Infectious Diseases Part II: Vaccinations, Bacterial Diseases and Antibiotics Flashcards
State the 4 types of immunity.
- Natural active immunity
- Natural passive immunity
- Artificial active immunity
- Artifical passive immunity
What is natural active immunity?
Antibodies made after exposure to an infection.
What is natural passive immunity?
Antibodies transmitted from mother to baby.
What is artificial active immunity?
Antibodies made after getting a vaccination.
What is artificial passive immunity?
Antibodies acquired from an immune serum medicine.
What is a vaccine?
Vaccines stimulate a real infection and induce the host to mount an immunological response to render immunity against the pathogen without causing the disease.
How do vaccines work?
What is herd immunity?
State the types of vaccines.
- Live attenuated vaccines (variants of pathogen that are less pathogenic)
- Inactivated or killed pathogen (contains destroyed pathogens)
- Subunit vaccine (contains only pathogenic antigens, not whole pathogen)
- Toxoids (contains bacterial toxins)
- Nucleic acid vaccine (contains DNA or mRNA that code for pathogenic antigens)
What is the implication of live attenuated vaccines?
What is the implication of inactivated or killed pathogen vaccines, subunit vaccines and toxoids?
What is the implication of nucleic acid vaccines?
What is Tuberculosis?
TB is a respiratory infectious diseased caused by Mycobacterium tuberculosis.
TB is a bacterial disease.
How does TB spread?
Via airborne transmission via small respiratory droplets in coughs or sneezes
How does TB enter the body?
Inhaled into lungs of individual
How does TB infect the body cells?
- Bacteria taken up by alveolar macrophages and dendritic cells via phagocytosis.
- M. tuberculosis can block fusion of lysosome to phagosome in macrophages –> replicate in macrophages
- Macrophages undergo macrophage necrosis –> release M tuberculosis to multiply extracellularly
How does the body respond to tuberculosis?
- Infected alveolar macrophages produce inflammatory cytokines –> recruit more immune cells to site of infection
- Dendritic cells with engulfed M. tuberculosis migrate to regional lymph node –> activate T cells that migrate to site of infection
- Accumulated macrophages, T cells form the granuloma –> limits spread of bacterial infection
Describe the reactivation of TB infection.
When the immune system is weakened, M. tuberculosis cells exit dormancy and escape from granuloma to spread throughout lungs and body –> active TB
What are antibiotics?
It is used to treat bacterial infection by killing the bacteria or inhibiting their growth.
How does penicillin (antibiotic) treat bacterial infection?
- Penicillin binds to and inhibits DD-transpeptidase, an enzyme that catalyses formation of cross-links in peptidoglycan
- Newly formed bacterial peptidoglycan cell wall to be weakened
- Daughter bacterial cell walls have weaker peptidoglycan cell wall are not able to withstand osmotic pressure –> cell lysis and death
