Microbiology Lab: Chapter 11

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

Limit exposure to mosquitos to prevent transmission of the West Nile virus

The causative agent for leprosy is the bacterium __________.

Mycobacterium leprae

What is the name for the dark-staining bodies observed in the brain cells from this patient?

Negri bodies

Analysis of the spinal tap shows the presence of Gram-negative bacteria cocci; for this age group which bacteria would be the probable cause of these symptoms?

Neisseria meningitidis

In the United States, most common exposure to Clostridium botulinum and its toxins occurs through __________.

ingestion of the spores or toxins in improperly canned foods

Transmission of the causative bacterial agent is via this route.

inhalation of respiratory droplets

What would be the best course of action to treat someone who has been exposed to Clostridium boltulinum toxin or has had a Botox injection that is spreading?

intravenous immunoglobulins

What determines which form of Hansen disease a person will develop after infection with the causative bacterium?

the state of a person's immune response during early development of the disease

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

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.

What is it called when there is only inflammation of the brain?

Encephalitis

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.

What was the best treatment for this patient once he had gone to the ER?

IV fluids, sedation, and respiratory support

What is the recommended course of treatment when a rabid animal bites a person?

Immediately wash the wound with soap and water, inject the bite area with rabies immunoglobulin, and begin a series of four rabies vaccine injections.

Why do symptoms persist after antibiotics have been used to treat and remove the bacterial infection?

The blebs containing lipid A are still present in the blood and in the tissues.

This disease is spread from person to person only. How contagious a disease is it considered to be?

The disease is rarely transmitted from person to person.

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.

Why should the actor worry about the spread of the injected Botox from the forehead to other parts of the body or face?

The toxin spreading to other areas of the body would inhibit muscle contractions required for normal daily activities.

Describe 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 diseases cause flu-like symptoms in most people infected, but can cause muscle weakness or paralysis? a) tetanus b) polio c) spongiform encephalopathy d) toxoplasmosis e) rabies

b) polio

The paralytic toxin from C. botulinum differs from the toxin from C. tetani in that __________.

botulism results in flaccid paralysis and tetanus results in a spastic paralysis

A 55-year-old actor is concerned about maintaining his star status as a leading man and doesn't like the "frown lines" on his forehead. He asks his dermatologist about a cosmetic treatment to relax the facial lines. The dermatologist explains that Botox—purified type A botulism toxin—is approved for use on the glabella (forehead between the eyes) and discusses with the actor the risks and benefits. The actor decides to have a treatment. Two weeks following the treatment, he calls the office reporting that his eyelids are sagging. Botulism is generally associated with ingestion of the toxin produced by Clostridium botulinum. The activity of the toxin will result in __________.

flaccid paralysis

What is the host range for rabies?

mammals

A Very Sick Sophomore In December, a 19-year-old college student experiences a severe headache, nausea, vomiting, and fever. The student suspects a case of flu and goes to the health center for a diagnosis. By the time he arrives he is feeling worse, with neck stiffness and disorientation. The doctor immediately prepares to perform a spinal tap. Based on the symptoms stated, what is the most probable disease that this student has developed?

meningitis

What cells or tissues will harbor the bacteria in a patient with Hansen disease?

peripheral nerve endings, mucous membranes, and skin cells in the fingers, toes, lips, and earlobes

A man arrived at an emergency room with neurological disorders: uncontrolled facial twitching, anxiety, and feelings of fear. He also had a sore throat, difficulty in swallowing, and complained of itching over his entire body. He remained alive for several days, but became increasingly agitated and refused to drink because of the pain involved in swallowing. He vomited repeatedly, and his temperature rose to 106 degrees Fahrenheit. He died one week after being admitted to the hospital. An autopsy revealed dark-staining bodies in the cells of his brain and a raised antibody titer in his blood. There were no obvious bites or scratches on his skin, though interviews with friends and family indicated that a bat had landed on the man's face about a month before he was admitted to the hospital. What disease is transmitted from bats to humans and produces the signs/symptoms displayed by this patient?

rabies

A Woman with No Feelings A 41-year-old woman arrives in the hospital emergency department with third-degree burns on the second and third fingers of her left hand. Through a family member who acts as an interpreter, the woman tells the triage nurse that she had moved to the United States from Brazil barely six months before. This evening she had been sitting in her living room, cigarette in hand, watching the nightly news, when she noticed the odor of something burning. As she rose to investigate, she saw that her fingers were blackened and smoking where the cigarette had burned down. With a jerk she discarded the cigarette and marveled that she felt no pain—it was as if her fingers were not her own. The symptoms point toward a form of Hansen disease. Which form of the disease best fits the symptoms that are being seen by the nurse?

tuberculoid leprosy

To reduce the chances of bacterial meningitis, the CDC recommends what actions be taken for military recruits and college freshman?

vaccinations for meningococcus