microbio

What can you conclude based on this map of yearly new cases of chlamydia published by the Centers for Disease Control?

Alabama has one of the highest incidence rates of chlamydia in the country.

When comparing a strain of Streptococcus pneumoniae that has capsules (encapsulated) with a strain that lacks capsules, what can you logically assume?

All of the choices are logical assumptions.

Which of these is the best example of a common source epidemic?

During a five-week period, 22,000 people across the United States become infected with Listeria monocytogenes after eating contaminated popsicle

Antiphagocytic factors are important for establishment of infection by a pathogen since they are the way the microbe binds to a host cell surface.

False

Any zone of inhibition around an antibiotic disc in a disc diffusion test indicates that the drug kills the bacteria on the plate and would be useful for treating a patient.

False

Chlorhexidine is widely used for skin sterilization prior to surgery.

False

Droplet transmission is classified as a type of indirect transmission since the hosts don't make physical contact with each other.

False

Every chemical used as a disinfectant kills all bacterial endospores.

False

Leukopenia is a blood sign indicating above normal levels of white blood cells.

False

Polymyxins disrupt the cytoplasmic membranes of bacteria but also damage host cell membranes at drug concentrations needed for effective treatment. Therefore this drug shows high selective toxicity and a high therapeutic index.

False

Selectively toxic means that the patient should not be resistant to an antimicrobial drug.

False

Sporadic diseases always exist in a population with at least a low prevalence.

False

Sterilization of the skin with a high level germicide is required before surgery can be performed.

False

Transmission from mother to fetus is one of the three main types of horizontal transmission.

False

Nurse Ferbenschtein is assisting Dr. Wurbeljanevinski with an important clinical research project. She removes some lung tissues from a deceased tuberculosis patient from the freezer and handles them with her bare hands. She thinks this is reasonable, as freezing should be germicidal. Is she correct?

No

Which of the following would make it LESS likely that a respiratory illness will occur following exposure to a pathogen?

The pathogen enters the body through the urinary tract.

A key way that the normal microbiota antagonize the growth of pathogenic organisms is simply by occupying most of the binding sites along body surfaces.

True

Per the CDC, the number one strategy for preventing HAI's, such as surgical site infections, is proper handwashing and/or the use of alcohol-based hand sanitizers.

True

Some organisms resist antimicrobial drugs by having membrane proteins that pump the drugs back outside the cell.

True

Based on the information presented in this table, which organism is the MOST VIRULENT?

Youknowyou gonnadie

This person is wearing a mask to reduce the possibility of acquiring a pathogen through ________ while sweeping this location that may be contaminated with rodent feces.

airborne transmission

Which of these chemical categories has no examples of a chemical that can be used for high-level disinfection to achieve sterility?

alcohols

An antifungal drug that binds to a lipid found only in the cytoplasmic membranes of fungi and forms pores:

amphotericin B

If a patient is exposed to a pathogen, develops symptoms within 2 days, and recovers within 7 days, this is an example of:

an acute infection

A Rotavirus outbreak occurred at an elementary school and continued for several weeks as it spread through the population. This is an example of:

an endemic disease

Which of the following best describes ESBL's?

bacterial enzymes that destroy most or all beta-lactam antibiotics

Which of the following explains the efficiency of autoclaves for sterilization?

both of the choices are correct

Which method(s) of microbial growth control are involved in preserving beef jerky?

both osmotic pressure and drying

Which of these is NOT one of the most common types of HAI illnesses?

brain infections and meningitis

Current thinking has shifted, and scientists now believe that babies acquire the first members of their normal microbiota from:

breast milk.

Which of these is NOT a way that virulence factors of pathogens can damage the host?

by increasing phagocytosis

Which of these is NOT a common portal of entry for pathogens?

central nervous system

Which of these is least likely to be a natural portal of exit for a human pathogen?

cerebrospinal fluid

This type of disease is generally characterized by mild but long-lasting symptoms.

chronic

Which type of carrier shelters an infectious microbe long after recovery due to latency of the agent?

chronic

Which of these is not an example of direct transmission?

contacting a pathogen on a fomite

Many germicidal chemicals kill microbes by ______ their proteins.

denaturing

Each of these is a physical method of microbial control except:

desiccation

Which of these classes of chemicals cannot be used to achieve sterility?

detergents

Which of the following would likely take the longest time to kill a population of bacterial cells?

dry heat exposure at 121°C

Endotoxin is another term for:

enzymes secreted by bacteria that damage tissues.

Instruments and fluids can be classified according to five categories of sterility: 100% sterile, 80% sterile, 60% sterile, 40% sterile, and 20% sterile.

false

Urine can generally be considered to be a noninfectious body fluid when working with a patient.

false

When characterizing the impact of an epidemic on two different locations with very different populations, the best method is comparing actual incidence numbers rather than the incident rates per 100,000 people.

false

Which of these is a common dry heat sterilization method used in the microbiology laboratory?

flaming inoculating loops

Which of the following types of physical control would be most appropriate for killing bacteria and fungi embedded inside strawberries destined for sale in a fresh produce section of a grocery store?

gamma irradiation

Selectively toxic drugs:

have a low therapeutic index.

It's most difficult to discover drugs with selective toxicity to treat which of these types of microbes?

helmiths

Clostridium perfringens and Staphylococcus aureus are two species that produce this type of virulence factor, which destroys both red and white blood cells:

hemolysins

COVID-19 was declared a pandemic in 2020. This means:

infections with the virus reached epidemic status on at least two continents

A drug with a high therapeutic index:

kills microbes at a much lower concentration than the toxic dose for the patient

Which of these is not an exoenyme of pathogenic microbes?

kinase

Which of these is an example of host damage triggered by an overly aggressive immune response?

lysis of blood cells by the hemolysins of Streptococcus pneumoniae

Which of these is NOT one of the key signs or symptoms of inflammation?

muscle paralysis

Organisms that can cause disease if the normal microbiota is disrupted by drug therapy:

opportunistic pathogens

Which of these is not a reason why antimicrobial drug resistance is increasing?

overuse of antimicrobials in poor countries where they can be purchased easily without a prescription

The M-protein spikes protruding from the surface of Streptococcus pyogenes increase the virulence of this bacterial organism by:

preventing early attempts at phagocytosis by White Blood Cells

Sulfonamides are antibiotics in the folic acid synthesis inhibitor group. They are useful for targeting microorganisms that:

produce their own folic acid. Humans are not affected because we acquire folic acid from the diet.

Which of these is NOT a characteristic of an ideal antimicrobial drug?

quickly inactivated in cells and tissues

Yersinia pestis, the bacterial organism that causes the plague, ordinarily lives in rats. Fleas that bite the rats can transmit the organism to humans. In this case, rats are the _________ of the organism, and fleas are the

reservoir; transmitter

These members of your normal microbiota are present for short periods of time until they are eliminated and/or out competed by other species

resident microbiota

____is the destruction of all microbial life; whereas, _____ destroys most microbial life and reduces contamination on the surfaces of inanimate objects.

sterilization; disinfection

If a patient has a localized infection with Bacillus anthracis (a Gram Positive organism and the causative agent of anthrax) in a wound but experiences widespread effects across his entire body (tissue damage, swelling, hemorrhaging), what does this likely mean?

the bacterial cells produce an exotoxin that has effects in locations far away from the site of infection

If two new antimicrobial drugs with equivalent MIC's have been discovered, the better one to use in patients will have:

the highest therapeutic index

A fly lands on some spoiling potato salad in your kitchen garbage can, picks up some Salmonella enterica cells from the salad, and then lands inside your mouth while you are snoring later that evening. You develop salmonellosis. This is an example of:

transmission by a mechanical vector

Some bacterial pathogens are phagocytosed by White Blood Cells but block the digestion step after they are taken inside the cell. This allows them to hide from the immune system and is a means of spread to other parts of the body. True

true

The shedding of dead skin cells could be considered a portal of exit for a skin pathogen.

true

The weekly prevalence of a disease will generally be higher than the weekly incidence rate if the typical acute phase lasts 12-18 days.

true

You are working in a microbiology lab and have been asked to select a nitrocellulose membrane to use for filter-sterilization of a water sample. You would select the smallest pore size possible if you know that your sample is contaminated with:

viruses