Microbial infection Flashcards
What are viruses?
Obligate parasites that divide by cytolysis or budding out of host cell.
What is a retro virus?
Has RNA as its genetic material. Has an enzyme called reverse transcriptase in capsid; RNA can be converted to DNA and viral DNA can be inserted into human genome by an integrase.
What cancer does human papilloma viruses cause?
Cervical cancer.
What kind of cell is bacteria?
Prokaryote
Key points of prokaryotes
Don’t have internal membranes. Single copy of chromosome (haploid). Contain peptidoglycan in cell wall. Divide by binary fission. Poorly defined cytoskeleton.
Why are mutations expressed immediately in prokaryotes?
Only contain one copy of the gene.
What gives bacteria its shape?
Peptidoglycan in cell wall.
How is shigella transmitted?
Faecal-oral transmission.
What is the infectious dose of shigella?
10-100 bacteria.
How does shigella spread?
Using host cell actin.
Damage caused by shigella?
Destroys cells in the GI Tract.
What is septicemia?
Severe inflammatory response that causes septic shock. Caused when bacteria enter the blood.
What kind of bacteria is Neisseria meningitidis?
Harmless commensal bacterium. Under certain conditions can become a potentially lethal disease that can cause sepsis and acute meningitis.
H. pylori (Heliobacter pylori) can cause what?
Peptic ulcer and gastric cancer.
Why are mutations more common in bacteria than humans?
Generation time is much quicker and haploid organism so only require one gene to have effect.
