Micro 4 Flashcards
What are common virulence factors?
Diverse secretion systems Flagella Pili Capsule Endospores Biofilms
What is a neurotoxin?
An exotoxin that work on nerves or motor end plates.
E.g. tetanus toxin, botulinum toxin
What is an enterotoxin?
Exotoxin that works on the GI tract and stimulates diarrhoea.
Infectious diarrhoea; e.g. E. coli, Shigella, Campylobacter jejuni, Vibrio cholera
Food poisoning; Staph aureus, Bacillus cereus
What is pyrogenic exotoxin?
Exotoxin that stimulates release of cytokines
e.g. Staph aureus, Strep pyogenes
What is a tissue invasive exotoxin?
Exotoxin which destroys and tunnels through tissue. Breaks down DNA, collagen, fibrin etc.
e.g. Staph aureus, Strep pyogenes, Clostridium perfingens
What is a miscellaneous exotoxin?
Specific to a certain bacterium/mechanism is poorly understood.
e.g. Bacillus anthracis and Corynebacterium diphtheriae
What is meant by an endotoxin?
Produced by gram-negative bacteria.
Lipid A moiety of LPS is shed, when bacteria is lysed, it sheds the LPS/endotoxin -> septic shock.
What is meant by septic shock?
It is when there is a dangerous drop in BP and/or organ dysfunction.
Treated by eradicating the microbe.
What is the action of shiga toxin?
AB5 subunit contains StxA enzyme active component and pentamer StxB binding component.
StxA enzymes cleave 28s ribosomal RNA in eukaryotic cells -> inhibition of protein synthesis
Bacterial ribosomes are substrates for StxA so there will be less bacterial proliferation.
What is the mechanism of virulence of Enteroagreggative E. coli (EAEC)?
Gene encoding aggregative adherence fibrin (AAF) is located on the plasmid.
Allows attachment to enterocytes.
Stimulates a strong IL-8 response which can create biofilms.
What are the communicable diseases in Europe?
Respiratory tract infections STIs Food and waterborne diseases, zoonoses Emerging and vector borne diseases Vaccine preventable diseases Antimicrobial resistance and healthcare-associated diseases
Which are the two respiratory tract infections caused by bacteria?
Legionnaire’s disease- Legionella pneumophila
Tuberculosis-mycobacterium tuberculosis
What is the virulence factor of Legionella pneumophilia?
Type IV secretion system so effector proteins can be secreted
Which are the STIs caused by bacteria?
Chlamydia trachomatis
Gonorrhoea
Syphilis
What is the virulence factor of neisseria gonorrhoea?
Pili and antigenic variation