Inhibiting the Growth of Pathogens In Vivo Using Antimicrobial Agents

Question 1

is the use of any chemical (drug) to treat
any disease or condition.

Answer 1

Chemotherapy

Question 2

A __ is any drug used to treat any
condition or disease

Answer 2

chemotherapeutic agent

Question 3

is any chemical (drug) used to
treat an infectious disease, either by inhibiting or by
killing pathogens in vivo. Some antimicrobial agents are antibiotics

Answer 3

An antimicrobial agent

Question 4

An is a substance produced by a microorganism
that kills or inhibits the growth of other microorganisms

Answer 4

antibiotic

Question 5

The Discovery of Penicillin by

Answer 5

Alexander Fleming

Question 5

Antibiotics that have been chemically modified to kill a wider variety of pathogens or reduce side effects are called

Answer 5

semisynthetic antibiotics

Question 6

Colonies are poorly developed in this
area of the plate because of an antibiotic
(penicillin) being produced by a colony of
___, shown at

Answer 6

Penicillium notatum (a mould)

Question 7

____ drugs inhibit growth of bacteria, whereas
____ drugs kill bacteria

Answer 7

Bacteriostatic
bactericidal

Question 8

destroy only Gram-negative
bacteria;

Answer 8

Colistin and nalidixic acid

Question 9

drugs inhibit production of folic acid (a
vitamin) in those bacteria that require p-aminobenzoic
acid to synthesize folic acid; without folic acid, bacteria
cannot produce certain essential proteins and die.

Answer 9

Sulfonamide

Question 10

Colistin and nalidixic acid they are referred to as

Answer 10

narrow-spectrum
antibiotics

Question 11

Antibiotics that are destructive to both Gram-positive and
Gram-negative bacteria are called

Answer 11

broad-spectrum

Question 12

Penicillins

Answer 12

(bactericidal; interfere with cell wall
synthesis)

Question 13

is when two antimicrobial agents are used
together to produce a degree of pathogen killing that
is greater than that achieved by either drug alone

Answer 13

Synergism

Question 13

is when two drugs actually work against
each other. The extent of pathogen killing is less
than that achieved by either drug alone

Answer 13

Antagonism

Question 14

Cephalosporins

Answer 14

(bactericidal; interfere with cell wall
synthesis)

Question 15

Carbapenem

Answer 15

(bactericidal; interfere with cell wall
synthesis

Question 16

Tetracyclines

Answer 16

(bacteriostatic; inhibit protein synthesis)

Question 17

Aminoglycoside

Answer 17

(bactericidal; inhibit protein synthesis

Question 18

Macrolides

Answer 18

(bacteriostatic at lower doses; bactericidal at
higher doses; inhibit protein synthesis)

Question 19

Fluoroquinolones

Answer 19

(bactericidal; inhibit DNA synthesis)

Question 20

Antiprotozoal agents work by

Answer 20

interfering with DNA and RNA synthesis (e.g.,
chloroquine, pentamidine, and quinacrine)
– Interfering with protozoal metabolism (e.g.,
metronidazole)

Question 21

Most antifungal agents work in one of three ways

Answer 21

By binding with cell membrane sterols (e.g., nystatin
and amphotericin B)
– By interfering with sterol synthesis (e.g., fluconazole
and miconazole; echinocandins)
– By blocking mitosis or nucleic acid synthesis (e.g.,
griseofulvin and 5-flucytosine)

Question 22

are microbes (mainly bacteria) that have
become resistant to one or more antimicrobial agents.

Answer 22

Superbugs

Question 23

are notorious
havens for multidrug-
resistant microbes.

Answer 23

Hospitals

Question 24

Some bacteria are naturally resistant because they lack
the specific target site for the drug or the drug is unable
to cross the organism’s cell wall or cell membrane and,
thus, cannot reach its site of action. Resistance of this
type is known as

Answer 24

intrinsic resistance

Question 24

If bacteria that were once susceptible to a particular drug
become resistant, this is called

Answer 24

acquired resistance.

Question 25

Before a drug enters a bacterial cell, it must first bind to
proteins on the surface of the cell; these proteins are
called

Answer 25

drug-binding sites

Question 26

plasmid that contains multiple genes for drug
resistance is known as a

Answer 26

resistance factor (R-factor).

Question 27

the “garage” is known as the

Answer 27

β-lactam ring

Question 28

here are three types of β-lactamases:

Answer 28

– Penicillinases
– Cephalosporinases
– Carbapenemases

Question 29

is when drug therapy is initiated before
laboratory results are available

Answer 29

Empiric therapy