Deck 43: Obligate Intracellular and Nonculturable Bacterial Agents

Question 1

The extracellular, metabolically inert, infective form of the Chlamydia is called the

A)reticulate body.
B)elementary body.
C)replicate body.
D)initial body.

Answer 1

B
Chlamydia have a unique developmental life cycle, with an intracellular growth, or replicative form, the reticulate body (RB), and an extracellular, metabolically inert, infective form, the elementary body (EB). Structurally, the chlamydial EB closely resembles a gram-negative bacillus; however, its cell wall lacks a peptidoglycan layer.

Question 2

Of the following organisms, which has a unique developmental life cycle including a replicative form, the reticulate body, and an extracellular, metabolically inert, infective form, the elementary body?

A)Rickettsia
B)Chlamydia
C)Ehrlichia
D)Coxiella

Answer 2

B
Chlamydia have a unique developmental life cycle, with an intracellular growth, or replicative form, the reticulate body (RB), and an extracellular, metabolically inert, infective form, the elementary body (EB). Structurally, the chlamydial EB closely resembles a gram-negative bacillus; however, its cell wall lacks a peptidoglycan layer.

Question 3

A prokaryote that differs from most other bacteria with respect to its very small size and obligate intracellular parasitism is

A)Rickettsia.
B)Ehrlichia.
C)Calymmatobacterium.
D)Coxiella.

Answer 3

A
The organisms addressed in this chapter are obligate intracellular bacteria or are considered either extremely difficult to culture or unable to be cultured. Organisms of the genera Chlamydia, Chlamydophila, Rickettsia, Orientia, Anaplasma, and Ehrlichia are prokaryotes that differ from most other bacteria with respect to their very small size and obligate intracellular parasitism.

Question 4

Rickettsia can be described as

A)fastidious extracellular parasites that multiply by binary fission in the cytoplasm of host cells.
B)fastidious obligate intracellular parasites that multiply by binary fission in the nucleus of host cells.
C)hardy obligate intracellular parasites that multiply by budding in the cytoplasm of host cells.
D)fastidious obligate intracellular parasites that multiply by binary fission in the cytoplasm of host cells.

Question 5

Diagnosis of C.trachomatis is done by which methodology?

A)Cytology
B)Culture
C)Direct detection of antigen or nucleic acid
D)Serologic testing
E)All of the above are correct.

Question 6

Which of the following bacteria are fastidious, pleomorphic, gram-negative bacilli, are obligate intracellular parasites that survive only briefly outside of a host (reservoir or vector), and can multiply only intracellularly?

A)Coxiella
B)Chlamydia
C)Rickettsia
D)Calymmatobacterium

Question 7

The most common sexually transmitted bacterial pathogen and a major cause of pelvic inflammatory disease is

A)Rickettsia.
B)Chlamydia.
C)Calymmatobacterium.
D)Coxiella.

Question 8

The organisms in the genus Chlamydia can be described as

A)having a replicative form called the reticulate body.
B)having an intracellular infective form called the elementary body.
C)having an extracellular, metabolically inert, infective form.
D)All of the above are true.

Question 9

Of the following organisms, which can be described as fastidious obligate intracellular parasites that multiply by binary fission in the cytoplasm of host cells and which infect humans as accidental hosts in most cases?

A)Rickettsia
B)Chlamydia
C)Calymmatobacterium
D)Coxiella

Question 10

The intracellular growth, or replicative form, of the Chlamydia is called the

A)reticulate body.
B)elementary body.
C)replicate body.
D)initial body.

Question 11

A prokaryote that differs from most other bacteria with respect to its very small size and obligate intracellular parasitism is

A)Ehrlichia.
B)Chlamydia.
C)Calymmatobacterium.
D)Coxiella.