Microbial Infection Flashcards
What is bacteria?
A prokaryote
Have poorly define cytoskeleton
Have flagellum for mobility
E.g. mycobacterium TB, Neisseria meningitidis
What can be found in the cell walls of bacteria?
Peptidoglycans
How does bacteria replicate?
Binary Fission
What is a virus?
An obligate parasite
Contain RNA or DNA
E.g. HIV, Smallpox, Polio, HPV
How are viruses transmitted?
Blood, airbourne vectors, faecal-oral
How do viruses replicate?
Use host cell machinery
Divide by budding out of host cell
What are fungi?
Single cell eukaryotes
Includes yeasts and filaments
E.g. Candida Albicans
How does fungi replicate?
yeast buds or divides
filaments extend
What are protezoa?
Unicellular eukaryotic organisms
Many have lifecycle including 2 hosts
E.g. Plasmodium falciparum, Leishmania Spp.
How is protozoan infection transmitted?
vector transmission or ingestion
How does protozoa replicate?
In host by binary fission or by formation of trophozoites inside cell
What are helminths?
Multicellular eukaryotes
They’re worms: Flatworm, roundworm, tapeworm
Have lifecycles outside human host
E.g. schistosoma Spp.
How do helminths replicate?
Sexally- adult produces shedding eggs
What is Neisseria Meningitidis?
Gram negative diplococci- bacteria
Lives harmlessly in 20% of population but can become hostile
Nose and throat commensals
Has rapid onset
What are symptoms of Neisseria Meningitidis?
non-blanching rash, septicaemia, blocked blood vessels, can penetrate blood-brain barrier and cause meningococcal meningitis
What is mycobacterium TB?
Bacteria Intracellular rod Causes TB Respiratory disease but can be systemic BCG vaccine doesn't work well in endemic regions Very hard to treat, can be lifelong
What is Shigella?
Bacteria
Has no flagella but moves using actin to push itself between cells
Infects the GI tract and in severe cases can lead to huge amounts of tissue damage and cause death
Faecal-oral transmission
Lots of blood diarrhea
What is HIV?
ssRNA Virus
Uses reverse transcriptase to turn RNA to DNA
Infects T- cells- very low CD4 count increases risk of infection
Leads to AIDS
What causes smallpox?
Variola Virus
What is Candida Albicans?
Fungi
Combination of yeast and filaments
Natural yeast in our bodies- commensal of mouth and skin but opportunistic
Can cause candidiasis (thrush)
What is plasmodium falciparum?
Protozoa
Mosquito vector
Infects liver and affects blood cells ability to develop
Forms trophozoites inside cells
People with sickle cell and B- thalassaemia can’t get malaria
What are symptoms of a plasmodium falciparum infection?
Fever Headache Anaemia Hepatosplenomegaly Jaundice
What is Leishmania Spp.?
Protozoa
Infection acquired via sandfly
Replicates in blood, immune cells and other tissues
Replicated by binary fission
Has 3 forms: cutaneous, mucosal and visceral
Can cause leishmaniasis: lesions, hepatosplenomegaly
What is Schistosoma Spp.?
Helminth
Is a flatworm
Intermediate vector is a snail
3 main types of schistosoma can be transmitted when people enter contaminated water
Adult lives in hepatic portal vein of humans
Produces spirey eggs which allows them to enter gut
