strep

what infections do s pneumo cause

meningitis, pneumonia, Otis media

describe meningitis and what causes it

40% mortality rate s pneumo is one of four bac causes (very deadly but easy to treat)

describe pneumonia, what are its causes

s pneumo easily crosses blood brain barrier and has a capsule (protects/prevents penitration)

describe Otis media and its causes

its an ear infection (commonly middle ear) most common culprit is strep commonly seen in kids

what must you never do with s pneumo (regarding infections)

NEVER put in fridge

how can you treat infections caused by s pnemonia and who is it given to

PCV (pneumococcal conjugate) vaccine -given to elderly and children who get frequent ear infections

does s pneumo have a capsule

yes (coin shape)

where is s viridians commonly seen and is it cause for conern

common flora in the respiratory track and mouth, not usually cause for concern but could be an opprotunistic pathogen

what is a common condition caused by s viridans

endocarditis: bacteria go to heart (on it) from the mouth (likely from dental work) more common in the US, but not very common in general

what is s pyogenes also called

group A

what infections does s pyogenes cause

sore throat, pharyngitis, scarlet fever, necrotizing fascitis

what are the after effects do infections caused by group a strep

glomerulonephritis and rheumatic fever, TSS, and cellulitis

What is pharyngitis?

inflammation of the pharynx caused by group A strep

what is scarlet fever

fever typically affecting children that is caused from an exotoxin produced by group A strep that causes red rash/dots on the arms or tongue

What is necrotizing fasciitis?

flesh eating bacteria that destroy skin a soft tissue (possibly cause loss of limbs) from group A strep

what is glomerulonephritis

it is an after effects of an infection caused by group A strep; an organism gets trapped in the glomerular 'basement' and causes antibody/antigen complexes to form at the base of the kidney. it typically causes PERMANENT kidney damage but can be detected in urine (via RBC casts)

what is rheumatic fever

it is an after effects of an infection caused by group A strep; this happens when the immune system fixes the infection caused by group A strep (no treatment is done) that then causes the body to produce antibodies which cause the immune system to attack its own heart (bc the epitopes on heart tissue looks similar to strep A) This then causes a cycle to form where antibodies are constantly produced and attacking own tissues which can cause permanent heart damage, inflammation and excess pericardial fluid

what is hyaluronidase

group of 'spreading'/traveling enzymes that breaks down connective tissue (breaking down perpetuates spreading) and are responsible for cellulitis and necrofacitis -virulence factor grpA

what is cellulitis

inflamed skin infection that is an after affect of infections caused by group A strep

what are the virulence factors of s pyrogens

streptolysin O, streptolysin S, M protein, and hyluronidase

what is streptolysin O

oxygen labile (falls apart with O2) anaerobic growth=hemolysis

what is streptolysin S

O2 stable, aerobic hemolysis, can destroy RBCs -virulence factor of grpA strep

what is M protein

prevents phagocytosis on surface of s pyrogens, can bind to mucosal wall (binding to WBCs allows this virulence factor of grpA strep to evade the immune system) M protein can destroy both WBCs & RBCs

what is treatment for any of the grpA infections

penicillin (universally sensitive: if resistant verify identity)

what Lancefield grouping is s agalacitae

grpB

what infections can grpB cause

meningitis: leading cause of death in infants (screening is done on mom 35-37 weeks-normal flora in mom, dangerous for baby)

is the Todd hewitt broth selective or not selective for grpB

selective (but doesn't change color, further testing needed)

what does the chromagar help do with s agalacitae

help identify the specific bacteria

where is grpD commonly seen and when is it a cause for concern

seen in normal flora in stool, but is an opprotunistic pathogen; if seen in the blood it is ALWAYS a pathogen

give examples of group D bacterium

s bovis, s gallolytius

what two genes cause VRE

VancA or VancB

what must infection control do in regards to enterococci and VRE

they must always screen for carriers

name common enterococci and give what hemolysis they have

e. faecium (gamma and beta sometimes alpha if VRE; this org. gets more VREs more often), e. faecalis (gamma, beta, alpha, e. gallinarium (gamma, beta, alpha)

what separates/ makes e. gallinarium so special in regards to VRE

it CANNOT be called VRE, its genes automatically encodes for its resistance (doesnt share resistance like e. fecium and e. faecalis)

how is VRE spread

through things like nosocomial infections (spread through plasmids)

enterococci is technically considered to be…

strep like

what is aerococcus

strep like organism

where is aerococcus commonly seen

as a pathogen in urine (common in 60+, rare in young people) -YOU DONT P IN POOLS BUT YOU DO LAPS

what is Leuconostoc commonly thought as

a RARE opprotunistic pathogen

where is pediococcus usually seen

usually infects GI tract or abdomy (RARE, mostly in immunocompromised)

what are abiotrophia and granilicatella categorized as and what do they need to survive

nutritionally deficient strep: they need vit b6,sulfhydryl or pyrodoxal compounds to survive

where are abiotrophia and granilicatella typically seen on a plate

satelliting around s.areus ( on BAP when s areus lyses RBCs (that release b6) these two org. are seen -not typically grown on choc. bc they're very picky

in what kind of infections are abiotrophia and granilicatella usually seen

endocarditis, appendix rupture, or perforated intestine

where are abiotrophia and granilicatella commonly seen

as normal flora in the respiratory and gut trat

when is the only time abiotrophia and granilicatella suspected (pathogen) in testing

only when seen on a blood culture gram stain, but NOTHING grows on media