Bacteria: Roles in Human Health Flashcards
Pathogen
A microorganism that causes sickness
Pathogenesis
Process by which how pathogens cause diseases
What are the 5 questions you should ask about Pathogenesis?
- How did it get into the body?
- Which host cell does it interact?
- Which proteins does it bind to?
- How does it affect the immune system?
- What mechanism triggers the disease?
Infection
Replication of a pathogen in or on the host
Primary vs Opportunistic Pathogens
Primary: Those that readily causes diseases in healthy hosts
Opportunistic: Diseases that are caused in unusual locations or to immunocompromised hosts
Case
Infected person with symptoms of the disease
Asymptomatic
A person who doesn’t exhibit symptoms of diseases
Who is an example of being a Asymptomatic?
Typhoid Mary
Case-to-infection ratio:
Proportion of infected people who developed the disease
Virulence
Capacity of a pathogen to cause disease
How do pathogens cause diseases?
- Entry
- Attach/invade host
- Evade host defenses
- Obtain nutrients
- Exit
Name ways how pathogens can be spread through direct human contact.
- Blood
- Air
- Sex
Name ways how pathogens can be spread through indirect human contact.
- Food
- Water
- Fomite Objects
- Insect Bites
- Animals
Explain Virulence Factors
Molecules or behaviors by a pathogen that contributes to its pathogenicity
How is the Host Range determined for pathogens?
Group of organisms the pathogen is able to infect
What are the challenges of Virulence Factors of Pathogens?
- Attachment
- Penetration of intact skin
- Resisting antibacterial peptides
- Escaping antibodies
- Evading Phagocytes
Molecules and Behaviors for intact skin
Molecules: None
Behaviors: Survive on skin and insect bites
Molecules for resisting antibacterial peptides
Molecules: -charged LPS in outer membrane, peptidases, and counter proteins for peraurablizing effects of channels
Molecules and Behaviors for escaping antibodies
Molecules: IgA proteases
Behaviors: Antigenic Variation and Camouflage with host proteins
Molecules for evading phagocytes
Catalase
A-B toxins are what?
Protein Subunits
A does what?
Enzyme Active
B does what?
- Binds to Membranes
- Specific Cell-Surface
- Cell Receptor induces endocytosis
When A-B are internalized what happens?
2 protein subunit must escape the endosome to reach its cellular target
Explain further what happens to A-B
- H+ pumps reduce eadosomal ph
- Acidification causes A-B to dissociate
A. B forms channel
B. A exits through the channel and enters the cytoplasm
Botulinum Toxins explain the two ways how they can be deadly.
1. Snare Proteins A. Acetycholine secreted B. Muscle Contraction 2. Snare Proteins A. Acet. not secreted B. Flaccid Paralysis
Tetanus Toxins explain the two ways how they can be deadly.
1. Synaotibrevin A. Glycine or GABA secreted B. Acet. not secreted C. Muscle contraction halted 2. Synaotibrevin A. Glycine or GABA not secreted B. Acet. secreted C. Spastic Paralysis
Shiga Toxin explain how they can be deadly.
- rRNA to make protein synthesis
2. Not normal cannot do protein synthesis
Cytolysins are what?
Enzymes that act on the host cell membrane
Ex: Lysis
Cytolysins functions
- Pore-formation
2. Phospholipid degradation
Endotoxins
Toxins that are part of Gram -cell membrane structure that induce inflammation of host cells.
Most common endotoxin
Lipopolysaccharide (LPS)
How are endotoxins released and where are they found?
Lysis of the bacteria cell and toll-like receptors mammal cells
What acid has very similar functions to endotoxins, but aren’t endotoxins?
Lipoteichoice acid
