0516 - Streptococcus pyogenes - EG Flashcards
Commensal flora tends to inhabit the?
skin and mucous membranes
What is the primary difference between resident and transient flora?
resident flora inhabits body sites for extended periods of time and re-establishes when disturbed, transient flora only inhabits body sites for short periods.
what are endogenous pathogens?
those that are part of the resident or transient normal flora, but become pathogenic under certain conditions.
What are exogenous pathogens?
those that are never part of normal or commensal flora, therefore always pathogenic when present. Such as mycobacterium tuberculosis, Neisseria gonorrhoea
Should normal pathogens be found below the level of the carina?
No.
What are normal flora of the upper respiratory tract?
Streptoccus, staph, candida
What microbes are part of normal flora of the mouth and teeth? What diseases can they cause?
Agents: anaerobes, streptococcus viridans, candidaDiseases caused: gingivitis, tooth abscess, oral thrush
What is a cause of endocarditis?
Normal flora such as those from the mouth and teeth disseminating into the blood to the heart.
What are some normal flora of the throat?
Strep. pyogenes most common, also S. pneumonia, H. influenza, S. aureus
What can cause bacteraemia or meningitis?
Dissemination of normal throat microorganisms, such as S. pneumonia, H. influenza.
What are some properties of bacteria used to classify them as a species?
morphology - Gram stain and colony appearancephysiology - environmental conditions under which growMetabolic activities - substrates utilised and by-products produced.
How does Strep. pneumonia grow differently to Strep. viridians as seen in gram stain?
Strep. pneumonia tends to appear as diplococcic, compared to Strep. viridans as cocci in chains.
How are bacteria classified in accordance to there growth in oxygen?
Aerobe - requires oxygenAnaerobe - grows without oxygenstrict anaerobe - will die in the presence of oxygenobligate anaerobe - will grow in a small amount of oxygenFacultative anaerobe - grows either in/out of presence of oxygen
What species of Streptococcus are beta haemolytic?
pyogenes and agalactiae
What species of Streptococcus are alpha haemolytic?
virdans and pneumoniea
What streptococcus species are gamma haemolytic? What is another species (not Strep.) that is gamma haemolytic?
bovis and some viridans.Enterococcus
What is the species known as Group A Strep?
pyogenes
What is the species known as Group B Strep?What is a common disease caused by it?
agalactiae.Neonatal sepsis
What is the species known as Group C and G Strep?What is a common disease caused by it?
dysgalactiaepharyngitis, cellulitis
What is the species known as Group D Strep?What is a common disease caused by it?
bovisbacteraemia, endocarditis
What is the most common cause of bacterial meningitis?
Strep. pneumoniae
What is the most common cause of abscess formation?
Strep. milleri.
What is the most common cause of dental caries?
Strep. viridans
Where are enterococcus species predominantly found?
In the bowel.
