Clostridium difficile-associated diarrhea is usually preceded by

extended use of antibiotics

Which of the following statements about salmonellosis is FALSE?

the mortality rate is high

Disease-causing exotoxins are produced by all of the following organisms EXCEPT

shigella dysenteriae

Which one of the following diseases of the gastrointestinal system is transmitted by the respiratory route?

mumps

Which of the following helminthic diseases is a common infestation found in the southeastern United States?

ascaris lumbricoides

Poultry products are a likely source of infection by

Salmonella enterica

All of the following infections can result from drinking contaminated water EXCEPT

trichinellosis

Which of the following organisms feeds on red blood cells?

Entamoeba histolytica

In humans, beef tapeworm infestations are acquired by ingesting

cysticerci of Taenia saginata in undercooked meat

Which of the following statements about staphylococcal food poisoning is FALSE?

It can be prevented by heating foods to 50°C for 15 minutes.

The most common cause of traveler's diarrhea is

Escherichia coli.

Acute gastroenteritis that occurs after an incubation period of two to three days and commonly affects children is probably caused by

rotavirus

Which of the following is mismatched?

hydatid disease — humans are the definitive host

Thorough cooking of food will prevent all of the following EXCEPT

staphylococcal food poisoning

Most of the normal microbiota of the digestive system are found in the

small and large intestine

Typhoid fever differs from salmonellosis in that in typhoid fever

the incubation period is much longer.

Which of the following organisms is likely to be transmitted via contaminated shrimp?

Vibrio parahaemolyticus

Which of the following organisms is likely to be transmitted via undercooked pork and horse?

trichinella spiralis

Which of the following causes inflammation of the liver?

hepatitis A virus

"Rice water stools" are characteristic of

cholera

Epidemics related to bacterial infection of the digestive system are typically caused by

contaminated food and water

The most common mode of HAV transmission is

contamination of food during preparation.

A 38-year-old man had onset of fever, chills, nausea, and myalgia while vacationing on the Gulf of Mexico. On April 29, he had eaten raw oysters and gone wading in the warm coastal waters. On May 2, he was admitted to a hospital because of a fever of 39°C and two circular necrotic lesions on the left leg. He had a history of alcoholic liver disease. He was transferred to the ICU; therapy with antibiotics was initiated. On May 4, he died. Which of the following is the most likely cause?

vibrio vulnificus

Microscopic examination of a patient's fecal culture shows spiral bacteria. The bacteria probably belong to the genus

Campylobacter jejuni.

Which of the following pertains to typhoid fever?

Causative microorganism multiplies in patient phagocytes.

All of the following are gram-negative rods that cause gastroenteritis EXCEPT

Clostridium perfringens

Helicobacter pylori can grow in the stomach because it

possesses an enzyme that neutralizes HCl.

All of the following are eukaryotic organisms that cause diarrheal disease EXCEPT

Campylobacter.

All of the following pertain to pinworm infections EXCEPT

it is most commonly transmitted by cysts in water.

What is a Dane particle?

the infectious virion that causes HBV

which of the following is mismatched

eggs - trichinella spiralis

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).

fecal samples should be cultured for all of the following EXCEPT

Giardia Lamblia

In Situation 25.1, fecal samples were found to be negative when cultured. The next step in diagnosing the cause of illness would be

microscopic examination of feces for oocysts.

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

true

Bacterial infections, but not intoxication can cause diarrhea

false

an outbreak of viral gastroenteritis occurs in a pediatrics ward. rotavirus is most likely causative agent

true

approximately 30% of the body's immune system is located in the intestinal tract.

false

gastroenteritis due to ingestion of food contaminated with staph aureus is due to intoxication by enterotoxins

true

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

false

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

true

staphylococcal food poisoning

pathogen: ingesting an enterotoxin produced by S. aureus. often an inhabitant of the nasal passages.

common foods are custards, cream pies, and hams

symptoms: nausea, vomiting, and diarrhea

shigellosis (bacillary dysentery)

pathogen: shigella

symptoms: tissue damage and dysentery. shiga toxin is responsible. Can cause 20 bowel movements in a day

treatment: quinolones

salmonellosis (salmonella gastroenteritis)

pathogen: salmonella enterica

symptoms: nausea and diarrhea

treatment: oral rehydration

they replicate in macrophages. incubation time is about 12 to 36 hours.

typhoid fever

pathogen: salmonella typhi

symptoms: high fever

treatment: quinolones, cephalosporins, chloramphenicol

known as the 14 day fever.

cholera

pathogen: vibrio cholerae

symptoms: diarrhea with large water loss

treatment: rehydration and doxycycline

exotoxin cholera toxin. "rice water stools"

Escherichia coli gastroenteritis

pathogen: EPEC, EIEC, ETEC

symptoms: watery diarrhea

treatment: oral rehydration

campylobacter gastroenteritis

pathogen: campylobacter jejuni

symptoms: fever, abdominal pain, diarrhea

no treatment

guilain-Barre syndrome: temporary paralysis

clostridium perfringens gastroenteritis

pathogen: C. perfringens

symptoms: diarrhea

treatment: oral rehydration

hepatitis A

pathogen: hepatitis A virus

symptoms: anorexia, fever, headache, malaise, jaundice in most cases

incubation time: 2-6 weeks

treatment: immunoglobin, vaccine

hepatitis B

pathogen: hepatitis B virus. double stranded DNA and enveloped.

symptoms: similar to HAV, liver damage. presence of Hepatitis B surface antigen (HBsAg). The presence HBeAg means the virus is replicating vigorously

treatment: vaccine

amebic dysentery

pathogen: entamoeba histolytica

symptoms: abscesses

treatment: metronidazole

tapeworms

pathogen: taenia saginata, T solium

treatment: praziquantel, albendazole

hydatid disease

pathogen: echinococcus granulosus

symptoms: larvae forms in body

treatment: surgery; albendazole

hookworms

pathogen: necator americanus, ancylostoma duodenale

symptoms: large infections may result in anemia

treatment: mebendazole

whipworm

pathogen: trichuris trichuria

symptoms: diarrhea, malnutrition

treatment: albendazole, mebendazole

can lead to anemia and malnutrition.

Ascariasis

pathogen: ascaris lubricoides

treatment: mebendazole

trichinellosis

pathogen: trichinella spiralis

symptoms: fever, eye swelling, upset GI

treatment: mebendazole, corticosteroids

enteropathogenic E. coli (EPEC)

major cause of diarrhea in developing countries and fatal in infants.

enteroinvasive E> coli (EIEC)

synonymous to shigella. inflammation, fever, and shigella dysentery

enteroaggregative E. coli (EAEC)

found only in humans. bacteria cause a stacked-brick configuration on tissue culture cells.

enterohemorrhagic E. coli (EHEC)

shiga-like toxin . Most outbreaks are due to EHEC serotype O157:H7