MMG 301 - Module 36: Vector-Transmitted and Soilborne Bacterial Diseases

Lyme disease and syphilis are similar in that they __________.

are both caused by spirochetes and are chronic infections that involve the nervous systems

Which of the following pathogens is spread by infected lice?

Rickettsia prowazekii

Which of the following explains why treatment of symptomatic tetanus requires an antitoxin and an antibiotic?

Because C. tetani bacteria excrete tetanus toxin, it is important to neutralize the toxin while also killing the bacteria that are producing more.

The causative agent of Lyme disease is ________, which is carried primarily by the ________.

Borrelia burgdorferi / Ixodes sp. (deer tick)

Clostridium tetani is an obligate anaerobe that can cause tetanus. When it enters the human body, it can produce tetanus toxin. Considering that C. tetani is an obligate anaerobe, which of the following explains how it can survive and cause disease in the human body?

Especially in deep wounds, C. tetani can sometimes survive in areas with damaged tissue that have become anoxic because of poor-to-no blood flow.

Tetanus is highly contagious through person-to-person contact. T/F

False

Which of the following diseases causes an influenza-like illness that can progress to include pneumonia?

Q fever

Wild rodents are the major reservoir of the plague organism, Yersinia pestis, but pandemic plagues were historically associated with crowded, unsanitary urban areas. Why is this the case?

Yersinia pestis can be transmitted by fleas from wild rodents to urban rats, which quickly die of the disease. Humans are accidental hosts due to fleas seeking out blood meals after most rats have succumbed to the disease.

In bubonic plague, buboes are swellings formed in the lymph nodes and filled with

Yersinia pestis.

Eradication of certain diseases is nearly impossible, because we cannot

control or immunize all vector and reservoir animals or eradicate organisms completely from the soil.

The primary disease reservoir for plague is

rats.

Soldiers or refuges in crowded unsanitary conditions are most susceptible to which rickettsial disease?

typhus

Tetanus develops from a puncture wound because

the organism's endospores germinate in anoxic conditions.

Controlling most rickettsial diseases involves managing

the vector

Rickettsia are obligate intracellular parasites that are transmitted by arthropods. In which of the following places would you most likely find the parasites living in the host organism during the course of infection?

within macrophages