infectious disease: bacteria and virus Flashcards
Streptococcus M protein
filamentous structure extending out cell surface
may contain hyaluronic acid capsule
antiphagocytic properties
Streptococci M protein gene
emm gene
Streptococci virulence factores
M protein (prevents complement binding)
Streptolysin O (lyses RBCs)
hyaluronidase (breaks down connective tissue)
DNAses A, B, C, D (break down DNA)
streptokinase (dissolves clots)
NADases, proteinases, esterases, amylase
erythrogenic toxins (scarlet fever)
Streptococcus epidemology
pharyingitis
scarlet fever
impetigo
necrotizing fasciitis
toxic shock syndrome
sequelae
rheumatic fever
acute glomerulonephristis
ASO reference method unit:
Todd unit (TU)
Todd Unit is…
the reciprocal of the highest dilution of patient serum that inhibits RBC lysis
(the last tube that shows no hemolysis)
Antistreptolysin O test principle
neutralization reactions
add patient serum, add streptolysin O (positive patient will bind with ASO neutralizing its effect), add indicator cell RBC (positive patient no RBC lysis)
Infectious mononucleosis symptoms
fever
pharyngitis
enlarged cervical lymph nodes
Infectious mononucleosis infects what cells?
B lymphocytes
heterophile antibodies are….
antibodies to a heterogeneous group of antigens found on the surface of unrelated animals and microorganisms
Forssman antibodies…
type of heterophile antibodies
non specific
Serum sickness is…
type of heterophile antibodies
immune complex disorders post injection with animal serum
Infectious mononucleosis heterophile antibodies..
Epstein Barr virus
Paul Bunnel screening test for Infectious mononucleosis
react patient serum with sheep RBCs
positive: caused by any type of heterophile antibodies
Davidsohn differential test
discovered the cause of differential reactivity of cells w/ sera for heterophile Ab
uses guinea pig kidney cells, sheep rbcs, beef erythrocytes
