H. Wang et al., ANALYSIS OF PLASMIN(OGEN) ACQUISITION BY CLINICAL ISOLATES OF GROUP-ASTREPTOCOCCI INCUBATED IN HUMAN PLASMA, The Journal of infectious diseases, 169(1), 1994, pp. 143-149
Group A streptococci isolated from throat swabs or blood cultures were
compared for the expression of plasmin(ogen) receptors. The majority
of isolates bound I-125-labeled Lys-plasmin and I-125-labeled Lys-plas
minogen while displaying minimal reactivity with I-125-labeled Glu-pla
sminogen. All streptococcal isolates could acquire surface enzymatic a
ctivity when incubated in human plasma but not if the plasma had been
depleted of plasminogen. The ability to acquire surface enzymatic acti
vity was limited by the quantity of streptokinase in the reaction mixt
ure. There was no statistically significant difference between group A
streptococci isolated from throat swabs and those from blood cultures
with respect to their interaction with components of the fibrinolytic
system in human plasma. However, these isolates could be divided into
two groups based on their ability to acquire surface enzymatic activi
ty when incubated in plasma with exogenous streptokinase. Surprisingly
, the acquisition of surface enzymatic activity when incubated in plas
ma containing streptokinase was not always correlated with the plasmin
(ogen) binding capacity determined by direct binding of radiolabeled l
igands. Analysis of this phenomenon suggests that group A streptococci
can use diverse mechanisms to acquire plasmin(ogen)-dependent enzymat
ic activity.