Microbiology ch 24 Digestive System Infections

Which of the following invade(s) intestinal cells? 1. Shigella species 2. Vibrio cholerae 3. Helicobacter pylori 4. Giardia lamblia

1

Which of the following produce functionally similar/identical toxins? 1. Shigella dysenteriae 2. E. coli O157:H7 3. Vibrio cholerae 4. Giardia

1 and 2

Please choose the INCORRECTLY matched pair.

Gall bladder - storage structure attached to pancreas.

Select the TRUE statements regarding this research.

Glucose causes increased expression of cholera toxin genes. Rice-derived starch causes increased expression of cholera toxin. The researchers used a model to show that rice-derived ORS would reduce cholera cases in an epidemic. The WHO now recommends rice-based ORS for cholera patients, based on the results of this work.

Which of the following is the correct order of the major parts of the gastrointestinal tract?

mouth, esophagus, stomach, small intestine, large intestine

The causative agent of the gastroenteritis at Reliant City was found to be

norovirus

Involuntary muscle contractions that move a bolus through the gastrointestinal tract are called ______.

peristalsis

The rapidly lethal effects of cholera are due to

severe dehydration.

Most nutrient absorption occurs in the ______.

small intestine

Hydrochloric acid is secreted in the _______.

stomach

Preventing cholera in endemic areas is by

water treatment and sanitation.

Which statement about rotaviral gastroenteritis is false?

The causative agent infects mainly the stomach.

Choose the most accurate statement about cryptosporidiosis

The life cycle of the causative agent occurs within small intestinal epithelial cells.

Select the TRUE statements regarding Vibrio cholerae and cholera toxin.

The organism is Gram-non-reactive. CT damages esophageal epithelial cells.

Which of the following about intestinal bacteria is false?

They are mostly aerobes.

Which of the following statements about noroviruses is false?

They generally cause vomiting lasting 1 to 2 weeks.

A patient, a 27-year old man, has severe vomiting and copious diarrhea—he is producing large volumes of watery diarrheal discharge that is milky-white in color, resembling water that has had rice cooked in it. He lives 30 minutes from the nearest hospital. Based on this information, what would be the correct course of action?

Transport him to the hospital immediately for intravenous rehydration.

Which of the following symptoms can be seen with acute gastroenteritis?

Vomiting and diarrhea

Vibrio cholerae pathogenesis involves all of the following except

acid resistance

Select the most important finding from this research.

Cholera patients receiving ORS containing a carbon source such as rice-derived starch do better than those receiving glucose-based ORS.

Pseudomembranous colitis is associated with infections caused by which of the following?

Clostridium difficile

Which of the following contributed to spread of gastroenteritis in Reliant City?

All of the choices are correct. Correct

Why does the report note whether the two patients had recently been getting antibiotic therapy?

CDI usually occurs in patients receiving antibiotics, because the medication causes dysbiosis, facilitating overgrowth of the causative agent, C. difficile.

What causes the diarrhea associated with cholera?

CT causes epithelial cells to leak electrolytes and water in volumes too large to be reabsorbed by the intestine.

What was the most likely source of the initial infection in this outbreak?

Contact with contaminated water post-Katrina. Correct

Which of the following is the BEST way to prevent E. coli O157:H7 infection?

Cooking meat thoroughly before eating it.

Which of the following pairs about dental diseases is FALSE?

Dental caries - associated primarily with Treponema species.

Which of the following statements about Vibrio cholerae and the disease it causes is FALSE?

Drinking several liters of pure water is effective for treatment.

Which of the following statements about E. coli infections is FALSE?

E. coli O157:H7 infections should be treated promptly with antibiotics.

A treatment given to counteract the effect of shiga toxin would also decrease the severity of infections caused by

E. coli O157:H7.

Which of the following best describes how Helicobacter pylori causes ulcers and cancer?

Epithelial cells are damaged by products released by H. pylori and immune cells; this reduces mucus production, which leads to stomach acids destroying the stomach tissue.

What types of toxins are associated with Vibrio cholerae?

Exotoxin and endotoxin

Select the factors that may predispose a person to CDI.

Extended stay in healthcare facilities. People receiving antibiotics for another infection. People with underlying health conditions.

Glucose-based oral rehydration salt solutions are ineffective in treating people with cholera. True or False

FALSE

T/F: A person with CDI cannot be treated. The infection either resolves spontaneously, or the patient dies of dehydration.

FALSE

T/F: All cases of acute gastroenteritis are viral in origin.

FALSE

T/F: Helicobacter pylori is a Gram-negative, microaerophilic acidophile.

FALSE

T/F: Hepatitis B used reverse transcriptase during its replication cycle and is thus classified as a retrovirus.

FALSE

T/F: The causative organisms of periodontal diseases and acute necrotizing ulcerative gingivitis have been well characterized in the laboratory.

FALSE

Select which of the following best describes how Helicobacter pylori infections may lead to cancer.

H. pylori doesn't actually cause the cancer; rather, as the stomach cells undergo mitosis to repair damage caused by stomach acid in the absence of the protective mucus, some cells mutate into cancer cells.

Chronic infections caused by which of the following are associated with stomach cancer?

Helicobacter pylori

Which of the following statements regarding hepatitis is TRUE?

Hepatitis A spreads via the fecal-oral route.

People with which type(s) of hepatitis are at risk of later developing liver damage or liver cancer?

Hepatitis B Hepatitis C

Which of the following statements about hepatitis B virus is false?

In the United States, infection rates have been steadily increasing over the last few years.

Which of the following control measures were used successfully in this case?

Isolating symptomatic people, distributing hand sanitizer, and educating staff and evacuees. Correct

Which of the following statements concerning Salmonella enterica serotype Typhi is false?

It is commonly acquired from domestic animals.

Please select the TRUE statement regarding cryptosporidiosis.

It is not prevented by routine chlorination of water.

Which of the following statements about hepatitis is false?

Lifelong carriers of hepatitis A are common.

What antimicrobial did both Patient A and Patient B receive?

Metronizadole

Inotropic medications affect the force or energy of the heart beat; positive inotropic agents increase the force of heart muscle contractions while negative inotropic agents decrease the force of the contractions. Given the medical information reported for Patient A, which type of inotropic agent do you think she was probably given?

Positive

Which of the following is correct, regarding the "ID" mentioned in this case?

Secondary spread indicated a low ID. Correct

Which of the following statements about shigellosis is FALSE?

Shigella dysenteriae is common in the United States.

Which of the following bacteria-resevoir pairs is INCORRECT?

Shigella species - chicken

Which of the following about giardiasis is FALSE?

Signs and symptoms include fever and diarrhea.

Select the TRUE statements regarding direct acting antivirals (DAAs) used in treatment of hepatitis C.

Some DAAs target polymerases involved in viral replication. Some DAAs interfere with peptidoglycan synthesis. Only one type of DAA is given to a person with hepatitis C.

T/F: Dysentery is the name given to a diarrheal illness in which blood and pus is present in the feces.

TRUE

T/F: Mouth normal microbiota includes obligate anaerobes.

TRUE

T/F: Salmonella gastroenteritis can be prevented by adequately cooking food, particularly poultry.

TRUE

T/F: Staff workers at Reliant City began to experience signs and symptoms similar to those of patients seen at the onsite clinic.

TRUE

If a Salmonella strain developed the ability to better resist low pH, the infectious dose (ID) of the organism would

decrease.

Secondary spread of the gastroenteritis likely occurred through

fomites and person-to-person contact.

Helicobacter pylori has all of the following characteristics except

it has not been cultivated in vitro.

All of the following attributes of Streptococcus mutans are important in tooth decay except

it produces endotoxin, which triggers an inflammatory response.

What organ produces bile?

liver