Re-Introduction Flashcards
What are the main microorganisms?
VIPE V = viruses I= infectious proteins P = prokaryotes (bacteria) E = eukaryotes (fungi/ protozoa)
What is protozoa and give an example?
What human disease is it important in?
Unicellular eukaryote e.g malaria, toxoplasma gondii
Malaria - often affect immunocompromised
What is fungi and give use
What is it structure like?
Eukaryotic organism - many forms (filamentous or yeast) - important commercially (baking, brewing)
External rigid chitin wall
Structure prokaryote?
No internal membranous compartments
Specialised cell wall
Gram positive? - give example
One membrane - thick peptidoglycan later
Retain stain - purple
e.g streptococci
Gram negative? - give example
Two membranes -periplasm between
Doesn’t retain stain - pink
E.g spirochete, fusobacteria
Explain surface structure and motility of bacteria
- PEPTIDOGLYCAN - polymer N-acetyl muramic acid and N-acetyl glucosamine (NAM and NAG) - cross linked via amino acid pentapeptide and anchored to cell wall
- PILI and FIBRIAE - proteinaceous filamentous structures, often used for attachment to host cell and twitching motility
What is a pathogen?
A disease causing bacteria e.g cholera
What is an opportunistic pathogen?
Commensals that cause disease e.g MRSA
Mainly harmless - colonise surfaces and mucosa
Common bacteria in GI tract?
E.coli - gram negative rod - some strain pathogenic
Clostridia species - gram positive anaerobic spore formers (inc. c.difficile)
Structure mycobacteria?
How do you detect?
Peptidoglycan later with glycolipid sugar attached to mycolic acid
Increase resistance
Gram +ve rods - need Ziehl-Neelsen stain as impervious to gram staining
What is a virus?
Obligate intracellular pathogen which is unable to reproduce w/o host factor
Basic structure of virus?
Nucleic acid encapsulated to proteinaceous capsid - some can be further coated w/ lipid
Explain retroviral replication?
Release mRNA into cells - form DNA via reverse transcriptase
Recombined human DNA
Integrate host genome
Transcription
What is prion?
Infectious protein that is heat resistance and sticks to instruments
How do prions cause damage?
Aggregte into long fibres and amyloid plaque
Transmission into brain tissue
Causes abnormal folding of proteins
E.G CJD
What is KURU?
Fatal brain disorder
Papua New Guinea - ritualised canabalism
