Antimicrobial resistance II Flashcards
This deck contains the lectures 'Antibiotic resistance in developing countries' and 'Phages to treat infection with resistant bacteria'
What ar the consequences of AMR? (4)
- Increased mortality
- Increased morbidity
- Costs (length of hospital stay)
- Disease spread
Where are the gaps in knowledge about AMR the largest?
Where health systems are weak
What should be taken into consideration when you try to create surveillance standards?
-What samples and information to collect
-How to analyze samples
-How to compile and share data
Data of which proportion of bacteria should be obtained?
Proportions of resistant bacteria causing specific diseases or affecting defined populations
Which connected factors form the ‘One Health Approach”?
- Human disease
- Animal disease
- Environment
Why do have to take the animal domain into account when we want to do something about AMR?
Antibiotic use (as growth promoters) in the animal food industry is huge
Which elements are present at the interplay between human disease, animal disease and the environment?
- Farming
- Environment
- Sewage water supply
- Nosocomial dissemination
- Contamination between all these factors
Criteria used to determine urgency of new antibiotics for pathogens (7)
- All-cause mortality
- Healthcare and community burden
- Prevalence of resistance
- 10-year trend of resistance
- Transmissibility
- Preventability in hospital and community settings
- Treatability and current pipeline
What factors contribute to AMR in low-middle-income countries
- Infectious disease burden is high
- Cost constraints
- Absent/rudimentary systematic surveillance systems
What does microbiology in developing countries lack? (5)
- Basic equipment
- Technicians
- Automation
- Specialized knowledge
- Quality assurance system
Which compound can counteract beta-lactamases?
Beta-lactamase inhibitors
What are the three categories of ESBL enzymes?
- SHV
- TEM-1
- CTX-M
What phenotypic test can you perform in the lab to determine if a bacterial suspension is ESBL positive/negative?
Double-disc synergy test
What are phages thought to do?
Important regulators of the bacterial populations in natural ecosystems
True or False: “The abundance of eukaryotic viruses is bigger than that of phages.”
False. The abundance of phages is generally greater than that of eukaryotic viruses
Which three categories of bacteriophages are there?
- dsDNA
- ssDNA
- RNA
Why are phages suspected to actively contribute to the homeostasis of the bacterial flora of humans?
They can get stuck in our mucosa
How does a phage recognize a bug?
- usually species specific - has to do with phage receptors (carbohydrate with helanin on the surface)
- pseudomonas: efflux pumps
- E.coli: different LPS forms
–> insert DNA
Transient phage?
Lysogenic vs lytic stage
Temperate bacteriophages can induce virulence factors
Temperate Bacteriophages can encode genes playing a role in.. (3)
- Colonization/ adhesion
- Resistance to serum/ phagocytes
- Toxins
Genetic exchange of bacterial DNA in phages
Formation of transducing phages
How are transducing phages formed?
- Prophages can be activated by UV Light
- part of genome ends up in phage
What are characteristics of bacteria in their natural habitat? (3)
- Hide underneath our mucosal layers.
- With tract in difficult to access area of the human body
- Form biofilms (clusters of bacteria curved by a matrix of extracellular material)
What kind of enzyme is actually designed to kill bacteriophages? Why?
Restriction enzymes. Cuts foreign DNA
What are the mechanisms a bacteria can use to become resistant to a phage? (2)
- Prevent attachment
- Kill DNA if it comes in
- Sensing
What are the mechanisms that a bacteria can induce after sensing a bacteriophage in itself? (2)
- Inhibition of growth
- Suicide
What do you prevent with these bacterial anti-phage measures?
Phage accumulation
What is the most common solution to avoid resistance?
Using a phage cocktail
How does phage resistance results in antibiotic sensitivity?
- Bacteria changes surface –> doesn’t produce efflux pump
- Safe from phages
- More susceptible to antibiotic exposure, because efflux pumps play a role in fighting off antibiotics
Bacteriophages used in phage therapy should .. (6)
- Not disturb the homeostasis of the human bacterial flora
- Not encode toxins
- Not be able to facilitate exchange of bacterial DNA
- Be able to circumvent bacterial defense systems
- Not be neutralized by the hosts humoral response
- Not cause direct/indirect anaphylactic shock
What is the added value of phages in opsono-phagocytosis?
Accumulation of antibodies on the surface of the bug
