Quiz 3 - Durrant - SSTIs Flashcards
T/F - Intact skin is the first line of defense.
TRUE
What permits microbial invasions?
Ducts in skin
What is the classic presentation of an SSTI?
Erythema, warmth, edema, tenderness
Crepitus - Gas bubbles under skin
Necrosis
Fluctuate
Purpura
Bullae
What are some other diseases that can mimic SSTIs?
Gout
Thrombosis
Drug eruption
Dermatitis
Folliculitis can be from what?
Friction and sweat gland activity
Staph aureus, pseudomonas aeruginosa
Acne is what? Caused by what?
Inflammation of hair follicles and associated sebaceous glands
Propionibacterium acnes - Multiplies behind/w/in sebum trapped in follicles/glands
Hormonal influences as well
What is the most common bug associated with an abscess?
Staph aureus is the most common culprit - Including MRSA - often polymicrobial
- Treatment is incision and drainage
- Staph aureus is gram + cocci
What is a furuncle?
Abscess in the area of a hair follicle
A boil
What is a carbuncle?
Multiloculated abscess
- Spread of infection to subcutaneous tissue
- Staph aureus
- I and D treatment
Necrotizing fasciitis. Tell me about it.
Digest facial barriers
Rapid infection
Due to Strep progenes (Group A strep), and/or staph aureus, or clostridium - anaerobic
What is Fournier’s gangrene?
Poly microbial infection of the genitals and perineum
Most common pathogen in surgical wounds?
S. Aureus
- Also any sort of skin/normal flora
- Transmission by fomites, hands, air, or environment
- Treatment is really prevention by taking antibiotics prior to surgery
Tinea cruris, corporis, etc. is what and causes what?
FUNGI, NOT BACTERIA
Dermatophyte fungi
- Ringworm, nail infections
- Caused by trichophyton, microsporum, epidermophyton
What is the most common yeast infection?
Candida albicans
-Topical antifungals
What are some other illnesses from yeast/fungi?
Diaper rash
Intertrigo
Thrush
What is impetigo from?
Group A strep, also S. Aureus
-Treatment is penicillin, topical antibiotic
What is erysipelas?
Caused by group A strep
Rapid spreading
Deep layers of dermis
Treated with penicillin
What is cellulitis?
Subcutaneous tissue
Group A Strep, S. Aureus
Systemic antibiotics
What factors would increase risk of wound infections?
Higher number of organisms
Higher virulence of organisms
Poor circulation near wound
Poor general health, poor nutrition, diabetes
S. Aureus. Tell me about it.
Champ of microbial pathogens
It is everywhere. Gut, skin, etc.
Acute, aggressive, locally destructive purulent lesions
MRSA - Methicillin-Resistant Staph Aureus
Staphylococcal toxin?
Alpha-toxin - Staph scalded skin syndrome
Exfoliatin is what?
Bullous impetigo
T/F - Certain strains of S. Aureus can cause toxic shock syndrome.
TRUE
Red, cracked hands
-Tampons, but also gauze/wound packing materials
Enterotoxins from what?
Staphylococcal food poisoning
Exotoxin - ?
Endotoxins - ?
Enterotoxin - ?
Exotoxin - Excreted out of the cell
Endotoxin- Intracellular
Enterotoxin - Causes GI issues
What is the target for beta-lactam antibiotics?
Penicillin binding proteins - PBPs
How is MRSA resistant to methicillin?
Using mecA gene - codes for the altered PBP
-Makes new PBP w/ reduced affinity for beta-lactams
—Resistant to all beta-lactams
MSSA
Methicillin-Sensitive S. Aureus
Risk factors for MRSA?
Skin-skin contact
Crowded living - gyms, wrestling mats
Poor hygiene
IV drug use
*Treatment: Vancomycin
MRSA is a big issue and should be screened for
What is Group A Strep (Strep pyogenes)?
Gram + chains
-Causes “Strep throat” - Pharyngitis
What is Post-Strep infection sequelae?
Once the body is infected, an autoimmune response could occur in the future as in rheumatic fever or glomerulonephritis
Why are Strep exotoxins so toxic?
Get thru multiple layers, break down protein, carbs, DNA, causes increased cytokine activity, and can make superantigens
Clostridium perfringens?
Anaerobic, spore forming, Gram + rod, number 1 cause of gas gangrene
*HAS A LEUKOCIDIN that kills white cells
Produces H2 and CO2
Rapidly fatal
Pasteurella multocida?
GRAM - rod
Usually from animal bites
Pseudomonas aeruginosa?
Burn victims are very susceptible to this infection.
GRAM - rod
Non-fermenter, and an environmental pathogen, water, hospital rooms
Causes numerous diseases, usually found on skin
Green tint
Vibrio vulnificus?
Gram - rod
In salt-water environments, brackish water, colonize shellfish
Fever -> sepsis -> hemorrhagic bulla
Associated with iron overload, cirrhosis
What is mycetoma?
Fungal
Causes “warty-foot”
*From Actinomyces, or Nocardia
Sporotichosis?
Rose gardener’s disease/thumb - Sporothrix schenckii
*Treatment is systemic antibiotics
How to get a diagnosis?
Diagnosis is often clinical
Surface cultures are often positive, rarely with the pathogen causing infection
Biopsies rarely positivity, infected areas often more inflamed from immune response rather than a lot of organisms
Pus is great
Blood cultures are good if infection is severe
Abscess of skin - What bug?
S. Aureus
Abscess in mouth/rectum/vagina?
Polymicrobial
Cellulitis and erysipelas - what bug?
Strep pygoenes (Group A Strep)
Also, consider the situation - meaning what?
Host, exposures, etc.
(Drug user, animal bite, hot tub use?
