Bacterial Infectious Diseases Affecting the Gastrointestinal Tract

Flashcards about Bacterial Infectious Diseases Affecting the Gastrointestinal Tract

Accessory Organs of the Digestive System

Salivary glands, Liver, Gallbladder, Pancreas

Gastrointestinal Tract Organs

Mouth, Pharynx, Esophagus, Stomach, Small intestine, Large intestine, Rectum, Anus

Function of the Digestive System

Digest food, absorb nutrients & water into the blood, and eliminate waste

Normal Biota of GI Tract

Oral cavity is heavily colonized with >600 species of microbes. Lower small intestine & colon microbiota here: ~1011/g contents

Exotoxins

Released by live bacteria

Enterotoxins

Type of exotoxins that target the GI causing tissue damage via immune responses

Dental Caries

Cavities in teeth caused by Streptococcus mutans or other normal microbiota, associated with high sucrose diets.

Gingivitis & Periodontal Disease

Typically polymicrobial, caused by Porphyomonas gingivalis. Tartar triggers gingivalis & proteases break down gum tissue

Peptic Ulcers

Caused by Helicobacter pylori. Transmission – fecal-oral

Bacterial Gastroenteritis

Inflammation of stomach or intestines due to the presence of bacteria associated with contaminated foods/water, poor living conditions

Cholera

Caused by Vibrio cholerae. Transmission – ingestion of contaminated water or raw/undercooked seafood

Shigellosis

Caused by Shigella dysenteriae, S. flexneri, S. boydii, S. sonnei. Transmission – fecal-oral

Acute Gastroenteritis (Traveler’s diarrhea)

Caused by Escherichia coli. Transmission – fecal-oral, contaminated beef

Typhoid Fever

Caused by Salmonella enterica serotypes Typhi & Paratyphi. Transmission – ingestion of contaminated food or water

Campylobacter Diarrhea

Caused by Campylobacter jejuni. Transmission – fecal-oral

Food Poisoning (Intoxication)

Caused by Staphylococcus aureus, also Bacillus cereus & Clostridium perfringens. Transmission - ingestion of toxins in food

C diff Infection (CDI)

Caused by Clostridioides difficile. Toxin disrupts GI lining & stimulates inflammation.

Fecal Microbiota Transplantation (FMT)

Healthy microbes from donor stool used to treat C. diff infection.

Clostridioides difficile

A bacterium that causes diarrhea and colitis. C. diff infections can be deadly.