MICROBIOLOGY- Antimicrobial resistance Flashcards
List the 6 main causes for antibiotic resistance
- Over prescribing of antibiotics
- Patients not finishing their treatment
- Over use of antibiotics in live stock and fish faming
- Poor infection control in hospitals and clinics
- Lack of hygiene and poor sanitation
- Lack of new antibiotics being developed
Name some mechanisms of antibiotic resistance
- Antibiotic target
- Efflux pump
- Enzymatic degradation
- Impermeability
- Inactivation
Describe how bacteria become resistant to antibiotics through the mechanism of antibiotic target
- Bacteria may lack a target for the antibiotic
- The antibiotic target may be inaccessibly
- The antibiotic target may be modified to prevent the action of the drug
How does an efflux pump help bacteria become resistant to antibiotics?
They actively pump the antibiotic out of the bacteria through these pumps
Describe how bacteria become resistant to antibiotics through the mechanism of Enzymatic degradation
Bacteria produce enzymes that are capable too chemically modifying or destroying the antibiotic
Describe how bacteria become resistant to antibiotics through the mechanism of impermeability
The bacteria has modified cell wall proteins which stop antibiotics getting in
Describe how bacteria become resistant to antibiotics through the mechanism of inactivation
The bacteria adds a phosphate group on the antibiotic which will reduce its ability to bind to the bacterial ribosomes
Which type of gene transforms does the dissmenination of antimicrobial resistance occur from
Horizontal gene transfer
What is the dissemination of antimicrobial resistance
Bacteria passing on its resistance chromatin to other bacteria
what is horizontal gene transmission
It is the transfer of genes from one bacteria to another similar or dissimilar bacteria
What is vertical gene transmission
Transfer of genes from parent cells to daughter cells
Name the different types of horizontal gene transfers
- Transformation
- Gene transfer agent
- Transduction
- Conjugation
Describe conjugation gene transfer
This type of gene transfer requires cell to cell contact via cell surface pilli (almost the bacterial version of sex)
Describe tranformation gene transfer
Defined as the uptake, integration and functional expression of extra cellular DNA (DNA found outside the bacteria)
Where does the extracellular DNA in transformation gene transfer come from ?
Cell death
Describe transduction gene transfer
Gene transfer happens via bacteriophages but only when the genes are beneficial to the host bacteria
What are bacteriophages
Viruses that infect bacteria
Describe Gene transfer agents gene transfer
Bacteriophages can carry random parts of reproducing cell genomes and can pass to host bacteria
Name the antibiotics most commonly prescribed in dentistry
- Amoxicillin
- Phenoxymethyl penicillin
- Metronidazole
Dentists are responsible for what percentage of all community antibiotic prescriptions in the uK?
7%
GPs are responsible for what percentage of all community antibiotic prescriptions in the uK?
80%
Name some bacteria that are beginning to show antibiotic resistance in dentistry
- Veillonella spp
- Prevotella denticola
- Oral streptococci producing beta lactamasea
- Eikenella corrodens
- Aggregatibacter actinomycetemcomitans
What are veillonella spp becoming resistant to?
Amoxicillin
What is prevotella denticola becoming resistant to?
Amoxicillin
What is Eikenella corrodens becoming resistant to?
Slow emergence of resistance to metronidazole
What is Aggregatibacter actinomycetemcomitans becoming resistant to
Slow emergence of resistance to metronidazole
