Summaries Flashcards
VL2: Infectious organisms: Bacteria
Take home:
- Importance of commensal and symbiontic microflora for health
- How we classify eubacterial pathogens
VL3: Pathogen & Surface structures
Take home:
- Overview of survival strategies of bacterial pathogens in a host
- The importance of some bacterial cell surface components for pathogenesis and survival
VL4: Molecular Methods in INfection Biology
Typical questions in infection biology
What organisms is causing the infections?
How does it cause the infection?
What are the relevant virulence factors?
What methodss can help address these questions?
Detection and quantification of DNA, RNA, protein
VL5: Regulation of virulence factors
Take home messages
- Virulence gene expression can be regulated at different levels
- Reversible instability of virulence gene sequences is common
- Be familiar with some specific examples of virulence factor regulation
VL6: Two component systems ans signal transduction
Take home:
- TCS are very widely used regulators
- They are used to regulate behaviour and/or gene expression
- They detect the environment and transmit a signal onwards
VL7: Bacterial Quorum sensing
Take home:
-QS is a process of cell-cell communication
Benefits of QS
-Bacteria to share information about cell density
then adjust gene expression accordingly
-Bacteria can express expensive processes as a collective
to maximize impact on the host
-QS inhibition- develop antibacterial therapeutics
VL7: QS in bacteria summary
- bacteria talk to each other
- multiple languagges (intra, inter species communication)
- bacteria distiniguish self from other
- more molecules may remain to be discovered (i.e. molecules that tell who the other is)
- QS allows bacteria to be multi cellular, similar to higher organisms
- opportun ities for novel nbiotechnological applications to impede enhance QS controlled functions
- natural anti QS strategies alredy exist
V8: Bacterial survival in environment
THM:
- some environments are potentially problematic for a bacterial cell
- there are different strategies used by bacteria to deal with problem environments
spore formation sos response oxyR response heat shock response osmotic stress response
VL9: Bacterial adhesion/adherence
THM
- bacterial adhesion to host cells/tissue is essential for maintaing normal, protective host microflora
- adhesion is also the crucial fist stage in any infectious disease
VL10: Bacterial secretion systems
THM
Why and what bacteria secrete:
-Pathogenesis effector molecules secreted into extracellular environment or into target cells
-Surface organelles must be built e.g. flagella
You should understand in outline the different secretion mechanisms
-Sec&Tat
-T1SS-T7SS
-Chaperone-Usher
VL11: Genetic identification of virulence factors
-Bioinformatics
-Brute force screening
-Screening for genes expressed in vivo
-Screening for genes required in vivo
advantages and disadvantages with each approach
VL12: HGTof Virulence factors
THM
- most virulence functions have been acquired by horizontal gene transfer (HGT)
- Mechanisms: transformation, transduction and conjugation
- detection of HGT
- examples of medically relevant HGT events
VL13: Bacterial Invasion
themes and THM
-first adhesion to a host surface-then invasion
invasion is a way to perpetuate the infectio cycle
-invasion can be divided into 2 types
extracellular invasion
intracellular invasion
- common tactics:
- secreting effector molecules into the host is common
- inducing actin polymerization isoften a critical step
VL14: Biofilms
THM
- definition of biofilm
- chemical nature of biofilm matrix
- signigicance of biofilms in infection
- significance of biofilms generally
- role of cyclic-di-GMP in signalling
VL15: The battle for iron
Outline:
