Microbiology Chapter 18 - Nervous System Infections

What is the vector for African sleeping sickness?

tsetse fly

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

negri bodies

Botulism Antitoxin Heptavalent (BAT) is given as treatment for symptomatic botulism or as prophylaxis following suspected exposure to botulism. Given Clostridium botulinum's pathogenesis, which of the following does BAT help to prevent?

BAT prevents toxin from binding to nerve cells, alleviating the blocked release of acetylcholine.

Based upon the signs and symptoms Jane is now experiencing, which of the following diseases should be considered as a possible cause?

Bacterial meningitis viral meningitis

Jane was prescribed dexamethasone, a corticosteroid that would help limit inflammation and reduce the risk of permanent damage to her central nervous system. How does this drug work?

Dexamethasone inhibits the production of arachidonic acid-a precursor to cellular inflammatory signals.

A 1-year old patient presents to the emergency room with fever, headaches, lethargy, stiff neck, and disorientation, with the absence of petechial rash. The mother noted that while her daughter was playing and eating normally that morning, later in the day she developed a non-specific fever and progressed quickly into her current state. When you ask the mother about her daughter's vaccination status, she states that she chose not to vaccinate her daughter due to her personal and religious preferences. Gram-stain analysis of the patient's cerebrospinal fluid reveals Gram-negative, encapsulated cells. Which of the following disease diagnoses is most likely?

Haemophilus meningitis

Which of the following strategies may have prevented the spread of Listeria at the party?

Heating the deli meats before serving

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

IV fluids, sedation, and respiratory support

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.

What would be the most appropriate prevention method for meningococcal meningitis for a healthy adolescent, aged 12 years old?

Meningococcal conjugate vaccines (Mentactra®, MenHibrix®, and Menveo®)

Your patient, an 8-year old boy, presents to the emergency room with a stiff neck, seizures, hallucinations, and is later found to be comatose. Two days prior, the patient had complained of severe frontal headache, nausea, fever, and vomiting. The child's mother explained that the boy's symptoms began one day after he went swimming in a warm, freshwater lake. Which of the following terms would most accurately describe your patient's symptoms?

Meningoencephalitis

Which of the following outcomes is observed during Rabies virus pathogenesis?

Negri bodies are a diagnostic sign of Rabies virus infection.

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

Did you make a mistake in ordering the tests on her CSF? Support your answer.

No. While LaTonia's CSF may be unremarkable, the negative CSF findings may help to reconfirm the correct disease diagnosis.

Your adolescent patient presents to the emergency room with "lock jaw" and is unable to open his mouth to speak. This spastic paralysis is due to which of the following?

Tetanospasmin blocks the release of inhibitory neurotransmitters that prevent muscle relaxation.

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.

A virus that is able to be transmitted via ______ like ticks, flies, and mosquitoes is considered a(n) ________

arthropods; arbovirus

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

Some arboviruses are able to move through the bloodstream and infect the brains of humans and animals. This disease manifestation is called______________

encephalitis

Botulism is generally associated with ingestion of the toxin produced by Clostridium botulinum. The activity of the toxin will result in __________.

flaccid paralysis

Several encephalopathies, such as Eastern equine encephalitis and West Nile virus encephalitis, are caused by the _____ and the ________. These viruses can infect humans and animals such as horses and birds.

flaviviruses; togaviruses

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

The doctor received a report from the clinical lab with the results of Jane's tests. Her blood culture was positive for bacteria, and her blood showed an abnormally elevated white blood cell count. Most of the WBCs in her sample had a single, circular nucleus. Strangely, Jane's CSF (cerebral spinal fluid) sample showed normal glucose levels despite elevated protein. When a Gram stain of the CSF was performed, purple, rod-like structures were seen. Based upon the attached data table, what is causing Jane's meningitis?

listeria

As the physician assistant on duty, you have narrowed down the possible causes of LaTonia's illness. What did you think was the most likely cause of her illness when you ordered the initial tests?

listeria meningitis

What is the host range for rabies?

mammals

What medication should this man receive to treat this disease?

melarsoprol

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

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

Which of the following is the most likely pattern of transmission for toxoplasmosis?

Ingesting undercooked meat containing T. gondii cysts.

Which of the following is a symptom associated with Jane's illness? Select all that apply.

Stiff neck Headache Malaise, a general feeling of illness or discomfort

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.

Which of the following statements help to explain the pathogenesis of human transmissible spongiform encephalopathy?

The shape of normal host PrpC protein is altered by abnormal PrpSc protein, transforming it into infectious PrpSc protein.

Transmission of the causative bacterial agent is via this route.

inhalation of respiratory droplets

Your patient (an 8-year old girl) presents to the emergency room with a stiff neck, seizures, and hallucinations. The day prior, the patient had high fever, intense headaches, and vomiting. Your patient appears to be up-to-date on all immunizations and denies leaving the country within the past month. The patient's father mentions that just one-week prior, the daughter seemed otherwise healthy and had spent all day at the warm freshwater lake near their house. Three days later, the patient dies from complications and an autopsy is performed. Which of the following protozoan forms would most likely be found in the brain and cerebrospinal fluid?

Trophozoites

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

intravenous immunoglobulins

The causative agent for leprosy is the bacterium __________.

Mycobacterium leprae

Your 30-year old patient presents to a Florida emergency room with fever, headache, flu-like symptoms, stiff neck, disorientation, and convulsions. You notice that there are several insect bites on her arm, which she tells you are mosquito bites from a camping trip two days ago. Based on the patient's case history and disease presentation, which of the following pathogens did your patient most likely contract?

west nile virus

A ________ is a disease that can be transmitted from animals to humans

zoonosis

What is the mortality rate for untreated cases of African sleeping sickness?

100%

Which of the following scenarios would most likely result in Listeria meningitis?

A pregnant woman consumes a sandwich with tainted deli meat and feta (a soft cheese).

What is the name of the disease this man is suffering from?

African sleeping sickness

Which of the following statements accurately describes a sensory neuron?

An afferent neuron specializing in input such as converting environmental stimuli into electrical impulses

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.

Which of the following statements concerning the blood-brain barrier is/are correct? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

Blood vessels are sealed much more tightly in the area around the central nervous system than in other areas of the body. Due to the blood-brain barrier defense mechanisms, infections of the nervous system are often the result of immune system malfunction or an injury to the system. Large essential molecules such as glucose can cross the blood-brain barrier using specialized transporters.

Given the 50-mile radius spread, what is the best description of what should be done?

Dead wild animals should be removed and disposed of properly. The area should be treated to reduce the number of mosquitoes.

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.

To confirm your diagnosis, what item(s) will you ask Denisha to bring to you?

Food items consumed (The canned green beans used to make the green bean salad are the primary suspect, although luncheon meats and potatoes are also known to harbor the pathogen.)

If your final diagnosis is confirmed, what public health steps, if any, must you take?

Immediately report the infection to the CDC Food samples associated with suspect cases must be obtained immediately, stored in properly sealed containers, and sent to laboratories for testing, so that a food recall may be issued if necessary.

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. Submit

The presence of a sudden high fever, when taken into context with Jane's other signs and symptoms, allows us to conclude that Jane's illness is caused by a

It is impossible to tell what is causing Jane's infection based only on her presented signs and symptoms. Submit

Which of the following characteristics help to explain why Mycobacterium leprae infects the peripheral nervous system?

Mycobacterium leprae prefers a lower growth temperature.

Which of the following statements concerning Cryptococcus neoformans pathogenesis is/are true? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

Once fungal spores enter the lungs, C. neoformans invade macrophages, which then carry the fungus to the lymphatic system. Cryptococcocis is the leading cause of death for individuals with HIV/AIDS. The pathogen's thick polysaccharide capsule shields the fungus from the host immune system.

Which of the following statements regarding polio vaccines is true?

One disadvantage of the oral polio vaccine is that immunocompromised individuals can develop illness from the attenuated virus and, in rare circumstances, develop paralytic polio.

Which of the following statements is true concerning Trypanosoma bruceii?

T. bruceii subsp. rhodiense produces a more rapid, acute disease than T. bruceii subsp. Gambiense.

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.

Which of the following statements concerning pneumococcal meningitis is/are true? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

The immune response to the pathogen is often the most damaging aspect of the disease. Pneumococcal meningitis is preventable by vaccination. Pneumococcal meningitis typically begins when normal flora spread from the nose and throat into the bloodstream.

Which of the following statements accurately describes the function of the meninges? To be marked correct, you'll need to select all applicable statements, as there may be more than one correct answer.

The meninges supply nutrients to the central nervous system. The meninges protect the central nervous system from physical shock. The meninges remove wastes from the central nervous system.

Which of the following choices are possibilities for WNV transmission?

The mosquitoes that were present at dusk, when Peter was working near the horses.

Which of the following is a valid difference between the central and peripheral nervous systems?

The peripheral nervous system inputs and transmits information, while the central nervous system integrates and responds to the information received.

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.

Look carefully at the peripheral blood smear. What parasite is present in the blood?

Trypanosoma brucei

Why was Jane's treatment reduced to only one antibiotic after the cause of illness was identified? Select all that apply

Using multiple antimicrobial agents is likely to cause more side effects.

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.

Provided your newest working diagnosis is correct, what do you expect the tests you ordered will reveal? Differential white blood cell and glucose level of the CSF sample ELISA for West Nile virus Gram stain and culturing of the CSF

White blood cell counts and glucose levels should be normal, the ELISA test should be negative, and the Gram stain and culturing of the CSF will most likely be inconclusive.

What are some possible factors that could account for WNV spread within this 50-mile radius?

Wild animals that fed on infected birds. Infected birds that migrated from one farm to another.

Based on LaTonia's drooping eyelids, what is your new working diagnosis?

botulism

What disease is transmitted from bats to humans and produces the signs/symptoms displayed by this patient?

rabies

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