Infection Flashcards
What are the four types of infectious diseases?
What types of medication treat these?
Bacteria = Antibacterial Viruses = Anti-viral Fungi = Anti-fungal Parasites = Anti-protozoal
State systemic signs and symptoms of infection
Fever Weakness Vomiting Diarrhoea Headache Sore throat Joint/muscle pain Rash
State 4 cultures to investigate infection
Blood tests (FBC, WCC, CRP)
Urine samples (dipsticks)
Swabs (of sites)
Stool (pH, blood, parasites)
A bacteria cell has __ nucle(us/i), with two types of DNA. _____ DNA carries genetic information, whilst ____ DNA carries extra info. They have a ______ wall for rigid structure.
Zero nuclei; chromosomal; plasmid; peptidoglycan
What is gram staining?
Differentiating between bacteria based on their cell wall
What gram result will a bacteria with thick peptidoglycan layer produce?
Gram positive
What gram result will a bacteria with thin peptidoglycan layer produce?
Gram negative
Why do gram negative bacteria have an additional peptidoglycan layer?
To prevent antibiotics from penetrating cell, so harder to treat
Distinguish bacteriostatic drugs from bactericidal drugs?
Bacteriostatic: Inhibit bacteria growth but doesn’t kill
Bactericidal: Kills bacteria
State 4 ways antibacterials work
- Inhibit bacterial cell wall synthesis
- Interact with plasma membrane
- Inhibit cell metabolism incl. DNA/RNA
- Disrupt protein synthesis
Outline beta-lactam rings in abx effectiveness
- Abx contain beta-lactam ring in molecular structure
- Beta-lactamases (enzyme) hydrolyses ring
- Makes abx ineffective
What do beta-lactamase inhibitors do?
Stop action of beta-lactamase enzyme, reducing abx resistance
Penicillins are bacteri_____. They interfere with ____ and affect cell growth/division by binding to _________.
Bactericidal; interfere with cell wall synthesis; Penicillin Binding Protein
What is the spectrum of activity of penicillins?
Active against gram-positive and gram-negative
What are side effects of penicillins?
Allergy, skin rashes, fever, GI disturbances, hypernatraemia (IV)
Cephalasporins are bacteri______. They inhibit ______.
Bactericidal; inhibit cell wall synthesis
What is the spectrum of activity of cephalasporins?
Broad. Primarily gram-positive, but new generations active against gram negative.
What are side effects of cephalasporins?
5-10% allergy, skin rashes, fever, GI disturbances
Macrolides are bacteri_________. They irreversibly bind to _____ so _____ synthesis is affected.
Bactericidal + bacteriostatic; ribosomes; protein synthesis
What is the spectrum of activity of macrolides?
Most gram-positive bacteria
What are side effects of macrolides?
GI disturbances, liver damage, jaundice
Tetracyclines are bacteri_______. They inhibit mRNA production by __________.
Bacteriostatic; reversibly binding to ribosomes
What is the spectrum of activity of tetracyclines?
Most gram positive and negative bacteria
What are side effects of tetracyclines?
GI disturbances, photosensitivity.
AVOID in children.
In what two ways can antibiotic resistance occur?
Natural (innate) = Entire species resistant before any abx introduced
Acquired = Once sensitive bacteria now resistant
What mechanism of resistance does the following describe?
Antibiotic will eliminate sensitive organism within a bacterial population meaning only the resistant ones survive
Selection
What mechanism of resistance does the following describe?
Susceptible bacterium becomes a resistant one and then proliferates
Mutation
What mechanism of resistance does the following describe?
Exchange of genetic material
Transferred resistance
What mechanism of resistance does the following describe?
Bacterium produces enzymes & target abx e.g. beta-lactamases on penicillins
Enzyme inactivation
What mechanism of resistance does the following describe?
Alteration to bacteria so less antibiotics can enter and bind to its targets
Altered permeability
What mechanism of resistance does the following describe?
Antibiotic target site (e.g. ribosomes) is altered so that antibiotic can no longer bind and is ineffective
Altered structure
What are 3 current examples of antibiotic resistance?
MRSA, VRE, ESBL
