Flashcards in T1- Infectios Dz of Skin Deck (99)
What environmental conditions allow for our Normal flora to survivie?
dry and salty conditions
What are the three types of normal flora?
1. Diptheroids (Propionbacterium acnes)
2. Micrococci (Staphylococcus epidermis)
3. Yeast (Candida albicans)
______ = Bacterial infection, follicle associated lesion... types include comedo, whitehead, blackhead, pustule, and cystic
What is the most common mode of transmission of acne (Propionibacterium acnes)?
What are the virulence factors associated with acne?
Lipase, inflammatory mediator, other enzymes
What is the treatment for most acne?
Antibiotics (topical or oral), Isotretinoin
What are the two bacteria that cause impetigo?
1. Staphylococcus aureus
2. Streptococcus pyogenes
Peeling of the skin =
Associated with a number of diseases, including impetigo ; Enzymes = Coagulase, Hyaluronidase, Staphylokinase, Lipases ; Most studied non-spore forming pathogen
Impetigo, peeling of the skin, can be caused by Staphylococcus aureus or Streptococcus pyogenes, or may be caused by a mixture of the two. In cases where Impetigo is caused by a mixture of the two, is the onset at the same time? Or one before the other?
S. pyogenes begins is ALL cases of the disease, but LATER S. aureus takes over and produces a bacteriocin that destroys S. pyogenes
What is the mechanism of transmission associated with impetigo?
Transmitted by direct contact, via fomites, and mechanical vectors
When is the peak incidence of Impetigo?
Summer and Fall
______ looks like peeling skin, crusty and flaky scabs, or honey colored crusts
Where is Impetigo most commonly found?
Mouth, Face, and Extremities, but can occur anywhere on the skin
Can a patients symptoms suggest whether the infection is caused by Staph or Strep?
T/F Using SEM (scanning electron micrograph) and colonies of Staphylococcus aureus could confirm the causative agent of impetigo.
What is the primary method of identifying Staphylococcus aureus?
Positive coagulase test
_________ = Beta Hemolytic, M protein, and is associated with impetigo
What is the pathogenesis of Streptococcus pyogenes?
Involves the conversion of plasminogen to plasmin, which can degrade host tissue
What are the virulence factors associated with Impetigo caused by Staphylococcus Aureus?
Exfoliative toxin A, coagulase, other enzymes
What are the virulence factors associated with Impetigo caused by Streptococcus Pyogenes?
Streptokinase, plasminogen-binding ability, hyaluronidase, M protein
What tests would you perform to diagnose Impetigo caused by Staphylococcus aureus?
Routinely based on clinical signs, when necessary, culture and Gram stain, coagulase and catalase tests, multitest systems, PCR
In what age group do you most often see Impetigo caused by Staphylococcus Aureus?
older children or adult
In what age group would you most often find Impetigo caused by Streptococcus pyogenes?
newborns; may have some involvement in all impetigo (preceding S. aureus in staphylococcal impetigo
_______ = Bacterial or Fungal infection of the dermin and subcutaneous tissues; lymphagitis; immunocompromised individuals are at risk
What are the signs and symptoms of Cellulitis?
Fever and swelling of the lymph nodes in the area may also occur
What is caused by red lines leading away from area that become visible as a result of microbes and inflammatory products being carried by the lymphatic system?
What organisms cause cellulitis?
What is the most common mode of transmission of cellulitis?