chapter 20
define drug resistance. how is it produced/ what measures can be taken to reduce drug resistance
Drug resistance is the lack of susceptibility of a microorganism to a chemotherapeutic agent. Drug resistance may develop when microorganisms are constantly exposed to an antimicrobial agent. Ways to minimize the development of drug-resistant microorganisms include judicious use of antimicrobial agents; following directions on the prescription; or administering two or more drugs simultaneously
This microorganism is not susceptible to antibiotics or neuromuscular blocks, but it is susceptible to protease inhibitor
Human immunodeficiency virus
The most selective antimicrobial activity would be exhibited by a drug that
Inhibits cell wall synthesis
Why does a cell die from the following antimicrobial actions? Colistimethate binds to phospholipids
Like polymyxin B, causes leaks in the plasma membrane
order of toughness
PRIONS BACILLUS CEREUS psuedomonas aeruginosa
why is it easier to kill bacteria vs worms
Selective toxicity human closely related to worms
List the advantages of using two chemotherapeutic agents simultaneously to treat a disease. What problem can be encountered using two drugs?
Simultaneous use of two agents can prevent the development of resistant strains of microorganisms, take advantage of the synergistic effect, provide therapy until a diagnosis is made, and lessen the toxicity of individual drugs by reducing the dosage of each in combination. One problem that can result from simultaneous use of two agents is the antagonistic effect
A patient with streptococcal sore throat takes penicillin for two days of a prescribed 10 day regimen. Because he feels better, he then saves the remaining penicillin for some other time. After three more days, he suffers a relapse of the sore throat. Discuss the probable cause of the relapse.
Studies that it takes time for an antibiotic to completely get rid of a pathogen. With strep 10 ten days is the usual time needed. After two days (with this patient) all of the beta strep were not destroyed. Another possibility is that there were penicillin resistant bacteria present.
cell membrane damage causes death because
cell contents leak out
an antimicrobial agent should meet al of the folowing criteria except
production of hypersensitivities in host
Vancomycin-resistant Enterococcus faecalis was isolated from a foot infection of a 40-year old man. The patient had a chronic diabetes-related foot ulcer and underwent amputation of a gangrenous toe. He subsequently developed methicillin-resistant Staphylococcus aureus bacteremia. The infection was treated with vancomycin. One week later, he developed a vancomycin-resistant S. aureus (VRSA) infection. This is the first case of VRSA in the U.S. What is the most likely source of the VRSA?
staphylococcus aureus
evolution of drug resistance requires;
variability in the popuation Not all individuals survive those most adapted to the environment survive