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realizată de Hend Montaseb 5 ani în urmă

105

Microbial Mechanisms of Pathogenicity

The text delves into the various mechanisms through which pathogens cause damage to their host cells and how they navigate through a host's defenses. It explains the roles of exotoxins and endotoxins, detailing the specific ways these toxins disrupt host cell function.

Microbial Mechanisms of Pathogenicity

Microbial Mechanisms of Pathogenicity

How Pathogens Penetrate Host Defenses

Antigenic Variation
Antibodies
Antigens
Actin in cytoskeleton
To move
To penetrate
The production of toxins
Antitoxin
Toxoid
Toxemia
Toxigenicity
Enzymes
IgA proteases
Hyaluronidase
Kinases
Coagulase
Cell Wall Components
Mycolic acid
Opa-protein
Capsules
Haemophilus influenzae
Streptococcus pneumoniae

How Pathogens Damage Host Cells

Exotoxins
superantigens
membrane-disrupting toxins

lysis the host cells

Disrupting phospholipid bilayer

Making protein channels

A-B toxins

B-part (the binding)

A-part (enzyme)

Endotoxins
cytokines
Direct Damage
Produce waste products
Disrupt host cell function
Using the Host’s Nutrients
receptors
siderophores

How microorganisms enter & exit a host

Portals of Exit (the same as the portals of entry for a given microbe )
Adherence
M protein

Streptococcus pyogenes

Fimbriae

Escherichia coli

Glycocalyx

Streptococcus mutans

Numbers of Invading Microbes
ID50
LD50
The Preferred Portal of Entry
Bacillus anthracis

Subtopic

multiple portal of entry

Streptococci

inhaled

Salmonella typhi

swallowed

Portals of Entry
Parenteral route

njections

wounds

Skin

hair follicles

sweat gland ducts

Mucous membranes

respiratory tract

gastrointestinal tract