L15 Flashcards
Strep can best be visualized on ____ Agar while H. Influenzae is best seen on ____ Agar
Blood Agar; Chocolate Agar
True or False: Most bacteria can grown on blood agar
True
MacConkey Agar is a selective and differential agar.
Which is Lactose (+) vs. (-)
- Shigella
- E. coli
E.coli = Lactose (+)
Shigella = Lactose (-)
Staph is Catalase __ while Strep is Catalse __
Staph = (+)
Strep = (-)
Staph is Coagulase ___ while Staph a. is Coagulase ___
Staph = (-)
Staph a = (+)
True or False: E coli. is oxidase (-) while P. aeruginosa is oxidase (+)
True
True or False: Cutibacterium, Diptheroids (e.g Corynebacterium) and Staph make up one’s NF
True
___ is the most common skin disease and can presents with comedomes (non-inflammatory lesions) or inflammatory lesions
Acne Vulgaris
True or False: Inflammatory acne occurs if there is overgrowth of C. acnes (NF)
True
In the case of inflammatory acne, a plugged comedome leads to ruptured follicle, inflammatory lesion, which can become a ___ => ___ => ___
papule, pustule, nodule
In non-inflammatory acne, an open or close microcomedome can form. What are another name for these?
Open Microcomedome =
Black Heads
Close Microcomedome =
White Heads
In non-inflammatory acne, microcomedome forms due to what two conditions?
- Increased sebum
- Plugged follicular canal
- Increased keratinization
- Desquamination of cells lining canal
Which 3 pathogens can lead to infections of the integument?
- S. pyogenes
- S. aureus
- C. acnes
Which pathogen of the skin is a cocci that is both coagulase/catalase (+), as well as B-hemolytic (blood agar)?
A. C. acnes
B. S. pyogenes
C. S. aureus
C. S. aureus
Which pathogen of the skin is a cocci, group A Strep (GAS), B-hemolytic (blood agar), and bacitracin sensitive
A. C. acnes
B. S. pyogenes
C. S. aureus
B. S. pyogenes
True or False: C. acnes is a gram (+), anaerobic, diptheroid that is the predominant anaerobic member of NF that colonizes hair follicles
True
C. acnes makes ___, which degrades sebum into inflammatory substance, attracts WBC’s
Lipase
Which of the following pathogens give rise to: Toxic (SSSS, Bullous Impetigo) or Non-Toxin Mediated Pyodermic Infections (Furuncle, Epidemic Impetigo, Carbuncle, Folliculitis)
A. S. aureus
B. C. acnes
C. S. pyogenes
A. S. aureus
Which of the following pathogens give rise to: Scarlet Fever, Cellulitis, or Epidemic Impetigo?
A. S. aureus
B. C. acnes
C. S. pyogenes
C. S. pyogenes
True or False: Bound coagulase causes bacteria to clump while free coagulase causes protective fibrin clot to form
True
Epidemic Impetigo, which arises due to S. pyogenes, can result in _____, a condition in which the kidney dysfunctions
Acute Glomerulonephritis
True or False: Cellulitis is often cause by either: Gram (+) Cocci, Gram (-) Rods, or E. corrodens
True
____ (St. Anthony’s Fire): A specific type of cellulitis associated with blocked lymphatics
Erysipelas
Which three Gram (+) cocci can cause cellulitis?
- S. pyogenes
- S. aureus
- S. pneumoniae
True or False: Both facultative anaerobes and obligate anaerobes (gram - rods) can cause cellulitis
True
If in animal bites you and you develop cellulitis, which pathogen is likely responsible?
- P. pestis
- Multocida
- C. Canimorsus
Which five pathogens can cause necrotizing skin lesions associated w/cellulitis?
M. ulcerans
M. marium
M. fortuitum
M. abscessus
M. chelonae
Cellulitis typically occurs in fat layer. However, it if occurs due to surgical site infection, it can occur in ___ or ____
deep dermis; stratum corteum
True or False: Systemic effects (flu) and local inflammation are associated with cellulitis due to surgical site infection
True
St. Anthony’s Fire occurs in the dermis, has sharp borders, and is caused by ___
It involves cutaneous lymphatics but may NOT involve cutaneous tissue
GAS (S. pyogenes)
How does St. Anthony’s Fire differ from Cellulitis?
- Starts w/ systemic signs and burning
- Turns into indurated erythema that is sharply demarcated
If a patient develops a surgical infection 10-30 days after surgery, it could either be gram (+) cocci or gram (- ) rod.
Specifically…
Gram (+)
- Staph
- Strep
- Entero
Gram (-)
- Facultative anaerobe
A patient develops an infection within 72 hrs of surgery. What three Gram (+) cocci pathogens might it be?
Gram (+)
- S. aureus
- C. perfringens
- B-hemolytic strepto
___ is a super antigen and potent immuno-modulatory agent known to cause scarlet fever
SPE (Streptococcal pyrogenic exotoxin)
True or False: Scarlet fever is a complication of either GAS pharyngitis or Impetigo. Therefore, it is associated with s+s of impetigo/pharyngitis + scarlet fever
True
Both Enanthem and Exanthem are symptoms of Scarlet Fever. What is the difference between them?
Enanthem: type of hyperemia
Exanthem: rash that starts on trunk and moves to rest of body – resolves w/ skin desquamination
What is the stages of progression of Enanthem in Scarlet Fever?
White strawberry tongue
Red strawberry tongue
Red rasberry tongue
True or False: Acute glomerulonephritis and Rheumatic Fever are possible complications of Scarlet Fever
True
You are looking at a test-tube and see growth throughout the tube, suggesting that metabolism is fermentative and the substance can grow with or without O2.
Therefore, it is…
A. Obligate Anaerobe
B. Aerotolerant/Facultative Anerobe
B. Aerotolerant/Facultative Anerobe
You are looking at a test-tube and see growth only at the bottom of the tube, which suggest the organism cannot tolerate O2. Therefore it is:
A. Obligate Anaerobe
B. Aerotolerant/Facultative Anerobe
A. Obligate Anaerobe
True or False: Poor blood supply and tissue necrosis can lead to anaerobe growth
True
True or False: Putrid odor, abscess, tissue necrosis, and gas suggests anaerobe
True
True or False: Anaerobes are the pre-dominant NF
True
S. aureus makes exfoliative toxins, which are ___ that split intracellular bridges in s. granulosum
A. Lipases
B. Proteases
C. Carboxylases
B. Proteases
Which of the following non-toxic mediated pyogenic infections (S. aureus) occurs on hair bearing sites and is a superficial infection of an INDIVIDUAL hair follicle?
A. Furuncle
B. Carbuncle
C. Folliculitis
D. Epidemic Impetigo
C. Folliculitis
____ involves several hair follicles and is associated with systemic sx (fever!!)
A. Furuncle
B. Carbuncle
C. Folliculitis
D. Epidemic Impetigo
B. Carbuncle
____ is an infection of a single hair follicle, which is associated with necrotic and pyogenic abscess. While tissue around it is hot, there are NOT systemic signs (e.g fever)
A. Furuncle
B. Carbuncle
C. Folliculitis
D. Epidemic Impetigo
A. Furuncle
True or False: Carbuncle and Furuncle are infections of hair follicle and dermis
False - infections of hair follicle and subcut tissue
Why does non-bullous impetigo not scar?
Which layer of skin does impetigo typically effect?
Non-bullous impetigo does not scar because it affect superficial epidermis
Usually effects stratum corneum
True or False: Non-bullous Impetigo is associated with ambered colored crust and systemic sx (fever!)
False - Non-bullous Impetigo is associated with ambered colored crust but NOT fever!!
True or False: Bullous Impetigo is a toxemia and each lesion contains ET (exfoliatin exotoxin) producing strains of S. aureus
False - while each
bullous impetigo lesion
does contains ET (exfoliatin exotoxin) producing strains of S. aureus, it is NOT a toxemia!
In bullous impetigo, ___ and ___ do NOT disseminate
and toxin causes the bullae
toxin and agent
____ is a toxemia from a focal infection that is associated with erythroderma and varnish like lesion. Occurs in immunocompromised and kids.
There IS dissemination of exfoliatin exotoxin but there is NOT dissemination of S. aureus
SSSS
True or False: All toxic mediated S. aureus infections produce ETA/B which lead to epidermal necrosis or painful bullae
True
True or False: All S. aureus infections are contagious
True
