21. Principles of Disease

The smallest cellular microbes are

a. rickettsias

b. mycoplasmas

c. chlamydias

d. both a and c

The most commonly reported sexually transmitted disease in the United States is caused

by the bacterium

a. Mycoplasma genitalium

b. Chlamydia trachomatis

c. Chlamydophila proctitis

d. Ureaplasma urealyticum

Treatment of chlamydial infections involves

a. erythromycin cream

b. doxycycline creams

c. surgical correction of eyelid deformities

d. all of the above

Suggest a hypothesis to explain why rickettsias are obligate parasites.

Describe the three developmental stages of the bacteria Ehrlichia and Anaplasma.

Describe the phases of untreated syphilis.

Discuss the prospects for the eradication of leptospirosis.

Beginning with the ingestion of water contaminated with V. cholerae O1 El Tor, describe the course of the disease it causes.

Match the disease with the causative pathogen in the list.

___ Spotted fever rickettsiosis

___ Murine typhus

___ Epidemic typhus

___ Scrub typhus

___ Ehrlichiosis

A. Rickettsia typhi

B. Rickettsia prowazekii

C. Rickettsia rickettsii

D. Orientia tsutsugamushi

E. Ehrlichia chaffeensis

Which of the following is not true of cholera?

a. The causative agent lives naturally in marine water.

b. There is an effective vaccine for cholera.

c. Strain 01 El Tor has been responsible for several pandemics.

d. Rice-water stool is a symptom.

The most common cause of bacterial gastroenteritis in the United States is

a. Vibrio parahaemolyticus

b. Campylobacter jejuni

c. Helicobacter pylori

d. Vibrio cholerae

Label the following stages and structures of the chlamydia life cycle: elementary body, endocytosis, vesicle, host cell, inclusion body, reticulate body. For B–D, indicate how many hours have typically transpired since infection. <IMAGE>

Label inclusion, elementary, and reticulate bodies of Chlamydia: <IMAGE>