Streptococcus: S. pneumoniae

Describe Frederick Griffith's experiment illustrating the presents of a "transforming factor"

what do Staph. aureus and Strep. pyogenes have in common?

both can cause toxic shock syndrome

S. pneumonia is frequently isolated as ___ ___ from the ___ respiratory tract of health individuals

normal flora; upper

S.pneumoniae is the most frequent cause of ___ ___ in infants and children

otitis media

S. pneumoniae is the major cause of ___-_____ ______

community-acquired pneumonia

S. pneumoniae is a common cause of ____ and _____ in all ages

bacteremia; meningitis

Is S. pneumonia pyogenic or a viridian

viridian

describe what alpha hemolysis looks like on blood agar and why it looks this way. What family of bacteria is this ONLY seen in:

where are viridans normal flora?

in the mouth, URT, intestinal tract and female genital tract

What group is seen in endocarditis and what are some organisms that belong to this group?

describe the morphology of S. mutans

gram-positive diplococci

Disesases caused by S. pneumoniae

describe the symptoms and what a chest x-ray might look like with pneumococcal pneumonia

what is the main concern of Oralis group streps and S. aureus following bacteremia?

meningitis

S. pneumoniae can be diagnosed by ___ ___ of normally sterile specimens:

Gram stain;

blood, sputum, CNS fluid, NOT THROAT SWAB

what term is used to describe the shape of diplococcus?

lancet shape

What should all isolates of S. pneumoniae be tested for?

resistance to penicillin

what is a major virulence factor of S. pneumoniae?

polysaccharide capsule, there are about a 100 different serotypes, some more virulent than others

what strain of S. pneumoniae are typically seen in the healthy URT?

non-encapsulated "rough" strains

Two exotoxins that are virulence factors of S. pneumoniae

pneumolysin and IgA1 protease

describe pneumolysin and its mechanism

describe IgA1 protease

thought to aide in colonization of mucosal surfaces (cleaves sIgA)

Is there a true vaccine for S. pyogenes

no

Describe the PPV (Pneumovax 23) "vaccine"

purified capsule polysaccharide, works well in adults but no response in children under 2, given every 5 years for persons at risk

describe the heptavalent conjugate "vaccine" (PCV7)

purified capsule polysaccharide conjugated to a protein, approved for all infants

Describe the PCV13 (Prevnar 13) conjugate vaccine

6 additional capsule polysaccharide serotypes, recommended be used over PCV - 7