Question 1

Which of the following is mismatched?

Accepted Answer

Trichinella spiralis is a parasite found in undercooked pork or wild game meat, not in eggs.

Question 2

Campylobacter gastroenteritis is the leading cause of foodborne illness in the United States.

Accepted Answer

Campylobacter gastroenteritis is indeed the leading cause of bacterial foodborne illness in the United States, primarily resulting from consuming undercooked poultry or products contaminated by raw poultry.

Question 3

A young child received a red-eared slider turtle as a birthday gift.Within a week the child was suffering from a severe gastroenteritis that required a visit to urgent care.What is the child likely suffering from?

Accepted Answer

Red-eared slider turtles are known carriers of Salmonella bacteria, which can cause severe gastroenteritis in humans. Children are especially susceptible to Salmonella infections, as their immune systems are not fully developed. It is important to wash hands thoroughly after handling turtles or any reptiles to prevent infection.

Question 4

An outbreak of viral gastroenteritis occurs in a pediatrics ward.Rotavirus is the most likely causative agent.

Accepted Answer

Rotavirus is a common cause of viral gastroenteritis in children, and outbreaks of this illness are often recorded in pediatric wards.

Question 5

Table 25.1 $$\begin{array} { | c | c | } 
\hline \text { Food } & \text { Relative Risk } \
\hline \text { Black beans } & 0.58 \
\hline \text { Corn soup } & 0.75 \
\hline \text { Jalapeño peppers } & 34.13 \
\hline \text { Roma tomatoes } & 5.40 \
\hline
\end{array}$$
The relative risks shown in Table 25.1 were calculated for foods suspected of transmitting Salmonella. Which food is the most likely source of infection?

Accepted Answer

Jalapeño peppers have a much higher relative risk than any of the other foods, indicating that they are the most likely source of Salmonella infection.

Question 6

Gastroenteritis due to ingestion of food contaminated with Staphylococcus aureus is due to intoxication by enterotoxins.

Accepted Answer

Gastroenteritis caused by ingestion of food contaminated with Staphylococcus aureus is due to intoxication by enterotoxins produced by the bacteria. These enterotoxins are heat-stable and resistant to digestive enzymes, and can cause symptoms such as nausea, vomiting, diarrhea, and abdominal cramping.

Question 7

Which structure or component of the small intestine is important to antimicrobial defense?

Accepted Answer

Paneth cells are specialized cells found in the small intestine that secrete antimicrobial peptides and enzymes, which help protect the intestine from harmful bacteria and other pathogens.

Question 8

Humans infected with Enterobius vermicularis may have hydatid cysts within their lungs or other organs.

Accepted Answer

The answer of Humans infected with Enterobius vermicularis may have...

Question 9

Aflatoxin poisoning is associated with liver cancer.

Accepted Answer

Aflatoxin poisoning is a known risk factor for the development of liver cancer. Aflatoxins are produced by the fungus Aspergillus, which can grow on crops such as peanuts, corn, and rice. When contaminated crops are consumed, the toxins can accumulate in the liver and cause damage over time, potentially leading to the development of cancer.

Question 10

Which is true of the Mumps virus?

Accepted Answer

The answer of Which is true of the Mumps virus?
...

Question 11

H.pylori is able to survive the acidic environment of the stomach as a result of adaptations that allow it to increase the pH of the immediate environment.

Accepted Answer

H.pylori has various adaptations that allow it to neutralize the acidic environment of the stomach and increase the pH of its immediate surroundings, which helps it to survive. These adaptations include producing urease enzymes that break down urea to produce ammonia, which acts as a buffer, and using mobile helical shape to burrow through the mucous lining of the stomach to reach the less acidic layer of the stomach wall.

Question 12

Bacterial infections,but not intoxications,can cause diarrhea.

Accepted Answer

Both bacterial infections and intoxications can cause diarrhea. Bacterial infections involve the bacteria multiplying in the host, while intoxications are caused by ingesting toxins produced by bacteria, both of which can lead to diarrhea.

Question 13

EHEC is a major cause of diarrhea in developing countries and may result in the death of small children.

Accepted Answer

EHEC (Enterohemorrhagic Escherichia coli) is a major cause of foodborne illness in developed countries, not developing countries. It can cause severe bloody diarrhea, and although it can be fatal in rare cases, it is not a major cause of death for small children globally. Other pathogens such as rotavirus and Shigella are more prevalent causes of diarrhea-related deaths in developing countries.

Question 14

Which is NOT true of HBV?

Accepted Answer

Individuals infected as adults are less likely to become chronic carriers of HBV compared to those infected as infants or young children. The risk of chronic infection is highest in neonates and decreases with age.

Question 15

Clostridium perfringens typically causes a self-limiting gastroenteritis.

Accepted Answer

Clostridium perfringens is a common cause of food poisoning, resulting in symptoms such as diarrhea and abdominal cramps. While the symptoms can be uncomfortable, the infection is usually self-limiting and does not require specific treatment. However, in severe cases, medical intervention may be necessary.

Question 16

Approximately 30 percent of the body's immune system is located in the intestinal tract.

Accepted Answer

About 70 percent of the body's immune system is located in the intestinal tract, highlighting the gut's crucial role in defending against pathogens.

Question 17

A rushed homemaker prepared a stew from a large cut of beef but the family only consumed a small portion for dinner.The still-hot large pot was placed in the refrigerator overnight.The next day the stew was warmed for lunch.By the evening the entire family was suffering from varying degrees of diarrhea,abdominal cramping and nausea.You most likely suspect the culprit of this event is

Accepted Answer

C. perfringes is known to grow in oxygen-deprived environments and is commonly found in meat and poultry products. When the stew was left in the refrigerator overnight, the bacteria had an opportunity to grow and multiply. When the stew was reheated, any C. perfringes that were present in the stew would have survived the heating process and caused illness. Symptoms of C. perfringes infection typically include abdominal cramping and watery diarrhea, which is consistent with the family's symptoms. The other options (Salmonella, H. pylori, Shigella, and B. cereus) are less likely because they have different modes of transmission or symptoms that don't match up with the scenario described.

Question 18

Situation 25.1
Following a county fair, 160 persons complained of gastrointestinal symptoms. Symptoms included diarrhea (84 percent), abdominal cramps (96 percent), nausea (84 percent), vomiting (82 percent), body aches (50 percent), fever (60 percent; median body temperature = 38.3°C); median duration of illness 6 days (range 10 hr to 13 days).
-In Situation 25.1,fecal samples were found to be negative when cultured.The next step in diagnosing the cause of illness would be The relative risks shown in Table 25.1 were calculated for foods suspected of transmitting Salmonella.Which food is the most likely source of infection?
A.black beans
B.corn soup
C.jalapeño peppers
D.roma tomatoes
E.The answer cannot be determined based on the information provided.

Accepted Answer

The relative risk for jalapeño peppers is the highest among the suspected foods, indicating that it is the most likely source of infection. If fecal samples were negative when cultured, the next step in diagnosing the cause of illness would be to collect and analyze additional samples from the suspected food sources, as well as to investigate other potential sources of contamination. Antibiotic therapy should not be initiated until the causative agent is identified. Blood cultures and microscopic examination of feces can also help to identify the causative agent, but in this case, additional testing of food samples would be the most appropriate next step. Muscular biopsy would not be necessary for the diagnosis of gastrointestinal illness.

Question 19

Situation 25.1
Following a county fair, 160 persons complained of gastrointestinal symptoms. Symptoms included diarrhea (84 percent), abdominal cramps (96 percent), nausea (84 percent), vomiting (82 percent), body aches (50 percent), fever (60 percent; median body temperature = 38.3°C); median duration of illness 6 days (range 10 hr to 13 days).
-In Situation 25.1,fecal samples should be cultured for all of the following EXCEPT

Accepted Answer

Giardia lamblia is a parasite that infects the small intestine and causes diarrhea. However, it is not a bacterium and therefore cannot be cultured from fecal samples. The other choices are all bacterial pathogens that can be culture from fecal samples and are common causes of gastrointestinal illness.

Question 20

What is a Dane particle?

Accepted Answer

The Dane particle is the infectious virion that causes Hepatitis B Virus (HBV) infection. It is distinguishable under an electron microscope and is responsible for transmitting the virus from one individual to another.

Quiz 25: Microbial Diseases of the Digestive System