Ch. 20 M Icro

This term is used to describe compounds that cause greater harm to microbes than to the human host

This term is used to describe the molecular method by which a compound might kill or inhibit a microbe

This term is used to describe the range of different microbes that a compound can kill or inhibit

What would be the effect of using a medication combination where one medication is bacteriostatic and the other is bactericidal for actively dividing cells only? A. The medications would interfere with each other and become less effective. B. The medications would enhance each others activity by killing microbes that are both slow growing and fast growing. C. The medications would have no effect on each other since they target two different things.

What are the possible adverse effects of using antimicrobials?

T/F: some antimicrobial fail to kill/inhibit a pathogen simply because the microbe is naturally (intrinsically) resistant to it

Please choose the class of antimicrobials that would have the most selective toxicity. A. Antimicrobials that inhibit cell wall synthesis B. Antimicrobials that interfere with nucleic acid structure and function C. Antimicrobials that interfere with cell membrane structure and function D. Antimicrobials that inhibit protein synthesis

4 major mechanisms or antimicrobial resistance

Please choose the method of antimicrobial susceptibility testing that involves measuring and evaluating zones of inhibition around antibiotic discs placed on a culture of bacteria prior to incubation. A. Beta-lactamase test B. Tube dilution test C. Kirby-Bauer test D. Gram stain test E. ELISA test

What are the two major mechanisms by which microbes can acquire resistance to antimicrobial medications?

Which of the following microbes have strains (called MRSA) that are highly resistant to many (beta)-lactam medications? A. Staphylococcus aureus B. Mycobacterium tuberculosis C. Streptococcus pneumoniae D. Enterobacteriaceae

Which of the following microbes is of growing concern due to increasing resistance to "first-line medications," including isoniazid and rifampin. A. Mycobacterium tuberculosis B. Enterobacteriaceae C. Staphylococcus aureus D. Streptococcus pneumoniae

Which of the following microbes, a leading cause of pneumonia in the United States, is of growing concern due to increased resistance to penicillin? A. Staphylococcus aureus B. Streptococcus pneumoniae C. Enterobacteriaceae D. Mycobacterium tuberculosis E. Mycoplasma pneumoniae

Which of the following is of growing concern due to increasing resistance to vancomycin? A. Mycobacterium tuberculosis B. Enterobacteriaceae C. Enterococci D. Streptococcus pneumoniae

Which of the following statements about antibiotic resistance is FALSE? A. A single mutation may be sufficient for a bacterium to develop resistance. B. Efflux pumps allow some bacteria to eject antibiotics. C. Combination therapy reduces the likelihood of a bacterium developing resistance. D. Patients should stop taking antibiotics as soon as they feel better, to avoid developing resistance.

What is the disadvantage of an antibiotic with a short half-life? A. It is likely to lead to bacterial resistance. B. It must be given in combination with another medication. C. It is bactericidal, not bacteriostatic. D. It is bacteriostatic, not bactericidal. E. It must be given multiple times daily

T/F: A person who frequently takes a particular antibiotic may become resistant to that medication.

T/F: Changing an antibiotic so that it could pass through a porin protein would likely cause A. Gram-negative cells to become sensitive to that medication. B. Gram-positive cells to become resistant to that medication. C. Gram-positive cells to become sensitive to that medication. D. Gram-negative cells to become resistant to that medication.

T/F: Alexander Fleming discovered penicillin when he noticed that bacteria contaminating his Penicillium cultures inhibited the growth of the fungus.

Alexander Fleming was working with the bacterium S. aureus when he discovered penicillin. He had cultured the bacteria on agar plates, one of which then became contaminated with a mold. He noticed that the S. aureus did not grow immediately next to the mold. After analyzing this observation, he went on to show that: A. the mold was out-competing the bacterium for space on the culture medium. B. the mold was synthesizing and secreting a bacteria-inhibiting compound. C. the mold was using the available oxygen needed by the bacterium for growth. D. the mold was depleting nutrients needed for the bacteria to grow.

T/F: All antibiotics are made by fungi such as Penicillium and Cephalosporium.

A pharmaceutical company is developing a new antibacterial medication that is safe for use in humans. What would NOT be a good target for the medication?

Which of the following pairs is INCORRECT? A. Therapeutic index - measure of the relative toxicity of a medication B. Short half-life - medication needs to be taken relatively frequently C. 70S ribosome - target of some antibacterial medications D. Broad spectrum - an organism that is susceptible to a wide range of medications E. Bacteriostatic - inhibits growth of bacteria

Which of the following matches about antibiotic resistance is INCORRECT? A. Chloramphenicol acetyltransferase - chemically alters chloramphenicol B. Penicillin binding protein - destroys penicillin C. Acquired resistance - R plasmid D. Methicillin - resistant to penicillinase E. β-lactamase - antibiotic-inactivating enzyme

Routine antimicrobial treatment of tuberculosis involves taking A. one medication for at least 10 days. B. two or more medications for at least 10 days. C. five medications for at least 5 years. D. one medication for at least 6 months. E. two or more medications for at least 6 months.

The MIC is A. the lowest concentration of an antimicrobial medication needed to enhance visible gorwth of a given bacterial strain in vitro. B. the highest concentration of an antimicrobial medication that kills 99.9% of cells of a given bacterial strain in vivo. C. the lowest concentration of an antimicrobial medication that kills 99.9% of cells of a given bacterial strain in vivo. D. the lowest concentration of an antimicrobial medication needed to prevent visible growth of a given bacterial strain in vitro.

Explain the difference between MIC and MBC. A .MBC is the maximum dose of an antimicrobial medication needed to prevent the growth of an organism, while MIC is the maximum dose of that medication needed to kill the organism. B. MBC is the minimum dose of an antimicrobial medication that prevents the growth of an organism, while MIC is the minimum dose of that medication that kills the organism. C. MIC is the minimum dose of an antimicrobial medication that prevents the growth of an organism, while MBC is the minimum dose of that medication that kills the organism. D. MIC is the maximum dose of an antimicrobial medication needed to prevent the growth of an organism, while MBC is the maximum dose of that medication needed to kill the organism.

Which of the statements about combination therapy is FALSE? A. Using combinations of medications may prevent the development of resistance. B. Developing successful medication combinations may reduce the need for the development of new medications. C. Using two medications simultaneously may enhance the effect of each medication. D. Using two medications is always twice as effective as using just one.

In 1928, the first antibiotic, __________, was discovered by Alexander Fleming

An enzyme produced by some bacteria that destroys penicillin is ___________.

Antimicrobial dugs such as penicillin that are naturally produced by microorganisms are called _________.

In terms of their antimicrobial action, drugs that kill bacteria are _________.

The relative toxicity of a given medication to humans is expressed as the ________ _________

Drugs such as streptomycin for which a single point mutation causes resistance are sometimes used in combination with one or more other drugs. This way, if any cell spontaneously develops resistance to one drug, another drugs ill still kill it. This approach is called _________ therapy