Gram +ve Pathogens Streptococus pyogenes Flashcards
What does Pyogenic mean?
causes temperature to raise in an individual - Fever
i.e. S.pyogenes
How do you identify Identification of Streptococcus spp.
- a (alpha)*
- b (beta)*
- y* (gamma) no haemolysis
What is associated with a-haemolysis ?
a-haemolysis
(oral or viridans streptococci)
Partial hemolysis of blood agar plates
S. pneumoniae
MOST ORAL STREPTOCOCCI
agar plate turns GREEN
What is associated with b-haemolysis ?
b-haemolysis
(pathogenic streptococci)
Complete hemolysis on blood agar plates
S. pyogenes & Anginosus group of oral Streptococci
on agar plate … clear haemolysis
What is associated with y-haemolysis ?
y-haemolysis
(Enterococci)
No hemolysis of blood agar plates
Enterococcus faecalis
on agar plates …. no haemolysis
What type of diseases can Group A Streptococcus cause?
Group A Streptococcus
Streptococcus pyogenes
b-haemolytic
Streptococcal sore throat (Scarlet fever)
Invasive diseases e.g. necrotising fasciitis
Puerperal sepsis (infection of pregnant & post natal women)
How do you identify Streptococcus pyogenes in Pharyngitis or Streptococcal sore throat, scarlet fever?
- Gram +ve cocci
- Haemolysis
- GAS (b haemolysis)
- S.pyogenes
- Bacitracin sensitive
What are some GAS skin diseases?
Impetigo (usually face)
• highly contagious through contact with discharge on the face
Cellulitis
• deeper skin infection in the dermis that is not associated with necrosis
Necrotizing fasciitis
• Invasive Streptococcus A strains penetrate mucous membrane & develop in lesion.
Acute Streptococcal gingivitis
• Infected Gingivae red/swollen/oedematous Often follows sore throat
What is the sympotoms of a bacterial S. pyogenes Strep Throat?
– Sudden onset (1-5 days post exposure)
– Sore throat/ pain on swallowing
– Fever
– Patchy discrete Tonsillar exudates
– Tiny red spots on soft hard palate
– Tender enlarged anterior cervical nodes
– Headache
What is the sympotoms of a Viral Strep Throat?
– Absence of fever
- Runny nose
- Cough
What is Scarlet Fever?
and what are the symptoms?
Scarlet Fever is a Severe form of Strep throat with associated rash.
Symptoms
Flushed red face
Red rash feels like sandpaper
Red skin underarms, elbows, groin
Coated Tongue (white)
Swollen Tonsils
What is Rheumatic Fever and what are the symptoms?
autoimmune disease
Early Symptoms
• Fever, joint pain, nose bleeds, abdominal pain, vomiting
Late Symptoms
- Migratory Polyarthritis, inflammation of joints & heart
- Pancarditis
What are some Antibiotic treatments?
- Penicillin V (most common)
- Amoxicillin
- Erythromycin
What is an example of an ADHESION component of pharynx?
M protein
involved in adhesion & evading immune system
