Antibiotics Flashcards
Define differential toxicity?
It is a concept that the drug is more toxic to the infecting organism than to the host.
Define Antibiotics?
Substance produced by microroganism, which in small amounts inhibit or kill the bacteria
Majority are based on naturally occurring compounds.
May be natural or synthetic
Used to treat infections inside the body or outside using creams
Before the discovery of antibiotic penicillin, which treatments were used?
Silver nitrate and Arsenic
Both were extremely cytotoxic
Who discovered antibiotics and the first antibiotic produced?
Alexander Flemming-
Peniciliin produced from penicillium fungus
What are the socio-economic and healthcare advances related to antibiotics discovery?
Low morbidity and mortality rates
Increased survival rates with co-morbidities
Increased surgical survival rates
More complex surgical procedures can be performed
Fewer healthcare admissions
Lower economic burden
Fewer lost working hours
Increased productivity
Give examples of gram positive bacillus which can produce antibiotics
Bacillus subtilis
Bacillus polymyxa
What antibiotic does bacillus polymyxa produce?
Polymyxin
What antibiotic does bacillus subtillus produce?
Bacitracin
Give an exmaple of fungi and the antibody it produces
Penicillium notatum - penicillin
What Are Actinomycetes?
Actinomycetes are a group of Gram-positive, filamentous bacteria that are kind of a hybrid between bacteria and fungi in behavior and appearance.
They can also produce antibiotics
What makes an ideal antibiotic
🧫 Appropriate spectrum- Targets the right type of bacteria (narrow when possible, broad when needed).
❤️ Non-toxic to host- No damage to human cells; minimal side effects.
🔒 Low resistance potential- Less likely to create resistant strains (big win in long-term effectiveness).
⚠️ No hypersensitivity- Doesn’t trigger allergic reactions or immune overdrive.
🫀 Good tissue penetration- Reaches the site of infection effectively.
⏳ Long half-life (means that the antibiotic stays longer in the body, which reduces dosage frequency)
💊 No drug interactions Safe to use with other medications.
🧃 Easy to administer
💸 Affordable- Accessible to patients and healthcare systems
Define broad spectrum
drug is effective against a wide range of antibiotics (both gram + and - bacteria) like tetracycline
Define narrow spectrum
Drugs are effective against a limited number of species ( either gram + or -)
Define minimum inhibitory concentration
Minimum concentration of antibiotic required to inhibit the growth of microorganism
Define minimum bactericidal concentration?
Minimum concentration required to kill the microorganisms
Define bacteriostatic
Stops the bacteria from growing
Define bactericidal
Kills the bacteria
Define time dependent killing
Time-dependent killing means that the antibiotic works best when it stays in the body at a certain level for a longer period of time.
Longer exposure- more effective at killing
Define concentration dependent killing
Concentration-dependent killing means that the higher the concentration of the antibiotic, the more effective it is at killing bacteria.
Define prophlaxis
Antimicrobial agents are administrered to prevent infection
Define treatment
Antimicrobial agents are administred to cure existing or suspected infection
List some features of bacterial cell
Cell wall, cell membrane, capsules, pilli or fimbriae, cytoplasm, bacterial dna and nucleic acids, ribosomes, flagella, spores
What are the 5 antibacterial target sites?
Cell wall
Cell membrane
Protein synthesis
Nucleid acid synthesis (DNA)
Antimetabolites
What are 2 classes of antibiotics which inhibit cell wall synthesis. Give example of antibody from each class
Beta-lactams - penicillin
Glycopeptides- vancomycin
