Lecture 2 - Streptococcal Infection Flashcards
Where are strep found
Everywhere
Gut, GI tract, mouth, URT
What is the classification of streptococcal
Streptococci
What is the pathogenic form of streptococcus
Strep pyogenes - Group A streptococcus
Who first described pyogenes infected patients with a ‘flesh eating disease’
Hippocrates
Who in 1874 designated the name strepto coccus
Theodore Billroth
Who in 1884 was the first person to recover and grow strep pyogenes from patients with puerperal sepsis (childbed fever)
Louis Pasteur
In 1884 which pioneer designated name streptococcus pyogenes
Anton rosenbach
Why is it called pyogenes
Pyo meaning inflammatory
Cause inflammation
Is strep pyogenes gram positive or gram negative
Gram positive
What is the size of strep pyogenes
0.5-1um
How do strep pyogenes gain energy E.g. Via oxygen or co2
FACULTATIVE ANAEROBES
What does capnophilic mean
Bacteria that live in high CO2
What temperate range does strep pyogenes fit into
18-40
Optimum 30
Is strep pyogenes positive or negative for catalase production
Catalase NEGATIVE
Where does S.salivarius live
MOUTH
What does S.agalactiae cause
Neonatal meningitis
Name 3 diseases caused by strep pyogenes
Tonsillitis, necrotising fasciitis (gangrene) and scarlet fever
What is a key factor of strep classification
Their haemolytic properties e,g, alpha, beta or gamma
And SURFACE ANTIGENS E.G. CHO antigens, classifies beta haemolytic strep into specific groups of carbohydrate surface antigen A,B,C,G,F
What enzymes are used in beta haemoyosis to break down our RBC
Streptolysin S and O
Who based classification on surface antigens
Rebecca lancefield
What strep species partake in partial haemolysis (alpha)
S. Pneumoniae and viridians strep
What does hydrogen peroxide produced by the alpha haemolytic species do the haemoglobin
Oxidises to green methaemoglobin
Which two species of strep partake in beta haemolysis
strep pyogenes and s,agalactiae