Term
| Which are the spore forming gram+ rods? Which are the acid fast and what is the stain? Which are the branched? |
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Definition
-The only ones are both gram+ rods; **Bacillus and Clostridium**
-They are properly called *endospores
-Nocardia and Mycobacterium are **acid fast (NO! MY acid!!!)
-Use Ziehl Nielsen stain for acid fast
-Actinomyces and Nocardia are branched (branching is NO ACT!)
-See table on page 248 for full info on gram+ rods |
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Term
| How would you define the genus Bacillus? What are its members? |
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Definition
-Gram+, *spore forming, aerobic rods
-B. anthracis and cereus |
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Term
| What does B. anthracis look like? |
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Definition
-Large and has a **capsule of polypeptide (D-glutamic acid)
-Is extracellular |
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Term
| What are the virulence factors for B. anthracis? |
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Definition
-Capsule; inhibits phags
-Anthrax toxin, coded by plasmids, three parts;
1. Protective antigen (B component)
2. Lethal factor
3. Edema factor (adenylate cyclase) |
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Term
| What are the diseases caused by anthrax? |
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Definition
1. Cutaneous; Starts as a boil/papule/vesiculations that eventually ulcerate with central *black necrosis (eschar), fever in 50%
2. Pulmonary; Starts with flu-like symptoms, progresses to **life threatening pneumonia, cyanosis, and finally to *mediastinal hemorrhagic lymphadenitis (massive neck and chest inflammation), from spore inhalation
-Also known as "wool sorter's disease from an association with **animal hides/hair
3. GI; rare, edema of GIT with vomiting and bloody diarrhea, high mortality rate |
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Term
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Definition
-*Ciproflaxacin or doxycycline (because B. anthraxis has been made resistant to beta-lactams)
-There is also a toxiod vaccine for high risk people |
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Term
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Definition
-**Fried rice (esp. buffet where kept *warm)
-Fast preformed *emetic toxin (1-6hrs)
-Slower in vivo *diarrheal toxin (18hrs) (similar to cholera toxin with a cAMP effect)
-Get watery diarrhea (no blood) +/- vomiting with rapid onset |
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Term
| How would you describe the **clostridium genus? What are its members |
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Definition
-Gram+, *spore forming, **anerobic (ABC anaerobes; Actinomyces, Bacteroides, Clostridium)
-C. tetani
-C. botulinum
-C. perfringens
-C. difficile |
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Term
| How can Clostridium perfringens be identified? |
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Definition
-On *milk media it has a *"stormy fermentation"
-On *blood agar it gives a *double zone of hemolysis
-In the **Nagler reaction, we use egg yolk agar (contains high lecithin content) with anti-alpha-toxin on one side to detect *lecithinase activity on side side with no antitoxin |
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Term
| What are the virulence factors for C. perfringens? |
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Definition
1. **alpha toxin; a lecithinase (a phospholipase) that chews through cells and causes the symptoms
-Basis for Nagler reaction
2. Enterotoxin; disrupts iron transport (not really important) |
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Term
| Where do we usually find C. perfringens and how is it transmitted? |
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Definition
| -In soil--->traumatic implantation |
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Term
| What diseases are there for C. perfringens and how do we treat? |
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Definition
-Gas gangrene; produces gas bubbles
-We have to treat rapidly with debridement and antibiotics, also we delay closure if we can as Clostridium species are *anaerobic
-(Don't confuse with necrotizing fasciitis from Strep pyogenes)
-Can also cause food poisoning |
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Term
| What distinguishes Clostridium tetani? What does it cause? |
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Definition
-**Tetanus toxin; goes retrograde to *CNS and binds *ganglioside receptors, blocking inhibitory mediator release (GABA & glycine)--> Rigid paralysis
-Is ridiculously toxic
-Look like tennis rackets on gram stain (from spore)
-Risus sardonicus; sardonic smile (lock jaw; early sign)
-Opisthotonus; arched back and neck
-Extreme muscle spasms
-Rem, they also have all the characteristics of the Clostridium genera (spores, anaerobic, etc.) |
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Term
| How do we treat tetanus? What is the vaccine? How do we treat wounds? |
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Definition
-*Human globulin (TIG) plus metronidazole or penicillin
-TIG only binds free toxin; takes months to wear off
-Can also give spasmolytic drugs
-Vaccine is inactivated toxin (*toxoid)
-In dirty cuts we give TIG and vaccine if unvaccinated or unsure, and just vaccine if they haven't been boosted in *5 or more years
-In clean cuts, we don't bother with TIG, but give vaccine if they haven't been boosted in *10 or more years |
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Term
| Clostridium botulinum? What does it case? |
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Definition
**Botulinum toxin; blocks ACh at NMJ causing *flaccid par.
-*Heat labile; but takes about 10mins
-Coded for by *prophage
-Found usually in **home canned veggies and **honey
Adult botulism-->flaccid paralysis and flu-like
-From **toxin ingestion (canned food, smoked fish)
Infant botulism-->**floppy baby (par. + constipation)
-From eating *spores (honey, dust) (adult stomachs kill)
-Toxin is produced in the gut from the bacteria |
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Term
| How do we diagnose and treat botulism? |
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Definition
-Presentation or look in serum, food, or stool (bac in infant)
Treatment; (not antibiotics!)
-Adults; treat with **trivalent (A-B-E) antitoxin; adults only have the toxin in them, not the bacteria
-Infant; treat with **hyperimmune human serum; do not give antibiotics either b/c toxin release may kill |
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Term
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Definition
-Normal flora that increases number during **broad spectrum antibiotic treatment** (esp. with *clindamycin, & *cephalosporins); *very common nosocomial
-**Toxin A & B secreted when in high titer
-Get diarrhea and colitis with *yellow plaques on colon
-Culture not helpful, must look for *toxin in stool
-Treat by discontinuing antibiotics when mild, or *vancomycin when severe |
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Term
| What sets the genus Actinomyces apart? |
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Definition
-"A" of ABC of **anaerobes
-**Branching (somewhat fungi-like)
-Part of normal flora
-Both it and Nocardia are branching and somewhat similar, but Nocardia is acid fast and aerobic |
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Term
| What are the species of Actinomyces? Where do we find it? How is it transmitted? |
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Definition
-Actinomyces israelii
-Find it in the gingival crevices, vagina, a few others (endogenous transmission) |
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Term
| What disease do we get with Actinomyces israelii? How can we diagnose it? |
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Definition
-Actinomycosis; invasive abscess formation, particularly **lumpy jaw, but can also infect many other areas (such as the vagina from growth on IUD)
-Note that with this and other anaerobes, abscess formation is particularly common and usually associated with a *foul smell
-Can diagnose by **"sulfur granules" in draining abscess |
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Term
| What sets the Mycobacterium genus apart? What are it's important members? |
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Definition
-**Acid fast (NO MY acid!); has lots of *mycolic acid in the cell wall making it resistant to drying and chemicals
-Not branching (even tho it sounds kinda fungi-ish)
-M. tuberculosis (skipped, look up)
-M. leprae
-(M. marinum for class)
-Note; Rifampin is a pretty common drug to treat these, acts on bacterial RNA Pol |
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Term
| What do we gotta know about M. marinum? |
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Definition
-M. marinum, and 3 others (do later, but are low yield), is part of the MOTTS group; Mycobacteria Other Than Tuberculosis
-Causes *cutaneous granulomas in **tropical fish enthusiasts
-Treat with *rifampin |
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Term
| What is distinguishing about Mycobacterium leprae? |
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Definition
-Again, *acid fast
-It is **obligate intracellular (can't be cultured in vitro) |
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Term
| Where do we find it and what is the transmission? |
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Definition
-In the mucosa and skin of infected
-Infected *armadillos in Texas and Louisiana
-Transmitted mostly by infected persons nasal discharge |
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Term
| What are the two forms? Treatment? |
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Definition
Tuberculoid; CMI response
-**Lepromin test +; to determine prognosis (not diagnostic); similar to a PPD test (relies on CMI response)
-Mostly just get cutaneous nerve damage
Lepromatous; Humoral response
-This is the disfiguring one where there are super high bacteria cell counts in the tissue
-Lepromin skin test is negative
-Treat with *dapsone + rifampin (and clofazimine added for lepromatous)
-Give dapsone to family |
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Term
| What are the identifying features of *Corynebacterium? What are the important species? Where do we find them and what is the transmission? |
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Definition
-Normal aerobic gram+ rod with no spores
-**Gray-black colonies on *tellurite medium (or *Tinsdale agar, class) with **club-shaped rods arranged in *letter-like formation ("Chinese letter formation");
http://www.webquest.es/files/u39194/Corynebacterium_diphtheriae_zoom.jpg
-Toxin-producing strains have a **beta-prophage gene with the toxoid information (from *transduction)
1. Corynebacterium diphtheriae; throat, resp droplet trans.
2. Diphtheroids (normal flora) |
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Term
| What is the pathogenesis and diseases of Corynebacterium diphtheriae? |
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Definition
-*Not invasive, colonizes
-**Diphtheria toxin (A-B toxin); ADP-ribosylates ***EF-2 inhibiting protein production and leading to cell death
Diphtheria; sore throat with **dirty gray/white pseudomembrane that bleeds easily when scraped (necrotic tissue), and **bull neck (very swollen)
-Can extend into larynx/trachea and cause obstruction
-Get heart and nerve damage if toxin gets to blood (**myocarditis, *recurrent laryngeal/other nerve palsy) |
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Term
| How do we diagnose Corynebacterium diphtheriae and distinguish from the normal Corynebacterium flora (diphtheroids)? |
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Definition
-Use the **Elek test which employs a strip of antitoxin with tox+ strains arcing away from the strip;
http://www.rahulgladwin.com/noteblog/bacteriology/images/elek-test-agar-plate.jpg
(1 & 4 are positive)
-Think of it as little elk antlers lol |
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Term
| What is the treatment for diphtheria? |
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Definition
-We have an **antitoxin we can give in addition to *erythromycin (blocks translocation on ribosome)
-Part of DTap vaccine (*toxoid vaccine) |
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Term
| What is the important Listeria species? What defines it? |
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Definition
Listeria monocytogenes;
-*B-hemolytic on blood agar
-**Tumbling motility in broth
-***Cold growth
-*Facultative intracellular
-**#3 for neonatal meningitis and septicemia** |
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Term
| Where do we find Listeria monocytogenes, transmission? |
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Definition
-All over, but especially *unpasteurized milk products and food that is eaten uncooked (deli, coleslaw, cheese, etc)
-Transmitted by food and can **cross the placenta |
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Term
| What is the pathogenesis and diseases? |
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Definition
PATH;
-**Listeriolysin O (a beta-hemolysin); phagosome escape
-Jets to adjacent cell using actin polymerization
DISEASES;
-Listeriosis; maybe diarrhea in health, **septicemia in pregnant woman-->**crosses placenta
-Neonatal; if in utero you get **septicemia and death, if on the way out you get **meningitis and septicemia
-AIDS; sep. and men. |
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