Microbiology Mastering Chapter 14 & 15

Which of the following would be the first sign of an infection that resulted in the release of endotoxin?

Fever

If mosquitoes are the mode of transmission for West Nile virus, why did the students in Bill's virology class focus on finding the virus in the dead birds rather than collecting mosquitoes to examine?

The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals.

When would endotoxins be released from a bacterial cell?

When the cell dies

If a new bacterial pathogen entered a human body through an accidental needle stick, the first cell that would try to kill the pathogen would likely be

a phagocyte.

Which of the following is the most effective way to reduce the number of nosocomial infections?

handwashing

Erythrocytes, leukocytes, and platelets are formed by a process called __________.

hematopoiesis

What is the reservoir for this disease organism, Salmonella enterica serotype Typhi?

humans

What are the clinical signs and symptoms of typhoid fever?

fever and rose-spotted rash

The health of the patient

should be the primary concern of the healthcare worker.

A person who attended a picnic early in the day develops a very high fever and is unresponsive by the evening. This person most likely has been exposed to a(n)

superantigen

Emigration is

the migration of phagocytes through blood vessels to the site of tissue damage.

Both the innate and adaptive defenses of the immune system work to prevent

the penetration and colonization by pathogens, and the diseases they cause.

Due to the action of tears, potential pathogens of the eyes and its membranes usually end up where?

the stomach

If a patient notices a healthcare worker not following suggested precautions,

they should immediately bring it to the attention of the healthcare worker.

A response that is uniquely directed against pathogenic Bordetella pertussis would involve what component?

Antibodies

In 1937, a man employed to lay water pipes was found to be the source of a severe epidemic of typhoid fever. The man, an asymptomatic carrier of Salmonella enterica serotype Typhi, the bacterium that causes typhoid, habitually urinated at his job site. In the process, he contaminated the town's water supply with bacteria from his bladder. Over 300 cases of typhoid fever developed, and 43 people died before the man was identified as the carrier. Based on the data supplied, what was the approximate mortality rate for this outbreak?

14%

Which of the following would be considered a vector?

A fly carrying disease from fecal matter to food

During his research on West Nile virus, Bill learned that this virus is placed within a functional grouping known as arboviruses. What is meant by the term arbovirus?

An arbovirus is maintained in nature through biological transmission. An arbovirus is an arthropod-borne virus.

Which of the following would be considered a fomite?

An infected toy

How might a patient who is not being treated with an antibiotic still be exposed to an antibiotic?

Antibiotics can be used in aerosols, thereby entering the environment.

Which domain of the A-B toxin binds to cell surface receptors on the host cell?

B domain

What type of nosocomial infection is likely to arise from intravenous catheterizations?

Bacteremia

Which of the following can release histamines?

Cells from damaged tissues and the complement pathway

Which of the following is considered a major category of transmission of disease?

Contact, vehicle, and vector transmission

How could this epidemic be stopped without firing the worker?

Educate the worker about personal hygiene and use of an outhouse or designated bathroom. Instruct him to thoroughly wash his hands with clean soap and water after using the facilities.

The brain tissue of the birds indicated the possibility of encephalitis. What is encephalitis, and why should this type of infection cause concern among health care professionals?

Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures.

Which of the following statements is true regarding hand washing?

Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction.

Why is vasodilation important to tissue repair?

It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage.

How does the protozoan Trypanosoma evade detection by the immune system?

It can change the surface antigens frequently, preventing the immune system from tracking it.

Why is a release of endotoxin into the bloodstream potentially deadly?

It can lower blood pressure and cause the patient to go into shock.

An inflammatory response would result from which of the following?

Jellyfish sting

Which of the following is the best mode of controlling the spread of West Nile infections?

Limit exposure to mosquitoes to prevent the transmission of West Nile virus.

Which is an example of vehicle disease transmission?

The presence of Listeria on undercooked chicken served for dinner

Endotoxins are also known as

Lipid A.

How can health care workers reduce the occurrence of nosocomial infections?

Practice more stringent aseptic techniques

Which of the following characteristics of a catheter should be considered, to help minimize the spread of nosocomial infections?

Single-use

How are superantigens different from other types of exotoxins?

Superantigens cause an overstimulation of the host immune system.

If a person turns their ankle, how would one determine if damage to the tissue in the ankle has occurred?

The ankle is red, swollen, and warm to the touch.

How does a capsule help certain bacteria evade detection by the immune system?

The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign.

Why are invasive procedures likely to increase the risk of nosocomial infections?

These procedures allow microbes from the skin to enter the bloodstream of the patient.

What direct effect do histamines and leukotrienes have on capillaries?

They allow capillary walls to open and become leaky.

How are immune cells able to detect foreign pathogens?

They are able to detect structures on the surfaces of foreign cells that are not found in the host.

First line defenses have what aspect in common with each other?

They are physical barriers against invading pathogens.

How can surgeons help to limit nosocomial infections?

They should perform surgeries and invasive procedures only when absolutely necessary.

What is the role of epidemiology?

To learn how to treat and prevent various diseases.

What is the function of inflammation in response to a burn from a hot iron?

To repair the damaged tissue

Which of the following microorganisms actually grows inside the macrophage?

Tuberculosis bacterium

What features of West Nile virus make it an emerging disease of special concern?

West Nile virus is an arthropod-borne virus transmitted by mosquitoes. West Nile virus has a high mortality rate in immunosuppressed humans and infects many species of birds in southern Europe, the Mediterranean basin, and North America. West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods.

Which of the following best describes why West Nile Virus is considered to be an emerging infectious disease?

West Nile virus outbreaks have increased in number and affected areas since 1937.

Which of the following types of diseases develops rapidly and lasts a short time?

acute disease

A differential white blood cell count that shows elevated levels of eosinophils probably indicates which of the following in the patient?

allergies

All of the following might lead to a disease caused by an opportunistic pathogen EXCEPT __________.

an encounter with an infected animal

All of the following are ways that neutrophils can directly or indirectly kill cells EXCEPT __________.

by forming MACs

When aerosols containing pathogens spread disease from a distance of less than one meter, it is considered

contact transmission.

An exotoxin that has the ability to kill or damage host cells is referred to as a(n)

cytotoxin

Pus is comprised of

dead phagocytes.

A patient's immune system is typically fully responsive during which of the following stages of disease?

decline

Infection and disease are NOT the same thing because __________.

disease does not necessarily result from an infection

The process of diapedesis is important because __________.

it allows white blood cells to leave the vessel system and attack pathogens in the tissues

E. coli living in the colon of a human is an example of a _________ relationship.

mutualism

A patient who has been hospitalized with uncontrolled muscle spasms has probably been infected with bacteria that secrete a(n)

neurotoxin

In 1937, a man employed to lay water pipes was found to be the source of a severe epidemic of typhoid fever. The man, an asymptomatic carrier of Salmonella enterica serotype Typhi, the bacterium that causes typhoid, habitually urinated at his job site. In the process, he contaminated the town's water supply with bacteria from his bladder. Over 300 cases of typhoid fever developed, and 43 people died before the man was identified as the carrier. How was this carrier identified?

urine culture

A patient contracted a disease just by being in the same room with an infected individual for an extended period of time. Which of the following modes of disease transmission is most applicable in this situation?

vehicle transmission

Epidemiology is defined as the study of

where and when a disease occurs, and how it is transmitted.