Micro quiz 111210

  1. Leukostatin
    • like leukocidin
    • does not kill phagocytes
    • interferes with the ability of phagocytes to phagocytize cells
  2. Lipases
    • present in staphylococci
    • action: digests lipids
    • purpose: helps the bacteria to colonize oily skin
  3. nucleases
    • aka DNase
    • present in staphylococci
    • action:digests DNA
    • purpose: destroy leukocytes
  4. Beta lacamases
    • present in many different species, especially staphylococci and streptococci
    • action: cleaves members of the penicillin drug family
    • purpose: confers resistance to beta lactam antibiotics
  5. beta-lactam
    • work on peptidoglycan preventing cell wall synthesis, ultimately leading to cell death
    • allows infection to persist
  6. Mucinase
    • present in Entamoeba histolytica
    • enzyme digests the protective coating on mucous membranes
    • is a virulence factor in amebic dysentery
  7. Keratinase
    • digest keratin-principal component of skin and hair
    • present in dermatophytes (fungal species that reside in the epidermal layer of the skin)
    • organisms cause superficial cutaneous infection
    • ex. ring worm (tinea)
  8. Mycotoxins
    • powerful fungi toxins
    • infections results form ingestion of poisonous
    • species
    • more than 400 mycotoxins. 150 species of fungi
    • effects: hallucinations, emesis, diarrhea, coma, death
    • ex. Aspergillus, Penicillium, Fusarium, Stachbotrys
  9. Aflatoxin
    • one of the most potent fungal toxin
    • occur in nuts, grains and cereals under conditions of high temperature and high humidity
    • consist of 10 types: B&G
    • target: liver damage and cancer of liver (jaundice, hepatitis, hepatic cancer)
    • produced by:Aspergillus flavus and Aspergillus parasiticus
    • B1 is considered the most potent naturally-occuring hepatocarcinogen
  10. Aspergillus flavus
    B aflatoxins
  11. Aspergillus parasiticus
    B and G aflatoins
  12. Hepatotoxicity
    • liver damage
    • aflatoxin
  13. hepatocarcinogenic
    • cancer of the liver
    • aflatoxin
  14. symptoms of aflatoxin
    • nausea
    • emesis
    • abdominal pain
    • diarrhea
    • cerebral edema
    • permanent brain damage
  15. Sterigmatocystin
    • Mycotoxin
    • produced by Aspergillus versicolor, Aspedillus flavus, Aspergillus parasiticus
    • considered a precursor to aflatoxins
  16. Ochratoxins
    • produced by Aspergillus and Penicillium
    • found on cereals, coffee and bread
    • most frequent contaminating mycotoxin in the world
    • A is the most toxic (nephrotoxic, nephropathogenic, immunosuppressive, carcinogenic, tetratogenic)
    • linked to idiopathic nephropathies
    • linked to rare tumors of the pelvis and ureter
  17. endemic nephropathy
    • ochratoxin
    • fatal renal disease in rural populations of Croatia, Bosnia, Bulgaria, and Romania
  18. Ergot Alkaloids
    • produced by Claviceps
    • present on the surface of grain
    • 40 types
    • divide in 3 main groups: lysergic acid, isolysergic acid, dimethylergoline
    • result in ergotism
    • gangrenous form
    • convusive ergotism
  19. Ergot Alkaloids (gangrenous ergotism)
    • Toxins constrict blood vessels and impair circulation
    • Affect CNS (neurotoxic effect)
    • Hallucinations and convulsions
    • Loss of mental function
    • Spasms and cramps
    • Paresthesia in calves and/or edema of the legs
    • Paresthesia: an abnormal touch sensation; feelings of burning or prickling in the absence of an external stimulus; Tingling or burning sensations
    • Feelings of intense cold
    • Can result in gangrene; this may require amputation
  20. ergot alkaloids (convulsive ergotism)
    • Gastroenteritis (nausea and emesis)
    • Dizziness
    • CNS symptoms:
    • Drowsiness
    • Prolonged sleepiness
    • Twitching
    • Convulsions
    • Paralysis
    • Blindness
  21. lysergic acid
    • Ergot Alkaloids
    • e.g. ergotamine, ergocristine
  22. isolysergic
    e.g. ergotaminine
  23. dimethylergoline
    e.g. agroclavine
  24. Paresthesia
    an abnormal touch sensation; feelings of burning or prickling in the absence of an external stimulus; Tingling or burning sensations
  25. Tricothecenes
    • produced by Fusarium, Trichoderma, Trichothecium, Mycrothecium, Stachybotyrs
    • associated with contaminated rice or wheat
    • more than 150
    • divided into 4 classes: T1-T4
    • example: Vomitoxin, Nivalenol, T-2 toxin
    • extremely toxic: causes cytolysic and necrosis, results in blistering lesions. prevents mitosis of cells lining the intestine and bone marrow cells
  26. Trichothecenes symptoms
    • Abdominal pain
    • Nausea
    • Emesis
    • Heachache
    • Dizziness and vertigo
    • Fatigue
    • Fever/Chills
    • Diarrhea
  27. Fumonisins
    • Produced by Fusarium moniliforme
    • Grow on corn (maize)
    • Two main types: A and B
    • A (1-2) and B (1-4)
    • B1 and B2 are most toxigenic
    • Considered a carcinogen
    • Associated with esophageal cancer
  28. Amatoxins
    • Toxin: alpha-amanitin
    • Made by different species of Amanita
    • e.g. Amanita phalloides
    • Deadliest mushroom
    • Common name
    • Death cap
    • Contains enough toxin in the cap of the mushroom to kill an adult
  29. Amanita phalloides
    • Deadliest mushroom
    • Common name: Death cap
    • Contains enough toxin in the cap of the mushroom to kill an adult
  30. Stachybotrotoxins
    • Produced by Stachybotrys chartarum
    • Typical symptoms include: irritation of the mouth, lips, nose and throat
    • Can progress to leukopenia and ulceration of the mucosal surfaces of the nose and throat and lungs
    • Presented as a possible etiological agent for acute idiopathic hemorrhage in infants (not conclusive)
  31. Phycotoxins
    • Also called cyanotoxins
    • Microcystin
    • Anatoxin-a
    • Cylindrospermopsin
    • Domoic acid
  32. Microcystin
    • Are hepatotoxins
    • Toxin targets the liver
    • Most commonly detected cyanotoxin in fresh water or brackish water
    • Produced by Microcystis and related species
    • Toxin cannot penetrate directly into animal membranes
    • Uptake through cell membrane transporters
    • Are heat stable
    • Linked to liver cancer in humans
  33. Anatoxins
    • Two main types: Anatoxin-a & Anatoxin-as
    • Are neurotoxins
    • Result in paralysis, respiratory distress, asphyxiation, convulsions and death
    • Are alkaloids
    • Are susceptible to breakdown by sunlight
  34. Domoic Acid
    • Some diatoms produce a toxin called domoic acid
    • Until recently, diatoms were thought not to produce toxins
    • Causes amnesic shellfish poisoning which results in the loss of short term memory
    • Symptoms: loss of memory, nausea, vomiting, diarrhea, and abdominal cramps
  35. Brevetoxin
    • dinoflagellate
    • Produced by Karenia brevis
    • This dinoflagellate causes red tides
    • Disease is called neurotoxic shellfish poisoning.
    • Fish eat dinoflagellate→ Humans eat fish→ food poisoning
  36. Brevetoxin symptoms
    • A tingling sensation in the mouth and fingers (paresthesia)
    • Dizziness
    • Ataxia: extreme lack of coordination
    • Myalgia: muscle pain
    • GI symptoms: diarrhea, vomiting, abdominal pain
    • Symptoms are mild and self-limiting
  37. Saxitoxin
    • dinoflagellate
    • Produced by Gonyaulax catenella
    • This organism also makes the toxin gonyautoxin
    • Both of these toxins are neurotoxins
    • Considered very potent toxins
    • Disease is called paralytic shellfish poisoning
    • Shellfish (clams, oysters, mussels) eat dinoflagellate→humans eat shellfish→paralytic shellfish poisoning
  38. Gonyaulax catenella
    • This organism also makes the toxin gonyautoxin
    • Both of these toxins are neurotoxins
    • Considered very potent toxins
  39. Saxitoxin symptoms (mild form)
    • Mild form
    • General numbness: mouth, lips, face and extremities (paresthesia)
    • GI symptoms: nausea, vomiting, diarrhea and abdominal pain
  40. Saxitoxin symptoms (severe form)
    • Severe form
    • General muscle weakness
    • Ataxia: lack of coordination; difficulty walking
    • Dysphonia: difficulty speaking
    • Dysphagia: difficulty swallowing
    • Respiratory failure: Impaired respiration from muscle paralysis
    • Death can result from respiratory failure
  41. Ciguatoxin
    • dinoflagellate
    • One of the most powerful toxins known
    • Produced by Gambierdiscus toxicus
    • Disease is called ciguatera (fish poisoning)
    • Fish eat dinoflagellate→Humans eat fish→Food poisoning
    • Toxin is heat stable and remains in flesh of fish even after the fish has been cooked
  42. Ciguatoxin symptoms
    • GI symptoms: vomiting, profuse diarrhea, abdominal pain
    • Reversal of cold and hot sensations (e.g.: ice-cream tastes hot, coffee tastes cold)
    • Bradycardia: reduced pulse rate; heart beat slows to less than 60 beats per minute
    • Myalgia: specifically, pain and weakness in the lower extremities
    • Coma and Respiratory failure (in severe cases)
  43. Pfiesteria exotoxins
    • Produced by Pfiesteria piscicida
    • Complex life cycle; has 24 intermediate forms
    • Produces two toxins: one toxin stuns fish & other toxin causes lesions on the fish
    • Organism feeds on the fish’s red blood cells which allows it to sexually reproduce
  44. Pfiesteria exotoxins symptoms
    • Prolonged amnesia
    • Confusion
    • Headaches
    • Muscle cramps
    • gastrointestinal complaints
    • Also bloody skin lesions in humans exposed to the toxins at the point of contact with infected fish
Card Set
Micro quiz 111210