chapter 20; antimicrobial drugs
questions with verified answers
Simultaneous use of penicillin and tetracycline is often less effective than when either drug is
used alone. This is called __________. - ANS ✔✔antagonism
Which of the following antibiotics is frequently used as an alternative for those who are allergic
to penicillin? - ANS ✔✔erythromycin
The __________ test is a commonly used disk-diffusion method for evaluating antibiotic
effectiveness. - ANS ✔✔Kirby-Bauer
Which of the following antibiotics is a common choice to treat streptococcal infections in
children? - ANS ✔✔erythromycin
What is the benefit of combining penicillins with potassium clavulanate (clavulanic acid)? - ANS
✔✔it inhibits penicillinase
A nucleoside analog used to treat HIV infection is __________. - ANS ✔✔zidovudine
You have a 200-milligram-per-milliliter antibiotic solution. You prepare serial dilutions (1:2, 1:4,
etc.) of the antibiotic. You then inoculate each tube with Salmonella. Bacteria grow in tubes 4, 5,
and 6. What is the MBC (minimum bactericidal concentration)? - ANS ✔✔there is not enough
information to determine the MBC.
Polyenes, azoles, and allylamines interfere with __________. - ANS ✔✔fungal cell membranes
, Which drug would be used to treat athlete's foot? - ANS ✔✔clotrimazole
What is the method of action of nucleoside analogs? - ANS ✔✔inhibition of DNA synthesis
A disk-diffusion test identifies __________. - ANS ✔✔agents to which a test culture is sensitive,
in terms of growth or survival
Semisynthetic penicillins are __________ antibiotics than is natural penicillin. - ANS ✔✔more
effective
Which of the following are common targets for bacterial resistance to antibiotics? - ANS ✔✔all
are common targets for bacterial resistance to antibiotics
You have a 200 mg/ml antibiotic solution. You prepare serial dilutions (1:2, 1:4, etc.) of the
antibiotic; the first tube contains 100 mg/ml. You then inoculate each tube with Salmonella.
Bacteria grow in tubes 4, 5, and 6. You subculture bacteria from tubes 1 through 3 to nutrient
broth. Growth occurs in the tube 3 subculture. You can conclude that the MIC is __________. -
ANS ✔✔25 mg/ml
The drug Flagyl is commonly used to treat an STD caused by __________. - ANS
✔✔Trichomonas vaginalis
Which of the following is used for treating influenza infections? - ANS ✔✔Oseltamivir
Ethambutol inhibits incorporation of mycolic acid into cell walls; therefore, it is effective against
__________. - ANS ✔✔mycobacteria
Rifampin blocks RNA polymerase and therefore inhibits __________. - ANS ✔✔transcription
questions with verified answers
Simultaneous use of penicillin and tetracycline is often less effective than when either drug is
used alone. This is called __________. - ANS ✔✔antagonism
Which of the following antibiotics is frequently used as an alternative for those who are allergic
to penicillin? - ANS ✔✔erythromycin
The __________ test is a commonly used disk-diffusion method for evaluating antibiotic
effectiveness. - ANS ✔✔Kirby-Bauer
Which of the following antibiotics is a common choice to treat streptococcal infections in
children? - ANS ✔✔erythromycin
What is the benefit of combining penicillins with potassium clavulanate (clavulanic acid)? - ANS
✔✔it inhibits penicillinase
A nucleoside analog used to treat HIV infection is __________. - ANS ✔✔zidovudine
You have a 200-milligram-per-milliliter antibiotic solution. You prepare serial dilutions (1:2, 1:4,
etc.) of the antibiotic. You then inoculate each tube with Salmonella. Bacteria grow in tubes 4, 5,
and 6. What is the MBC (minimum bactericidal concentration)? - ANS ✔✔there is not enough
information to determine the MBC.
Polyenes, azoles, and allylamines interfere with __________. - ANS ✔✔fungal cell membranes
, Which drug would be used to treat athlete's foot? - ANS ✔✔clotrimazole
What is the method of action of nucleoside analogs? - ANS ✔✔inhibition of DNA synthesis
A disk-diffusion test identifies __________. - ANS ✔✔agents to which a test culture is sensitive,
in terms of growth or survival
Semisynthetic penicillins are __________ antibiotics than is natural penicillin. - ANS ✔✔more
effective
Which of the following are common targets for bacterial resistance to antibiotics? - ANS ✔✔all
are common targets for bacterial resistance to antibiotics
You have a 200 mg/ml antibiotic solution. You prepare serial dilutions (1:2, 1:4, etc.) of the
antibiotic; the first tube contains 100 mg/ml. You then inoculate each tube with Salmonella.
Bacteria grow in tubes 4, 5, and 6. You subculture bacteria from tubes 1 through 3 to nutrient
broth. Growth occurs in the tube 3 subculture. You can conclude that the MIC is __________. -
ANS ✔✔25 mg/ml
The drug Flagyl is commonly used to treat an STD caused by __________. - ANS
✔✔Trichomonas vaginalis
Which of the following is used for treating influenza infections? - ANS ✔✔Oseltamivir
Ethambutol inhibits incorporation of mycolic acid into cell walls; therefore, it is effective against
__________. - ANS ✔✔mycobacteria
Rifampin blocks RNA polymerase and therefore inhibits __________. - ANS ✔✔transcription
