CHAPTER 10

Question 1

are chemicals used to treat diseases.

Answer 1

Chemotherapeutic agents

Question 2

kind of chemotherapeutic agents

Answer 2

Antimicrobial agent or antimicrobials

Question 3

Antimicrobials include

Answer 3

Antibiotics, semisynthetic antimicrobials, and synthetic drugs

Question 4

Biologically produced agents

Answer 4

Antibiotics

Question 5

Chemically modified antibiotics

Answer 5

Semisynthetic antimicrobials

Question 6

Successful chemotherapy against microbes is based on ___, that is, using antimicrobial agents that are more toxic to pathogens than to the patient.

Answer 6

selective toxicity

Question 7

penicillins, carbapenems, cephalosporins—have a functional lactam ring. They prevent bacteria from cross-linking NAM subunits of peptidoglycan in the bacterial cell wall during growth

Answer 7

Beta-lactams

Question 8

also disrupt cell wall formation in many Gram- positive bacteria.

Answer 8

Lipoglycopeptides and cycloserine

Question 9

blocks NAG and NAM transport from the cytoplasm

Answer 9

Bacitracin

Question 10

Block mycolic acid synthesis in the walls of mycobacteria

Answer 10

Isoniazid (INH) and ethambutol

Question 11

block synthesis of fungal cell walls.

Answer 11

Echinocandins

Question 12

Antimicrobial agents that inhibit protein synthesis
by interfering with 70S ribosomes include __ which inhibit
functions of the 30S ribosomal subunit,

Answer 12

Aminoglycosides and tetracyclines

Question 13

which inhibit 50S subunits.

Answer 13

chloramphenicol, lincosamides, streptogram-
ins, and macrolides,

Question 14

block initiation of translation.

Answer 14

Oxazolidinones

Question 15

molecules inhibit protein synthesis by preventing ribosomes from assembling on mRNA.

Answer 15

Antisense nucleic acid

Question 16

binds to isoleucine aminoacyl-tRNA synthetase—the enzyme that loads isoleucine onto the tRNA.

Answer 16

Mopirocin

Question 17

disrupt the cytoplasmic membranes of fungi.

Answer 17

Polyenes, azoles, and allylamines

Question 18

are structural analogs of para-aminobenzoic acid (PABA), a chemical needed by some microorganisms but not by humans.

Answer 18

Sulfonamides

Question 19

Drugs that inhibit nucleic acid replication in pathogens include

Answer 19

actinomycin, nucleotide analogs and nucleoside analogs, quino- lones, and rifampin.

Question 20

Chemotherapeutic agents have a

Answer 20

Spectrum of action

Question 21

Types of spectrum of action

Answer 21

Narrow and broad

Question 22

such as the Kirby-Bauer test, reveal which drug is most effective against a particular pathogen;

Answer 22

Diffusion susceptibility tests

Question 23

the larger the __ around a drug- soaked disk on a Petri plate, the more effective the drug.

Answer 23

zone of inhibition

Question 24

usually deter- mined by either a broth dilution test or an Etest, is the smallest amount of a drug that will inhibit a pathogen.

Answer 24

Minimum inhibitory concentration

Question 25

ascertains whether a drug is bacteriostatic and the lowest concentration of a drug that is bactericidal.

Answer 25

Minimum bactericidal concentration

Question 26

is essentially a ratio of the drug’s tolerated dose to its effective dose. The higher the TI, the safer the drug.

Answer 26

Therapeutic index

Question 27

Clinicians use the term __ to indicate the range of concentrations of a drug that are effective without being exces- sively toxic.

Answer 27

therapeutic window

Question 28

Some members of a pathogenic population may develop resis- tance to a drug because of extra DNA pieces called

Answer 28

R plasmids or the mutation of genes

Question 29

Microorganisms may resist a drug by producing enzymes such as

Answer 29

Beta-lactamases

Question 30

by removing the drug from the cell with ___ or by protecting the drug’s target by binding another molecule to it

Answer 30

efflux pumps,

Question 31

occurs when resistance to one chemotherapeutic agent confers resistance to similar drugs

Answer 31

Cross resistance

Question 32

are resistant to three or more types of antimicrobial drugs.

Answer 32

Multiple drug resistant pathogens

Question 33

describes the interplay between drugs that results in efficacy that exceeds the efficacy of either drug alone. Some drug combinations are antagonistic.

Answer 33

Synergism