Micro HW Practice Questions - ch 19, 32, 33

anthrax

- can be contracted in several ways, but the most serious form of illness develops after spores are inhaled - can be prevented with a vaccine for those at highest risk (such as military personnel who may be exposed through bioterrorism)

Hantavirus

- contracted through contact with rodents, including inhalation of dust from mouse excreta - can be prevented by avoiding rodent habitats and reducing rodent populations in human dwellings

tetanus

- occurs after the causative pathogen gains access to the body, usually through a soil-contaminated, deep wound - can be prevented through toxoid vaccination or, if symptomatic, can be treated with antibiotics and an antitoxin

non-ionizing radiation

- physical control method used to control microbial growth - DNA of exposed organisms will absorb UV light - longer wavelength than ionizing radiation

filtration

- physical control method used to control microbial growth - passage of liquid or gas through a material with small pores; vacuum is sometimes used - sterile liquid/gas collected on the other side

rabies

- transmitted through contact with blood or other bodily fluids from infected endotherms, generally through bites or contact with mucous membranes - can be prevented through vaccination or immediate post-exposure prophylactic treatment following a mammal bite

- the phylogenetic diversity of an environmental sample - whether a specific piece of mRNA is being produced - how many Salmonella typhimurium cells are present in a sample of unpasteurized apple juice

Fluorescent in situ hybridization (FISH) can be used to determine __________.

orthologs

Genes that retain their function yet change over evolutionary time as organisms diverge

Enterobacteriaceae group; enteric bacteria

Gram-negative bacillus found in many locations including animal intestines

yellow fever

Of the arthropod-borne diseases (West Nile, dengue fever, yellow fever), there is a vaccine to prevent _____________ ____________.

Vibrio cholerae and Salmonella enterica serovar Typhi

On a global scale, the most important waterborne bacterial pathogens are

B. anthracis spores can remain dormant for hundreds of years without needing nutrients, remaining capable of causing anthrax when they germinate.

Bacillus anthracis is an endospore-forming bacterium. Which of the following is most likely?

Use of salt or sugar to draw water out of foods (preservatives).

Best method for prevention of food spoilage - bacon

High-heat treatment for a short period of time (pasteurization).

Best method for prevention of food spoilage - cheese

- Not linked: ocean water - Linked: hot water tanks, spas, swimming pools

Legionella pneumophilia can grow in water and is transmitted in aerosols. Which of the following has NOT been linked to an infection? Which sources HAVE been linked to infection?

Use of more than one food processing type (for example, canning and use of preservatives).

Best method for prevention of food spoilage - peas

Use of more than one food processing type (for example, canning and use of preservatives).

Best method for prevention of food spoilage - soup

amplifying host isolated

Birds serve as an __________________ ___________ for West Nile virus, meaning that means that the number of viral particles is increased dramatically within this host. It is more likely that the virus can be __________________ from these animals.

it has a linear chromosome

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?

determine the community genome expression at the moment of sampling

By isolating total community RNA, using reverse transcriptase to make cDNA copies of it, and then sequencing the cDNA, ecologists can __________.

microbial sample collection DNA extraction PCR of target genes sorting by elecrophoresis analysis

List the steps necessary for PCR analysis of a microbial community in the correct order.

phylotype

Organisms with identical or very similar orthologous genes belong to the same __________.

enrichment bias

Phylogenetic analysis of microbial communities in nature using various PCR techniques has revealed that only a minority of phylotypes have been cultured from the environment and the most common phylotypes have not been grown in in the laboratory. This is due in part to __________.

using insect repellant

The common methods to control the spread of West Nile virus include

common source epidemic

a single food source is responsible for many individuals getting sick

spirochetes chronic nervous

Lyme disease and syphilis are similar in that they are both caused by ___________________ and are _____________ infections that involve the __________________ system.

genes

Metagenomics involves the analysis of a microbial community by sampling and sequencing all of the ________ in an environment.

genes do not have to be amplified by PCR before being sequenced

Metagenomics is a more sensitive analysis of community diversity than rRNA-based analyses because __________.

phylochips

Microarrays that have been designed to screen samples for specific groups of bacteria are called __________.

fermentation regenerates NAD+ so that glycolysis can continue

Microbes capable of fermentation are often used in food. What is the main function of fermentation for the microbes?

Salmonella noroviruses Clostridium perfringens Campylobacter jejuni

Nearly 90% of all foodborne illnesses are associated with

Toxins may be heat-stable above temperatures that kill bacteria.

Reheating food to a temperature sufficient to kill bacteria is helpful in making food safer. However, is there a way that one can get food poisoning despite food having been reheated?

inside macrophages

Rickettsia are obligate intracellular parasites that are transmitted by arthropods. In which of the following places would you most likely find the parasites living in the host organism during the course of infection?

foodborne illnesses

Salmonella enterica, E. coli, and Toxoplasma gondii can all cause diseases known as _______________________ __________________.

flaviviruses togaviruses

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.

Bubonic plague

transmitted by bites from fleas

Rocky Mountain fever

transmitted by bites from ticks

dengue fever

transmitted by mosquito bites

C13/C12 stable isotope analysis

A NASA ecologist wants to design an instrument to send to Mars on the next space probe to determine whether living organisms ever carried out carbon fixation on that planet. Suggest an assay that she could use on Martian soil samples.

diarrhea fever fatigue

3 common symptoms of food borne illnesses via toxins or microorganisms

a food infection, most likely Salmonella

A patient reported a headache, chills, vomiting, and diarrhea that occurred 12 hours after having a meal at home that included chicken. The physician suspected which type of organism?

Antibiotic therapy addresses only the growth of V. cholerae; it doesn't address the extreme dehydration suffered by a person infected with V. cholerae.

Although cholera can be treated with antibiotics, data suggest that antibiotic treatment alone is NOT the most effective therapy. Which of the following statements describes the most likely reason for supplementing antibiotic therapy?

zoonosis

An animal disease transmitted to humans; may be transmitted by direct contact, inhalation of aerosols, or bites

neurotoxin flaccid paralysis

Clostridium botulinum secretes a _________________ that results in ______________ __________________.

enterotoxin

Clostridium perfringens produces an __________________.

Especially in deep wounds, C. tetani can sometimes survive in areas with damaged tissue that have become anoxic because of poor-to-no blood flow.

Clostridium tetani is an obligate anaerobe that can cause tetanus. When it enters the human body, it can produce tetanus toxin. Considering that C. tetani is an obligate anaerobe, which of the following explains how it can survive and cause disease in the human body?

pressure cooker

Device that uses high pressure and high heat to sterilize food; kills most contaminating microbes and their endospores

select both for and against certain bacteria

Enrichment cultures are often effective for isolating bacteria from complex communities in natural samples because they __________.

Clostridium tetani typically causes infection when a wound is contaminated with soil, it's natural habitat

Everyone, but particularly individuals who are farmers, gardeners, foresters, or others who spend significant time outdoors, are urged to adhere to a tetanus booster vaccinations schedule, receiving a booster if planning to travel and cannot remember when his or her last one. Why?

protein cellular structures molecules lethal

Exotoxins are __________________ molecules that target specific ________________ __________________ or ________________. Even small amounts of exotoxins can be ___________.

coliforms

Gram-negative, rod-shaped bacteria that are facultative anaerobes, are non-spore formers, and ferment lactose to acid and gas are __________.

emerging rodent Ebola hemorrhagic

Hantaviruses are an example of an ________________ infectious disease. They are transmitted to humans by contaminated _____________ droppings. They are similar in disease presentation to __________ and other ____________________ viruses.

1) white blood cells, lymph vessels 2) filter, vessels, yellow fever virus 3) replicate

How does yellow fever arrive in lymph nodes? 1) The yellow fever virus is phagocytosed by ____________ _____________ _________, and then travels through the ___________ _______________. 2) Lymph nodes contain white blood cells and they ___________ lymph as it moves through the lymph ______________. White blood cells with _____________ ___________ ____________ can become established there. 3) Some viruses, like the yellow fever virus, can ___________ inside of white blood cells like those in lymph nodes.

It is determined by water activity: the more water, the more perishable

How is the perishable class determined for food products?

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

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?

lysogenic

Staphyloccocus aureus is an important cause of food poisoning. Several gene-encoding exotoxins are associated with S. aureus food poisoning, including SEA, an exotoxin encoded by a viral gene. What sort of life cycle must this phage have?

heat-stable, acid-tolerant superantigen toxins

Staphylococcus aureus is a particularly dangerous organism when in food due to the enterotoxins some species produce. These toxins are dangerous because they are

If fecal coliform level is low, the likelihood of fecal contamination is low, but the water may still be unsafe due to the presence of other pathogens

Tests to monitor water safety often report the number of fecal coliform bacteria found in samples. Which of the following statements accurately reflects water safety recommendations based upon fecal coliform levels?

flow cytometry

The ability to analyze multiple parameters at the same time within a microbial sample can be done using __________.

most probable number technique

The best choice for estimating the viable cell number of a water sample would be the __________.

to ensure enough cells survive the acidic pH environment of the stomach

The ingestion of a large number of Vibrio cholerae cells is necessary for infection. Why is such a large concentration of bacteria needed?

infection

The ingestion of a significant number of Clostridium cells could cause food _________________.

poisoning

The ingestion of botulism toxin would best be described as a food _________________.

Typhus fever

The most important rickettsial diseases in humans include

is highly conserved over evolutionary time

The phylogenetic diversity analysis of complex microbial communities often targets small subunit (SSU) ribosomal RNA genes. This is because rRNA is found in all organisms and __________.

cutaneous - least severe, easily treatable inhalation - most deadly form

There are three forms of human anthrax. Which of the following forms are correctly matched with their description

fluorescent viability stain

There is a small lake on campus that students like to use for recreational activities. A study has begun on the microbial community in the lake at different times of the year. In order to quickly determine the approximate number of reproducing bacteria in a sample, it would be best to use __________.

Klebsiella Serratia Enterobacter

Three examples of coliform genera

osmotic conditions, nutrients, and pH

To be successful, an enrichment culture for an environmental isolate must take into account __________.

- Lyme disease (Borrelia burgdorferi) - tetanus (Clostridium tetanii) - anthrax (Bacillus anthracis) - Rocky Mountain spotted fever (Rickettsia rickettsii)

What 4 diseases are caused by bacteria?

- washing off vegetables before serving them - using bleach to clean the kitchen counters - placing leftovers in the refrigerator after a meal

What are some examples of microbial controls?

The family consumed botulism toxin in the canned green beans (organism survives in canned foods that are not prepared properly; tomatoes are too acidic to support C. botulinum)

What was the MOST likely source of the family's botulism food poisoning?

vibrio - curved rod

Vibrio cholerae is a human pathogen that causes cholera. It has an unusual shape distinctive of its genus. Considering that it does not have one of the most common bacterial shapes, what is the shape of this species?

Legionella tends to form biofilms and infect other microbial cells as intracellular pathogens.

Water supplies are treated with chlorine to kill pathogens. Chlorine reacts well with many other chemicals and bacterial cells because it is a strong oxidant. However, Legionella pneumophila can sometimes evade being killed by chlorine. How does it do this?

If there are no (or only very few) viral particles in the blood, then they are not picked up by vectors feeding on the blood in sufficient amounts to cause infection.

West Nile Virus is an arbovirus that can be transmitted by birds because they develop viremia when infected. In contrast, infected humans cannot spread the disease because they do not develop viremia. Why is viremia associated with the ability to transmit the disease?

Hentavirus Rabies

What 2 viruses are single stranded, minus sense RNA viruses?

yellow fever West Nile

What 2 viruses are single stranded, plus-sense RNA viruses?

Flask A would contain nitrogen fixers that could grow without ammonium; flask B would not contain nitrogen fixers but would contain organisms that could use ammonium.

When Beijerinck enriched for nitrogen fixers, he inoculated soil into two types of liquid media: one containing mineral salts and mannitol but no nitrogen source (flask A), and one containing mineral salts, mannitol, and an ammonium salt (flask B). After incubation in the presence of air, what types of organisms did he expect to find in each flask?

Diarrhea causes the loss of electrolytes, not just fluids. It is important to replace the electrolytes as well as the water.

When an individual has severe diarrhea, as can occur with cholera, rehydration solution with glucose, salt, sodium bicarbonate, and potassium chloride can be administered. Why is it important to use a solution like this rather than simply giving the individual water?

a killed control

When measuring microbial community metabolic activity, __________ is always necessary.

food intoxication (food poisoning)

When toxins are consumed instead of live microorganisms

- there is no vaccine - you should kill all infected animals to control an arbovirus

Which 2 statements are NOT true of arboviruses? - supportive therapy is the best treatment - there is no vaccine for arboviruses - many arboviruses have endemic areas where infections are more common - to control an arbovirus, you should kill all infected animals - preventing infection involves water control

- gaining access to host via a portal of entry - evading host defenses - adherence to host tissues

Which 3 are the requirements for causing disease within a host?

Escherichia coli and Salmonella

Which bacteria involved in food infections produce toxins to cause host damage?

Because C. tetani bacteria excrete tetanus toxin, it is important to neutralize the toxin while also killing the bacteria that are producing more.

Which of the following explains why treatment of symptomatic tetanus requires an antitoxin and an antibiotic?

R. rickettsii is transmitted to the human host during a bite, when tick saliva enters the wound.

Which of the following is a characteristic of biological transmission from Dermacentor (tick) to a human host?

- washing vegetables before using - heating to 80*C for at least 10 minutes before consumption

Which of the following methods would have prevented the botulism outbreak?

To establish infection, V. cholerae must survive the host immune response and the acidic environment of the stomach.

Which of the following most likely explains the requirement for this relatively high ID50 in Vibrio cholerae?

Antibiotics target bacteria; they do not damage toxins.

Why are antibiotics often ineffective in treating food poisoning (food intoxication)?

Extremely concentrated solutions are very hypertonic and therefore desiccate microorganisms, so lower temperatures through refrigeration are not needed to slow microbial growth

Why do heavily salted or candied foods not need to be refrigerated?

it destroys intestinal cells in its host

Why does cholera produce watery diarrhea?

Yersinia pestis can be transmitted by fleas from wild rodents to urban rats, which quickly die of the disease. Humans are accidental hosts due to fleas seeking out blood meals after most rats have succumbed to the disease.

Wild rodents are the major reservoir of the plague organism, Yersinia pestis, but pandemic plagues were historically associated with crowded, unsanitary urban areas. Why is this the case?

by using a micro sensor

You would like to determine the rate of production of carbon dioxide in a specific microbial habitat. How could you do this without growing the microorganisms in the lab?

not C. perfringens: - fever, vomiting could be C perfringens: - severe stomach cramping - sudden onset diarrhea - short incubation period

______________ and _____________ are not characteristics of Clostridium perfringens food poisoning. What symptoms ARE characteristic of C. perfringens food poisoning?

arbovirus

an arthropod-borne virus that is maintained in nature through biological transmission; may be transmitted by ticks, flies, mosquitos, etc

encephalitis

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.

limit exposure to mosquitoes

best mode of controlling the spread of West Nile infections

metaproteomics

study of the diversity and abundance of proteins in a microbial community

yellow fever

can be prevented by vaccination before traveling to areas in which it is endemic and by avoiding mosquito bites

Lyme disease

can be prevented through avoiding tick habitats, using tick repellants, removing ticks before they become embedded, and using post-exposure antibiotic treatment

botulism food poisoning

caused by endospores that survive boiling and then begin to grow and produce exotoxins that cause disease

food infection

caused by the consumption of living microorganisms via pathogen-contaminated food

spoilage

change in appearance, smell, or taste of a food that makes it undesirable to a consumer.

alcohols

chemical control method that exerts action by denaturing proteins and dissolving lipids

phenolics

chemical control method that exerts antimicrobial activity by injuring lipid-containing plasma membranes, which causes the cellular components to leak out of the cell

surface-active agents (surfactants)

chemical control method which decreases surface tension among molecules of a liquid

multiple displacement amplification

process that will amplify DNA from a single cell isolated from a natural microbial community

metagenomics

study of the DNA sequences found in a microbial community

metatranscriptomics

study of the RNA sequences found in a microbial community