Ch. 30 Microbio

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.

HIV infection

-HIV uses it gp120 spike protein to bind to the immune system cells. -HIV needs a coreceptor like CCR5 to be able to infect the host cell. -Often HIV patients die from opportunistic infections not the HIV itself.

Hepatitis A virus:

-entrance of the virus is via the oral route -the virus is shed in the feces and also found in blood and urine -oysters in contaminated water can be a source of infection

Which of the following microbes are known to be able to resist drying and thus are easily spread through the aerosol route?

Gram positive bacteria. Mycobacterium. The thick Gram positive cell wall and waxy mycolic acid coat make these microbes more resistant to drying.

Lyme disease is caused by ____________ and is transmitted by __________.

B. burgdorferi; Ixodes

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.

Yellow fever was named because it can cause liver damage, resulting in a yellowish appearance. Which of the following explains why liver damage causes someone to have a yellowish appearance?

Bilirubin is a breakdown product of hemoglobin that has a yellowish color. When bilirubin is not being properly excreted as bile, it can build up in the blood.

Gram negative bacterium, that can cause a violent cough that can last for up to six weeks

Bordetella pertussis

Virus transmitted most often through the bite of an infected while animal including bats. Deadly once it reaches the central nervous system

Rabies

An animal disease transmitted to humans by direct contact, inhalation of aerosols, or bites is called __________.

a zoonosis

Caused by a spiral bacteria which is transmitted through the bite of a deer tick. Often produces a bulls-eye rash

Lyme disease

What do the letters MRSA stand for?

Methicillin Resistant Staphylococcus aureus

Which of the following are true with regard to tuberculosis?

Mycobacterium are intracellular colonizers. Isoniazid treats tuberculosis by blocking mycolic acid synthesis. A healthy person can have a positive tuberculin test.

Which form(s) of the plague in humans is/are OFTEN treatable with modern antibiotics?

bubonic plague

Who was the FIRST microbiologist to study Bacillus anthracis and its ability to cause disease in mice?

Robert Koch

A tick borne disease that can lead to a rash. The pathogen is an obligate intracellular parasite bacterium. Often contracted while camping

Rocky Mountain Spotted Fever

Neurological diseases that result from West Nile virus infection include which of the following?

encephalitis and meningitis

There are three forms of human anthrax. Which of the following choices contains a form of human anthrax correctly matched with its description?

cutaneous: easily treatable

The pathogen Rickettsia rickettsii, which causes Rocky Mountain spotted fever, is MOST commonly transmitted by

exposure to infected ticks.

The onset of many rickettsial diseases, such as Rocky Mountain spotted fever, human monocytic ehrlichiosis, and granulocytic anaplasmosis, includes ________ and ________.

fever / headache

This STD has more obvious symptoms in males with painful burning of the urethra. Many strains are antibiotic resistant and since there are so many strains recovery from one strain does not protect from reinfection with a different strain

gonorrhea

This viral disease can lead to infections of the skin on the face or the genitals. It goes through periods of latency and can return at a later date. Pregnant women with the sexual form of the disease are advised to get a cesarean section so as to not transmit it to the newborn baby

herpes simplex 2

Which animal is MOST commonly vaccinated against the West Nile virus?

horse

Which of the following diseases is NOT caused by a Rickettsia species?

human monocytic ehrlichiosis Rocky Mountain spotted fever typhus Q fever --- NOT

Certain strains of this virus are known not only to cause warts to develop in the genital area but can lead to the development of cancer. A vaccine is designed to protect people but must be administered before the person is sexually active because not all infections develop obvious warts

human papillomavirus

Hantaviruses are most commonly transmitted by ________ of virus-contaminated rodent ________.

inhalation / excreta

Borrelia burgdorferi is an interesting spirochete that is unusual when compared to other bacteria. Which of the following is the reason that it is so unusual?

it has a linear chromosome

Also called rubeola. Caused by a highly infectious paramyxovirus. Can be prevented by a vaccine.

measles

Hepatitis C kills more people than AIDS in the United States and >3 million people i the U.S. are chronically infected. Preventing Hepatitis C virus depends on

minimizing exposure to the virus

STD cause by a spirochete. Primary infection leads to the development of a lesion called a chancre. A rash develops next, and if untreated with antibiotics damage to vital organs can lead to death

syphilis

Proliferation of the rabies virus occurs especially in the

thalamus and hypothalamus of the brain.

Many West Nile virus infections are not properly identified becau

the symptoms are often subacute.

A patient exhibiting arthritis secondary to Lyme disease is likely in which phase of the infection?

third

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

typhus

Which of the following is NOT a commonly applied method to eradicate rabies in the United States?

vaccinating wild animal reservoirs --- NOT vaccinating domestic animals vaccinating humans quarantining a potentially infected animal after it bites a human

Rickettsia are obligate intracellular parasites that are transmitted by arthropods. Which of the following places would you be most likely to find the parasites in a living organism during the course of infection?

within macrophages

Which of the following is MOST likely to be vaccinated against Bacillus anthracis?

wool sorter

Approximately what percentage of people infected with the West Nile virus develop serious neurological disease?

<1%

The tetanus exotoxin, produced by Clostridium tetani, __________.

prevents inhibitory signals that allow for muscle relaxation

Which of the following cannot cause meningitis?

viruses, bacteria, fungi, protists

Progression of bubonic plague

1. Rodent is infected with Yersinia pestis. 2. Flea is infected with Yersinia pestis. 3. Yersina pestis reproduces in intestine of infected organism. 4. Human is bitten by infected flea. 5. Yersinia travels to lymph nodes. 6. Septicemia occurs.

Gram positive club shaped cells, some strains produce a powerful exotoxin that can block protein synthesis

Cornebacterium diphtheriae

Zhang et al. studied possible reassortments and mutations of influenza viral gene segments to determine which genes are critical to airborne droplet transmission between mammals. Influenza viruses have their genes organized on 8 segments. If two different influenza viruses co-infected the same animal cell, theoretically how many different reassortments could be made?

256 This is a combinatorial problem: 8 things (genome segments) taken 2 at a time: 2 to the 8th power = 256.

Once a person is bitten by a West Nile virus-infected mosquito, how much time does it take for a fever to appear (if the person does develop symptoms)?

3-14 days

Which of the following is true with regards to the chickenpox virus?

Also called varicella. Caused by a type of herpes virus.

What is meant by the term arbovirus?

An arbovirus is an arthropod-borne virus. (blood-feeding ones such as mosquitoes) An arbovirus is maintained in nature through biological transmission.

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.

True or False: In humans, an untreated rabies infection that becomes symptomatic is RARELY fatal and attenuates over time, leading to acquired immunity.

FALSE

A ssRNA virus with a BSL of 4. Mimics flu-like symptoms and is transmitted by deer mice

Hantavirus

How is a rickettsial disease MOST commonly diagnosed, and how would the patient be treated if the infection had been present for roughly one week?

Immunological or DNA-based testing will identify the pathogen, and an antibiotic such as tetracycline would be given.

A red inflammed, crusty lesion on the skin, often on the face. Can be due to either Streptococcus pyogens or Staphylococcus aureus.

Impetigo

Why are infections of the lower respiratory tract considered more dangerous then infections of the upper respiratory tract?

Infections in the lower respiratory tract can lead to inflammation and fluid buildup. This can interfere with gas exchange.

Why is meningococcemia a more dangerous conditions than meningitis?

Intravascular coagulation leads to death of tissues

What could be leading to the increase in pertussis in the United States?

Some people were not getting themselves or their children vaccinated. Pertussis is more common than other illnesses such as diphtheria. Vaccines do not provide life-long immunity for pertussis.

Gram positive chains of microbes, contains a capsule, invasive and can travel through the blood and lead to endocarditis

Streptococcus pneumonia

Gram positive chains of microbes. Can cause sore throats, scarlet fever, and nectotizing fasciitis

Streptococcus pyogens

True or False: Humans are dead-end hosts for the West Nile virus, because they do NOT develop the viremia necessary to infect mosquitoes.

TRUE

Why does the introduction of birth control pills lead to an increase in gonorrhea incidence?

The birth control pills change the environment of the vagina and less lactic acid bacteria grow. This leaves more changes for gonorrhea to attach and grow.

How pathogenic are alpha toxin-containing clostridia compared to those lacking it, and why?

They are more pathogenic, because the toxin enables the clostridia to lyse healthy human cells and grow/spread further.

If a human is bitten by an animal that has rabies, then it is recommended that the human receive immune globin (human rabies antibodies) and a rabies vaccination (with inactive virus) as well. Which of the following is the best (and most specific) explanation for why both are recommended in this case?

The rabies antibodies provide a rapid response but short-lived response while the vaccination provides slower but longer-lasting protection.

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.

Based on the concept map, which of the following must happen during Lyme disease?

There is an adaptive immune response. Since antibodies are used in the diagnosis of the disease, there must be an adaptive immune response.

Which of the following statements about hantaviruses is true?

They are related to Ebola and other hemorrhagic viruses. They are transmitted to humans by contaminated rodent droppings. They are single-stranded, segmented, negative-sense RNA viruses.

Which disease causes over 1.5 million deaths per year worldwide, which is approximately 11% of all deaths related to infectious diseases?

Tuberculosis

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.

Clostridia that cause gas gangrene ferment ________ from human tissue into H2 and CO2 gases in addition to producing foul-smelling organic compounds.

amino acids

Which condition promotes germination of Clostridium tetani endospores during a tetanus infection?

anoxia

Rickettsial diseases are LEAST commonly spread by

ants --- LEAST common fleas. lice. ticks.

Which feature or structure of Bacillus anthracis enables it to evade death by macrophages and grow inside macrophages?

capsule

Which of the following is the LEAST common reservoir for the rabies virus in the United States?

chicken --- LEAST common raccoon skunk fox

This STD is an intracellular colonizer and a prokaryotic cell. It often goes undetected due to the lack of obvious symptoms, especially in females, but can lead to sterility if untreated

chlamydia

Most common infectious disease. Most commonly caused by rhinoviruses and infect the upper respiratory tract.

common cold

Which form of anthrax is usually treatable with an antibiotic?

cutaneous anthrax

Which of the following would be the best strategy to prevent the spread of yellow fever and dengue fever into the southern United States?

mosquito avoidance and eradication

Caused by a highly infectious paramyxovirus. Leads to swelling of the salavary glands but can spread to other areas such as the testes or pancreas. Can be prevented by a vaccine.

mumps

The rhabdovirus that causes rabies is a

negative-stranded RNA virus.

If you were exposed to a sick animal that was found to have negri bodies in its nervous system in a postmortem examination, how would you be treated to prevent disease?

passive and active immunization against rabies

You have isolated viral particles from a patient, but you are not sure whether they are rhinoviruses or influenza viruses. The presence of which class of biological molecules would allow you to distinguish between the two types of virus?

phospholipids

The lesion shown below is caused by damaged host cells and cells of C. diphtheriae. This lesion is called:

pseudomembrane

Death from tetanus is usually due to

respiratory failure

You have been battling strep throat all semester long. It just doesn't want to go away. Finally it seems gone, but about a month later you start having joint pain. When you go to the doctor and she listens to your heart she hears a heart murmur. What have you developed?

rheumatic fever

Also called German measles. Most dangerous to a fetus in the first trimester and can lead to stillbirth, deafness, and heart defects. Can be prevented by a vaccine.

rubella

The reactivated version of chicken pox is called:

shingles

Which situation is MOST likely to result in death by Bacillus anthracis?

shoveling dirt on a windy day

What is the natural reservoir of Clostridium tetani?

soil

Of the arthropod-borne diseases, there is a vaccine to prevent __________.

yellow fever