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