BIOL2421 Ch 31&32 Mastering

Animal diseases transmissible to humans are known as

zoonoses.

There are over 250 foodborne illnesses that have been characterized, ________________ like Salmonella enterica, E. coli, and Toxoplasma gondii can all cause disease.

Microorganisms

The EMB results would accurately be reported as two fecal coliforms / 100 mlml water sample. True False

True

The next day Richard examines the plates. The EMB agar plates average two blue colonies / plate. The HE agar plates have only a few yellow/orange colored colonies.

blue- Fecal coliform Red- Non-fecal coliform

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

coliforms

In a ______________, a single food source is responsible for many individuals getting sick

common source epidemic

The introductory passage describes the way that improper canning and food preparation led to a botulism outbreak following a common pattern, even though an unusually large number of individuals became sick in this incident. What would have been a possible sequence of steps by which the outbreak occurred? Place the following in the order that they occurred.

1. The potatoes were contaminated with soil containing Clostridium botulinum endospores. 2. The Clostridium botulinum endospores survived boiling and canning. 3. The anoxic conditions in the cans of potatoes were favorable for germination. 4. Clostridium botulinum replicated and increased in number within the canned potatoes. 5. Bacterial cells produced and secreted toxin in increasing amounts as their numbers grow. 6. The contaminated potatoes were used to prepare potato salad. 7. The participants in the church potluck consumed the contaminated potato salad and became ill. ***************** To have a risk of botulism, Clostridium botulinum must contaminate the food. This often happens when food is taken from soil containing the bacteria. The potatoes were cooked and canned, but the temperature was not sufficiently high to kill the endospores. Within the cans, the conditions were right for the bacteria to germinate and then increase in numbers. As the bacteria multiplied, they produced increasing amounts of toxin. The potato salad was prepared from the contaminated potatoes, then made people sick when they consumed it.

Which of the pairs below are matched correctly for these clostridial pathogens involved in food poisoning? C. perfringens: produces enterotoxin C. botulinum: must grow in the body to produce toxin C. perfringens: requires only a small number of cells to produce toxin C. botulinum: produces endotoxin

C. perfringens: produces enterotoxin

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? Diarrhea causes the loss of electrolytes, not just fluids. It is important to replace the electrolytes as well as the water. The salt helps to reduce bacterial contamination and spoilage of the rehydration fluids. It is not necessary; water would be equally effective. Patients suffering from diarrhea loose mainly water through their stools, and dehydration is dangerous. This type of solution is hypertonic to human body fluids and, therefore, causes water to flow into cells.

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

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? Toxins may be heat-stable above temperatures that kill bacteria. Even if the toxins have been denatured, they can return to a functional form after cooling. Even if only a few bacteria survive, those bacteria may be sufficient to start an infection and produce toxins. No, it is not possible to develop food poisoning if all of the bacteria have been killed.

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

A _________________ is caused by the consumption of living _______________

food infection microorganisms

When toxins are consumed instead of live microorganisms, this is considered ________________.

food intoxication

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? budding lysogenic cytocidal infections lytic

lysogenic

Nearly 90% of all foodborne illnesses are associated with __________. Salmonella, Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes norovirus, Salmonella, Clostridium perfringens, and Toxoplasma Staphylococcus aureus, Salmonella, Clostridium perfringens, and Campylobacter jejuni norovirus, Salmonella, Clostridium perfringens, and Campylobacter jejuni

norovirus, Salmonella, Clostridium perfringens, and Campylobacter jejuni

The HE results indicate the presences of Salmonella. True False

False

Rabies is just one of the pathogens discussed in this chapter. While all of the pathogens discussed in this chapter are vector- or soilborne, the specifics of their transmission vary. Choose the correct method of transmission for each pathogen.

1. Anthrax can be contracted in several ways, but the most serious form of illness develops after spores are inhaled. 2. Bubonic plague is transmitted by bites from fleas. 3. Hantavirus is contracted through contact with rodents, including inhalation of dust from mouse excreta. 4. Dengue fever is transmitted by mosquito bites. 5. Rocky Mountain spotted fever is transmitted by bites from ticks. 6. Rabies is transmitted through contact with blood or other bodily fluids from infected endotherms, generally through bites or contact with mucous membranes. 7. Tetanus occurs after the causative pathogen gains access to the body, usually through a soil-contaminated, deep wound. ***************** Anthrax may be transmitted through ingestion or contact with the skin, but it causes most severe illness when the spores are inhaled. Hantavirus is also transmitted through inhalation, but it involves inhalation of viruses on rodent excreta. Rabies is transmitted by mammal bites, while bubonic plague (as opposed to pneumatic or septicemic plague) is transmitted by flea bites, and Rocky Mountain spotted fever is transmitted by tick bites. Dengue fever is transmitted by mosquito bites. Tetanus occurs when Clostridium tetani bacteria from the soil enter a deep wound.

The introductory passage describes the death of an individual due to rabies exposure. Rabies is almost always lethal after symptoms appear, so prevention is critical. Choose the correct word for each sentence to describe the most effective prevention for the disease listed.

1. Rabies can be prevented through vaccination or immediate post-exposure prophylactic treatment following a mammal bite. 2. Lyme disease can be prevented through avoiding tick habitat, using tick repellants, removing ticks before they become embedded, and using post-exposure antibiotic treatment. 3. Hantavirus can be prevented by avoiding rodent habitats and reducing rodent populations in human dwellings. 4. Anthrax can be prevented with a vaccine for those at highest risk (such as military personnel who may be exposed through bioterrorism). 5. Tetanus can be prevented through toxoid vaccination or, if symptomatic, can be treated with antibiotics and an antitoxin. 6. Yellow fever can be prevented by vaccination before traveling to areas in which it is endemic and by avoiding mosquito bites. ***************** Understanding transmission of a pathogen is important in developing ways to prevent transmission and infection. Yellow fever is caused by a virus that is spread by mosquitoes, so approaches that reduce mosquito populations or risk of mosquito bites are effective in reducing its spread. Lyme disease is carried by ticks. While there is no approved human vaccine at present, reduction of exposure to ticks or postexposure antibiotic treatment reduces the risk. Rabies is transmitted by bites, but immediate postexposure treatment can prevent development of the disease and effective vaccination programs reduce the risk of transmission from domestic animals. The bacterium that causes anthrax is found in soil, but rarely causes disease. Vaccination can be used to reduce the risk of infection for those at particular risk. Hantavirus is best prevented through reducing rodent populations and avoiding inhalation of rodent excreta. Finally, the bacterium that causes tetanus is common in soil, but effective vaccination programs reduce the risk that tetanus will develop following exposure.

The introduction discusses how 29 people became sick after consuming potato salad containing botulism toxin produced by the bacterium Clostridium botulinum. Match the following terms associated with this outbreak with the statements that best describe them.

1. The ingestion of botulism toxin would best be described as a food poisoning. 2. The ingestion of a significant number of Clostridium cells could cause a(n) infection. 3. Spoilage is a change in appearance, smell, or taste of a food that makes it undesirable to a consumer. ***************** Food poisoning occurs when an individual ingests a preformed toxin in the food item. When the toxin is ingested, it causes the illness. The organism itself does not need to colonize or cause an infection for the food poisoning to occur. However, an infection will occur if an individual has ingested a significant number of viable pathogens. The pathogen can then colonize the host and result in an active infection. Spoilage refers to a change in appearance, smell, or taste of a food that makes it undesirable to a consumer, usually as a result of microbial contamination.

There has been concern that diseases may reach new locations as a result of climate change. For example, there has been speculation that new rabies vector species may reach the United States in future years. What is an example from the chapter of a species that has specifically become a greater concern in the United States due to climate change resulting in warmer average temperatures, as opposed to other reasons for range expansions?

Aedes aegypti and Aedes albopictus, vectors for Dengue fever ***************** Climate change is predicted to cause a variety of changes, not simply increases in temperatures. However, one possible consequence is that some tropical species may be able to move into temperate latitudes. In other cases, new pathogens could also be introduced. In the book, the spread of Aedes aegypti and Aedes albopictus, which carry Dengue fever, is described as a specific possible consequence of climate change. Additionally, changes in mosquito spraying programs (with less spraying) may also contribute to the spread of mosquitoes.

Why are antibiotics often ineffective in treating food poisoning (food intoxication)? Antibiotics target bacteria; they do not damage toxins. Oral antibiotics are degraded by stomach acid and, therefore, do not work well in the digestive tract. Food poisoning is caused by viruses, which are not targeted by antibiotics. Pathogens in food pass through the digestive tract too rapidly to be targeted by antibiotics.

Antibiotics target bacteria; they do not damage toxins.

Bacillus anthracis is an endospore-forming bacterium. Which of the following is most likely? B. anthracis spores can remain dormant for hundreds of years without needing nutrients, remaining capable of causing anthrax when they germinate. B. anthracis uses spores to reproduce, which develop into new offspring capable of causing anthrax. B. anthracis spores can be killed by boiling water or ultraviolet light, so these can be used to prevent anthrax. B. anthracis spores require a moist environment in order to stay dormant for an extended time. These spores will germinate and be capable of causing anthrax when they dry out.

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

Which of the following explains why treatment of symptomatic tetanus requires an antitoxin and an antibiotic? It is always better to use multiple treatments to elicit a stronger response. The tetanus toxin binds irreversibly, causing damage to axons. The only way to heal the axons is with an antitoxin. Because the toxin is within the cell wall of the bacteria, it can only be eliminated by killing the bacteria. Because C. tetani bacteria excrete tetanus toxin, it is important to neutralize the toxin while also killing the bacteria that are producing more.

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

Heating is a common method of sterilization in microbiology. It is not uncommon to see recommendations to boil water for safety when there is a problem with the water supply. However, boiling the potatoes used in the potato salad was not sufficient to prevent botulism in the outbreak described in the introductory passage. Which of the following is the best explanation for why boiling the potatoes was not sufficient to prevent botulism? Botulism food poisoning is caused by endotoxins that are present even after Clostridium botulinum bacteria are killed and that are not removed by boiling. Botulism food poisoning is caused by an infection with Clostridium botulinum that survives boiling in its vegetative form. Botulism food poisoning is caused by endospores that survive boiling and then begin to grow and produce exotoxins that cause botulism. Botulism food poisoning is caused by endospores that survive boiling and then produce endotoxins that cause botulism.

Botulism food poisoning is caused by endospores that survive boiling and then begin to grow and produce exotoxins that cause botulism. ***************** Although boiling kills vegetative cells, endospores can survive. When water is boiled and then consumed immediately, the endospores do not have a chance to germinate and produce toxins prior to ingestion. When foods are stored, though, endospores can germinate and the vegetative cells produce exotoxins that cause botulism.

Prompt treatment of botulism is imperative because the illness has a high mortality rate if untreated. Why does botulism have such a high mortality rate? Clostridium botulinum secretes a neurotoxin that results in tetanus. Clostridium botulinum secretes a neurotoxin that results in toxic shock. Clostridium botulinum secretes a neurotoxin that results in gas gangrene. Clostridium botulinum secretes a neurotoxin that results in flaccid paralysis.

Clostridium botulinum secretes a neurotoxin that results in flaccid paralysis.

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? Clostridium tetani typically causes infection when a wound is contaminated with soil, it's natural habitat. Accidental ingestion of Clostridium tetani toxin would lead to rapid onset of symptoms and an inability to call for help. There are no antibiotics available to treat this bacterial infection. Clostridium tetani typically causes infection when it produces quick-acting exotoxins that affect the nervous system. Quick treatment would not be available to victims who succumb far from help.

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

The Midwest is known for its contribution to the dairy industry. Fermented dairy products include milk, yogurt, and cheese. The fermentation process relies on lactic acid bacteria and pasteurization. Fermentation can vary based on what food is being produced, the type of bacteria used to produce lactic acid, and the time and temperature of pasteurization. It is important to the manufacturer to produce a product that won't spoil before it is packaged and sold and that won't result in disease for those who ingest and enjoy it. Julie, a food inspector for a local Michigan health department is going to a nearby cheese plant for a biannual inspection. When she gets there, she will take a tour of the plant and allow the operators to describe what makes their cheese so special. She will use what she understands about fermentation to inquire about their production practices. Please sort the following statements as being true or false regarding fermentation and its role in food production. Please recall the role that microorganisms can play in the production of foods.

Correct Statements: *Fermentation allows for sugars to be broken down or metabolized to make food such as bread, vegetables and cheese. *Some grains, fruits and vegetables have their own microbes that facilitate fermentation. *Lactic acid is produced by certain microorganisms and aids in fermentation. *Starter cultures are used to initiate the process of fermentation in modern food processing. Incorrect Statements: *Fermentation can be used only to make dairy products *Bacteria are the only microorganisms used in the fermentation process *Fermentation occurs when undesirable metabolic reactions allow for the growth of pathogens or presence of unwanted microorganisms in food.

Richard decides to use Hektoen Enteric Agar (HE) to detect the presence of Salmonella and differentiate it from Escherichia. He carefully notes the composition of HE agar and the expected results.HE contains the following:- bile salts to inhibit most Gram positive bacteria- lactose, sucrose, salicin sugars available for fermentation- bromothol blue as pH indicator to detect acid produced by fermentation- sodium thiosulfate available for bacterial sulfur reduction- an iron compound that will react with any H2S produced and turn blackPossible HE results in the following:- Pink/orange/yellow colonies indicate sugar fermentation.- Blue/green colonies indicate no fermentation and no sulfur reduction.- Black colonies indicate sulfur reduction and no fermentation.He pours 100 mlml of the sample water through a filtration membrane, and then he places the membrane on HE agar. He makes two duplicate plates and places these in the incubator at 37 degrees Celsius. Richard cleans up and disinfects his work area. Next, he takes a quick inventory of the media, places an order for a few reagents, and heads home for the day.Which of the following are coliforms? Select all that apply. Enterobacter Serratia Shigella Klebsiella

Enterobacter Serratia Klebsiella

In water quality sampling, it is typical for the technician to look for fecal coliforms to indicate sewage contamination. Rapid carbohydrate fermentation is a reliable test for detecting the presences of fecal coliforms. Richard runs this test routinely: He pours 100 mlml of the sample water through a filtration membrane, and then he places the membrane on an eosin methylene blue (EMB) agar. He makes two duplicate plates and places the samples in the incubator at 44.5 degrees Celsius so that the bacteria can grow into colonies. These colonies will appear blue if rapid carbohydrate fermentation is occurring. Each blue colony on the filter is assumed to be the result of one fecal coliform in the original water sample. Richard is also planning to test for the presence of Salmonella in his samples, as local people had been reporting concerns about a large, new chicken ranch in the area. Richard needs to design a method to differentiate Salmonella from other similar species, so he gets out reference material that includes a dichotomous key, a tool to identify organisms through the process of eliminating characteristics that do not apply to it.

Escherichia: rapid lactose fermentation, noH2S production Salmonella: no rapid lactose fermentation, H2S production ***************** When using the dichotomous key, note that both Salmonella and Escherichia are motile and neither genera tests positive for urease, so these tests will not help distinguish them.

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? It doesn't survive but instead simply releases toxin as it dies. C. tetani can only survive when other bacteria are available to consume oxygen and to keep oxygen levels low. 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. C. tetani can't access atmospheric oxygen, so it can grow as long as it stays on the surface of the skin rather than in well-oxygenated deeper tissues.

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.

During her tour, Julie starts to notice a lot of equipment such as walk-in refrigerators, huge ovens, and industrial canners. She knows that a part of her inspection is to look at the factors that can affect food spoilage, so she starts to make a list of things she wants to come back to once the inspection begins. There are many factors, both internal and external, that can affect spoilage in food production. It is the responsibility of food manufacturers to know what these factors are and to make sure that everything that is made is in compliance. During Julie's study of microbiology, she learned about inherent properties of food, such as nutrient content, water activity, and pH, that play a role in food spoilage. There were also important external factors, such as how food is processed, handled and stored, that were critical to food spoilage and preservation. Please sort each of the following statements as being either an external or internal factor that affects the growth of microorganisms in food. Please recall from your reading the causes of food spoilage and how it can be prevented.

External Factors: *Temperature of food storage during processing. *Humidity of the storage environment *Presence of gases, such as CO2, during packaging *Preservatives, such as salt and sugar *Handling of food by manufacturers Internal Factors: *pH of the food *Presence of antimicrobial compounds *Nutrient content (Such as vitamins and minerals) *Moisture content or water activity *Protective structure of food, such as feathers, hide and skin

Food that is heavily salted or candied does not need to be refrigerated. Why not? Extremely concentrated solutions are very hypertonic and therefore desiccate microorganisms. As a result, there is no need for lower temperatures through refrigeration to slow growth. Extremely concentrated solutions are very hypotonic and cause microbes to desiccate. As a result, there is no need for lower temperatures through refrigeration to slow growth. The sugar used is of a type that cannot be used by microbes, leaving a lack of suitable nutrition for them. As a result, there is no need for refrigeration to slow growth. Having a high concentration of salt or sugar lowers the food's pH, making it too acidic for common pathogens to grow. As a result, there is no need for refrigeration to slow growth.

Extremely concentrated solutions are very hypertonic and therefore desiccate microorganisms. As a result, there is no need for lower temperatures through refrigeration to slow growth.

Microbes capable of fermentation are often used in food. What is the main function of fermentation for the microbes? Fermentation makes large quantities of ATP to compensate for the lack of an electron transport chain. Fermentation generates oxygen, allowing aerobic respiration to occur. Fermentation regenerates NAD+ so that glycolysis can continue. Fermentation uses up oxygen in the environment, allowing obligate anaerobes to survive.

Fermentation regenerates NAD+ so that glycolysis can continue.

Richard loves his job working for the Tri-County Water District. In his seven years with the district, he has had many different jobs; currently he is a Waste Water Treatment Laboratory Technician. Today, he is doing his routine visit to one of the three Waste Water Treatment Facilities, where he'll collect samples of the treated water to take back to the lab. At the lab, his coworker Joey will do a chemical analysis of the water, while he does the microbiological analysis. To collect the samples at the waste water facility, Richard first dons his gloves, and then he uses the grab sample technique to fill his various containers, filling the sterile glass flasks he will use for his micro analysis last. To preserve the chemical integrity of the water sample and accurate microbial population estimates, these samples have to be chilled, and the analysis must begin within the hour. Once all of his samples are collected, he disinfects the outside of the containers, removes his gloves, and disposes of them in the biohazard bin. After washing his hands, he gets out a waterproof pen to label the containers with his name, the sample site location, and the date and time of the sample collection. Back at the lab, Richard gives the chemistry samples to Joey, and then heads to his microbiology lab. He starts setting up his tests to look for Enterobacteriaceae in the water samples.Which of the following best describes the Enterobacteriaceae group (enteric bacteria)? pathogenic species only Gram-negative bacillus found in many locations including animal intestines all motile, encapsulated non-pathogens found only in the intestine of mammals Gram-positive bacillus

Gram-negative bacillus found in many locations including animal intestines

Botulism food poisoning is a preventable illness. Which of the following methods would have prevented the botulism outbreak described in the introductory passage? Select all that apply. Allow the canned potatoes to sit for at least two weeks. Heat the potato salad to at least 80ºC for 10 minutes before consumption. Mix the potatoes with spices and flavorings before canning them. Chill the potato salad before consuming it. Wash and scrub the potatoes, then prepare and consume the potato salad immediately.

Heat the potato salad to at least 80ºC for 10 minutes before consumption. Wash and scrub the potatoes, then prepare and consume the potato salad immediately.

Please recall what you have learned about microbial metabolism and food processing methods and choose the best method for prevention of food spoilage for the food type below. [cheese] Packaging into cans and jars and exposure to high heat under pressure (canning). High-heat treatment for a short period of time (pasteurization). Use of more than one food processing type (for example, canning and use of preservatives). Use of salt or sugar to draw water out of foods (preservatives). Freezing and vacuuming to dry foods (lyophilization).

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

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? If the level of fecal coliform bacteria is low, the likelihood of fecal contamination is low, but the water may still be unsafe because of the presence of other pathogens. If the level of fecal coliform bacteria is low, then the water is safe for drinking and recreational purposes. If the level of fecal coliform bacteria is high, then the water is safe for drinking and recreational purposes. If the level of fecal coliform bacteria is low, then the water was probably contaminated by sewage.

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

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? The virus is only found within red blood cells if there is no viremia, so it cannot be spread by mosquitoes that do not consume those cells. Direct contact with blood is required for infection. If there are no viral particles in the blood, then infection can't occur using this mechanism. Because white blood cells are found in the blood, any virus in the blood would be attacked by the immune system. With no viral particles available for the immune system to attack, the virus cannot be spread. 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.

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.

The introductory passage explains that rabies is a major public health problem and that it causes 60,000 human deaths each year, mostly in developing countries in which vaccination of domestic animals is less common. Many of these cases result from scratches and bites by domestic pets, such as dogs, that are not vaccinated. In contrast, the figure below depicts the incidence of rabies in animals per year in the United States (where there are fewer than five cases of rabies in humans per year). Considering that humans who contract rabies usually contract it from an infected animal, does the figure below suggest that domestic animals are also the most common rabies vector to humans in the U.S.? No, while domestic animals are important vectors internationally, they are outcompeted by more abundant species in the United States. Yes, domestic animals are important vectors and are represented by the teal blue line on the graph. It is impossible to tell because domestic animals are not included in this figure. Yes, domestic animals are important vectors and are represented within the dark blue line on the graph. No, while domestic animals are important vectors internationally, they less commonly transmit the virus in regions where vaccination rates of pets are high.

No, while domestic animals are important vectors internationally, they less commonly transmit the virus in regions where vaccination rates of pets are high. ***************** The species that most commonly carry rabies in mainland North America are skunks, raccoons, foxes, and bats. Mongooses are important in Puerto Rico. While domestic dogs and cats can carry rabies, that is unusual in the United States due to the frequency of vaccination. Opossums may be able to carry rabies, but seem to be relatively resistant (some have speculated that this may be due to their relatively low body temperature compared with other mammals). Herbivores such as rabbits and horses rarely carry rabies. The low numbers of cases of rabies in domestic animals in the United States shows how effectively vaccination can help to reduce rabies cases. Unfortunately, vaccination rates are not as high in some other parts of the world and therefore rabid dogs are a major cause of rabies transmission worldwide.

During her inspection, Julie took many samples of the cheeses that were manufactured in her local plant back to the health department laboratories. She decided to pay particular attention to testing for the presence of microbial products in the cheeses. She will use a variety of tests depending on the sample, but these will most likely include the inoculation of selective and differential media to characterize the use of specific carbohydrates and the production of certain enzymes. Julie knows that since milk is used in the processing of cheeses, organisms like Salmonella enterica, Campylobacter jejuni, and Listeria monocytogenes can all be found in raw milk and dairy products. These microorganisms are introduced into the milk and other food products in many ways. Microorganisms are everywhere, and often when food products such as milk are collected and handled, these microorganisms are able to enter the food. In order to ensure the health of the millions of people every day, a food microbiologist like Julie ensures that food is kept in the best conditions during processing, packaging, and when it gets to stores for purchase. Please consider what you have learned about foodborne illness from the text, and choose the correct description of the term below that is best associated with foodborne illness.

Questions next

As described in the introductory passage, there are efforts underway to develop improved rabies vaccinations using recombinant vaccines. At present, though, these new vaccines are not in standard use. Following possible exposure to rabies (e.g., following a bite from a potentially infected animal), several steps should be taken at present. If a human is bitten by a domestic animal, such as a dog, the animal should be quarantined. What treatment is recommended for an exposed human if the animal either can't be tested or quarantined, or if the animal shows evidence of rabies during quarantine? Choose all correct answers. The human should not be treated because domestic animals do not carry rabies. The human should be injected with a rabies vaccination. The human should be injected with rabies immune globulin. The human should be carefully observed for 10 days and only treated if symptoms appear.

The human should be injected with a rabies vaccination. The human should be injected with rabies immune globulin. ***************** Because rabies is so dangerous, the recommended treatment involves giving an immune globulin shot for rapid protection as well as a rabies vaccination for longer term protection. Immune globulin provides passive immunity; it consists of purified human rabies antibodies that can immediately target the rabies virus. However, it does not provide longer-term protection and the rabies virus can have a long incubation time. The rabies vaccine provides longer-term 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? The rabies antibodies provide a rapid response but short-lived response while the vaccination provides slower but longer-lasting protection. Using both is needed because an individual who has received this type of bite is more likely than someone else to receive another bite. While the immune globin is sufficient to prevent rabies infection, the vaccination helps to prevent the individual from the risk of a future bite. The rabies vaccination is relatively new and ineffective, so it is important to give the immune globin as well to make certain that the viruses cannot cause disease. Because rabies is such a serious illness, using antibodies and a vaccine provides the strongest possible immediate protection. Both antibodies and the vaccine provide a rapid immediate response to prevent illness from developing.

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

Along her tour, Julie noticed many types of cheeses that were being aged for texture and taste. In the processing of cheese there are many things that can be done to prevent the introduction of microorganisms. This same concept applies not only to cheese, but to wine, vegetables, and meat products. Based on the food that is being manufactured, various processes like pasteurization, chemical preservation, and radiation can all be used. All of these preservation methods take into consideration characteristics of microorganisms, such as the presence or absence of a cell wall, the role of osmotic pressure, their growth at preferred temperatures, and many other important characteristics.Please recall what you have learned about microbial metabolism and food processing methods and choose the best method for prevention of food spoilage for the food type below. [fresh green peas] Use of more than one food processing type (for example, canning and use of preservatives). Use of salt or sugar to draw water out of foods (preservatives). Freezing and vacuuming to dry foods (lyophilization). High-heat treatment for a short period of time (pasteurization). Packaging into cans and jars and exposure to high heat under pressure (canning).

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

Please recall what you have learned about microbial metabolism and food processing methods and choose the best method for prevention of food spoilage for the food type below. [soups] High-heat treatment for a short period of time (pasteurization). Packaging into cans and jars and exposure to high heat under pressure (canning). Freezing and vacuuming to dry foods (lyophilization). Use of more than one food processing type (for example, canning and use of preservatives). Use of salt or sugar to draw water out of foods (preservatives).

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

Please recall what you have learned about microbial metabolism and food processing methods and choose the best method for prevention of food spoilage for the food type below. [bacon] Use of salt or sugar to draw water out of foods (preservatives). Use of more than one food processing type (for example, canning and use of preservatives). Freezing and vacuuming to dry foods (lyophilization). Packaging into cans and jars and exposure to high heat under pressure (canning). High-heat treatment for a short period of time (pasteurization).

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

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? At one time, it was fashionable for city dwellers to keep rats as pets, bringing humans into close contact with these plague hosts. Wild rodents tended to have high plague mortality rates, but most urban rats survived infection. This allowed the disease to be passed on to nearby humans by the vector. Crowded urban areas have more garbage and filth, allowing plague to spread more easily due to unsanitary conditions. 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.

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.

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? a spherical shape a curved rod a straight rod a rigid spiral shape

a curved rod

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? a food infection, most likely Salmonella norovirus a food infection, most likely Enterohemorrhagic E. coli or Shigella a food intoxication, most likely from Staphylococcus

a food infection, most likely Salmonella

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

a zoonosis

Rabies is an important vector-borne disease. Like the pathogen that causes rabies, the other vector and soil borne pathogens discussed in the chapter can be classified as viruses or bacteria as well. Choose the correct classification for the causative pathogen for each disease.

single stranded minus sense: rabies, hantavirus single stranded plus sense: yellow fever and west nile fever bacteria: rocky mountain spotted fever, lyme, anthrax, tetanus ***************** Rabies and hantavirus are both caused by single-stranded, minus-sense RNA viruses. West Nile fever and Yellow fever are caused by single-stranded, plus-sense RNA viruses. Rocky Mountain spotted fever, anthrax, tetanus, and Lyme disease are caused by bacteria. Rocky Mountain spotted fever is caused by Rickettsia rickettsia (small obligate intracellular parasites). Tetanus is caused by Clostridium tetani, a rod-shaped obligate anaerobe bacterium. Anthrax is caused by a rod-shaped bacterium, Bacillus anthracis. Lyme disease is caused by the spirochete bacterium, Borrelia burgdorferi.

Food poisoning is usually accompanied by signs like diarrhea, fever, and fatigue. These are all _____________ that either toxins or _____________________ may have been ingested

symptoms microorganisms