CD 12 Flashcards
What are staphylococci and streptococci?
Staphylococci are Gram-positive bacteria’s and they are grape-like clusters
Streptococci are gram-positive bacteria’s and they look like chain or strep
Staphylococcus is divided into 2 different groups and they are?
Coagulase-negative staphylococci (CoNS)
Coagulase-positive staphylococci (CoPS)
How we can distinguish staphylococcus aureus infection by looking?
Staphylococcus can be distinguished by looking the golden colour of its colonies.
What is SSTI mean?
Skin and Soft Tissue Infections
What is the epidemiology (distribution) of Staphylococcus aureus?
50% carried by human Can spread via exposure to a career like community or hospital Environmental sources Injecting drug use Medical procedures
What is the pathogenesis (how cause disease) of Staphylococcus aureus?
Once bacteria get Damaged epithelial barrier they go inside the body and colonize in tissue or blood.
Once it inside the body by causing an infection, it starts colonizing like set up shops in our tissue then Immune cells come into place to get rid of the bacteria.
At the same time, Macrophages get activated which attracts neutrophils that secrets all sorts of cytokines or inflammatory mediators. Bacteria fight back destroy NETS (kill neutrophils) and produce toxins & superantigens, by forming an abscess (jaty antibody bacteriar dharer kasy na ashty pary).
(Macrophages are immunity cells)
What is GAS?
Group A streptococcus
What are the virulence factors of GAS?
Capsules
Toxins
Superantigens
What is the pathogenesis of Streptococci?
Cause coagulation
Can cause tissue damage
Can inactivate immune cells.
Tissue damage, bacteriemia (presence of bacteria in blood) and organ damage
GAS streps what they can cause?
Superficial (SC or outer layer of the skin) infection. Impetigo Rheumatoid heart disease Rheumatoid fever Cellulitis
Which medical conditions are the higher death rate caused by GAS S. pyogenes bacteria?
Toxic Shock syndrome
Bacteriemia
Who are the risk groups for invasive disease?
Immunocompromised
Very young and elderly
Who is the most vulnerable of skin infection in NZ by S. aureus and s. pyogenes?
Highest in pre-school aged boys
Serious skin infection in NZ is in?
Pacific and Maori children in deprived areas.
What are the risk factors for cellulitis?
Homeless Very young Elderly Immune compromised obesity
What is cellulitis?
Bacterial infection of the skin and in the subcutaneous tissue caused by s. pyogenes, s. aureus.
Commonly occur in the leg.
How to diagnose cellulitis?
Biopsy (means tissue taken)
Culture only
What cause sinusitis in children?
S. pneumoniae, H. influenzae
What are the symptoms of Cellulitis?
Ill-defined lesions Painful Red Swollen May or may not have systemic symptoms like fever chills
Treatment options for cellulitis is
Uncomplicated (when symptoms are localized and not reached systemic) treat with oral antibiotics.
Complicated (Systemic) so need surgical drainage.
What is Toxic shock syndrome?
Caused by staph & strep of their toxic superantigens.
So, what happen here is when immune system gets activated as a result cytokine storm which shock to our human body as a result multi organ failure and high mortality
What are the symptoms of Toxic shock syndrome?
Redness swelling and pain (So it can’t be tell by looking its symptoms at the early stages however it might be more profound in late stage because the patient might drop blood pressure very quickly or patient will be very disoriented or unwell.)
What are the treatment options available for Toxic shock syndrome?
Antibiotics
Wound care or drainage
Aggressive support needed.
What is Necrotising Fasciitis (Flesh eating bacterial wound)?
Caused by s.pyogenes & s.aureus gets entry by bacterial wound, by they produce toxins and the toxin is so toxic that they eat up the whole cell tissue and blood vessels. It is also known as streptococcal gangrene.
What are the risk factors for Necrotising Fasciitis?
Diabetes
Obesity
NSAIDs users
Heart disease
What are the symptoms of Necrotising fasciitis?
Early symptoms: Slight trauma and then local discomfort in that area, then headache, fever, joint and muscle pain.
Advanced symptoms: blisters, skin or tissue looks dead.
Final stage: systemic symptoms and death.
What are the Treatment options of Necrotising fasciitis?
Seek early treatment
Hospitalisation
Amputation
