Streptococcus and enterococcus
Streptococci
IS gram +, is differentiated by hemolysis of RBC's
Streptococcus pneumoniae and a group of oral streptococci (Streptococcus viridans or viridans streptococci) display what hemolysis
alpha
non suppurative diseases from strep
antibodies are shaped so they stick to other non pathogens this is autoimmune disease, filtering in kidneys goes wrong, leads to renal failure
rhumatic fever is
antibodies from a strep infection 4 weeks ago stick to damaged heart valves, so people with rhumatic fever can never get strep again.
viridians streptococci) strep mutans ( S. mutans) in dental caries secrete dextransucrose
creates glucan which is plaque. leads to tooth decay
two types of syndromes associated with group B strep
early onset first 5 days (24 hours) 50% fatality , 33% meningitis 40% pulmonary...... 2. LATE ONSET, 7 days to 4 months lower fatality, commonly menigitis rarely pulmonary
Distinguised from group D streptococci because they have the ability to grow in high salt concentration
enterococcus
comes from normal flora of intestines and is resistant to antibiotics
enterococcus
epidemiology it si higher incidence in winter in cold dry areats and spread by nasal aerosols
epidemiology of strep
Toxins produced by strep:
erthrogenic: causes scarlet fever rash, produced only by LYSOGENIC strains, (has virus genes)
Group A (antigenic constituation by rebeccalancefield) is supperative and has 4 types they are:
erysipelas, impetigo, sepsis, pharyngitis.
Enterococcus faecalis (formerly called Group D Strep) displays ______ hemolysis?
gamma
hemolysis (streptococci classification method) what is alpha?
greening
this strp is predominant in hospital nurseries
group B, risks to babies mothers must be tested
Toxin 2 produced by strep:
hemolysisns strptolysins, S+O hemolysisn kill WBC
what does gamma look like?
nothing happens
colony morphology : small grayish circular slightly raised non-pigmented colonies...
strep
non suppurative disease from strep (1-4 weeks after getting disease syptoms show up)
streptococcal endocarditis, inflamation of the heart, acute are quick (ulceration of heart), subacute not as quick and involve abnormal valves, due to normal flora in Resp tract, causes progressibe damage, can come from dental work.
is a facultative anaerobeGeneral Characteristics: Fermentative metabolism: Carbohydrates are fermented without the production of gas; Major endproducts are lactic acid, ethanol, acetate
streptococcus
what is gram +, and displayed in chains or pairs? Some strains have hyaluronic acid capsule; Produce hyaluronidase later in growth cycle
streptococcus
Catalase negative: Oxidase negative
strptococci
what does beta hemolysis look like?
transparent around colonies
group B streps are resistant to antibiotics and require a combo for treatment?
true
ARe group A streps sensitive to pennicillin?
yes rgoup a streps are sensitive to penicillin
