BMS 212 Final Exam Last Minute Things

Genome Structure of HIV

RNA initially, converts itself to DNA inside host using reverse transcriptase.

Why is HIV treated with multiple anti-virals?

Because it mutates rapidly, and multiple anti-virals can attack each stage of development instead of one.

Genome structure of Influenza

Enveloped, Negative sense ssRNA, segmented genome

Mode of transmission of Influenza

Respiratory droplet/aerosol

Structure/adsorption of Influenza

Enveloped, containing proteins Neuraminidase (release virion) and Hemagglutinin (facilitate receptor-mediated endocytosis)

Antigenic shift

Influenza specific, big jump in antigen allowing new subtypes of H and N, usually from animal to human (reassortant virus)

Treatment of Influenza

Annual vaccine trivalent subunit vaccine (preventative), Tamiflu if diagnosed (Neuraminidase inhibitor)

Genome structure of COVID

Enveloped RNA virus known for spike proteins

Mode of transmission of COVID

Droplet (most cases), aerosol, fomite

Kind of disease COVID causes

Severe acute respiratory syndrome, cough, fever, loss of taste/smell

COVID Treatment

Preventative: Distance, PPE, handwashing, mRNA vaccine (Pfizer/Moderna)

Diagnosed: Drugs, antibodies, anti-inflammatories, supportive care (intubation at worst)

Virulence factors of S. aureus

1. Protein A

2. Exfoliative Toxins

3. Toxic-shock syndrome

Protein A

Coats host cell surface, binding Fc region of IgG (antibody), blocking opsonization and complement

Exfoliative Toxins

Cause separation/sloughing off of skin cells → Scalded skin syndrome

Toxic-shock Syndrome (TSS)

TSS binds to TCR and MHC-II binding, activating cytokine storm = chaos and immune degradation

Rheumatic Fever and complication

Untreated pharyngitis leading to inflammation of heart valves and muscle, creates autoimmune response against heart antigens

What is significant about the M protein regarding Rheumatic fever?

M Protein, found on S. pyogenes cell wall is similar looking to a protein found on the heart wall, immune system has autoimmune response leading to permanent damage

Virulence factors of S. pyogenes

1. M Protein

2. Erythrogenic toxin

Erythrogenic toxin

Secreted by bacteria, damages capillaries, blood rushes to surface of skin

What is given to treat S. pyogenes

Antibodies fighting against M Protein, antibiotics

Gram Positive Bacterial Pathogens

S. aureus, S. pyogenes, C. tetani

Tetanospasmin (AB toxin)

Clostridium tetani specific toxin that inactivates proteins that regulate the release of inhibitory neurotransmitters → Spastic paralysis

How does the AB toxin work?

AB unit attaches to cell receptor, endocytic vesicle encloses, drop in pH allows A unit to leave vesicle (now in cytoplasm) and administer cell damage