Pathogen & Infection Flashcards
What is a pathogen?
An organism that can cause disease in a healthy host
What two conditions can opportunistic pathogens cause disease under?
- introduction into a niche they do not normally occupy
2. introduced to an immunocompromised host
What four characteristics are caused by virulence factors?
- allows attachment
- invasion of host tissue
- resistance of host defenses
- cause signs and symptoms of disease
(T/F) Virulence factors are responsible for the signs and symptoms of pathogens
True!
Where are genes for virulence factors often found?
In clusters on the genome of pathogenic bacteria
How do VIRUSES bind?
Via surface proteins that binds to receptors on the host
What are three ways that BACTERIA can bind to host cells?
Fili/fimbriae as adhesin protein
Capsule
Surface Proteins
What is the primary hurdle when invading host cells?
What is usually used to handle this problem?
Getting past the mucous membranes
Enzymes such as collagenases and elastases
What do FUNGI and BACTERIA use to avoid phagocytosis?
How does it work?
Capsules
It covers up the molecule so the phagocytes will not recognize them
How do some gram (-) BACTERIA resist antimicrobial peptides?
They make extra long polysaccharide chains on the LPS
What are two ways in which a pathogen can avoid an ADAPTIVE immune system?
- hide via capsules
2. bind to host proteins to hide on the surface of the cel
What does RNA viruses high mutation rate allow for in terms of antibody recognition?
It allows surface proteins to change their amino acid sequence so they won’t be recognized by pre-existing antibodies
What will BACTERIA change to adapt to antibody recognition?
They will switch what flagellin is being made
What are endotoxins?
What is an example? What do it do?
Structural components of the pathogenic cell
LPS, causes inflammation
What are exotoxins?
Proteins that are secreted and act on the host cell
