Heredity

—Variation

—genotype

Variationphenotype

VariationMorphological

VariationBacteriaL

form

bacteriaL

FormVariationStructure

Variation

(1)CapsuleCulture

mediumLose

of

capsuleMouseSpore40℃

~

42

℃lose

of

Spore10~20dStructure

Variation(2)0.1%

carbolic

acidlose

of

FlagellaOFlagellaHColony

shape

VariationSmooth

colonyRough

colonyThis

variation

always

follow

somevariation

of

other

charactervirulence

VariationBovine

tuberclebacillus13

yearsBCG230

generationsvirulence

VariationDiphtheria

bacilliWithout

virulenceGaining

virulenceLysogenic

conversionresistance

VariationStaphylococcus

>90%PNCDysentery

bacteria

(Sensitive

Strain)S.M.Resistant

StrainS.M

dependent.

(SD).Bacterial

genetic

material

is

DNA.

DNA

is

tobe

carrier

of

gene

and

carryvariousgeneticinformation.Bacterial

genetic

information

islocatedgenome,

it

include

chromosome

and

geneticmaterial

which

locate

outside

ofchromosome.I.

Chromosomeclosed

double-Strandedcircular

DNA

moleculesCharacter1、Single

copy

sequences,repeat

sequences

is

less

2、Function

dependence

gene

concentrate

to

operon3、Having

continuous

gene,

no

intron4、Its

amount

depend

on

its

growth

conditions5

、Bidirectional

replicationPathogenicity

island (

PAI

)－－

位于致病菌染色體上－－ 常為分子量較大（20～100kbp）的基因群－－ 攜帶毒力相關(guān)基因的外源性DNA片斷－－

兩側(cè)往往含有重復(fù)序列或插入序列－－ 其G＋C％與密碼使用與宿主菌染色體有明顯差異II.

PlasmidPlasmids

are

small，

circular/line

，extra-chromosomal

，double-stranded

DNAmolecules；

They

are

capable

of

self-replicationand

contain

genes

that

confer

some

properties,such

asantibioticresistance

，virulencefactors

；They

are

not

essential

for

cellular

survival.Transfer

propertiesConjugative

plasmids；Non－conjugative

plasmidsPhenotypic

effectsF

factor；Col

plasmids；R

factor；Vi

plasmidCopy

NumbersStringent

plasmid；Relaxed

plasmidsCompatibilityCompatibility

plasmid；Incompatibility

plasmidsClassification

of

PlasmidsIII. Bacteriophage

(phage)1.

Definition--- viruses

that

infect

bacteria,

fungi,spirichaete

et

al.---

obligate

intracellular

parasites--- being

highly

host-specific--- being

a

type

of

bacterial

genetic

materials--- Virulent

phageand

Temperate

phage2. Properties

of

phageMorphologyUnit

of

measurement --- nm

;

Visible

with

EMDifferent

sizes

and

shapesStructureHeadTailCompositionNucleic

acid:

either

DNAor

RNA

but

not

bothds

DNA,

ss

RNA,

ss

DNAencode

3-5

gene

productsto

over

100

gene

productsProtein:

function

ininfection

and

protect

thenucleic

acidRelation

between

host

cell

and

phageLytic

or

Virulent

PhagesDefinition:Lytic

or

virulent

phages

are

phageswhich

can

only

multiply

in

bacteria

and

killthecellbylysisat

theendofthelife

cycle.Lytic

CycleAdsorptionPenetrationBiological

SynthesisMaturation

and

ReleaseAdsorptionPenetrationBiological

SynthesisMaturation

andReleaseLytic

cyclenormalbacteriophageBacteriophagebinding

to

andinjecting

theirDNA

into

abacterial

cellPlaquePhenomenon

of

lytic

bacteriaPlaque熒光假單胞菌Assay

for

Lytic

PhageLytic

phage

are

enumerated

by

a

plaque

assay.噬菌斑測定A

plaqueisaclear

areawhichresultsfrom

thelysis

of

bacteria.A

plaque

arises

from

a

single

infectious

phage,

itis

called

a

pfu

(plaque

formingunit).2) Lysogenic

or

Temperate

PhageThe

phage

DNA

actually

integrates

into

the

hostchromosome

and

is

replicated

along

with

thehost

chromosomeandpassed

ontothedaughtercells.This

phage

can

enter

a

quiescent

state

in

the

cell.

In

thisquiescent

state

most

of

the

phage

genes

are

not

transcribed;the

phage

genome

exists

in

a

repressed

state.The

phage

DNA

integrated

into

the

host

chromosome

iscalled

a

prophage

because

it

is

not

a

phage

but

it

has

thepotential

to

produce

phage.The

cell

harboring

a

prophage

is

termed

a

lysogenicbacterium.AdsorptionPenetrationProphageFormationLysogenic

bacteriumLysogenic phage

can

either

enter

a

quiescent

state

in

thecell

or

multiply

via

the

lytic

cycle.It

posses

a

potential

to

produce

daughter

phage

andsplitting

bacterium.InductionReplicationMaturation

andReleaseUsed

in

treatment

of

bacterial

infectionsUsed

for

the

identification

of

pathogenicbacteria

(phage

typing

噬菌體型分型)Used

in

molecular

biology4. Application

of

phageTransposon,TnMu

phage--- jumping

genes

or

movable

genes--- Insertion

sequence,

ISTransposaseABCDEFG

GFEDCBAISISISISResistanceGene(s)ResistanceGene(s)IV. Transposable

elementInsertion

sequences

(IS)Being

transposable

genetic

elements

that

carry

noknown

genes

except

those

that

are

required

fortranspositionSmall

stretches

of

DNA

that

have

at

their

ends

repeatedsequences.

Between

the

terminal

repeated

sequencesthere

are

sequences

that

can

control

transposition

butno

other

nonessential

genes

are

present.TransposaseABCDEFG

GFEDCBATransposons

(Tn)

Being

transposable

genetic

elements

that

carry

one

or

moreother

genes

in

addition

to

those

which

are

essential

fortranspositionIts

structure

is

similar

to

IS.The

extra

genes

are

locatedbetween

the

terminal

repeated

sequences.Many

antibiotic

resistance

genes

are

located

on

transposons.,these

antibiotic

resistance

transposons

are

a

major

factor

inthe

development

of

multiple

drug

resistance.ISISISISResistanceGene(s)ResistanceGene(s)Type

of

TransposonComposite

Transposon IS

+resistancegene+

ISComplex

Transposonrepeat

sequence(30-40bp)+

resistance

gene

andtransposition

gene

+

repeat

sequence(30-40bp)Transposition

MechanismNon-replicativetranspositionReplicative

transpositionConjugative

transposition一種運(yùn)動性的DNA分子，具有獨(dú)特結(jié)構(gòu)可捕獲和整合外源性基因，使之轉(zhuǎn)化為功能性基因的表達(dá)單位?？纱嬖谟谌旧w、質(zhì)?；蜣D(zhuǎn)座子上，是細(xì)菌固有的遺傳單位。integron

-gene

cassettes

systemV. Integron(In)5’3’intIgene1Structure

ofInattI

gene2A

B

CP5′3′geneRYYYAACGTTRRRYattCattC3￠CS5￠CSVariable

regionP2P1gene

cassettes5￠CS

intI

geneEncode

integrase，catalyze

integrationbetween

gene

cassettes

and

shorthomology

Integration

Site

of

exogenous

gene

Priming

regionsequence

（attI

or

attC）According

intI

gene,

In

can

be

divide

6

groupPromotor

of

integrasePromotor

of

V-regionGene

cassettes基因盒

Small

movable

DNA，Only

phore

ageneand

a

specific

recombination

site（attC），having

no

promotor

Itsgene

cassettes

carry

resistancegenemostly

3

open

reading

frameqacED1 編碼季胺類化合物耐藥性sul1 編碼磺胺類藥物耐藥性O(shè)RF5 功能不明3￠CSI.

Mutation1.

Type--- spontaneous

mutation

and

induced

mutation--- point

mutation

and

chromosomeaberration2.

Mechanism--- substitution

(transition

and

transversion)--- deletion

or

insertion---

rearrangement3.

CharacterWild

strainMutant

strain--- occur

with

a

frequency

of

10-9~10-6

,but

can

be

induced

by

artificialstimuli--- posses

spontaneityand

random--- reverse

mutationII Gene

transfer

and

recombinationGene

transfer

and

recombination

is

mainreason

of

bacterium

producing

various

genecombination

to

fit

environment

in

short

time.The

finish

of

this

process

need

donor

cell,recipient

cell

and

carrier.1.

TransformationRecipient

cellDonor

cell

Cell-free

DNAdirect

uptakeCondition

of

transformationThecompetence

ofrecipient

cellConfiguration,

purity

and concentration

of

DNADouble-stranded

DNARestriction-enzymesystem

and

other

nuclease

ofrecipient

cellEnvironment

condition,

such

as

temperature,pHPreparation

of

competence

cell---

The

competence

always

in

the

end

of

growth

cycle---

Its

length

of

time

dependent

on

strains---

Treatment

with

Calcium

chloride

and

temperature

shock2.

ConjugationDonorcellRecipientcellSex

piliConjugative

PlasmidCharacter--- Donor

cell

can

carry

genes

coding

sexpilus--- Contactofthetwocells

directlyPhysiologicalStatesofF

FactorF+F+HfrHigh

frequency

of

recombinationF+HfrPhysiologicalStatesofF

FactorF’Hfr

F’MethodF+

ⅹ

F-F+Hfr

ⅹ

F-F-F’

plasmidR

plasmidF+F-F+F-F+F+F+F+DonorRecipient1)

F+

ⅹ F

-

2F+-- high

transfer

of

donor

F

factor2) Hfr

ⅹ F

-F-HfrF-HfrF-HfrF-HfrF--- F-

rarely

becomes

Hfr

while

Hfr

remains

Hfr-- High

transfer

of

certain

donor

chromosomal

genesF’F’F’F’F’F-F’F-3)

F’

ⅹ F

-

2F’-- F-

becomes

F’

while

F’

remains

F’-- High

transfer

of

donor

genes

on

F’4)

RPlasmid---

component

ofRTF(coding

sex

pili)Resistance

determinant---

relate

with

mutipleantibiotic

resistanceRTFR

determinant3.

TransductionDonorcellcellPlasmid

or

chromosome

DNA

RecipientBacteriophageGeneralized

transductionRestricted

transduction1) Generalized

transduction--- Occurs

in

the

end

of

lytic

cycle--- Caused

by

assembly

mistake--- any

of

donor

genetic

information

transfer

tothe

chromosome

of

recipientGeneralized

transduction2) Restricted

transduction--- Occurs

in

the

end

of

lysogenic

cycle--- Caused

by

drop

mistake--- some

certain

donor

genetic

information

can

transfer

tothe

chromosome

of

recipientRestricted

transductiongalbiogalbiogalbiogalbiobio4. ly