MICRO EXAM 4

What would you call an antibiotic resistant bacteria?

reemerging pathogen

The natural habitat of a pathogen is referred to as its

reservoir.

Which of the following is an example of indirect contact transmission?

respiratory droplets

What is an advantage of an inactivated vaccine?

safe for immunocompromised patients

An antibiotic made by microorganisms and modified by chemists is called

semi-synthetic.

Which of the following is an example of direct contact transmission?

sexual transmission

So far, the only disease that has been globally eradicated is

smallpox.

The reservoir of infection for botulism and tetanus is

soil

What do you call a subjective evidence of disease which is sensed by the patient?

symptom

Drugs that are more effective when taken together are

synergistic

The toxicity of a given drug is expressed as the

therapeutic index.

What is the prevalence of a disease?

total number of cases om the population

Certain antimicrobials may be life-threatening.

true

Drugs that target peptidoglycan do not affect eukaryotes.

true

The key characteristic of a useful antimicrobial is selective toxicity.

true

Diseases that primarily exist in animals, but may be transmitted to humans are called

zoonotic

A picnic was attended by 1,000 people. Potato salad was served at the event. The next day, 140 people reported vomiting and diarrhea. What was the attack rate of this food-borne illness?

14%

Select the sequence that indicates the steps that occur in the chain of infection. 1. Transmission. 2. Susceptible host. 3. Reservoir of infectious agent. 4. Portal of exit. 5. Portal of entry.

3, 4, 1, 5, 2

Please identify the CORRECT statement regarding basic epidemiology concepts.

Attack rate—the number of susceptible people developing illness in a population exposed to an infectious agent.

All of the following are commonly associated with nosocomial disease EXCEPT A. Pseudomonas species. B. Clostridium botulinum. C. Clostridium difficile. D. Enterococcus species. E. Staphylococcus aureus.

B

Bacteria may become antibiotic resistant due to A. alteration in the target molecule. B. All of the choices are correct. C. increased elimination of the drug. D. increased elimination of the drug. E. drug-inactivating enzymes.

B

Which of the following groups of microorganisms produces antibiotics?

Bacillus, Penicillium, AND Streptomyces

How can drugs become inactive (i.e. mechanism of drug resistance? A. inactivation by cellular enzymes B. cells have efflux pumps C. All of these are correct D. mutations in target

C

Please select the FALSE statement. A. A case-control study occurs when all of the cases result from exposure to a single source of the infectious agent. B. Emerging infectious diseases are those that are novel or have recently increased in incidence. C. Herd immunity can never be overcome by a pathogen. D. The natural habitat of a pathogen is called the reservoir of infection. E. A common source epidemic occurs when all of the cases result from exposure to a single source of the infectious agent.

C

Which of the following contributes to nosocomial disease? A. Other patients B. Patient's own normal microbiota C. All of the choices are correct. D. Susceptible population E. Hospital environment

C

Which of the statements about transmission of pathogens is TRUE? A. Vertical transmission of a pathogen is from the environment to a person. B. Horizontal transmission refers to spread of a pathogen from mother to fetus. C. Droplet transmission is a particularly important source of contamination in densely populated buildings such as schools. D. Sexual intercourse is an example of indirect contact. E. Droplet nuclei are large drops of pathogen-containing fluid discharged by talking; they fall to the ground within a meter of the person.

C

What is the best way to prevent spreading of a highly infectious disease? A. prevent infected individuals from coming into contact with each other B. test for the presence of disease in at risk individuals C. vaccinate the population at risk (if possible) D. All of these are correct

D

Fluoroquinolones typically target

DNA gyrase.

One of the earliest researchers to explore the use of chemicals to kill microbial pathogens was

Ehrlich

Generally, the smaller the infective dose, the lower the chance of disease.

False

The portal of entry typically has little effect on the course of a disease.

False

Which of the following is not a vector?

Fomite

What type of factor which affects disease is specific to the patient getting the disease?

Host factors

In what clinical situation is it most appropriate to use a broad-spectrum antimicrobial?

In a case of bacterial meningitis. The infection spreads so quickly that we must treat it with an antibacterial drug as quickly as possible. We don't have time to determine which drug will work best, because the patient will die in the meantime.

The amount of infecting agent received by susceptible individuals is called the

Infectious dose.

Which of the following best defines an endemic disease?

It is a disease that is always present at some level in a population.

Which test provides qualitative results regarding antibiotic susceptibility and is reported as susceptible, intermediate, or resistant?

Kirby-Bauer test

Which of the following bacteria have an innate resistance to penicillin?

Mycoplasma

Why are nucleoside analogs active only against replicating viruses?

Nucleoside analogs work by being incorporated into growing strands of DNA/RNA. This indirectly shuts down further extension of these chains. However, new strands of viral DNA/RNA are only being created when the virus is replicating. Thus, these drugs can only work when the virus is actively replicating as well.

Sulfonamides are similar in structure to

PABA

Match the clinical presentation on the left with whether it is a sign or symptom on the right fever

Sign

Match the clinical presentation on the left with whether it is a sign or symptom on the right tachycardia

Sign

Match the clinical presentation on the left with whether it is a sign or symptom on the right pain

Symptom

Match the clinical presentation on the left with whether it is a sign or symptom on the right sore throat

Symptom

Please select the FALSE statement regarding tissue distribution, metabolism, and excretion of medications.

The half-life of a medication is the time it takes for the serum concentration of that chemical to decrease by 100%.

What do you call the minimum dose per kg bodyweight that stops a pathogen's growth?

Therapeutic dose

What is a negative effect of overusing broad spectrum antibiotics?

They can destroy normal microbial species

A fly may serve as a mechanical vector.

True

A gradual rise in numbers during an epidemic indicates a common source epidemic.

True

Antifungal drugs usually target the cell membrane.

True

Beta-lactam drugs are only effective against growing bacteria.

True

Diseases with long incubation periods are more likely to spread extensively.

True

Human population growth and expansion contribute to emergence of diseases.

True

Nosocomial infections are those acquired at a hospital.

True

The very young and the elderly are more susceptible to infectious disease.

True

The World Health Organization (WHO) is part of the

United Nations.

Why would antimicrobials that have toxic side effects be used at all? (select the BEST reason)

We want the largest possible number of choices of drugs in case a microbe shows resistance. With more possible weapons (even toxic ones), we have greater ability to eliminate infections.

A new serotype of Vibrio cholerae, V. cholerae 0139, has picked up the ability to produce

a capsule.

If drugs are less effective when taken together than when each is taken separately, they are

antagonistic

The antimicrobials produced by some molds and bacteria are generally called

antibiotics

Gonorrhea is a disease that may be

asymptomatic.

Antibiotics that affect various strains of Gram-positive bacteria and various strains of Gram-negative bacteria are called

broad-spectrum.

Apparently healthy people who may transmit a pathogen they harbor are called

carriers

Your class decides to celebrate the last day of spring break by having a picnic. You arrange to meet at your local park and everyone agrees to bring a dish of food to the event. On the day, there is a wide variety of things to eat, but the snack that everyone agreed was the best was the hot chicken wings made by Paul. Almost everyone ate at least two to three wings. The picnic was a huge success. The next morning you wake up feeling awful. You have a low grade fever and you have both vomiting and diarrhea. You call your friend Susan to tell her you won't make it to class that day and to please take good notes, which she promises to do. About 20 minutes later, Susan calls you back and tells you that three other people have also called her and are experiencing the same symptoms as you. You realize that you must have all eaten something at the picnic that is causing your illness. After finding out that none of the vegetarians or vegans in the class are ill, you figure out that it was likely a meat product. In this case, the reservoir of infection was likely the

chicken wings.

Diseases that can be transmitted from one person to another are termed

communicable

Sulfonamides work as

competitive inhibitors.

What was the first vaccine (hint - it was used by Edward Jenner)?

cowpox

What is a potential drawback to using tetracycline antibiotics?

discolored teeth

Diseases constantly present in a population are called

endemic

What do you call it when statistics indicate that the prevalence of a disease is increasing beyond what is expected for a population?

epidemic

A dramatic increase in the incidence of a specific disease in a given population is referred to as a(n)

epidemic.

The target of most antifungal drugs is

ergosterol.

Sulfonamide and trimethoprim are both

examples of metabolic inhibitors AND folate inhibitors.

Inanimate objects capable of transferring infectious disease agents are

fomites.

The immunity of some black Africans to malaria is probably due to their

genetic background.

The single most important measure to prevent the spread of disease is

hand washing.

When an infectious disease cannot spread in a population because it lacks a significant number of susceptible hosts, the phenomenon is referred to as

herd immunity.

What are the three factors which affect epidemiology?

host, environmental, etiological factors

The period of time between exposure to an agent and the onset of disease signs and symptoms is called the

incubation period.

What do you call the first case of a disease that brought the epidemic to the attention of officials?

index case

Drugs that are bacteriostatic

inhibit the growth of bacteria.

The threat of bioterrorism

is due largely to the ease of spread and severity of diseases AND may include rarely seen infectious agents.

A fly that walks on feces and picks up E. coli O157:H7 then lands on food and transfers the microorganisms, is considered a

mechanical vector.

A fly that walks on feces and picks up E. coli O157:H7thenlands on food and transfers the microorganisms, is considered a

mechanical vector.

What do you call the number/rate of persons affected with certain diseases in a population?

morbidity rate

What do you call the total number of deaths in a population due to a certain disease?

mortality rate

Your class decides to celebrate the last day of spring break by having a picnic. You arrange to meet at your local park and everyone agrees to bring a dish of food to the event. On the day, there is a wide variety of things to eat, but the snack that everyone agreed was the best was the hot chicken wings made by Paul. Almost everyone ate at least two to three wings. The picnic was a huge success. The next morning you wake up feeling awful. You have a low grade fever and you have both vomiting and diarrhea. You call your friend Susan to tell her you won't make it to class that day and to please take good notes, which she promises to do. About 20 minutes later, Susan calls you back and tells you that three other people have also called her and are experiencing the same symptoms as you. You realize that you must have all eaten something at the picnic that is causing your illness. After finding out that none of the vegetarians or vegans in the class are ill, you figure out that it was likely a meat product. The portal of entry of the pathogen causing illness in this case is the

mouth.

An infection acquired during hospitalization is referred to as a(n) ______ infection.

nosocomial

What type of pathogen only causes disease when a host defense is compromised, or when it gets into an area of the body where no defense is available?

opportunistic pathogen

An epidemic that spreads worldwide is called a(n)

pandemic

In 1918-1919, an influenza virus infected about 500 million people worldwide, killing at least 50 million of them. This disease is best described as a(n) ______.

pandemic

What do you call a epidemic which spreads across continents?

pandemic

WHO has targeted for elimination of

polio, dracunculiasis AND measles.

Vertical transmission involves

pregnant woman to fetus.

Approximately what percentage of hospitalized patients may develop a nosocomial infection?

5%

The minimum bactericidal concentration is the lowest concentration of a specific antimicrobial drug that kills _______ of a specific type of bacteria.

99.9%

All of the following is/are reservoirs of infection in a hospital setting EXCEPT A. sterile surgical equipment. B. visitors. C. patient's normal microbiota. D. medical personnel. E. other patients.

A

Which of the following is NOT a political/societal reason for a decrease in rates of childhood immunizations?

A lack of a proper "cold chain" for stable transport of vaccines into tropical areas.

Which of the following pathogens/diseases would be the easiest to eradicate?

A pathogen that only infects humans and causes obvious signs and symptoms.

A pathogen that only infects humans and causes obvious signs and symptoms. A. Neisseria gonorrhoeae—urethral and vaginal secretions. B. Vibrio cholerae—feces. C. Influenza virus—respiratory droplets. D. Mycobacterium tuberculosis—droplets of saliva and mucus. E. E. coli—urine.

E