Microbiology Video 3
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- Who gets Mycobacterium Marinum?
- cutaneous granulomas occurs in tropical fish enthusiasts (fish tank ganuloma) or scuba divers from abrasions on coral.
- What keeps the mycobacterium TB from being killed after being phagocytosed?
- Sulfatides (sulfolipids in the cell envelope) inhibit the phagosome-lysosomal fusion
- What are the three virulence factors of mycobacterium TB?
- sulfatides, cord factor, and tuberculin
- What is a cord factor?
- mycolic acid polymer that inhibits leudocyte migration an disrupts mitochondrial respiration and oxidative phosphorylation.
- What is responsible for the delayed hypersensitivity and CMI (cell mediated immunity)?
- tuberculin and mycolic acid
- What does tuberculosis do its damage.
- No endo and exo toxins; damage done by immune system
- What is the screen of the sputum for mycobacterium TB?
- auramine-rhodamine stain
- What are the five characteristics of mycobacterium Tuberculosis?
-
auramine-rhodamine staining bacilli
acid fast
aerobic, on lowenstein-jensen medium
produces niacin
heat-sensitive catalase (other mycobacterial catalases are heat insensitive) - What is the treatment for TB?
- consists of multiple drugs including isoniazid and rifampin
- What types of mycobacterium are very dangerous in HIV patients?
- M. tuberculsis and M. avium-intracellulare (MAI) are major problems in HIV-infected and AIDS patients
- Where is mycobacterium avium-intracellulare found and what is the most important fact about it?
- it is found in soil and it is the number 1 mycobacterium that causes death in HIV patients
- What causes leprosy?
- Mycobacterium leprae
- What are the distinguishing characteristics of mycobacterium leprosy?
-
Acid fast rods
obligate intracellular parasite (cannot be cultured in vitro) - How is a diagnostic sample of mycobacterium leprae obtained?
- punch biopsy
- Where is mycobacterium leprosy located and what does it do?
- skin, nerves and it produces a LOSS OF SENSATION, so that the patient is no longer able to feel, touch etc.
- What are the two forms of leprosy?
- tuberculoid and lepromatous
-
What is the difference between tuberculoid and lepromatous leprosy and which is worse?
CMI system?
Lepromin skin test?
Number of organisms in tissue?
Damage from?
Number of lesions and symptoms? -
Lepromatous is worse
Tuberculoid
CMI = Strong CMI
Lepromin skin test = positive
Number of organisms = low
Damage from = immune response (CMI killing infected cells)
Number of lesions and symptoms = fewer lesions (macular)
nerve enlargement (paresthesia)
Lepromatous
CMI = weak CMI
Lepromin test = negative
Number of organism in tissue = high (foam cells totally filled)
Damage from = large number of introcellular organisms
Number of lesions and other symptoms = Numerous lesions becoming nodular; loss of eyebrown; destruction of nasal septum
paresthesia
leonine facies - What is the treatment for leprosy?
- multiple drug treatment
- How would you characterize all clostridium?
-
gram-positive rod
spore forming
anaerobic - How would you distinguish clostridium titani?
-
gram positive rod
terminal spore forming, makes it look like tennis raquet)
anaerobic
large - How do we get Clostridium tetani?
- result of wound where it will have low Oxygen
- what is the clostridium toxin known as?
- tetanospasmin
- What are the clinical signs of tetanus?
-
RISUS SARDONICUS (facial grimase because the muscles will not relax...risus means laughter)
OPISTHOTONUS = head is bend backwards and the ankles and feet are bend backwards to the back - What is the treatment for tetanus?
-
antibiotics
hyperimmune human globulin (TIG) to neutralize toxin
antispasmotic drugs such and diazepam
and hyperbaric oxygen - What is the best prevention for tetanus?
- DTP vaccine shots
- How long does the tetanus immunization last?
-
10 if it is a clean wound
5 years if it is a dirty wound - Where is clostridium tetani dangerous for neonates?
- developing countries because the mother is not immunized and thus does not pas son antibodies.
- What is the mechanism of action of tetanus toxin?
- Neurotoxin block release of inhibitory mediators glycine and GABA
- describe a clean would
- clean LINEAR cut less than 1 cm deep, no contaminants and LESS THAN 6 HOURS OLD
- describe a dirty would
-
blunt/missile, burn, frostbite, and 1 cm or more deep
if it has a rough appearance and contaminants within
ANY WOUND OVER 6 HOURS OLD -
What is the treatment for a clean would?
if Not completed primary or vaccination history unknown?
if completed primary? -
Not comp. primary or vacc. history unknown = Vaccine
If completed primary = Vaccine if more than 10 years since last booster -
What is the treatment for a dirst wound?
if Not completed primary or vaccination history unknown?
if completed primary? -
if Not completed primary or vaccination history unknown = Vaccine and TIG (tetanus immunoglobulin)
if completed primary = Vaccine if more than 5 years since last booster - How would you distinguish Clostridium botulinum
-
anaerobic
gram-positive
spore-forming rods - What is the most common source of clostridium botulinum?
- home canned foods where the spores were not killed when it was cooked and thus the botulinum toxin is produced
- Wher is the mechanism of action of botulinum toxin?
-
Absorbed by gut
Blocks release of acetylcholine at the myoneuranal junction resulting in a reversible flaccid paralysis - How do you die from botulinum toxin?
- nerve to the diaphragm quits and you die of respiratory failure.
- Where is clostridium botulinum found
- soil
- What are the clinical signs of clostridium botulinum?
-
double vision
difficulty swallowing
difficulty speaking
fixed pupels - What type of toxin is botulinum toxin and how is it killed?
- it is a AB toxin and it is heat labile (heat kills it) = boiling food
- How do adults get botulism?
- home canned foods (preformed toxin ingested = TOXICOSIS)
- How do infants get botulism?
- Spores ingested when eats HONEY (toxin produced in gut = TOXI-INFECTION)
- What is the way that both adults and infacts can get bolulism?
- traumatic inplantation of spores in a wound (in vivo production of spores = TOXI-INFECTION)
- What are the four types of Clostridium?
-
Clostridium tetani
Clostridium botulinum
Clostridium perfringens
Clostridium difficile - What is Clostridium perfringens known as?
- the gangrene organism
- What are the distinguishing characteristics of Clostridium perfringens?
-
Gram-positive
spore-forming rod
Anaerobic
Double zone of Beta Hemolysis - How do you get Clostridium perfringens?
- wound
- What is the gangrene toxin and what is its mechanism?
- Alpha toxin which is a lecithinase. It damages membranes, killing all cells it comes into contact with
- What are the two powerful toxins of Clostridium Perfringins?
- Alpha toxin (cell lysing) and Enterotoxin (diarrhea, vomiting toxin)
- How do we get the entertoxin?
- when Clostridium perfringins is ingested
- What is the name of a reaction which indicates the presence of Clostridium perfringins?
- Naegler's reaction
- On what media and how is Clostridium perfringens diagnosed?
-
Milk media = "stormy fermentation"
Naegler's reactoin: egg yolk agar plate - one side with anti alpha-toxin. Lecithinase activity is detected on side with no antitoxin. - What does a patient with gas gangrene look like? (4 things)
-
INCREASEING pain at wound
tense tissue (edema) with blistering
fever and tachycardia - What is the prognosis for someone with gas gangrene?
- rapid, high mortality
- what is the treatment for gas gangrene? (3 things)
-
EXTENSIVE DEBRIDEMENT (cut away all tissue)
administration of penicillin
hyperbaric oxygen - When looking at the bacteria, what does the endospore look like?
- it is the white area inside the bacteria
- What is clostridium difficile also known as?
- antibiotic-associated disease
- Why is Clostridium difficile also known as antibiotic-associated disease
- When someone is given antibiotics it distroys many of the organisms in the digestive tract and allows clostridium difficile to overgrow.
-
What is one main specific disease associated with clostridium difficile (due to the antibiotic associated disease)?
and what does it look like? - pseudomembranous colitis which has YELLOW PLAQUES ON COLON
- What antibiotic is especially associated with antibiotic associated disease?
- Clindamycin and cephalosporins
- What are the toxins produced by clostridium difficile?
-
Toxin A and Toxin B:
Toxin A: Enterotoxin damaging mucosa leading to fluid increase
Toxin B: cytotoxin: cytopathic - What is the treatment for a Clostridium difficile infection?
- Metronidazole or vancomycin
- What are the two diseases that result from gram negative cocci?
-
meningitis
gonorrhea - What are the distinguishing characteristics of all Neisseria?
-
gram-negative
diplococci
oxidase POSITIVE - What are the two type of neisseria
-
Neisseria meningitides
Neisseria gonorrhoeae - What are the distinguishing characteristics for Neisseria meningitidis?
-
Gram-negative
oxidase positive
gram negative paired diplococci
grows only on chocolate agar
ferments maltose - gonococci do not ferment maltose -
What is another name for neisseria meningitidis?
neisseria gonorrhoeae? -
Meningococcus
Gonococcus - What test is helpful in the identification of Neisseria meningitidis?
- oxidate test
-
Describe each of the following for N. Meningitidis and N. gonorrhoeae.
Capsule?
Vaccine?
Portal of Entry?
Glucose Utilization?
maltose Fermentation?
Beta-bactamase Production? -
N. Meningitidis
Capsule? Yes
Vaccine? Yes
Portal of Entry? Respiratory
Glucose Utilization? yes
maltose Fermentation? Yes
Beta-bactamase Production? Rare
N. gonorrhoeae
Capsule? No
Vaccine? No
Portal of Entry? Genital
Glucose Utilization? Yes
maltose Fermentation? NO
Beta-bactamase Production? 16% - What is the vaccine for N. Meningitidis?
- YWCA
- How would you differentiate N. meningitidis from N. gonorrhoeae (?
-
N. meningitidis ferments glucose and maltose. N. meningitidis also has a capsule and vaccine.
N. gonorrhoeae germents glucose but not maltose. N. gonorrhoeae does not have a capsule or vaccine. - What are the results of a CSF with a bacterial meningitis? 3 things
-
decreased glucose
increased protein
increased bacterial/capsular antigens - Where is the reservoir for N. meningitidis and how is it able to do this?
- Human nasepharyngeal area and it is able to do this due to IgA protease.
- What are some signs of N. meningitidis?
-
fever, chills, PETECHIAL RASH
fulminant cases = ecchymoses, DIC, shock , coma, death - What causes newborn meningitis?
-
group B strep
E.Coli
Listeria - What causes adult meningitis?
-
Neisseria Mengigitidis
Strep. Pneumoniae - What preventative measure must be done to people in very close contact to someone who is infected with N. meningitidis?
-
YWCA vaccine and
rafampin - What are the two most common type of vinarial disease?
-
1. chlymidia
2. gonorrhea - What is very diagnostic for N. gonorrhoeae?
- gram negative diplococci in PMNs from urethral smear. This is 100% diagnostic in a male, but in a female the specimen must be cultures.
- What media is used to culture Neisseria gonorrhoeae?
- Thayer Martin media
-
Why does N. gonorrhoaea frow on Thayer-Martin media?
what else is special about htis medium? - Because the other organisms are killed due to the antibiotics on the medium. This medium is also an oxidase test.
- Why is N. gonorrhoeae diagnosed on Thayer Martin?
- N. gonorrhoeae will grow and N. gonorrhoaea is oxidase positive
- What does N. gonorrheae ferment.
-
glucose
NOT MALTOSE - wHAT MUST n. gONORRHEAE HAVE IN ORDER TO BE VIRULENT?
- Type I or Type II pilus
-
What does N. gonorrheae cause in males?
females?
infants? -
males: urethritis
females: endocervicitis
infants: ophthalmia - What would you do it you found N. Gonorrhaea on a female?
-
Culture on Thayer-Martin medium
Do oxidate take
Do glucose fermentation test - Why is Gonorrhea worse in women?
- endocervicitis leads to PID 9clogging of fallopian tubes), leads to arthritis (usually a monoarthritis)
- Why is gonorrhea bad in newborns
- it shows up as a ophthalmia and leads to blindness if untreated
- What is the treatment for gonorrhea?
- Ceftriaxone due to penicillin resistance
- If someone who has been permincuous chlymidia or gonorrhea how are they treated?
- They are treated for both even if they are not known to have both
-
What is a close relative of neisseriae and what does it look like?
what does it cause -
Moraxella catarrhalis
gram-negative diplococcue
otitis media - What can ear infections in adults be due to>?
-
Strep. pneumonia
Non typpeable H. Influenza
moraxella catarrhalis - What are the three gram negative cocci?
-
Neisseria meningitidis
Neisseria Gonorrhoeae
Moraxella catarrhalis - What distinguishes all pseudomonas?
-
gram-negative rod
oxidase-positive
aerobic
nonfermenter - What are the distinguishing characteristics of Pseudomonas aeruginosa (7 things)
-
oxidase-positive
gram negative rods
non-fermenting
Pigments - pyocyanin
Grape like odor
slime layer
non-lactose-fermenting - What is the best media for gram negative organisms and what will P. aeruginosa do on it.
- Because it is a lactose negative organism it will be CLEAR on MACCONKEY medium
- Where is pseudomonas aeruginosa found and how is it transmitted?
- Found in water and transfered via raw vegetables, flowers, water aerosols, etc.
-
What is the primary target of Pseudomonas aeruginosa?
secondary? - Liver, also respiratory
-
Who does Pseudomonas aeruginosa occur in?
Know this one! -
1. Burn patients
2. Neutropenic patients (white cell count less than 500)
3. Catheterized patients
4. Cystic fibrosis patients - What is the exotoxin of Pseudomonas aerugenosa and how does it work?
- Exotoxin A ADP robosylates EF-2 (just like diphtheria toxin)
- When could a normal person become infected with Pseudomonas Aerugenosa?
- hot tub folliculitis
- What are the characteristics of all legionellae?
-
Weakly Gram-negative - MUST USE SILVER STAIN
pleomorphic rods
very picky...require cysteine and iron for lab culture
water organisms
Facultative intracellular pathogens - Where is Legionelle found?
- Found in water...notorious for being found in air conditioners
- Who get Legionella?
- Old, smokeing, alcoholics, immunocompromized patients
- What are the diseases caused by Legionella?
-
Legionnaires' Disease !!(AKA Atypical Pneumonia)!!
Pontiac Fever - What is Legionairres Disease also known as?
- Atypical Pneumonia
- How is Legionella diagnosed?
- DFA - Direct Fluorescent Antibody test
- What characterizes Bordetella?
-
Gram negative small rods
strict aerobes - What disease does bordatella cause?
- Whooping Cough
- How is bordetella pertussis disgnosed
- DFA Direct immunofluorescence
- On DFA how would bordetella be distinguished from Legionella?
- a different antibody would be used
- What will a person with whooping cough look like?
-
-frenulum of tongue is swollen
-people cough so hard that they almost vomit and they rupture the capillaries of the eyes (thus the eyes are red) - What is the best way to prevent whooping cough?
- DTaP vaccine
- What parts of pertussus is in the DTaP vaccine?
- Capsule, toxoid, hemagglutinin
- What is the lymphocyte count of a person with whooping cough?
- increase of lymphocytes to 70 to 80 percent
- What is the mechanism for pertussus toxin?
- ADP ribosylation of Gi - thus inhibiting negative regulator of adenyl cyclase
- What does the pertussis toxin actually do (effects of ADP rybosylation)?
-
Lymphoctosis promation
islet activation causing hypoglycemia
Blocks immune effector cells
increases histamine sensitiveity
causes fluid production in the throat - What are the three stages of whooping cough?
-
1. catarrhal
2. paroxysmal
3. convalescence - what is another name for whooping cough?
- pertussis
- Describe each stage of whooping cough
-
1. catarrhal - runny nose, feel bad, fever, CONTAGIOUS
2. paroxysmal - strong whooping cough, vomiting and severity of cough cause neurological damage and eye hemorrhages
3. convalescence - less cough - secondary mcomplication manifest; pneumonia, seizures, encephalopathy - What is the time period for each of the stages of whooping cough?
-
catarrhal = 1-2 weeks
paroxysmal = 2-4 weeks
convalescence = >3 weeks - How long does the whooping cough vaccine last?
- 5-7 years
- What does Francisella cause and how do you get it?
-
Francisella tularensis causes Tularemia.
you get this from skinning rabbits and not washing hands - Where are Francisella tularensis infections found?
- Arkansas and Missouri
- How is Brucella contracted?
- unpasturized milk
- What is two names for the disease caused by Brucella?
-
Brucellosis or
undulant fever - What animals is Brucella found in?
- cattle, pigs, goats
- What three organisms are found in unpasturized milk?
-
mycobacterium bovis
brucella
listeria - What three bacteria are transmitted through unpasturized milk?
-
Brucella
Listeria
Mycobacterium bovis