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27 Cards in this Set
- Front
- Back
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GI Tract Defenses: |
-Oral cavity: lysozyme, saliva, tonsils, normal flora -Secretory IgA -Stomach: low pH, mucus -Intestines: bile, GALT, normal flora, peristalsis |
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Diseases: |
-Tooth and gum infections -Streptococcus mutano -Mixed infections of gums -Gastric ulcers -Acute Infectious Diarrhea -Acute diarrhea with vomiting -Hepatitis -Plaque development, cariogenesis and Streptococcus mutant -Periodontitis and Gingivitis |
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Gastritis and gastri ulcers
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-Bacterial infection with ----Helicobacter pylori up to half the population is colonized -Pain and lesions (peptic ulcers) in the abdomen -Bacteria neutralizes stomach acid environment -Immune response damages epithelium |
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Bacterial causes of diarrhea: |
-Salmonella -Shigella -Shiga-toxin producing E.coli -E.coli 0157 H7 -Campylobacter (C.jejuni) -Cholera (Vibrio cholera) |
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CDC Data 1998-2002 |
-total outbreaks 6,647 -3,072 had contributing factor -contamination, proliferation, survival -4,480 had unknown etiology -1,184 were bacterial (585 Salmonella) -709 viral (657 Norovirus) -23 parasitic -221 chemical |
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Salmonella: Typhoid Mary! |
Human carrier (and reservoir) of Salmonella typhi |
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Salmonella enterica serovars |
-infect domestic animals -eggs and contaminated meat -one of the most prevalent causes of food-borne illnesses -transmission dose as few as 10 organisms -attachment is key virulence factor |
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Salmonella enterica servars: |
Gram negative bacillus Classification based on serology and phage susceptibility assays |
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Salmonellosis: |
-40,000 cases annually in US -if mild disease, goes unreported -1 million cases suspected annually --Invades intestinal epithelial cells --- Motility, LPS, fimbriae -Nausea, cramps, diarrhea -Recovery in a few days but may shed organism for 6 months |
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Shigella |
-Exclusively a human parasite -infects the large intestine -called "Dysentery" -Exotoxin (shiva-toxin) affects intestine, inhibiting protein synthesis |
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E.coli 0157 H7 |
-Mostly a bovine intestinal commensal -infects the large and small intestine -Exotoxin (shiva-toxin) produces like Shigella, affects intestine and kidneys -Hemolytic uremic syndrome (HUS) |
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Campylobacter jejuni |
-Small curved Gram negative rod -Lives in large intestine of birds mostly chickens and mammals -Fecal contamination of water and foods |
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Campylobacteriosis |
-leading bacterial cause of human gastroenteritis in the world and USA -2.4 million U.S. cases/year -Undercooked poultry, selfish, unpasteurized dairy products, contaminated water -Watery ---> bloody diarrhea |
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Camplyobacteriosis: |
-Adhesion -Invasion -Catalase -Treated with antibiotics |
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Vibrio cholerae |
-Cholera -Cholera toxin (CT) -A-B toxin -Bacteria never enter host cells -Heavy loss of fluid "rice-water stool" -Untreated cases can be fatal |
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Acute diarrhea with vomiting: |
-Enterotoxins made by bacteria in inappropriately stored food can cause acute diarrhea with vomitting |
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Bacillus cereus: |
often from rice |
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Clostridium perfringens: |
often meats |
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Staphylococcus aureus: |
meats, salads |
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Parasite infection of the GI Tract |
Guardia lambda Cryptosporidium parvum |
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Guardia lamblia |
-Protozoan -Cysts survive in environment Insensitive to chlorine -Contaminated water source of infections |
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Giardiasis |
-Shed by wild animals into water supply as well as by infected humans -G.lamblia attached to human intestinal wall -Diarrhea lasting weeks -Treated with parasitic drugs |
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Cryptosporidium |
-First identified in 1976 -Contamination via fecal-oral route Also in contaminated water - 1993 outbreak in Milwaukee, WI Largest waterborne illness outbreak in US history 403, 000 infected 4400 hospitalized > 100 killed |
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Rotavirus |
-Responsible for most childhood morbidity and mortality from diarrhea -Stomach flu -Fecal- oral route of infection -Babies lacking maternal antibodies are at risk -Unique morphological appearance -Vaccine (MLV) now available |
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Norovirus |
-Commonly referred to as "Norwalk virus" -Highly infectious,fecal-oral route -The cause of almost all acute diarrhea outbreaks in adults (90%) -Recent "famous" outbreaks on cruise ships |
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Hepatitis |
-Viral infection Hep A -Fecal/ Oral Hep B- Blood borne and STD Hep C - Blood Borne (and other ?) Hep E - Fecal / Oral -Infection and inflammation of the over cells -Jaundice of the skin -Noninfectious conditions can cause hepatitis |
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Hepatitis B virus |
-High virulence - high infectivity -"Serum" (i.e., blood-borne) hepatitis -Cirrhosis = scarring of the liver -S antigen present in blood -Chronic infection - particularly children -Associated with hepatocellulr carcinoma -Purified component vaccine (S antigen) |
