Microbial Growth 2 Flashcards
An antiseptic (or germicide) is distinguished from other sterilizing compounds by
A: its ability to protect from subsequent microbial infections–not just initial sterilization.
B: being able to inhibit growth of microorganisms but not necessarily kill all of them.
C: killing all bacteria and microscopic fungi but not being effective against viruses.
D: being able to be used on living tissues without harm.
D
The major distinguishing difference between antiseptics and disinfectants is __________.
A: antiseptics can be used on living tissue
B: disinfectants work well on biofilms
C: antiseptics are not affected by the presence of organic matter
D: disinfectants can be used on living tissue
A
What does the minimum inhibitory concentration (MIC) of a chemical tell you?
A: It tells you the smallest concentration of an organism that is needed for chemical control.
B: It tells you the smallest concentration of the chemical that is needed to inhibit the growth of any microorganism.
C: It tells you the smallest concentration of the chemical that is needed to inhibit the growth of a specific microorganism.
D: It tells you the smallest concentration of the chemical that is needed to kill a specific microorganism.
C
An antimicrobial compound that targets a pathway or structure that is present in a pathogen but not in the host exhibits \_\_\_\_\_\_\_\_\_\_. A: antibiotic resistance B: narrow spectrum activity C: selective toxicity D: complete toxicity
C
Some antibiotics inhibit protein synthesis by disruption of translation through interactions with the A: protein. B: chromosome. C: DNA. D: ribosome.
D
Which of the following antibiotics inhibits RNA synthesis? A: penicillin B: erythromycin C: rifampin D: azithromycin
C
Penicillin and other β-lactam antibiotics inhibit cell wall synthesis. What makes them effective antibiotics?
A: They may burst or desiccate when lacking a cell wall.
B: They are generally hypertonic relative to their environment, so they burst when lacking a cell wall.
C: They are generally hypotonic relative to their environment, so they burst when lacking a cell wall.
D: They are generally hypertonic relative to their environment, so they desiccate when lacking a cell wall.
B
The first antibiotic to be characterized was a A: macrolide. B: cephalosporin. C: β-lactam. D: quinolone.
C
Which of the following antibiotics are properly matched with their target of action? A: macrolide-30S ribosomal subunit B: Platensimycin-lipid biosynthesis C: aminoglycoside-50S ribosomal subunit D: tetracycline-50S ribosomal subunit
B
Which of the following is a mechanism of aminoglycosides?
A: targeting the 30S ribosomal subunit
B: inhibition of cell wall biosynthesis
C: prevention of peptidoglycan crosslinking
D: inhibition of DNA replication
A
Antibiotic resistance is a major concern as microbes can rapidly develop resistance when antibiotics are not used appropriately. Which of the following examples best describes how this occurs?
A: Microbes respond to the presence of antibiotics by deliberately developing resistance mechanisms.
B: Antibiotics are mutagenic. They cause mutations, like other mutagenic chemicals.
C: Exposure to too much of an antibiotic causes resistance.
D: In any population of microbes, some individuals may have resistance genes. When exposed to an antibiotic, there is selection for the microbes that have these genes.
D
Among the recommendations from the Centers for Disease Control and Prevention to limit the development of antibiotic resistance are __________.
A: to treat with broad spectrum drugs
B: to treat with the newest, effective antimicrobial
C: to stop taking the antimicrobial as soon as symptoms disappear
D: to treat with the oldest, effective antimicrobial
D
Which antibiotic is overcome by beta-lactamases?
A: Tetracycline
B: Sulfonamide
C: Penicillin
D: Tetracycline, Penicillin, and Sulfonamide are all affected by beta-lactamase.
C
How might efflux pumps increase antibiotic resistance in bacteria?
A: Resistant bacteria may have a greater number of efflux pumps on their cell surfaces.
B: Some bacteria can decrease the specificity of their efflux pumps, increasing the number of different antibiotics the pumps can eliminate.
C: Some bacteria can change the chemical structure of the antibiotic.
D: Efflux pumps can never be modified to increase antibiotic resistance.
E: Resistant bacteria can have more efflux pumps, and can have less specific efflux pumps.
E
Bacteria that are resistant to sulfonamide have enzymes that have a greater affinity for what? A: PABA B: Sulfonamide C: Tetrahyrdrofolic acid D: Tetracycline
A
Why would an efflux pump for penicillin located on a bacterial cell membrane not be effective at providing resistance to the drug?
A: The efflux pumps would not stop penicillin from blocking metabolic pathways.
B: There are fewer efflux pumps on the cell membrane.
C: The cell membrane is the target of penicillin.
D: Penicillin disrupts the cell wall, which is located outside of the cell membrane.
D
Membrane transport proteins are required for which mode(s) of antibiotic resistance?
A: Modification of a porins
B: Modification of a metabolic enzyme
C: Efflux pumps
D: Efflux pumps, beta-lactamases, and modification of porins all utilize membrane transport proteins.
E: Beta-lactamases
D
What is meant when a bacterium is said to become “resistant” to an antibiotic?
A: The antibiotic kills or inhibits the bacterium.
B: The antibiotic is metabolized by the bacterium, providing more energy for growth of the cell.
C: The bacterium is neither killed nor inhibited by the antibiotic.
D: The antibiotic mutates in a way that benefits the bacterium.
C
When a patient is treated with antibiotics, __________.
A: mutations occur in all of the bacterial cells
B: sensitive bacterial cells multiply uncontrollably
C: the drug will kill or inhibit the growth of all of the sensitive bacterial cells
D: the drug will kill or inhibit the growth of all of the resistant bacterial cells
E: mutations will occur in the sensitive bacterial cells, but not in the resistant bacterial cells
C
The process of acquiring antibiotic resistance by means of bacteriophage activity is called
The process of acquiring antibiotic resistance by means of bacteriophage activity is called
A: transduction.
B: R-plasmid acquisition.
C: point mutation.
D: transformation.
A
Which of the following mutations would not result in antibiotic resistance? A: Missense mutation B: Nonsense mutation C: Silent mutation D: Frameshift insertion E: Frameshift deletion
C
Transduction:
Transformation:
Bacterial conjugation:
Transduction: Resistance comes from a bacteriophage (who has grabbed bacterial DNA
Transformation: Picking up DNA from the environment
Bacterial conjugation: Bacteria can transfer R plasmids by conjugating
Transduction:
Transformation:
Bacterial conjugation:
Transduction: Resistance comes from a bacteriophage (who has grabbed bacterial DNA
Transformation: Picking up DNA from the environment
Bacterial conjugation: Bacteria can transfer R plasmids by conjugating
Widespread antimicrobial drug resistance is usually passed by A: gene splicing. B: heterologous gene expression. C: reverse transcription. D: horizontal gene transfer.
D
Most drug-resistant bacteria isolated from patients contain a(n)
Most drug-resistant bacteria isolated from patients contain a(n)
A: T1 phage.
B: β-lactam.
C: R plasmid.
D: reverse transcriptase.
C
Which of the following is a cause of drug-specific resistance in disease-causing organisms?
A: nosocomial infection
B: poor immunity
C: indiscriminate nonmedical use of antimicrobials
D: inappropriate hygiene
C
How is drug-resistant Neisseria gonorrhoeae treated?
A: with tetracycline
B: with vancomycin
C: with synthetic analogs of tetracycline
D: with penicillinase-resistant β-lactams
D
A mechanism for penicillin resistance in bacteria is
A: phosphorylation of the antibiotic.
B: splitting the β-lactam ring of the antibiotic.
C: confirmation change of the antibiotic.
D: acetylation of the antibiotic.
B
In the search for new antimicrobial drugs, to minimize resistance developing scientists should focus on __________.
A: modifications of current antimicrobial compounds
B: new targets of action found only in eukaryotes
C: combinations of current antimicrobial compounds
D: new targets of action found only in bacteria
D
Which of the following is a novel antimicrobial target?
Which of the following is a novel antimicrobial target?
A: inhibition of cell wall biosynthesis
B: disruption of lipid biosynthesis
C: inhibition of protein synthesis
D: inhibition of peptidoglycan crosslinking
B
