Antimicrobial Therapy and Stewardship Flashcards
What is the common cold most commonly caused by ?
Virus - rhinovirus
What is a sore throat commonly caused by ?
A virus or possibly a bacterial infection called streptococcus.
What is candidiasis (thrush) caused by ?
A fungus called Candida albicans
Which a bacteria that quickly develops resistance to new antibacterial drugs?
Methicillin resistant staphylococcus aureus (MRSA)
What is a antimicrobial drug ?
Any drug targeted at a microbe.
Name 3 microorganisms
Virus
Bacteria
Fungi
Define bacteria
Single called
Flagella- ability to move
Prokaryotes
Divide by binary fission
Explain the structure of gram negative bacteria
- A thin peptidoglycan layer sandy witch between two phospholipid bilayers
Explain the structure of a gram positive bacteria.
Thick peptidoglycan layer and no outer membrane
What type of bacteria is more resistant to antibiotics and why ?
Gram negative - Due to their cell wall being more complex and this makes drug penetration more difficult.
What are the two largest groups of bacteria and what are their shapes ?
Bacilli - Rod shapes
Cocci - spherical
How do bacteria cause disease
Releasing toxins
What are the two types of drugs that can kill bacteria
Bacteriostatic or bacteriocidal
What does a bacteriostatic drug do ?
Inhibit bacterial cell growth but do not destroy cell.
What do bacteriocidal drugs do ?
Directly kill bacteria
Who invented the gram stain and when ?
Christian gram 1884
How do antibiotics target bacteria ?
They target structures within the bacteria that are different from human cells so that they don’t kill any human cells.
Name a beta-lactam antibiotic
Penicillin
How do beta lactam antibiotics work ?
They block the enzymes involved in the production of peptidoglycan, an essential component of the bacterial cell wall. This bactericidal action causes the cell wall to erupt, killing the cell.
Do beta-lactam drugs have a bactericidal action or a bacterostatic action and why ?
It’s bactericidal as it causes the cell walls to erupt and results in cell death.
Name a bacteriastatic antibiotic
Clarithromycin and erithromycim
How do bacteriostatic drugs that target ribosomes work ?
Target the bacteria’s ribosomes, disrupt them from making proteins which makes the bacteria ineffective.
Bacteria will be alive but unable to make anything
How does antimicrobial resistance occur ?
When bacteria DNA genetically mutate, causing changes in the bacterial structure, DNA replication and protein production so that antibiotics aren’t effective.
The overuse and misuse of antibiotics speeds up the bacterial multiplication and mutation process making infections harder to treat and easier to spread.
How does antibiotic resistance spread?
Antibiotics resistance can be acquired from another bacteria ?
What are the two ways in which antibiotics resistance is spread from bacteria to bacteria?
Horizontal gene transfer or vertical gene transfer
Correct way to take antibiotics ?
The full course to remove ALL harmful bacteria and prevent the bacteria from re-emerging and mutating.
Antibiotics should not be over prescribed
Why should the right dose and right time be adhered to with antibiotics ?
To maintain plasma concentration of antibiotics to destroy or suppress bacteria growth.
What can be done prior to giving antibiotics ?
Microbial (blood) cultures, prior to initial dose.
What should be avoided in terms of antibiotics?
Giving broad spectrum antibiotics
What considerations should be given when prescribing antibiotics ?
- pregnancy
- contraceptive pill
- renal and liver function
When can prophylactic antibiotics be given ?
- after intestinal surgery
- after orthopaedic surgery
- after insertion of a prosthesis
How can nurses prevent infections ?
- follow infection control procedures
- use of aseptic technique - insertion of indwelling catheters
- microbial cultures prior to initial dose
- timely removal of in dwelling devices
What does HPV stand for ?
Human pappiliomvirus
What is HPV ?
A are for a very common group of virus
What does HIV stand for ?
Human immunodeficiency
What does HIV do ?
Attacks the bodies immune system and it can lead to AIDS
What can HIV lead to ?
AIDS
What does AIDS stand for ?
Acquired immunodeficiency
What does HBV stand for ?
Hepatitis B
What is HBV
A vaccine prevented liver infection caused by the hepatitis b virus. Spread by blood, semen or other body fluids of a person that’s infected.
How does a virus multiply and why does this make treatment difficult?
Needs host cell to multiply. Can’t kill the virus without killing the human cells.
What do antiviral drugs do ?
They do not inactive or kill viruses, they merely inhibit viral reproduction.
What is the structure of a virus ?
- A virus is composed of a genome, DNA or RNA wrapped inside a protein coat called a capsid.
- Most animal viruses also have an additional lipid membrane called an envelope with protein spikes that serve to attach host cells.
What are the 5 steps to a viral cycle
1 - Attachment to host cell receptor
2 - Viral entry via endocytosis, fusion or both.
3 - Release of Genome (uncoating)
4 - Replication of Viral Genome
5 -Assemble and release of new viruses from the host cell.
How to antiviral drugs work?
To block the viral life cycle at any point.
Which antiviral drugs work by stopping the virus attaching to a host cell ?
HIV drugs bind to the host cells receptor as an antagonist
-ccr5 antagonist (maraviroc)
Why does gram positive bacteria retain the crystal violet dye ?
The gram stain detects peptidoglycan, sine gram positive bacteria a have a thick peptidoglycan layer they retain the crystal violet die
Why does gram negative bacteria not retain the crystal violet dye ?
The crystal violet dye detects peptidoglycan, gram negative bacteria does not retain retain the die as it had a outer phospholipid layer and it lacks peptidoglycan
Explain what fungi is
- eukaryotic
- unicellular or multicellular eg yeast is unicellular, mould is multicellular.
- Nourished by absorption of organic matter from their environment
- Can NOT be treated with antibiotic
