Very few microbes are always pathogenic. potentially pathogenic. Most microbes are never pathogenic

Cut Yulvizar, M.Sc

Very few microbes are always pathogenic

Many microbes are potentially pathogenic

Most microbes are never pathogenic

 Our

bodies rich in microbial biodiversityy  What are they? 

Bacteria Protozoa, Bacteria, Protozoa Fungi

 composition

of normal flora varies from individual to

individual some bacterial species carried only transiently  most permanent 

Bacteria are everywhere  . resident vs. Transient 

--Resident id  Relatively fixed  Komensal and mutualism  If disturbed, reestablishes itself

Ex:  streptococcus viridans. S. Faecalis, Candida albicans  Transient 

   

Derived from the environment Resides for hours, days or weeks: finite time few, competition from resident Microbes elimination by the body’s immune system

Kategori Patogen Patogen opportunistik biasanya adalah flora normal dan menyebabkan penyakit bila menyerang bagian b i yg tidak tid k terlindungi, biasanya terjadi pada orang yg kondisinya tidak sehat. Patogen virulen (lebih berbahaya) dapat menimbulkan berbahaya), penyakit pada tubuh kondisi sehat/normal

P t Patogen opportunistik t i tik

Patogen opportunistik

Patogen virulen

ADHESI

BACTERIUM

adhesin receptor

EPITHELIUM

6

B a c t e r i a l

Bacteria

Bacterial Adhesin

Host Receptor

Staph. aureus Staph. sp. A d Strept. group A h

LTA (lipo-teichoic acid)

Unknown

Slime

Unknown

LTA-M protein complex

Fibronectin

Strept. pneumoniae

Protein M

N-acetylhexosamine-gal

E. coli

Type 1 fimbriae

d-Mannose

e r e n c e

M e c h a n i s m s

ganglioside g 1 GM g Colonization factor antigen g fimbriae P fimbriae

P blood gp glycolipid

Enterobacteriaceae

Type 1 fimbriae

d-Mannose

N. gonorrhoeae

Fimbriae

GD 1ganglioside

Treponema pallidum

P ,1P ,2P3

Fibronectin

Chlamydia sp.

Cell surface lectin

N-acetylglucosamine

Myco. pneumoniae

Protein P1

Sialic acid

V. cholerae

Type 4 pili

Frucose and mannose

 Under

normal conditions, resident and transient microbes cause the host no harm

normall fl flora can overpopulate l t or move iinto t areas  the balance of normal microbes is disrupted, antibiotic tibi ti 

 Some 

bacteria occupy more than one niche

Skin, nose, pharynx, mouth, lower intestine, anterior urethra, vagina

Staphylococcus epidermidis, Staphylococcus aureus, Corynebacterium spp. spp  Some     

bacteria occupy only one niche

BACTERIUM TISSUE Corynebacterium diphtheriae Throat Streptococcus mutans Tooth surfaces Streptococcus salivarius Tongue surfaces Vibrio cholerae Small intestine epithelium

 Large

intestine

 Skin  Vagina g  Mouth  Nose  Throat

1014 1012 1010 1010 1010 1010

Normal flora at  various body  sites Mims C et al.  Medical Microbiology  Textbook. 2004. 

Normal gut flora 

Mims C et al.  Medical Microbiology  Textbook. 2004. 

NUMBERS OF VIABLE BACTERIA FOUND IN THE FECES OF ADULT ANIMALS (Log # viable cells per gram feces)

Median values from 10 animals

Clinical conditions that may be caused by members of the normal flora

 Play

a key role in protecting us from pathogens  Represent the most common causes of bacterial infections in humans  Composition varies with niche and is in constant flux – collectively we carry h d d off species i hundreds  Composition is influenced by environmental variables i bl

 Skin Ski

– hostile h til environment, i t variable i bl and d subject bj t tto extreme changes, generally acidic, high in salt, gram + dominate ((veryy few g gram -), ), p pores and sweat g glands are protected by lysozyme and toxic lipids  skin-associated lymphoid tissue (SALT)  Pseudomonas P d aeruginosa i d Staphylococcus dan St h l aureus are caused infection at hospital  Nares – only a few species species, usually transient transient,  Oral cavity – ?????  Intestine test e ????

 Esophagus

– devoid of microflora – mechanical actions make colonization diffi lt difficult  Stomach – highly acidic, only a few species present, t interact i t t ti tightly htl with ith epithelial ith li l cells ll for protection, Helicobacter and Lactobacilli U it l ttractt – only l the th anterior t i urethra th  Urogenital and vagina are permanently colonized, composition is influenced by hormonal state, state lactobacilli are dominant and protect by maintaining low pH

 Food

metabolism - proteolytic enzymes  Vitamin Production – produce essential vitamins  Protective effects – compete with foreign organisms for nutrients and receptors, produce antibacterials (Bacteriocins – toxic t b li b d t ) metabolic by products)  Immune stimulation

INVASI 2 Mikroba menghasilkan protease IgA 2. Tubuh apabila kemasukan mikroba maka akan dihasilkan antibodi (i (imunoglobulin/Ig). l b li /I ) Imunoglobulin yang disekrasikan adalah IgA padapermukaan mukosa Ada 2 tipe IgA, yaitu: IgA1 dan IgA2 Bakteri patogen mempunyai enzim PROTEASE yg akan memecah ikatan spesifik prolin-threonin atau prolin-serin pada IgA1, sehingga IgA tidak aktif

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