BIOL 251 Chapter 24

Gastritis

inflammation of stomach lining

Enteritis

Inflammation of the intestinal mucosa

Gastroenteritis

inflammation involves both the stomach lining and the intestinal lining

Hepatitis

inflammation of the liver

Dysentery

damage to the epithelial cells of the colon; causes bleeding and excess mucus, watery stools.

Food poisoning by Staphylococcus

-associated with raw or undercooked foods

-ingestion of the exotoxins produced by the bacteria cause symptoms

-Symptoms occur within a couple hours of ingestion and most are resolved within 24 hours

-Problematic when the food is kept below 60 degrees celsius

Salmonellosis

-Motile, Gram-negative rod; Enteric bacteria

-S. enterica most common in humans

-Symptoms include diarrhea, abdominal pain, nausea, vomiting , fever

Escherichia coli

-part of the normal microbiota of the colon

-Gram-negative rod closely related to shigella but ferment lactose

-there is a range of symptoms like vomiting, loose stools, profuse watery diarrhea, severe cramps and bloody diarrhea

-Pathogenic strains have virulence factors like enterotoxins and adhesion molecules

strict sanitary measures for food and water, treatment with fluid and electrolyte replacement, antibiotics

What are some treatments and preventions for Shigellosis?

Helicobacter pylori

-symptoms are gastritis, abdominal pain, tenderness, bleeding, may be asymptomatic

-Short, Gram-negative spiral

-Microaerophile

-Multiple polar flagella

-neutralizes environment around itself so it survives in extreme acidity

-flagella s used to corkscrew through mucosal lining

Clostridium difficile

-antibiotic-associated diarrhea

-Especially elderly and immunocompromised

-the most common infectious cause of nosocomial diarrhea

-Gram-positive, obligate anaerobic rod

-endospore former

-toxin A (enterotoxin) and toxin B (cytotoxin)

stop antibiotics, electrolyte replacement, fecal transplant, metronidazole, vancomycin

preventions and treatments for clostridium difficile infection?

Cholera

-gram-negative, curved rods, salt tolerant, tolerates high alkaline environment

-Symptoms include watery diarrhea, vomiting, muscle cramps

-Requires a high infectious dose

-in small intestine, bacteria adhere to epithelial lining and multiply

-bacteria produce cholera toxin (symptoms) and A-B toxin (action causes excess secretion of fluid)

Hepatitis Virus

-inflammation of liver

-five main viruses

-symptoms include malaise, anorexia, loss of appetite, dark urine, pain in upper right quadrant of abdomen, vomiting, nausea, diarrhea, joint pain, gray stool, jaundice

C

Which of the following is NOT a way the normal microbiota of the intestine helps to prevent infection?

A. Peristaltic action helps to move microbes through and flush them from the digestive tract

B. It produces acids that lower the pH of the stomach

C. Normal microbiota microbes generate large amounts of oxygen which kills off anaerobic pathogens

D. All of these ways in which normal microbiota protect against infections

E. Normal microbiota microbes occupy space and help outcompete potential pathogens

C

Which species of Shigella includes a stereotype that produces Shiga toxin?

A. all shigella species produce have been shown to produce shiga toxin

B. S. sonnei

C. S. dysenteriae

D. S. flexneri

E. S. boydii

C

Which of the following produces an A-B toxin?

A. E. coli

B. Shigella dysenteriae

C.Vibrio cholerae

D. ETEC

E. Salmonella

A

Which bacterial species causes antibiotic associated pseudomembranous cloitis?

A. Clostridium difficile

B. E. coli

C. Clostridium botulinum

D. Vibrio cholerae

E. Shigella flexneri

C

How does food poisoning caused by Staphylococcus aureus typically occur?

A. by ingesting neurotoxins that are released into the food by the bacteria

B. by the bacteria reproducing in the stomach, then making their way into the GI tract

C. by ingestion of exotoxins produced by the bacteria growing in the food

D. by the bacteria reproducing in the intestines, causing enteritis

E. by the LPS released from the bacterial cell wall when the bacteria die

A

Which of the bacterial species lives in the stomach, produces urease, and is associated with peptic ulcers?

A. Helocobacter pylori

B. Vibrio cholerae

C. Salmonella typhi

D. Clostridium difficile

E. E. coli O157:H7

B

To prevent food poisoning, poultry should be cooked to what internal temperature?

A. 150 degrees celsius

B. 74 degrees celsius

C. 100 degrees celsius

D. 40 degrees celsius

E. 55 degrees celsius

A

A virus that infects cells of the liver and is transmitted through contaminated blood or body fluids is ____________________.

A. HBV

B. influenza

C. HEV

D. norovirus

E. HAV

C

The most virulent strain of E. coli that can result in HUS is

A. ETEC

B. EVEC

C. EHEC

D. EPEC

E. EIEC

E

Typhoid fever is caused by a highly virulent serotype of what bacterium?

A. Vibrio

B. Clostridium

C. Shigella

D. E. coli

E. Salmonella