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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

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)

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
leonine facies
What is the treatment for leprosy?
multiple drug treatment
How would you characterize all clostridium?
gram-positive rod
spore forming
How would you distinguish clostridium titani?
gram positive rod
terminal spore forming, makes it look like tennis raquet)
How do we get Clostridium tetani?
result of wound where it will have low Oxygen
what is the clostridium toxin known as?
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?
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
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
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
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?
spore-forming rod
Double zone of Beta Hemolysis
How do you get Clostridium perfringens?
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?
What are the distinguishing characteristics of all Neisseria?
oxidase POSITIVE
What are the two type of neisseria
Neisseria meningitides
Neisseria gonorrhoeae
What are the distinguishing characteristics for Neisseria meningitidis?
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?
What test is helpful in the identification of Neisseria meningitidis?
oxidate test
Describe each of the following for N. Meningitidis and N. gonorrhoeae.
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?
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
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
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.
Type I or Type II pilus
What does N. gonorrheae cause in males?
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
What are the distinguishing characteristics of Pseudomonas aeruginosa (7 things)
gram negative rods
Pigments - pyocyanin
Grape like odor
slime layer
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?

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?
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
What three bacteria are transmitted through unpasturized milk?
Mycobacterium bovis

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