INFECTIONS OF GASTROINTESTINAL TRACT Flashcards
- live bacteria in food & water are ingested & grows in body.
- then produces toxins that damage host cells
INFECTION
bacterial toxin or poison was ingested fr. food or water
INTOXICATION
- inflammation of mucosal lining of stomach
Gastritis
Establishment of infectious disease in digestive system is:
1.Pharmacologic action
2. Local inflammation
3.Deep tissue invasion
4.Perforation
-inflammation of small intestine
Enteritis
-inflammation of mucosal lining of stomach & small intestine
Gastroenteritis
3 mechanisms of Food poisoning
1.Ingestion of preformed toxin
2.Infection by toxigenic organisms
3.Infection by enteroinvasive organisms
- inflammation of colon (large intestine)
Colitis
- inflammation of liver
Hepatitis
- low-volume, painful, bloody diarrhea
Dysentery
Bacterial food poisoning is an illness caused by consumption of food contaminated w/ bacteria or bacterial toxins
Bacterial enterocolitis (food poisoning)
- present in contaminated food.
S/s dev hrs consisting of explosive diarrhea, abd pain. - Staph aureus, Vibrio. Clostridium perfringes
Ingestion of preformed toxin
involves secretory - enterotoxin, dysentery
Infection by toxigenic organisms
- is an inflammation of the lining of the intestines.
- Bacterial are; Escherichia coli, Salmonella sp. Shigella sp,Yersinia enterocolitica, Vibrio cholera, Clostridium perfringes, Clostridium difficile, Bacillus anthracis, Mycobacterium tuberculosis
Gastroenteritis (Diarrhea)
- proliferate, invade, destroy epithelial cells
- dysentery
Infection by enteroinvasive organisms
- is a soil organism; commonly contaminates rice
- When large amounts of rice are cooked and allowed to cool slowly, the _________ spores germinate, and vegetative cells produce toxin during log-phase growth or during sporulation.
B cereus
- gram (+)
- spore-forming bacilli (rods)
- facultative anerobe
- arranged in long-chains (square ends)
- spores in center of nonmotile bacilli.
- Most are Saprophytic (soil, water, air & on vegetation)
Bacillus cereus
- Main Reservoir: SOIL
- Transmission/ Predisposing Factor: Spores germinate in reheated rice, then bacteria produce exotoxins, which are ingested
- with Beta-lactamase- (resistant to penicillin)
- DISEASE: Food poisoning
B. cereus
a) emetic type: Fried rice, occasionally pasta
> Source: Rice
> begins 1–5 hours after ingestion
> appears when food containing pre-formed toxin produced during B. cereus growth is consumed
emetic toxin (vomiting)
toxin is heat-LABILE
> Tx: No antibiotic tx
> Profuse diarrhea w/ abdn’l pain & cramps;
> fever, vomiting uncommon.
> Required. Self limiting.
> Rice should not be Kept warm for long periods
Diarrheal type
b) Diarrheal type- meat Dishes & sauces
> incubation period: 8–24 hrs
> produced when enough B. cereus cells are consumed & microorganism is implanted & grows in small intestine producing the toxin,
enterotoxin (diarrhea)
Heat -stable
> N & V, abdominal cramps, occasionally diarrhea
> recovery w/n 24 hrs (self Limiting)
Emetic form
is uncommon w/ B anthracis but common w/ B cereus & saprophytic bacilli. Gelatin is liquefied, & growth in gelatin stabs resembles an inverted fir tree
Hemolysis
> can grow in foods and cause food poisoning by producing either an enterotoxin (diarrhea) or an emetic toxin (vomiting).
This is due to the way in which it is cooked; it is boiled in large quantities, kept unrefrigerated for several hours, depending on consumer’s demand, before being further processed (fried or heated). During this unrefrigerated storage the microorganism can grow and/or produce the emetic toxin that will not be destroyed or inactivated by a subsequent processing step [
B cereus
a ___________ heat-labile protein may lose its structure as it unfolds at very high temperature. The opposite of __________ in this regard is heat-stable.
heat-labile
A ____________ substance is capable of maintaining its form, structure, and function even at high temperatures.
heat-stable
- Impt cause of food Poisoning
- Enterotoxin are produced When organism grow in Carbohydrate or protein food
- Ingestion of contaminated Foods: salads, custards, Milk products
Staphylococcus aureus
comes from contaminated hands of cook/ food handler (wx. nasopharyngeal)
> if food is not properly stored… bacteria grows more & allows to grow the toxin itself
Stap bacteria
are produced when S aureus grows in carbohydrate and protein foods.
enterotoxins
> Food poisoning caused by _______________ is characterized by a short incubation period (1–8 hours); violent nausea, vomiting, and diarrhea; and rapid convalescence.
There is no fever.
staphylococcal enterotoxin
- incubation period (1–8 hrs)
- Vomiting w/ nausea:more common than diarrhea.
- No fever
- Tx: No antibiotic therapy Required.
- Mgt: supportive. rapid convalescence
Staphylococcus aureus
- Anerobic Gm (+) Spore forming rod
- Enterotoxin producer
Clostridium perfringes
> can be found on raw meat and poultry, in the intestines of animals, and in the environment.
These bacteria make spores, which act like protective coatings that help the bacteria survive.
Clostridium perfringes
- Ingestion of food contaminated w/soil containing spores reheated food Like meat dishes
Clostridium perfringes
> food poisoning usually follows the ingestion of large numbers of clostridia that have grown in warmed meat dishes. The toxin forms when the organisms sporulate in the gut, with the onset of diarrhea—usually without vomiting or fever—in 7–30 hours. The illness lasts only 1–2 days>
when food is kept at an unsafe temperature external icon (between 40°F–140°F), can grow and multiply. After someone swallows the bacteria, it can produce a toxin (poison) that causes diarrhea.
Clostridium perfringes
> food poisoning usually follows the ingestion of large numbers of clostridia that have grown in warmed meat dishes. The toxin forms when the organisms sporulate in the gut, with the onset of diarrhea—usually without vomiting or fever—in 7–30 hours. The illness lasts only 1–2 days
Clostridium perfringes
- Curved Gm ( -) coccobacillus
- Marine organism
- Produces enterotoxin
- Similar to cholera toxin
Vibrio parahemolyticus
Ingestion of raw seafood, Shellfish oysters
DISEASE:Vibriosis
Vibrio parahemolyticus
> cases occur during warmer months of the year,
vibriosis
> naturally inhabit coastal waters where oysters live. Because oysters feed by filtering water, bacteria can concentrate in their tissues.
Vibrio bacteria
cause an intestinal infection that is characterized by lower gastrointestinal distress such as diarrhea and cramps. in some cases, nausea, vomiting, fever and headache may also be present
vibrio parahaemolyticus
A food commonly associated with Bacillus cereus food
poisoning is
(A) Fried rice
- Gm (-) motile, Encapsulated rod.
- Normal flora
- Most commom Cause of UTI & sepsis
Escherichia coli
- acquired by ingestion of food or water (contaminated w/ human feces)
- Travellers diarrhea (Watery, nonbloody diarrhea )
- Antibiotic tx: Not usually Indicated In diarrheal E.coli disease
- self-limited, of short duration (1–3 days).
Escherichia coli
- Enterohemorrhagic E. coli O157
- main reservoir of cattle
- acquired in undercooked beef, ex. hamburgers
Escherichia coli
- Has pili (adherence to cells of jejunum & ileum» Once attached, the bacteria
- synthesize enterotoxins» cause diarrhea), Capsule, Endotoxin, enterotoxin
Escherichia coli
Serves as Fecal index For contamination of water
Escherichia coli
- Gm (-), Encapsulated, Motile, rod, Has 3 Antigens
- Their antigens—cell wall O, flagellar H, and capsular Vi (capsular polysaccharides: virulence)
Salmonella sp
- Acquired: ingestion of undercooked eggs, unpasteurized dairy products, raw vegetables, or undercooked poultry.
: Also by exposure to pet snakes and turtles
Salmonella spread to people
Gm(-) rod, non- motile, non-encap S. Dysenteriae
Has shigatoxin (causes local areas of erosion»_space; give rise to bleeding and heavy mucous secretion)
MOT:
- Food, Finger, Flies, Fomites, Bloody Mucoid Diarrhea
Shigella sp
3 types of Salmonella infections:
1) Enterocolitis
2) Typhoid or Enteric fever,
3)Septicemia
- S/s: Diarrhea with blood or pus usually; abdominal cramps (With tenesmus; can be febrile <Syndrome></Syndrome>
- generation time is 40 mins
- Lab Dx: Stool Culture (EMB or Mc conkey’s Agar)
- Tx: Ciprofloxacin
Shigella sp
- Gm(-) ureaseProducing Rods
- MOT: Ingestion of food (meat & dairyProducts) contaminated
By feces of Domestic Animals Fomites Watery to Bloody diarrhea
Yersinia enterocolitica
- s/s: Fever, diarrhea
- suggest Appendicitis Arthralgia (Causes mesenteric adenitis that can mimic appen)
- Lab Dx: Stool Culture of Specimen From rectal Swabs with “Cold Enrichment”
- Self-limiting, Do not require Antibiotic therapy
Yersinia enterocolitica
- Comma-Shaped, gram-negative rods
- Motile, w/ polar flagellum
- Disease—Cholera
- Habitat and Transmission—Habitat is the human colon & shellfish
- Transmission is by the fecal–oral route (water Food Flies)
Vibrio cholera
which enhances attachment to intestinal mucosa
Mucinase
- Has Mucinase - which enhances attachment to intestinal mucosa
- Prolonged Hypersecretion Of water (Enterotoxin: Increase in cyclic AMP causes outflow of chloride ions and water)
- “rice watery” Stool
- Severe Dehydration & shock
- Tx: Water Fluid & Electrolyte replacement
- Tx: Tetracycline
Vibrio cholera
- segmental necrotizing infection of jejunum & ileum caused by Clostridium perfringens
- occurs in parts of Asia, Africa, South Pacific; primarily affects children w/ severe protein malnutrition
Enteritis necroticans
- Toxin producing organisms (Type C)
- enterotoxin
Clostridium perfringes
- Anerobic Gm (+), Spore forming Rod
-is a germ (bacterium) that causes severe diarrhea and colitis (an inflammation of the colon). - most common cause of antimicrobial-associated diarrhea (Allowing C. diff. to multiply)
Clostridium difficile
(yellow-white plaques in colon mucosa) w/ bloody diarrhea, fever, & severe abdominal pain.
pseudomembranous colitis
- MOT: Fecal oral Route, Hospital Personnels Are impt Intermediaries
- Most common Cause of Nosocomial Diarrhea (antibiotic-associated diarrhea )
- Lab:ELISA
- Diarrhea Watery to bloody
– Antibiotic - Associated PseudoMembranous Colitis.
- Clindamycin 2nd-3rg gen cephalosporins
- Tx: metronidazole
Clostridium difficile
- rare but serious illness caused by spore-forming bacteria
- spores are formed by anthrax bacteria that occur naturally in soil
- spores remain dormant for yrs until they find their way into a host.
- Common hosts for anthrax include wild or domestic livestock, such as sheep, cattle, horses and goats.
Bacillus anthracis
- MOT: Ingestion Of improperly Cooked meat From infected animals
- S/S: Vomiting, Abdominal Pain, Bloody Diarrhea
- Dx: exam of Specimen & culture
- DOC: Ciprofloxacin.
- Doxycycline Is alternative
- Drug.
- Control Measures: Immunization Of domestic animals
Bacillus anthracis
- TB of GIT (Extrapulmonary TB )
- Affect any part of GI tract (ileocecal involvement - most common)
Mycobacterium tuberculosis
READDDDDDDDDDD!!!!!!!!!!!!!!!!!
4 mechanisms:
: swallowing infected sputum (after being Coughed Up from Lung lesion),
: hematogenous spread from active pulmonary or miliary TB,
: ingestion of contaminated milk or food (by M. bovis when Ingested By unpasteurized Milk products),
: contiguous spread from adjacent organs
- S/S: Abd’l pain (most common), Chronic diarrhea
- Only 15% of pt w/ GI TB show evidence of pulmonary disease
- Dx. histology and positive mycobacterial culture of biopsy material obtained by colonoscopy.
- DOC: RIPES
- Prev: BCG vaccine, Pasteurization of milk
M. tuberculosis
Streptococcus mutans
Dental caries(tooth decay)
-inflammation of structures that support teeth
Periodontal disease
chronic gum disease can cause bone destruction & tooth loss
Periodontitis
