Bacterial Pathogenesis Flashcards
Define the terms:
- commensal
- symbiont
- pathogen
- opportunity pathogen
- primary pathogen
- virulence
- avirulent
- infective dose
Lecture 3, slide 3
What does the outcome of a bacterial infection depend on? What is the meaning of the term pathobionts?
Lecture 3, slide 5
-outcome does not only depend on the bacterium
What are some pathogen and host factors that affect bacterial infection outcome?
-Lecture 3, slide 6
What are the key attributes of a pathogen? What are pathogenicity islands?
- Lecture 3, slide 12-13
- pathogenicity islands: clusters of virulence genes
What is the criteria for a pathogen?
Lecture 3, slide 15
What are some potential routes/sources of infection?
Lecture 3, slide 17
What is the structure of Vibrio cholerae? What are the symptoms and treatment for the disease it causes?
Lecture 3, slide 20-21
What is the structure and role of cholera toxin?
Lecture 3, slide 22
How does Vibrio cholerae cause diarrhoea?
Lecture 3, slide 23-24
How did Vibrio cholerae acquire its toxin?
Lecture 3, slide 27
What is Clostridium difficle? What disease does it cause?
Lecture 3, slide 28-29
What are the two toxins Clostridium difficle releases?
Lecture 3, slide 30
How do Clostridium difficle toxins cause disease?
Lecture 3, slide 31
- glycosylation of Rho-GTPases results in the inactivation of Rho proteins.
- Rho proteins are the key members in many biological processes and signalling pathways, inactivation of which leads to cytopathic and cytotoxic effects and immune responses of the host cells
How does Staphylococcus aureus confer tropism?
Lecture 3, slides 33-34, 37
How does Staphylococcus aureus evade the immune system?
Lecture 3, slide 34, 38
What are some Staphyloccocus aureus exotoxins? What diseases do they cause?
Lecture 3, slide 39
-correction: exfoliation toxin is not a superantigen
What are superantigens?
Lecture 3, slide 40
What Gram type of Neisseria meningitidis?
Gram-negative
How does its capsule allow Neisseria meningitidis to evade the immune system and vaccine development?
Lecture 3, slide 43-44
How does Neisseria meningitidis evade complement-mediated lysis?
Lecture 3, slides 42, 45-46
- factor H is a negative regulator of complement, so they recruit it to prevent complement
- capsule
How does Neisseria meningitidis control the expression of virulence factors depending on temperature?
Lecture 3, slide 47
Give some examples of intracellular bacteria.
Lecture 4, slide 2
Name three methods of immune evasion for intracellular pathogens.
Lecture 4, slide 5
What is the inflammasome/its components? What is pyroptosis?
Lecture 4, slide 6-7
What is the pathogenesis of Shigella and Salmonella?
Lecture 4, slide 8, 13
How does Shilgella enter epithelial cells?
Lecture 4, slides 11-12
What are the roles of Salmonella’s T3SS
Lecture 4, slides 14
What is the zipper mechanism of bacterial entry?
Lecture 4, slide 17
What are core genes, accessory genes and the pangenome?
Lecture 4, slide 21
What are the three main mechanisms of horizontal gene transfer?
Lecture 4, slide 22
-there is evidence that our own microbiota is a major source of antibiotic-resistant genes in pathogens
What is the process of conjugation?
Lecture 4, slide 23
What is the process of transformation?
Lecture 4, slide 24
What is the process of transduction?
Lecture 4, slide 25
How do bacteria prevent horizontal gene transfer?
Lecture 4, slide 27-28
What is intragenomic variation in bacteria? What are the different types?
Lecture 4, slide 30
What is phase variation?
Lecture 4, slide 31
Give Type I pili as an example of phase variation. Explain the process.
Lecture 4, slide 32-33
Give PorA (a porin) as an example of phase variation. Explain the process.
Lecture 4, slide 34-35
-OMP: outer membrane protein
Give PorA (a porin) as an example of antigenic variation. Explain the process.
Lecture 4, slide 36
-OMP: outer membrane protein
What is localised hypermutation?
Some DNA sequences are a substrate for higher rates of mutation when compared with the rest of the genome.
What would intragenomic mutation of restriction/modification systems lead to?
Lecture 4, slide 38
-restriction/modification systems are products of/encoded by repeat-associated genes
Give Tfp as an example of antigenic variation. Explain the process.
Lecture 4, slide 39, 41
What is sense environment? What are the two causes of genetic variation/gene regulation in bacteria?
Lecture 4, slide 43-44
-quorum sensing regulates virulence gene expression in many bacterial pathogens.
What is quorum sensing?
Quorum sensing is the ability to detect and respond to cell population density by gene regulation.
How does the microbiota protect us from bacteria that can sense their environment?
Lecture 4, slide 47
What is the two component system?
Lecture 3, slide 48
