chapter 20 microbe definitions/study guide + physical and chemical method examples

antimicrobials

medications (naturally or artificially) that inhibit or kill microbes

chemotherapeutic agent

designed to treat infections; exhibit selective toxicity. (drugs that damage pathogens but not human hosts)

antibiotic

naturally produced antimicrobial

narrow-spectrum

antimicrobial affect a limited range of microbes

broad-spectrum

antimicrobials that affect wide range of microbes

LEARN THE CHART

LEARN THE CHART

you are in a hospital and sterilizing re-usable glass syringes. List all physical methods that can be used for this purpose:

dry heat, steam heat under pressure, ionizing radiation (gamma)

Let’s say the re-usable syringes are made of a plastic that can melt at high temperatures. What chemical methods could be used for sterilization as an alternative:

chlorine&chlorites, formaldehyde, hydrogen peroxide 10%

you are a nurse in a hospital and are wiping the surface of the skin of a patient whose blood is about to be drawn. You really want to make sure you get all microbes off the skin. What antiseptics could you choose:

alcohols, hydrogen peroxide 3%, chlorohexidine

you are head of research and development at a meat-packaging facility, and a co-worker asks advice on what kind of physical method for microbial control should be used on raw steak products. what would you suggest:

cold temps, desiccation

you are cleaning a hospital room after a patient staying in the room came down with a case of C.diff. what chemical method would you use to clean:

Halogens(bleach), hydrogen peroxide 10%, aldehydes (formaldehyde and glutaraldehype)

you are cleaning a kitchen counter after cooking a meal. Keep in mind that you are most interested in cleaning up most microbes, what are some methods of microbial control that you could use:

alcohol, halogens(chlorites and chlorine), quaternary ammonium compounds

Aminoglycosides

primarily made by soil bacteria (e.g streptomycin, neomycin, tobramycin)

macrolides

some drugs are erythromycin, clindamycin, azithromycin(name brand:Z-pack)

Fluorquinolones

targets DNA gyrase in bacteria, therefore inhibiting both DNA replication and transcription (e.g ciprofloxacin and levofloxacin)

Rifampin

targets RNA polymerase in bacteria. therefore inhibiting both DNA replication and transcription ; effective at treating tuberculosis which is caused by mycobacterium tuberculosis

Sulfonamides (sulfa drugs)

Blocks folic acid synthesis in bacteria, bacteria require folic acid for nucleotide production, humans require folic acid (vitamin B9) for production of red blood cells (humans cannot make folic acid-must get from diet)

metronidazole

inhibits dan synthesis under anaerobic conditions only (and is thus used for bacterial GI tract infections and many protozoans infections as well)

antifungals

inhibits fungi

antivirals

can slow/inhibit replication of viruses in our cells (ex. paxlovid inhibits viral replication; used to treat COVID-19

antimicrobial resistance bacteria are _______ by antimicrobials

not inhibited

antimicrobial susceptible bacteria are ________ by antimicrobials

inhibited

what are the mechanisms of antimicrobial resistance

inactivation, pump, modification, impermeability