Question | Answer |
Antimicrobial Agents | chemicals that contol the growth of microbes |
Disinfectants | chemical agents used on inanimate objects to lower levels of microbes on surfaces |
Antiseptics | chemicals used on living tissue to decrease the number of microbes |
Bactericidal Agents | cause bacterial death |
Bacteriostatic Agents | cause temporary inhibition of growth |
American Official Analytical Chemist's use-dilution test | standard method for measuring the effectiveness of a chemical agent |
Conclusion #1: Was your test chemical effective? | Yes, it killed bacteria ( S aureaus)after 5 minutes |
Conclusion #2: Was it more effective than the lab disinfectant? | Yes |
Question #2: Read the label of the preparation you tested. What are the active ingredients? | Pine oil, water, surfactants |
Antibiosis | against life |
Antibiotic | inhibiting substance |
Antimicrobial Drugs | antimicrobial chemicals absorbed or used internally (natural or synthetic) |
Pathogen | disease-causing organism |
Disk-Diffusion Method | a Petri plate containing an agar growth medium is inoculated uniformly over its entire surface. Paper disks with antimicrobial agents on them during incubation the agent will diffuse from disk from high concentration to low. |
Zones of inhibition | measurement of the effectiveness of the agents ability to inhibit bacterial growth |
Kirby-Bauer Test | for agar diffusion methods, uses mudeller-hinton agar which allows antimicrobial agent to diffuse freely |
Minimum Inhibitory Concentration (MIC) | of an antibiotic is determined by testing for bacterial growth in dilutions of the antibiotic in nutrient broth |
Conclusion #1: Which antimicrobial agents were most effective against each organism? | Tetracycline, Cloramphenicol, Neomycin |
Question #3: Why is the disk-diffusion technique not a perfect indication of how the drug will perform in vivo? | Variables such as effects of serum, the bodies pH and ionic content and oxygen level |
What other factors are considered before using the antimicrobial agent in vivo? | how drug is metabolized and excreted and side effects of drug |
Normal Microbiota | microorganisms that are more or less permanent |
Transient Microbiota | microbes that are present only for days or weeks |
Question #1: What is a surgeon trying to accomplish with a 10-minute scrub with a brush followed by an antiseptic? | to remove the transient and many of the resident microbiota |
Question #2: How do normal microbiota and transient microbiota differ? | Normal are more or less permanent; transient are present only for days or weeks |
Critical Thinking #1: If most of the normal microbiota and transient microbiota aren't harmful, then why must hands be scrubbed before surgery? | To help prevent nosocomial infections |