Microbiology Lecture - 06 Microflora

8/14/2019 Microbiology Lecture - 06 Microflora

1/28

Normal microflora

of a humans bodymicro ecology


2/28

2

Normal microflora

- is the composition of symbiotic microorganismsformed during evolution, inhabiting skin and

mucous membranes of a human body, stayed inthe dynamic stable balance


3/28

3

Qu alitative and q u antitative compo u nd of Normal microflora

depends on:-State of Health

- Age-Type of a diet

-Climate conditions-Ecological conditions


4/28

N ormal microflora may be arranged into the groups:

1. Skin microflora

2 . Microflora of conj u nctiva

3 . Microflora of a mo u th and u pper respiratory tract

4 . Microflora of gastrointestinal tractand rect u m

5 . Microflora of u rine genital tract


5/28

5

Symbiotic microorganisms

inhabiting the same area of a body form one ecosystem.

All microorganisms of one ecosystem may be arranged into 2 groups :

Indigeno u sIndigeno u s or or residentresidentmicrofloramicroflora

Transient microfloraTransient microflora

relatively fixed types

of microorganismsregularly found in a given areaat a given age

nonpathogenic or potentially pathogenic microorganisms

that inhabit some areafor a short period


6/28

6

microflora ofmedicinepersonal

Mothers

intestinal and vaginal microflora

microflora of theenvironment

Microflora

of the newborn baby

3 sources of newbornsmicrobiota


7/28

7

T he role of Normal Microflora

C olonization resistance - protection fromdiseases:NM inhibits pathogens by prod u ction of

lactic and acetic acids and bacteriocinsocc u pies cell receptors of m u co u smembranesmetabolizes n u trient s u bstratesactivates imm u ne system


8/28

8

T he role of Normal Microflora

A ssimilation of n u trientsoligosaccharides - by Bifidobacteri u mPolysaccharides - by Bacteroides

Reg u lation of Gas balance in the intestineA cid balance in the intestineprod u ce vitamins K, B; amino acids


9/28

9

Skin microflora

T he predominant m/o of the humans skin areaerobic and

anaerobic grampositive cocci androds.

Limitation factors of skin microflora:

pH of skinSecreting of fatty acidsSecreting of lysozymePresence of oxygen

S taphylococcus aureus


10/28

10

Propionibacteri u mA ctinomyces

Gram positive rods can bedetected

in normal microflora of skin


11/28

11

Normal microflora of Skin

Resident m/oGram positivecocci:MicrococcusStaphylococcusGram positiverods:CorynebacteriumPropionibacteriumBrevibacterium

Transient m/oGram positivecocci:Sarcina

Gram positiverods:Bacillus

Actinomyces Yeasts:CandidaFu ngi


12/28

12

Microflora of a mo u th and u pper respiratorytract

V eilonella spp Haemophillus influenzae

Bacteroides fragilis Neisseria meningitidis


13/28

13

Normal microfloraof nasopharingx and oral cavity

ResidentGram positive cocci:StreptococcusMicrococcusStaphylococcusGram negative cocci:NeisseriaVeilonella

Gram positive rods:CorynebacteriumLactobacteriumGram negative rods:Bacteroides

TransientGram positive cocci:PeptococcusGram positive rods:

ActinomycesBacillusGram negative rods:Fusobacterium

Yeasts:Candida


14/28

14

Normal microfloraof u rine genital tract

V aginaResident m/o

Gram positive cocci:

StreptococcusStaphylococcusGram negativecocci:

VeilonellaGram positive rods:LactobacillusGram negative rods:Prevotella

D ifferent species ofL actobacillus are

predominant


15/28

15


V aginaTransient m/o

Gram positive cocci:

PeptococcusStreptococci group BGram positive rods:BifidobacteriumCoryneforming bacteriaGram negative rods:Fusobacterium

Yeasts:Candida

Streptococcusgroup B


16/28

16


Transient m/o

Gram negative rods:PrevotellaE. coli

Yeasts:Candida

Resident m/o

Gram positive cocci:StreptococcusStaphylococcusPeptococcusPeptostreptococcusGram negative cocci:Veilonella

Urethra


17/28

17

Microflora of Gastrointestinal tract (GI T)

The most heavily colonized area .

All microorganisms of GI T are arranged into

ecosystems:

Stomach and duodenum - 10 bacteria per gramm

Jejunum and ileum - 10 4-10 7

Colon and rectum - 10 7 -10 12


18/28

18

Intestinal Microflora of a newborn(1 month of life)

BreastBreast- -fed childfed childT he predominant residentm/o are differentB ifidobacterium species(about 90%)and Lactobacillus,Bacteroides, Streptococcigroup D, E. coli

transient m/o:Klebsiella, Staphylococcus,

Clostridium

BottleBottle --fed childfed childBifidobacterium and

Lactobacillus assosiatedwith Bacteroides,

Clostridium, Streptococcigroup D , E. colitransient m/o:Enterobacter,Klebsiella

Proteus, Citrobacter,Staphylococcus,Bacillus,Candida


19/28

19

Intestinal Microflora of ad u lts

Resident m/oGram positive rods:Bifidobacteri u mLactobacill u s

PropionibacteriumGram positive cocci:Streptococci group D(=Enterococci )

Gram negative cocci:VeilonellaGram negative rods:Bacteroides, Fusobacterium

E. coli

B ifidobacteriumlongum


20/28

20

Intestinal Microflora of ad u lts

Transient m/o

Gram positive cocci:PeptococcusGram positive rods:C lostridi u mBacillusGram negative rods:Enterobacteriaceae

Yeasts:Candida

Clostridium


21/28

21

D ysbiosisis q u alitative and q u antitative alterations of normal

microflora, ind u ced by violation of ecological balance

between microbial pop u lations

D ysbiosis isnt a disease , it appears as a symptomafter:

1. Infection process or somatic disease2 . Prolonged therapy with antibiotics, hormones etc .3 . Radiation or imm u nos u ppressive therapy4 . Total changing of diet, climate

5 . Prolonged stress6 . Prolonged staying in the excl u sive space

(cosmona u ts, sailors in s u bmarines)7 . Radiation sickness


22/28

22

D ysbiosis

Compensatory stage:

I nsignificant

decreasing of one group of resident m/o.

Sub

compensatory stage:decreasing of

several residentsand increasing of transients .

D ecompensatory stage:

elimination of severalgro u ps of residents,translocation of

some transients intothe other ecosystems .

May appier localinfection


23/28

2 3

Biopreparations to correct D ysbiosis

P robiotics contain pure culture of a resident m/o(living)

P rebiotics contain nutrient substrate (growth factor ) which can be fermentated by resident m/o

Synbiotics - contain mixed nutrient substrate and

pure culture of a resident m/o


24/28

24

D iagnosis of D ysbiosis

C u ltu ral (Bacteriologic) method - q u alitative andq u antitative examination

Molec u lar-genetics methods:Polymerase Chain reactions (PCR, RT-PCR)


25/28

2 5

Polymerase Chain reaction


26/28

2 6

Results of PCR will be visibale in gelelectrophoresis


27/28

2 7

Ampliphycator for PCR


28/28

2 8

Gnotobiology

Is the science which st u dies mechanisms of microbial infl u ence to host imm u ne systemon a model of germ-free animals

Germ-free animals have no their ownmicroflora sterile animalsGerm-free animals live in sterile conditions

Germ-free animals eat sterile food

Documents

Microbiology Lecture - 06 Microflora