Microbiology Ch 26

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Why can an infection in the brain's ventricles usually be detected in spinal fluid obtained from the lower back (lumbar region)? A. Cerebrospinal fluid (CSF) originates in the ventricles, but percolates over and around the brain and spinal cord. B. There is a high degree of vascularity that exists, allowing easy transfer of bacteria in the cerebrospinal fluid (CSF) and the blood. C. There is a set of lymph nodes specifically in place to drain the cerebrospinal fluid (CSF) from the ventricles. They are housed in the lumbar region of the spinal column, adjacent to the spinal cord. D. This is an incorrect statement. Since the central nervous system (CNS) is a protected site due to the blood-brain barrier, there can never BE an infection in the ventricles.

A. Cerebrospinal fluid (CSF) originates in the ventricles, but percolates over and around the brain and spinal cord.

Characteristic inclusion bodies formed in cells of organisms infected with rabies are called A. Negri bodies. B. metachromatic bodies. C. polyphasic bodies. D. Koplik spots.

A. Negri bodies.

Why would the Sabin oral polio vaccine need to be eliminated as we get closer and closer to eradication of the polio virus? A. Since it is a live, attenuated viral vaccine, there's always the chance it could revert back into a pathogenic state by mutation. This would introduce new strains still capable of causing the illness into human populations, thwarting elimination. B. The Sabin vaccine is cheaper than the Salk (killed virus) vaccine, but it isn't as effective at producing a protective response. We'll need to shift to the more effective Salk vaccine worldwide eventually to complete the eradication process. C. The Salk vaccine is far cheaper than the Sabin vaccine. To effectively eradicate polio, we'll need to shift all of our resources into the cheapest and easiest to deliver vaccine possible. That is the Salk vaccine. D. The Sabin vaccine can only be administered to human beings. We need to vaccinate bird populations as well to effectively control the spread of polio. Birds are a natural reservoir for the virus.

A. Since it is a live, attenuated viral vaccine, there's always the chance it could revert back into a pathogenic state by mutation. This would introduce new strains still capable of causing the illness into human populations, thwarting elimination.

The chief source of central nervous system (CNS) infections is through the A. bloodstream. B. genitourinary system. C. skin. D. nerves.

A. bloodstream.

The central nervous system is made up of the A. brain and spinal cord. B. spinal cord and spinal nerves. C. sympathetic and parasympathetic system. D. brain and endocrine organs.

A. brain and spinal cord.

To determine the causative agent of a central nervous system (CNS) infection, a sample is taken from the A. cerebrospinal fluid. B. arterial blood. C. venous blood. D. urine.

A. cerebrospinal fluid.

Painful spasms of the throat triggered by swallowing or the sight of water is called A. hydrophobia. B. hydrophagia. C. tetany. D. paralysis.

A. hydrophobia.

6. The nervous system typically A. is sterile. B. has a small number of normal flora. C. contains Gram-positive bacteria. D. contains a small number of viruses.

A. is sterile.

. In rabies, the virus multiplies in one kind of cell then binds to receptors in the A. neuromuscular region. B. spinal cord. C. respiratory area. D. brain.

A. neuromuscular region.

Cryptococcal meningoencephalitis caused by Cryptococcus gattii differs from the general pattern of fungal central nervous system (CNS) disease by occurring in A. otherwise healthy people. B. children. C. AIDS patients. D. immunosuppressed people.

A. otherwise healthy people.

The polio viruses usually enter the body through A. the oral route. B. contaminated blood. C. cuts in the skin. D. the respiratory route.

A. the oral route.

The early symptoms of rabies generally begin A. 1 day after viral entry. B. 1-2 months after viral entry. C. 6 months after viral entry. D. 1 year after viral entry.

B. 1-2 months after viral entry.

What underlying infection should a physician immediately suspect when confronted with a patient with confirmed cryptococcal meningoencephalitis caused by Cryptococcus neoformans, and why? A. Influenza infection. The 2 viruses are often transmitted together in respiratory droplets. B. HIV infection. People with normal immune systems generally fend off this fungal infection before it becomes clinically symptomatic. C. Varicella zoster virus (chicken pox). During the incubation period for chicken pox, and during its latency, C. neoformans has an increased ability to colonize the respiratory tract. D. Syphilis. This sexually-transmitted illness depletes CD4+ helper T cells that are necessary to directly attack the fungal infection of C. neoformans.

B. HIV infection. People with normal immune systems generally fend off this fungal infection before it becomes clinically symptomatic.

A pathologist claims it's much easier to determine the causative agent of meningitis than an infection of the skin or intestines. Is this true? Why or why not? A. It's not true-an infection is an infection, and it's always difficult to track down the exact causative agent. The organ system involved in the illness has nothing to do with identification of the causative agent. B. It's true-because the central nervous system (CNS) is generally microbe free, whereas the skin and intestines have a diverse normal flora. Separating out a pathogenic causative agent from the normal microbiota in these areas would be much harder to do than in the central nervous system (CNS). C. It's not true-the ventricles of the brain can provide a direct route for microbes to enter the central nervous system (CNS) from the bloodstream/extracellular fluid. Therefore, it would be just as likely to find a pathogenic microbe in the central nervous system (CNS) as it would be in the skin or intestines. D. It's true-there are only 1 or 2 microbes that can cause meningitis, yet there are hundreds (if not thousands) that can cause skin/intestinal infections. This makes it much easier to determine the causative agent for a case of meningitis.

B. It's true-because the central nervous system (CNS) is generally microbe free, whereas the skin and intestines have a diverse normal flora. Separating out a pathogenic causative agent from the normal microbiota in these areas would be much harder to do than in the central nervous system (CNS).

The more severe form of African sleeping sickness is called the A. Gambian form. B. Rhodesian form. C. Guyanan form. D. Brazilian form.

B. Rhodesian form.

The poliomyelitis virus is in the picornavirus family in the subgroup A. adenoviruses. B. enteroviruses. C. arboviruses. D. dermotropic.

B. enteroviruses.

An infection of the membranes covering the brain is called A. encephalitis. B. meningitis. C. arachnitis. D. ventriculitis.

B. meningitis.

The menigococcus attach to the mucus membrane via A. flagella. B. pili. C. cilia. D. a capsule.

B. pili.

Naegleria fowleri may cause A. meningitis. B. primary amebic meningoencephalitis. C. African sleeping sickness. D. AIDS.

B. primary amebic meningoencephalitis.

Meningococcal meningitis is typically acquired through the A. genitourinary tract. B. respiratory tract. C. gastrointestinal tract. D. skin.

B. respiratory tract.

Identification of the various strains of N. meningitidis is through A. Gram staining. B. serogrouping. C. fluorescent antibodies. D. titering.

B. serogrouping.

The cavities inside the brain are termed A. sinuses. B. ventricles. C. cavities. D. sulci.

B. ventricles.

Corneal implants have been implicated in a few cases of A.botulism. B. trypanosomiasis. C. Creutzfeldt-Jakob. D. scrapie.

C. Creutzfeldt-Jakob.

Epidemics of meningitis appear to involve A. Streptococcus pneumoniae. B. Haemophilus influenzae. C. Neisseria meningitidis. D. Streptococcus pyogenes.

C. Neisseria meningitidis.

The leading cause of bacterial meningitis in adults is A. Escherichia coli. B. Haemophilus influenzae. C. Streptococcus pneumoniae. D. Neisseria meningitidis.

C. Streptococcus pneumoniae.

You're a famous eye surgeon, specializing in corneal transplants. Give your choice, would you rather have a cornea for transplantation from a 20 year old individual, or a 60 year old individual (assuming there are no optical defects due to age), and why? A. The 60 year old-clearly, if the individual has gone 60 years with no optical defects, this is a very good organ for transplantation. The 20 year old cornea may have defects that simply haven't become apparent yet. B. The 20 year old cornea-younger is always better when dealing with tissue transplants. You want to give the transplant the longest possible time for survival in the recipient. C. The 20 year old cornea-while extremely rare, it may be possible to transmit prions through corneal transplants. It's less likely that a 20 year old would have encountered and become contaminated by prions than the 60 year old. D. The 20 year old cornea-never mind prions, there are a variety of agents that can hide in corneal tissues and that might cause disease. It's far more likely that the 60 year old would be harboring one or more of these pathogens than the 20 year old.

C. The 20 year old cornea-while extremely rare, it may be possible to transmit prions through corneal transplants. It's less likely that a 20 year old would have encountered and become contaminated by prions than the 60 year old.

Which animal is used as an early warning system for encephalitis? A. armadillos B. mice C. chickens D. foxes

C. chickens

The membranes that cover the surface of the brain and spinal cord are known as the A. neurolemma. B. dura mater. C. meninges. D. collagen.

C. meninges.

The principal mode of transmission of rabies is through A. blood. B. fomites. C. saliva. D. pus.

C. saliva.

The nerves that carry information to the central nervous system (CNS) are termed A. motor nerves. B. endocrine nerves. C. sensory nerves. D. cerebrospinal nerves.

C. sensory nerves.

The symptom at the site of an animal bite that suggests rabies as a possible diagnosis is A. inability to heal. B. blue-green pus. C. tingling or twitching. D. festering without fever.

C. tingling or twitching.

Why is it important to learn about rabies when only a few cases occur in the United States each year? A. The US isn't the entire world. Rabies might be more common in other areas, and it's important to understand due to its lethality. B. The only reason why rabies isn't common in the US is due to our lack of interaction with animal carriers. We could very easily have an outbreak on our hands if we don't know the warning signs to watch for that we've learned about by studying the virus and disease. C. Rabies can never be completely eliminated-it has too many different animal reservoirs/carriers. As such, we need to remain constantly aware of how to protect human populations, both by preventing and treating the illness. We can only do that by learning about it. D. All of the above are correct.

D. All of the above are correct.

Mycobacterium leprae has a generation time of A. 20 minutes. B. 1 hour. C. 6 hours. D. 12 days.

D. 12 days.

The incubation period of leprosy is A. 1 week. B. 3 weeks. C. 3 months. D. 3 or more years.

D. 3 or more years

The only known human pathogen that preferentially attacks the peripheral nerves is A. N. meningitidis. B. polio virus. C. E. coli. D. M. leprae.

D. M. leprae.

Why are such a high percentage of infant botulism cases associated with ingestion of honey? A. Bees cultivate C. botulinum bacteria within their hives as a food source, so it gets mixed in with the honey. B. The infant digestive tract is far more susceptible to the effects of botulism toxin (found in the honey in relatively high levels) than the adult digestive tract. C. The spores of C. botulinum produce a strong endotoxin. This endotoxin has little effect on adults due to their overall size. Infants, however, are significantly smaller (and therefore far more susceptible) than adults. D. There can be endospores from C. botulinum in honey. They may germinate in the intestines of infants following consumption of honey, leading to colonization and pathogenesis as the bacteria begin forming botulism toxin. Adults' normal intestinal microbiota will out-compete the new microbes, but very young infants may not yet have this normal flora established.

D. There can be endospores from C. botulinum in honey. They may germinate in the intestines of infants following consumption of honey, leading to colonization and pathogenesis as the bacteria begin forming botulism toxin. Adults' normal intestinal microbiota will out-compete the new microbes, but very young infants may not yet have this normal flora established.

Food contaminated with Clostridium botulinum often A. looks odd. B. smells bad. C. tastes bad. D. appears normal.

D. appears normal.

Intestinal botulism, especially in infants, has been linked to ingestion of A. seafood. B. milk. C. applesauce. D. honey.

D. honey.

The poliomyelitis virus appears to selectively destroy A. sensory nerve cells. B. mixed nerve cells. C. autonomic nerve cells. D. motor nerve cells.

D. motor nerve cells.

Stained smears of the surface of the eye might be useful in diagnosing A. influenza. B. herpes. C. polio. D. rabies.

D. rabies.

Humans acquire the arbovirus that causes epidemic encephalitis by A. the fecal-oral route. B. human to human contact. C. contaminated food. D. the bite of an infected mosquito.

D. the bite of an infected mosquito.

African sleeping sickness is transmitted by A. ticks. B. black flies. C. Aedes mosquitoes. D. tsetse flies.

D. tsetse flies.

The limited type of leprosy in which cell-mediated immunity suppresses proliferation of the bacilli is called A. lepromatous. B. limited. C. immune. D. tuberculoid.

D. tuberculoid.

Central nervous system (CNS) diseases caused by fungus may occur in A. cancer patients. B. diabetics. C. AIDS patients. D. immunosuppressed people. E. All of the choices are correct.