C-12 Flashcards
anatomy, physiology, and normal flora of the oral cavity
crown, enamel, periodontium tissue around tooth
flora: bacteria, yeast
How is saliva produced and how does it help protect teeth and prevent infection?
by salivary glands; contains lysozyme, calcium, IgA and antimicrobial peptides, and neutral pH - Calcium helps re-mineralize enamel
What are the structures of teeth and periodontium?
gingiva
alveolar bone
cementum
PDL
formation of plaque and calculus, roles of Streptococcus mutans and acid-producing bacteria
s. mutans grows on teeth and anchors biofilms to teeth
formation of dental caries, roles of Streptococcus mutans and acid-producing bacteria
s. mutans and yeast interact and enhance infections that lead to dental caries - yeast overgrows
What type of metabolism produces acid in the mouth and what environmental conditions are required for this metabolism
lactic acid - anaerobic fermentation
Porphyromonas gingivalis - gingivitis
virulence: Adhesins, anaerobe
transmission: normal flora
signs: swollen gums
tx: proper hygiene and avoid sugars
morphology: gram - rods
affected tissues: gums (gingiva)
Porphyromonas gingivalis - periodontitis
virulence: same
transmission: same
signs: bone loss, receding gums
tx: same
morphology: same
affected tissues: gums and bone
Porphyromonas gingivalis – how does it cause inflammation?
pro-infammatory organism - bacteria buildup under tooth and detachment of gingiva
Which is reversible – gingivitis or periodontitis?
gingivitis
Oral thrush (Candida albicans)
yeast
Mumps (Mumps virus)
virulence: adhesions
transmission: direct contact, fomite contaminated with saliva
signs: swollen salivary glands
tx: MMR vaccine
morphology: enveloped, ssRNA
affected tissues: parotid salivary gland
anatomy, physiology, and normal flora of the gastrointestinal tract, role of the stomach, small intestine, large intestines, and liver
flora: bacteria, enterics, virome, fungi, archaea
What are the mechanisms of diarrhea?
Diarrhea is the increase in
volume of stool or frequency of defecation
What is meant by secretion versus absorption in the intestines? What sorts of things are absorbed and secreted by the small intestine and large intestine?
into cells = absorption
into lumen = secretion
absorbs nutrients, water, salts
What must microbes be able to do to survive stomach acid and make it to the intestines?
hydrolyze macromolecules (?)
Staphylococcal enterotoxicosis – Staphylococcus aureus
disease: Bacterial intoxication - Staphylococcal food poisoning
virulence: enterotoxin
transmission: Contaminated food – bacteria survive salt, toxin is heat stable and can withstand cooking
signs: Intense cramping, vomiting, and diarrhea ~24 hours
tx: Self-limiting, proper food handling, fluid replacement
morphology: Bacteria – gram positive staphylococci
affected tissues: intestines
Aflatoxin poisoning – Aspergillus
disease: Fungal intoxication - Aflatoxin poisoning, liver cancer, liver cirrhosis
virulence: Aflatoxin
transmission: Contaminated food – improperly stored grains and legumes
signs: Nausea, vomiting, pain, severe damage to liver (jaundice)
tx: Regulate foods – no specific antidote for poisoning
morphology: Fungus – mold
affected tissues: liver
enterotoxigenic E. coli
disease: Travelers’ diarrhea/ dysentery
virulence: Shiga toxin, T3SS, enterotoxins
transmission: Fecal-oral: contaminated produce/meat
signs: Dysentery – bloody diarrhea
tx: Rehydration/fluids – no
antibiotics if EHEC
morphology: Gm (–) rods, flagella
affected tissues: intestines
Salmonella typhimurium
disease: Salmonellosis, Typhoid fever
virulence: T3SS (Type 3 secretion system) Enterotoxins. S. typhi - capsule
transmission: Fecal-oral: food/carriers
signs:
Shigellosis – can cause dysentery
Typhoid fever: rash and fever
tx: Rehydration/fluids - Fluoroquinolones or macrolides, S. Typhi vaccine
morphology: Gm (–) rods, flagella
affected tissues: intestines
Shigella dysenteriae
disease: Shigellosis / dysentery
virulence: Shiga toxin, T3SS, enterotoxins
transmission: Fecal-oral: food/water
signs: Dysentery – bloody diarrhea
tx: Rehydration/fluids – Fluoroquinolones
morphology: Gm (–) rods, no flagella – actin “comets”
affected tissues: intestines
Vibrio cholerae
disease: cholera
virulence: Cholera Toxin – electrolyte loss
transmission: Fecal-oral route through contaminated water
signs: Rice-water stool
tx: Doxycycline and fluid replacement, Vaccine
morphology: Water-dwelling gram (-) vibrio
affected tissues: intestines
Campylobacter gastroenteritis – Campylobacter jejuni
disease: Most common diarrhea in US
virulence: Endotoxins, cytotoxins
transmission: Fecal-oral, particularly undercooked chicken
signs: Diarrhea, dysentery potentially
tx: Antibiotics, avoid antacids
morphology: Gm (-) helical, flagella
affected tissues: intestines
Clostridioides difficile (C. diff)
disease: C. diff – pseudomembranous colitis –
antimicrobial-associated diarrhea
virulence: Toxin A and Toxin B
transmission: Endogenous flora – overgrowth triggered by antibiotic therapy
signs: Diarrhea, colitis
tx: Fecal Microbial Transplant (FMT), fluid replacement, antibiotics (if they still work)
morphology: Anaerobic gram (+) endospores
affected tissues: intestines
Helicobacter pylori
disease: Stomach ulcers, associated with gastric cancer (peptic ulcers)
virulence: urease
transmission: fecal-oral
signs: Stomach pain, potentially stomach bleeding
tx: Antacids and antibiotics
morphology: Gm (-) helical, flagella
affected tissues: stomach
Norovirus/Astrovirus/Rotavirus
disease: Viral gastroenteritis (“stomach flu”)
virulence: adhesions
transmission: Fecal-oral route, direct person-to-person or
contaminated food or water
signs: Mild diarrhea, usually over quickly
tx: Proper food handling, wash hands; Rotavirus – live attenuated vaccine for infants
morphology: Naked RNA (ds rota, +ss noro)
affected tissues: intestines
Giardia lamblia
disease: Giardiasis (back packer’s disease)
virulence: Forms stomach acid-resistant cyst / inflames lumen of intestine
transmission: Ingesting cysts from contaminated water, fecal-oral
route
signs: Greasy diarrhea, weight loss, fatigue
tx: Metronidazoles
morphology: Protozoan – flagellate
affected tissues: intestines
Entamoeba histolytica
disease: Amoebic dystentery
virulence: Forms stomach acid-resistant cyst / creates ion channels and invades intestine
transmission: ingesting cysts from contaminated water, fecal-oral route
signs: Dysentery (bloody diarrhea)
tx: Metronidazoles
morphology: Protozoan – pseudopod
affected tissues: intestines
Hepatitis A virus
disease: HAV-Infectious hepatitis
virulence: Viral adhesins
transmission: Fecal-oral
signs: Jaundice
tx: vaccine
morphology: +ssRNA naked
affected tissues: liver
Hepatitis B virus
disease: HBV-Serum hepatitis
virulence: same
transmission: blood
signs: same
tx: same
morphology: DNA enveloped
affected tissues: same
Hepatitis C virus
disease: HCV, Non-A, Non-B chronic hepatitis
virulence: same
transmission: blood
signs: same
tx: Can be cured with nucleoside analogs
morphology: +ssRNA enveloped
affected tissues: same
Hepatitis delta virus
disease: HDV – Hepatitis delta
virulence: same
transmission: blood
signs: same
tx: Hepatitis B vaccine
morphology: -ssRNA enveloped
affected tissues: same
Hepatitis E virus
disease: HEV – enteric hepatitis
virulence: same
transmission: same
signs: same
tx: Supportive care, fluids
morphology: same
affected tissues: same
osmotic diarrhea
you ingest a solute like Epsom salts or mannitol/sorbitol/xylitol – these solutes are not absorbed and remain in the intestinal
lumen, water follows the solutes into the lumen, waters down the stool
secretory diarrhea
bacterial enterotoxins stimulates secretion of water into the lumen of the intestine causing uncontrolled water loss – diarrhea; peristalsis
inflammatory/infectious diarrhea
Inflammation caused by tissue invasion or adhesion by pathogens causes fluids to leak out of the tissue; may also interfere with absorption of
nutrients or water; dysentery
