Toxin-gene profile heterogeneity among endemic invasive European group A streptococcal isolates.
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.
Schmitz
Franz-Josef
FJ
Eijkman Winkler Institute for Medical Microbiology, Infectious Diseases and Inflammation, University Hospital Utrecht, Utrecht, The Netherlands.
Beyer
Andreas
A
Charpentier
Emmanuelle
E
Normark
Birgitta Henriques
BH
Schade
Marc
M
Fluit
Ad C
AC
Hafner
Dieter
D
Novak
Rodger
R
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000302:isolation & purification; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics* / Q000302:isolation & purification; D003428:Cross Infection / Q000382:microbiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005060:Europe; D014644:Genetic Variation; D006801:Humans; D016133:Polymerase Chain Reaction; D013297:Streptococcus pyogenes / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001427:Bacterial Toxins; D002352:Carrier Proteins; D004269:DNA, Bacterial; C014689:streptococcal M protein