Digestive Tract - Joy

• structures of the teeth and mouth


  enamel

  dentin

  pulp

  cementum

  gingival crevice
• how does a cavity form


  normal flora/ secondary colonizers ferment sucrose resulting in acid production

  leads to destruction of enamel and gingival crevice
• normal flora of mouth


  streptococi (oral, alpha hemolytic)

  some yeasts (some people)

  many others
• cavities are caused by what?


  NF making acid

  acid destroys enamel
• what resides ion the gingival crevice?


  anaerobes (normal flora)
• bacteria that causes caries ( cavities )


  Streptococcus mutans

  Streptococcus sobrinus
• bacterial infections of the mouth

  caries

  gingivitis

  peridontitis

  ANUG
• what causes gingivitis, peridontitis, and ANUG?


  anaerobes in the gingival crevice

  destroy GUMS and structures that support teeth (bone)
• treatment for bacterial infections of the mouth

  antibiotics
• gingivitis


  gum infection
• peridontitis


  chronic gingivitis

  bone deterioration
• ANUG (acute necrotizing ulcerative gingivitis)


  WORST case scenario

  tissue damage ( necrosis) due to inflammatory response
• key structures of the digestive tract

  stomach

  small intestine
• order of small intestine segments

  duodenum

  jejunum

  ileum
• barriers to infection in digestive tract

  mucus, secretory IgA, peristalsis

  fluids with antimicrobial properties

  GALT tissue

  microbial antagonism (normal flora)
• examples of fluids with antimicrobrial properties (digestive tract barrier)

  saliva

  stomach acid

  bile
• GALT tissue


  peyer's patches (M cells)
• where is the majority of normal flora in the digestive tract?


  colon
• normal flora of digestive tract

  COLIFORMS (lactose fermenters, GNR)
• why is there no normal flora in the stomach?


  acidity of stomach doesn't allow normal flora to grow
• what kind of microorganism is BAD in the digestive tract?

  NON FERMENTING
• Hecktoen Enteric agar (HE)


  selects for LF/NLF

  differentiates samonella and shigella
• how does salmonella show on HE?


  pale green with black centers (H2S+)
• how does shigella show on HE?

  pale green
• MacConkey Agar


  LF/NLF
• MacConkey Sorbitol


  sorbitol negative is EHEC
• diarrhea


  loose stool
• dysentery


  diarrhea + mucus and blood
• gastroenteritis


  inflammation of stomach and intestinal mucosa (both ends) symp are nausea vomiting and diarrhea
• entercolitis


  inflammation of the small and large intestine
• food intoxication


  toxin

  associated with quick onset (4-6 hrs)
• food infection


  bacteria needs time to grow

  caused by organism

  2-3 days onset
• bacterial causes of food intoxications


  -Staph food poisoning

  -Bacillus cereus

  -C. diff

  -C. perfringens

  -Vibrio cholera

  -Shigella dysenteriae

  -E. coli (EHEC)
• toxin release by staph food poisoning

  SEA (enterotoxin)

  quick onset ( 4-6 hours)
• gram stain of staph food poisoning

  gram positive cocci
• diagnosis of staph aureus intoxication


  beta hemolytic ( golden colored )

  catalase +

  coagulase +
• symptoms of staph food poisoning

  nausea vomiting diarrhea chills ( self limiting 24-48 hours)
• common foods that lead to staph food poisoning

  dairy

  meat

  mayo
• how does staph aureus intoxication spread

  food handlers shedding staph aureus from skin to food

  temperature abuse
• what is the most common food infection in the United States?

  campylobacter