Toxin-Gene Profile Heterogeneity among Endemic Invasive European Group A Streptococcal Isolates.
Schmitz, Franz-Josef 1,2; Beyer, Andreas 3; Charpentier, Emmanuelle 5; Normark, Birgitta Henriques 6; Schade, Marc 2; Fluit, Ad C. 1; Hafner, Dieter 4; Novak, Rodger 5
[Article]
Journal of Infectious Diseases.
188(10):1578-1586, November 15, 2003.
(Format: HTML, PDF)
: We determined the toxin-gene profiles of 239 endemic, invasive group A streptococcal (GAS) isolates that circulated, within a 5-year period, in European university hospitals. Profiling was performed by use of multiplex polymerase chain reaction that screened for 9 streptococcal pyrogenic exotoxins (speA, speB, speC, speF, speG, speH, speJ, ssa and smeZ). Analysis revealed that invasive GAS isolates do not share a common toxin-gene profile. Although all emm types were characterized by several different toxin-gene profiles, a predominance of 1 or 2 toxin-gene profiles could be observed, reflecting that a few invasive clones have spread successfully throughout the world. Remarkably, statistical pair-wise analysis of individual toxin genes revealed that strains that did not share the predominant profile still showed a nonrandom distribution of key toxin genes characteristic of the specific emm type. This could indicate that M proteins function, directly or indirectly, as barriers for horizontal gene exchange
(C) Copyright Oxford University Press 2003.