Introduction to ArtificiaI Intelligence in Higher Education
Pathogenesis
1. M. SRI ARAVIND LAL
ROLL NO 17
Madurai kamaraj university
PATHOGENESIS
2.
3. INTRODUCTION
2) Pathogenesis
The step by step
development of a
disease from
infection by a
pathogen to
termination of either
the germ or the host.
4. Introduction of Bacterial
Pathogenesis
1. Infection: growth and multiplication of a
microbe in or on the body with or without the
production of disease.
2. The capacity of a bacterium to cause disease
reflects its relative “Pathogenicity.”
3. Virulence is the measure of the pathogenicity of
a microorganism.
4. Pathogenesis refers both to (1) the mechanism
of infection and to (2) the mechanism by which
disease develops.
5. Host Susceptibility
1. Susceptibility to bacterial infections
=> Host Defenses vs Bacterial Virulence
2. Host Defenses:
- Barriers (skin & mucus) – the first line
- Innate Immunity (complement, macrophages & cytokines)
– the early stage
- Adaptive Immunity (Ag-specific B & Tcells)–the later stage
3. Host defenses can be comprised by destructing barriers or
defective immune response.
e.g. Cystic Fibrosis => poor ciliary function => NOT clear
mucus efficiently from the respiratory tract =>
Pseudomonas aeruginosa => serious respiratory distress.
6. Strict pathogens
are more virulent and can
cause diseases in a normal
person.
Opportunistic
pathogens are typically
members of normal flora
and cause diseases when
they are introduced into
unprotected sites; usually
occur in people with
underlying conditions.
7. Transmission of infection
Carrier: a person or animal
with asymptomatic infection
that can be transmitted to
another person or animal.
The clinical symptoms of
diseases produced by
microbes often promote
transmission of the agents.
Zoonosis: infectious diseases
transmitted between animals
and men.
Hospital- (nosocomial) vs.
community-acquired infections
By producing asymptomatic infection or mild disease, rather than
death of the host, microorganisms that normally live in people
enhance the possibility of transmission from one person to another.
Many bacteria are transmitted on hands
