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
