO QUN THT Vi sinh vt ph bin gy bnh t thtSamonella Bacillus anthracis Clostridium botulinum, clostridium welchii

Cc dng h hng ca tht:Ha nhy: giai on u ca qu trnh h hng tht. Cc vi khun thng thy lp nhy: Micrococcus albus, M. liquefaciens, M. aureus, M. candidus Streptococcus liquefaciens; E. coli Bact. alcaligenes, Bac. mycoides, Bac. mesentericus Pseudomonas Leuconostoc Lactobacillus, v mt s loi nm men.LeuconostocII. VI SINH VT TRONG CH BIN V BO QUN THT

Cc dng h hng ca tht:Ha nhy tht gia cm do PseudomonasII. VI SINH VT TRONG CH BIN V BO QUN THT

II. VI SINH VT TRONG CH BIN V BO QUN THTCc dng h hng ca tht: Ln men chuaCc vi khun thng thy: vi khun lactic mt s loi nm men. nm mc vi khun gy thi

II. VI SINH VT TRONG CH BIN V BO QUN THTCc dng h hng ca tht: S thi raCc vi khun thng thy: Vi khun hiu kh: Proteus vulgaris, Bacillus subtilis, Bacillus mesentericus, Bacillus megatherium, Vi khun k kh: Clostridium perfringens, Clost. putrificum, Clost. sporogens, Qa trnh thi ra u tin phn hy protein ri n ng ha cc sn phm phn hy.

II. VI SINH VT TRONG CH BIN V BO QUN THTCc dng h hng ca tht: S bin i sc t: tht chuyn t mu sang xm, nu hoc xanh lcBacterium prodigiosum vt Pseudomonas pyocyanea xanhPs. fluorescens - lcCc vi khun thng thy khi lp xng, xc xch i mu: Lactobacillus, Leuconostoc (to mu xm)

II. VI SINH VT TRONG CH BIN V BO QUN THTCc dng h hng ca tht:Cc vi khun thng thy : Bacterium prodigiosum hoc Serratia marcerans: vt Pseudomonas pyocyanes: vt xanh Pseudomonas fluorescens: vt xanh lc Chromobacterium: xm nht, nu en Micrococcus: vt vng S hnh thnh vt mu: ph thuc vo lai vi khun hiu kh

II. VI SINH VT TRONG CH BIN V BO QUN THTCc dng h hng ca tht: S pht sng: xut hin khi tht bo qun chung vi cCc vi khun thng thy : Photobacterium

II. VI SINH VT TRONG CH BIN V BO QUN THTCc dng h hng ca tht: S i: khi tht cha mCc vi khun thng thy : Pseudomonas Achromobacter Pseudomonas

II. VI SINH VT TRONG CH BIN V BO QUN THTCc dng h hng ca tht: S mc: pht trin trn b mt thtCc nm mc thng thy : Mucor Penicillium Aspergillus

II. VI SINH VT TRONG CH BIN V BO QUN THT Vi sinh vt trong 1 s sn phm t tht: Tht mui: ph thuc vo lai vi khun hiu khCc vi khun thng thy : vi khun chu mn

II. VI SINH VT TRONG CH BIN V BO QUN THT Vi sinh vt trong 1 s sn phm t tht: Tht bo qun lnh: p lnh v lnh ngCc vi khun thng thy : Tht p lnh: Pseudomonas, Achromobacter, Flavobacterium, Alcaligenes, Aerobacterium, Micrococcus, Lactobacillus, Streptococcus, Leuconostoc, Proteus Tht lnh ng: t thy

II. VI SINH VT TRONG CH BIN V BO QUN THT Vi sinh vt trong 1 s sn phm t tht: Tht hpCc vi khun thng thy : Bacillus subtilis Bacillus mesentericus Clostridium botulinum

II. VI SINH VT TRONG CH BIN V BO QUN THT Xc xch, gi, lp xngCc vi khun thng thy : Bacillus subtilis Bacillus mesentericus Bac. Mycoides E. coli Proteus vulgaris, Vi sinh vt trong 1 s sn phm t tht:

III. VI SINH VT TRONG CH BIN V BO QUN C Vi sinh vt trong 1 s sn phm t c: C p lnh Cc vi sinh vt thng thy : Pseudomonas fluorescens Bact. Putrifaciens Mucor stolonifer Mucor mucedo Aspergilus niger Penicilium glacum Rhizopus

III. VI SINH VT TRONG CH BIN V BO QUN C Vi sinh vt trong 1 s sn phm t c: C ng lnhCc vi sinh vt thng thy : Sarcina Micrococcus aurantiacus, M. flavus, M.roseus Bac. subtilis, Bac. Mesentericus Pseudomonas E.coli Aspergillus, Penicillium, Mucor

III. VI SINH VT TRONG CH BIN V BO QUN C Vi sinh vt trong 1 s sn phm t c: C mui : ph thuc vo hm lng muiCc vi sinh vt thng thy : Serracia salinaria Torula wemeri Micrococcus rocus

III. VI SINH VT TRONG CH BIN V BO QUN C Vi sinh vt trong 1 s sn phm t c: C kh : ph thuc vo mCc vi sinh vt thng thy : Vi khun : m 30% Nm mc: m 15%

III. VI SINH VT TRONG CH BIN V BO QUN C Vi sinh vt trong 1 s sn phm t c:C ngm cht bo qun : thnh phn vi sinh vt ph thuc vo hm lng cht bo qun Acid acetic Benzoat Acid salisilic Acid boric Hydroperoxyd Acid formic Cht khng sinh

III. VI SINH VT TRONG CH BIN V BO QUN C Vi sinh vt trong 1 s sn phm t c: C hpCc vi sinh vt thng thy : Bacillus subtilis Bacillus mesentericus Bacillus thermophylus Clostridium sporongenes Clostridium botulinum,

IV. VI SINH VT TRONG TM MC V NG VT NHUYN TH Vi sinh vt trn tm: S bin ca tm Do astaxanthin b tch ra v b oxy ha. Xy ra khi tm 8 12h sau khi nh bt ti nhit 30 40oCCc vi sinh vt thng thy : Pseudomonas Lactobacillus Coryneformes

IV. VI SINH VT TRONG TM MC V NG VT NHUYN TH Vi sinh vt trn tm: S bin en ca tm : C th do 1 trong cc nguyn nhn sau Do vi khun ly nhim Do tyrozin b oxy ha Do phenylalanin b oxy ha

IV. VI SINH VT TRONG TM MC V NG VT NHUYN TH Vi sinh vt trn mc: S hnh thnh vt mu : Mu vng: Do Pseudomonas putida Mu : Do Serratiaa marcescens

IV. VI SINH VT TRONG TM MC V NG VT NHUYN TH Vi sinh vt trn ng vt nhuyn th: S thi ra: Salmonella, Vibrio S hnh thnh vt mu Mu hng: Do Rhodotorula Mu vng: Do oxy ha

V. VI SINH VT TRONG SA V SN PHM T SA Vi khun ln men chua: Streptococcus lactis Streptococcus cremoris Lactobacterium bulgaricum Lactobacterium lactis Lactobacterium casei Lactobacterium plantarun Lactobacterium helveticum Propionibacterium Nm men

V. VI SINH VT TRONG SA V SN PHM T SA Vi khun sinh hng: Streptococcus citrovorus Streptococcus paracitrovorus Streptococcus diacetilactis Lactobacterium lactis Leuconostoc citrovorum Nm mc

V. VI SINH VT TRONG SA V SN PHM T SA Vi khun gy h hng sa:Vi khun gy ng Streptococcus liquefaciens Trc khun ng rut Vi khun butiric Vi khun gy thi Hiu kh: Bacterium fluorescen, Proteus vulgaris, Bacillus subtilis, Bacilus mesentericus. K kh: Bacillus putrificus, Bacillus botulinus

V. VI SINH VT TRONG SA V SN PHM T SA Vi khun gy h hng sa:Vi khun hai sinh Staphylococus Tetracoccus Bacillus megatherium Bacillus mycoides Bacillus sporogenes Nm men: Mycoderma Nm mc: Endomyces lactis, Mucor, Aspergillus, Penicillium, Oidium

VI. VI SINH VT TRONG NG Vi sinh vt trong syrup: Leuconostoc mesenteroides Bacillus subtilis Bacillus cereus Bacillus megatherium Bacillus mesentericus Micrococcus Flavobacterium Achromabacterium Escherichia

VI. VI SINH VT TRONG NG Vi sinh vt trong ng th: Vi khun: Bacillus Nm mc: Penicillium glaucum Aspergillus sydowi Aspergillus niger Aspergillus alaucus. Nm men: SaccharomycesTorulaMonillia

VI. VI SINH VT TRONG NG Vi sinh vt trong ng ct trng: Bacillus stearothermophilus Clostridium thermosaccharolyticum Clostridium nigrificans Bacillus subtilis Bacillus megatherium Bacillus cereus Leuconostoc Sarcina Aerobacter Pseudomonas Bacillus

VI. VI SINH VT TRONG NG Vi sinh vt trong glucose: Trong nguyn liu: Bacillus subtilis, Bacillus mesentericus, Bacillus megatherium, Bacillus mycoides Vi khun lactic khng in hnhVi khun butiric Trong cng ngh: Bacillus subtilisBacillus mesentericusVi khun butiricE.coli Lactobacillus

VII. VI SINH VT TRONG BT V TINH BT Vi sinh vt c li: Saccharomyces cerevisiae Lactobacillus plantarum Lactobacillus brevis Lactobacillus fermentum Saccharomyces

VII. VI SINH VT TRONG BT V TINH BT Vi sinh vt c hi: Vi khun: Bacillus Nm men: Trichosporon variabileEndomycopsis fibuligeraRhodotorula Nm mc: Penicillium islandicum to luteoskirinAspergillus niger to alfatoxin Aspergillus

VII. VI SINH VT TRONG BT V TINH BT Vi sinh vt gy h hng bnh m: Vi khun: Bacillus mesentericus Nm mc: Penicillium olivaceumAspergillus nigerRhizopus nigricans Penicillium

VIII. VI SINH VT TRONG BNH KO Vi sinh vt t nguyn liu Vi sinh vt gy h hng sn phm: Ko: t tn ti Mt: thng gp nm men, nm mc (Rhizopus, Mucor) Bnh kem:E.coliBacillus coliBacillus subtilisBacillus mycoidesMicrococcus,

IX. VI SINH VT TRONG RAU QU Cc dng h hngH hng do nm mc Aspergillus niger : gy thi en rau qu ti, mc en hnh Penicillium : gy thi xanh rau qu ti, thi mc c chua, thi nhn qu ti. Fusarium: gy thi mc c rt, thi kh khoai ty Mucor: gy mc thi cn ty Rhizopus: gy nhn en rau ti

IX. VI SINH VT TRONG RAU QU Cc dng h hngH hng do vi khun Pseudomonas nh P. fluorescens: gy thi nhn rau ti; P. cepacia gy thi hnh Corynebacterium : gy thi khoai ty theo vng Clostridium: gy phng hp, sinh c t. Bacillus : lm nhn, en, nht rau ngm dm. Lactobacillus, Acetobacter: lm chua nc p rau, nc p tri cy

IX. VI SINH VT TRONG RAU QU Cc dng h hngH hng do nm men Candida Debariomyces Hanse Kloeckera Pichia Rhodotorula Saccharomyces Torulopis,

NGO OC THC PHAM DO VI SINH VT

NG C THC PHMNg c do ngun gc vi sinh vt nhim vo thc phmNg c do thc n h hng, i thiuDo thc n bn thn c cht cDo ha cht b sung hoc nhim vo thc n

NG C THC PHMNg c do ngun gc vi sinh vt nhim vo thc phmNg c do thc n h hng, i thiuDo thc n bn thn c cht cDo ha cht b sung hoc nhim vo thc n

NG C THC PHM DO C T CA VI KHUNExotoxin- Ngoi c t: l cht c do vi sinh vt sinh ra trong t bo ri tit ra ngoi t bo. Tnh c cao

Endotoxin- Ni c t: c t lin kt vi cc thnh phn ca t bo vi sinh vt. c t ch gii phng ra ngoi khi t bo cht v b phn hy

NG C THC PHM DO C T CA VI KHUNNi c t c tnh c yu hn ngoi c t nhng bn vi nhitNg c thc n c 2 dng:Ng c do n phi thc n c c t ca VSV m khng cn c t bo sng ca VSV.Ng c do n phi lng ln VSV, c kh nng sinh ni c t. Gi ng c thc n c iu kin hay ng c thc phm nhim khun-c t (toxincoinfection)

NG C DO NHIM KHUN C TDng trung gian gia nhim khun gy bnh v ng c c t thc phmCc triu chng xy ra ging nh ng c do c t, nhng c tnh ly truynNg c c iu kin: thc n b nhim lng vi khun sng kh ln v sinh ra ni c t. (105-106 t bo/ g thc phm)

NG C DO NHIM KHUN C TNhim khun c t do Salmonella: ch sinh c t khi vo rut hoc mu.Ng c do nhm Proteus: trc khun nh, khng sinh bo t, chuyn ng, pht trin thch hp 25-37oC. Khun lc kt thnh m.

NG C DO NHIM KHUN C TNg c do nhm vi khun ng rut:Coliformparacoli (hnh que ngn v nh)Clostridium perfringens (Welchii)Enterococcus hoc Streptococcus faecalis (chng S. faecalis v liquefaciens gy ng c)a s dng hnh que hoc que ngn (ging hnh cu) v hnh cu. Khng sinh bo t, chuyn ng, d tnh v dinh dng, sng k kh hoc k kh ty tin.

Ng c do nhim khun Clostridium perfringens (Welchii)Trc khun dng bo t, khng chuyn ng, gram dng. Nhit ti thch 37-45oC, to c t nhiu 37oC, pH>5 To 2 loi c t: hoi t v dung gii mu. C kh ng to cht tin c t (kch hot bi protease trong tiu ha, khng pht trin pH 4, ). Bo t c th sng 100oC trong 1-5h.C th b tiu dit nhit thp

NAM MOC ASPERGILLUS FLAVUS

NAM MOC ASPERGILLUS FLAVUS

Ng c do AflatoxinBn vi nhit cao (b phn hy trn 200oC)Lin kt DNA, RNA gy ri lon sinh tng hp protein. Tc nhn gy ung th.Thng mc trn cc ht lng thc c du.

NAM MOC

FUSARIUM GRAMINEARUM- Hin tng say bnh m- c t tc ng vo trung tm thn kinh

Ng c do c t nm fusariumNhim vo ht v bt, c t bn nhit, khng b phn hy khi nu. Triu chng ph thng, au x thc qun v ming.

Ng c thc n b h hngL sn phm ca qu trnh phn hy cc cht dinh dng (ch yu l protein v lipid), sinh NH3, idol, scatol, cc acid bay hi Amin gy c to thnh putrexin, cadaverin, tyramin, tryptamin, histamin, betain, Cc cht chuyn ha t lipid: glycerine, acid bo t do, peroxyt, aldehyt, xeton,

K thut phn tch kim tra vi sinh vt thc phmChn v thu nhn mu vt v chuyn n PTN phn tchX l mu, nghin trn v ha tan trong mi trng dch treo vi t l ph hp.Nui cy v phn lp vi sinh vtm qun th vi sinh vtPht hin v xc nh tn ging (genus), loi (species) hoc chng ni (strains) vi sinh vt.

K thut mi trong phn tch kim travi sinh vt thc phm Kim tra bng b test sinh ha hc (Biochemical identification test kits): nhanh, c th xc nh c nhm vsv hoc chng. Vd: Rosco API Listeria, K thut lc mng mng (Membrane filter techniques)Ly tm tc cao (~10 000 xg/10 pht) Tham kho ti liu: Bi ging ca ThS. Nguyn Tin Dng (H KHTN)

Kim nghim mt s vi sinh vt trong thc phm1. Tng s vi sinh vt hiu kh1.1 Nguyn tcTng vi sinh vt hiu c m bng cch v trong iu kin hiu kh 300C/726 gi1.2 Mi trng v thit b- Dch pha long: Saline Peptone Water (SPW)- Mi trng nui cy: Platecount agar (PCA)- T m: 30 10C

1.3 Quy trnh.- a: chuyn 1ml dung dch dung dch mu sau khi ng nht hot pha long nng thch hp vo a petri v trng, mi nng mt a. Trong 15 pht, vo mi a 15-20ml mi trng nui cy (PCA) c lm ngui n 450C . Sau trn u mu v mi trng nui cy- Nui : Cc a c lt ngc v trong 726 gi 3010C1.4 c kt quc kt qu c th dng mt thng hoc qua knh lp c phng i 2,3 ln m s khun lc mc trn petri (ch m a petri c s khun lc 30-350 khun lc) sau nhn vi h s pha long.

2. Coliforms-Phng php: tham chiu theo phng php NMKL 44 n bn ln 4, 19952.1 Nguyn tcDa vo s ln ln men ng lactose mi trng thch hp (thch Violet red bile) 370C trong 24 gi. Sau c khng nh li trong mi trng canh Brilliant Green Bile Salt. Coliforms s sinh kh trong mi trng ny 370C trong 24 gi.2.2 Mi trng v thit b- Dung dch Salin Pepton- Thch Violet red bile (VRBL)- Canh Brilliant Green Bile Salt (BGBL)- Thch Tryptone Soya (TSA)- T m 3710C

2.3 Quy trnh- a: chuyn 1ml dung dch dung dch mu sau khi pha long cho vo a petri v trng, s dng hai nng pha long lin tip. vo mi a khong 5ml mi trng TSA 450C. Sau ch mi trng ng hon ton thm 10-15ml mi trng thch VRBL 450C- Nui : Cc a c lt ngc v trong 243 gi 3710C2.4 c kt qum cc a c s khun lc di 100 sau 24 gi nui cy. Khun lc coliforms c mu ta, ng knh 0.5mm, i khi c bao quanh bi mt vng hi do ta. Tnh gi tr trung bnh t cc pha long qui v s coliform trong mt g mu.

2.5 Khng nh.Cy ring t nht 5 khun lcn nghi ng ca mi loi vo cc ng nghim cha mi trng canh BGBL c ng Durham , 370C trong 24 gi. Phn ng c coi l dng tnh khi c s to kh d ch mt trong 5 ng nghim trn.

3. Escherichia coli-Phng php: tham chiu theo TCVN 5287, n bn ln 2, 19943.1 Nguyn tcCy mt lng dch mu vo mi trng tng sinh (canh Brilliant green bile lactose), la cc khun lc in hnh trn mi trng chn lc (EMB) cc php th sinh ha ph hp (nghim php IMViC)3.2 Mi trng v thit b- Dung dch Saline (SPW).- Canh Brilliant green bile lactose BGBL.- Thch Eosin Methylene Blue Lactose (EMB)- Canh Methyl Red Voges Proskauer (MR-VP)- Canh Tryptone (hoc peptone)- Thch Simmons Citrat- Thuc th Methyl red 0,2%, -naphtol 5%, kovacs.- Dung dch KOH 40%- T m 3710C, 4410C

3.3 Quy trnh- Tng sinh: Cy 1ml dch mu nng 10-1vo ng nghim cha 5ml mi trng tng sinh (BGBL), 44,00,50C 24 gi.- Cy phn lp: Sau khi tng sinh cy dch mu t ng nghim c phn ng dng tnh (mi trng chuyn c v sinh hi) sang mi trng EMB, 371/24 gi. Trn mi trng EMB: khun lc mu tm, nh kim, trn, b u, ng knh khong 0,5mm3.4 Khng nh- Chn ch nht 2 khun lc in hnh trn mi trng chn lc sang mi trng thch khng chn lc (TSA) 3710C trong 19-24 gi.- Kt qa th nghim sinh ha E. coli ph hp: indol(+), methyl red(+), voges proskauer(-), s dng citrat(-)3.5 c kt qu & bo caoPht hin hay khng pht hin

4. Salmonella - Phng php: tham chiu theo phng php NMKL 71 n bn ln 5. Nm 1999 4.1 Nguyn tc - Phng php ny ch dng nh tnh pht hin hay khng pht hin - Quy trnh kim tra Salmonella bt buc phi qua bn giai on: tin tng sinh, tng sinh, phn lp v khng nh. 4.2 Mi trng v thit b - Canh Peptone m (BPW). - Canh Rappaport-Vasiliadis soy peptone. - Thnh Brilliant Green Phenol Red Lactose Sucrose (BPLS) - TSI, TSA - Canh Lysine decarboxylase, Urea phenol red, Manitol Phenol red be - B iu nhit 0.20C - T m 3710C

4.3 Quy trnh - Ly mu: Ly mu vng b mt cng rng cng tt - Tin tng sinh: trn 25g mu vi 225ml nc m peptone m, ng nht bng my dp mu. 370,10C t 18 n 24 gi - Phn lp: t mi trng sinh cy chuyn khun dch ln b mt mi trng phn lp XLD sao cho c th to c nhng khun lc tch ri. Lt ngc a 370,20C trong 243 gi. Trn mi trng XLD khun lac Salmonella in hnh trong, hi nhum do s thay i ca cht ch th trong mi trng, phn ln c tm en. Bao gi cng nhn thy mt vng mi trng ln hay nh.

4.4 Khng nh Nhng khun lc nghi ng c kim tra khng nh bng th nghim sinh ha: Lactose (-), Sucrose (-), Glucose (+), Urease (-), Indol (-), Mannitol (+), VP (-), LDC (+), ODC (+) v amygdaline (-) 4.5 c kt qu & bo co Pht hin hay khng pht hin

5. Clostridium perfringens - Phng php: tham chiu theo phng php NMKL 56 n bn ln 3. Nm 19945.1 Nguyn tc nh lng Clostridium bng cnh cy mt lng mu bit vo mi trng thch hp c cha ion Fe3+v ion (S2O3)2- 370C trong 1-2 ngy5.2 Mi trng v thit b - Thch iron sulphite - Dung dich mui peptone pha long

5.3 Quy trnh - Cy mu: Chuyn 1ml mu nng thch hp vo ng nghim. Sau , 12ml mi trng thch iron sulphite vo ng trn iu mu trc khi mi trng ng li. Sau khi mi trng ng thm 2-3ml mi trng thch iron sulphite ln b mt 3710C trong 28-48 gi.5.4 c kt qu - m tt c khun lc en, xung quanh c qung en nhn vi nng pha long

Bo qun thc phmNgn nga hoc lm chm cc phn ng enzyme c ch vi sinh vt sinh trng v pht trin hoc tiu dit vi sinh vt

Bo qun thc phmNhit pHp mui, ngKh iu chnhHa chtV trngmChiu x

-18oC hao ht Vit C rt t. Cc bin i hn ch hn, nhng bin i ca cht bo v Vit A vn din ra mnh -12oC.Mui 3.5 4.4% khng ngng pht trin ca VK gy bnh. 12% mt s VK gy thi v a mui cn sng.ng 60-65% c th lm ngng sinh trng nhiu loi VSV.Nhiu nm mc c th mc pH 2-4.5; nm men 4-4.5; vi khun gy bnh v vi khun thi ra thng ch pht trin tt mi trng trung tnh hoc kim, pH =4.5 c 2 u khng th sinh sn.Ngm dm: pH = 2.3 2.5 tng ng vi nng acid 1.7 2%. Nhng men v mc vn c kh nng pht trin.Bq l cn 2% Oxy v 4% CO2; Tri cy ni chung CO2 cn 2-5%.Ha cht bo qun phi c kim sot, kim tra, khng c gy c hay c tc hi nguy him lu di, bnh mn tnh. m ti thiu cho VSV pht trin: vi khun 18%; nm men 20%; nm mc 13-16%. Bt tht cn 10-11%, bt go 13-15%, sa bt v b 15%; tinh bt 18%, ht 13%...

** -18oC hao ht Vit C rt t. Cc bin i hn ch hn, nhng bin i ca cht bo v Vit A vn din ra mnh -12oC.Mui 3.5 4.4% khng ngng pht trin ca VK gy bnh. 12% mt s VK gy thi v a mui cn sng.ng 60-65% c th lm ngng sinh trng nhiu loi VSV.Nhiu nm mc c th mc pH 2-4.5; nm men 4-4.5; vi khun gy bnh v vi khun thi ra thng ch phat trin tt mi trng trung tnh hoc kim, pH =4.5 c 2 u khng th sinh sn.Ngm dm: pH = 2.3 2.5 tng ng vi nng acid 1.7 2%. Nhng men v mc vn c kh nng pht trin.Bq l cn 2% Oxy v 4% CO2; Tri cy ni chung CO2 cn 2-5%.Ha cht bo qun phi c kim sot, kim tra, khng c gy c hay c tc hi nguy him lu di, bnh mn tnh. m ti thiu cho VSV pht trin: vi khun 18%; nm men 20%; nm mc 13-16%. Bt tht cn 10-11%, bt go 13-15%, sa bt v b 15%; tinh bt 18%, ht 13%...

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