Flashcards in Skinny bacteria III Deck (81):
Drum stick appearing rods =?
What is the gram stain and morph of clostridium? Aerobic? Spores?
Gram positive, spore forming rods
Where is clostridium found?
Soil, water, sewage
What are the three species and toxins of clostridium that cause disease?
C. perfringens (hemolysin)
C. difficile (enterotoxins)
C tetani (Neural toxins)
Growth of C perfringens produces a lot of what?
CO2 and H gas
What skin infection does C perfringens cause?
What is the most important toxin associated with C perfringens? What is its function?
Phospholipase destroys cell membrane
Why will you not see leukocytes in the area surrounding C perfringins?
Alpha toxin kills them
What are the four skin diseases that C perfringens usually causes?
3. Suppurative myositis
What are the reservoirs of Clostridium?
Soil, or GI tract
Why is it called GAS (not group A strep) gangrene?
C. perfringens produces CO2, so there are crepitations of the wound
What are the symptoms of gas gangrene?
Cellulitis initially, later supprative myositis
Gas on x-ray = ?
How do you diagnose gas gangrene?
Microsopic deteaction of rods WITHOUT leukocytes
What is the treatment for gas gangrene?
Surgical debridment and high dose PCN
What is the MOA of C. tetani infection from a rusty nail?
Small local infection allow for anaerobic growth of C tetani, producing exotoxin
What is the MOA of tetanospasmin?
Inhibition of interneurons
Is tetanospasmin heat liable?
What are the symptoms of tetanus?
True or false: Tetanospasmin is readily degraded by the GI tract?
What is the most common site of infection for tetanus?
Umbilical stump of noenates
What is the risus sardonicus?
Tetanus infection smile
Why is it hard to culture tetanus?
How do you diagnose tetanus?
What population is usually infected with tetanus in the U.S.?
What is the treatment for tetanus?
Debride the wound
What is the gram stain and morphology of mycobacterium? Anaerobic? Spores?
Weakly gram positive
What is the lipid found in mycobacterium that allows them to be stained with the acid fast stain?
True or false: mycobacterium are resistant to lots of stuffs
How fast do mycobacterium grow?
What are the two major mycobacteria that cause disease?
Are there endotoxins or exotoxins with mycobacterium?
What is the agar needed to grow mycobacteria? (board question)
What is the primary infection associated with mycobacterium?
Pulmonary disease (mycobacterium TB)
What is Potts disease?
Skeletal TB (osteomyelitis) in the upper lumbar and lower thoracic vertebrae
What is the gibbus deformity?
Strange, painful lump in the back d/t Potts disease
How do you diagnose pott's disease?
See in biopsy in macrophages
What cells do mycobacteria live in?
What is the host response to infection with mycobacteria? How?
**(T cells differentiate into Th1 and produce IFNgamma)**
What is the treatment for mycobacteria?
Isoniazid and rifampin for a **long time**
What cells does Mycobacterium Leprae target?
Macrophages and Schwann cells
What is the causative agent of Leprosy? How fast do symptoms present?
What are the antigens of Mycobacterium Leprae? (2)
Cell wall's phenolic glycolipid and phenolase
What are the two distinct stages of M. Leprae?
What are the two different immune responses to M. Leprae?
Th1 = tuberculoid (cell mediated)
Th2 = lepromatous (immunoglobin mediated (not choose wisely)
What is Hansen's disease?
How do you diagnose leprosy? Can you culture?
Lepromin skin test (should be negative since no cell mediated rxn)
Does mycobacterium leprae have exo or endo toxin?
How is leprosy transmitted?
What are the symptoms of lepromatous leprosy?
Raised granulomas all over the skin
What are the symptoms of tuberculoid leprosy?
Single area infection that is flat
What is the gram stain and morphology of Nocardia? Aerobic? Acid fast? Aerobic?
Aerobic gram positive rod that forms
Weakly acid fast
What are aerial hyphae?
Bacterial "hyphae" produced by Nocardia
What is mycetoma? Cause? Pain?
Chronic infections of the skin and underlying tissues caused by Nocardia
What is the most common site of mycetoma? How is it transmitted?
Foot, from walking around in the environment (gardening)
What are the two major infections associated with Nocardia?
1. Lymphocutaneous disease
2. Cellulits and cutaneous abscess
How do you diagnose Nocardia? Treat?
What is the gram stain and morphology of actinomyces israelii? Aerobic?
Filamentous rod that looks like fungi
True or false: Actinomyces israelii is an opportunistic pathogen
What is Actinomyces israelii infxs associated with?
Abscesses from Dental work
What does Actinomyces israelii look like microscopically?
Sulfur granules = ?
How do you diagnose Actinomyces? What is the treatment for Actinomyces israelii?
Acid fast culture
What is the cause of cervicofacial actinomycosis?
How do you differentiate Actinomyces israelii from Norcardia?
Lack of staining with modified acid fast stains for Actinomyces israelii
What are the bacteria that causes acne vulgaris? Is it normal flora?
Propionibacterium acnes, which is normal flora
What is the gram stain and morphology of propionibacterium acnes?
Small, anaerobic gram positive rof
What is the treatment for propionibacterium acnes?
Topical benzoyl peroxide
What is peridontitis?
Chronic inflammatory disease which includes the gingiva along with loss of CT and bone support to the teeth
What is the cause of Gingivitis and periodontitis?
Bacteria in dental plaques (polymicrobial)
What is dental plaque?
What is the dominant organism associated with dental caries?
What is the the underlying cause of dental caries?
Acid products of Strep mutans in biofilm
Culture without any lymphocytes = ?
What are the skin lesions present with tuberculoid leprosy? Lepromatous leprosy?
Tuberculoid leprosy= few plaques
Lepromatous leprosy= many red macules with nerve involvement
What is the histopathology with tuberculoid leprosy? Lepromatous leprosy?
Tuberculoid leprosy= few to no acid fast rods observed
Lepromatous leprosy= numerous acid fast rods in skin lesions
What is the infectivity of tuberculoid leprosy? Lepromatous leprosy?
Tuberculoid leprosy= Low
Lepromatous leprosy= High
What is the immune response to Tuberculoid leprosy? Lepromatous leprosy?
Tuberculoid leprosy= DTH rxn to lepromin
Lepromatous leprosy= no reactivity to lepromin
What is the clinical pattern seen with Actinomycosis? Nocardiosis?
Actinomycosis = lump with draining siinus
Nocardiosis = cellulitis
What is the site associated with Actinomycosis? Nocardiosis?
Actinomycosis = Face/neck
Nocardiosis = Extremities