[Detection of pyrogenic exotoxin SpeA, SpeB and SpeC genes in Chilean streptococci isolates and their association with clinical manifestations].
BACKGROUND
The virulence of Streptococcus pyogenes is determined by a variety of structural molecules, toxins and complex enzymes. Pyrogenic exotoxins cause fever, erythematous reactions, cytotoxic and immunological effects.


OBJECTIVE
To assess the frequency of speA, SpeB and SpeC genes in Chilean Streptococcus pyogenes strains and their association with the invasiveness of infections.


METHODS
The genes for pyrogenic exotoxins SpeA, SpeB and SpeC were determined by polymerase chain reactions in 114 strains of group A Streptococcus pyogenes isolated from Chilean patients with invasive or non invasive infections.


RESULTS
The gene for SpeA was present in 30.7% of isolates, the gene for SpeB was present in 69.3% and the gen for SpeC in 44.7% of isolates. The gene for SpeA was present in 20 of 33 invasive infections and in 15 of 81 non invasive infections (p < 0.0001). On the contrary, the gene for SpeC was present in 11 of 33 invasive infections and in 41 of 81 non invasive infections (p < 0.05). The frequency of speB was similar in invasive and non invasive infections.


CONCLUSIONS
There is a clear relationship between the presence of SpeA genes and the severity of infections caused by Streptococcus pyogenes.
Ulloa
M T
MT
Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile. mtulloa@machi.med.uchile.cl
Giglio
M S
MS
Porte
L
L
Santa Cruz
A
A
McNab
P
P
Fica
A
A
Pinto
M E
ME
Kawaguchi
K
K
Carmi
A
A
D001426:Bacterial Proteins / Q000235:genetics*; D003546:Cysteine Endopeptidases / Q000235:genetics*; D005098:Exotoxins / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011749:Pyrogens / Q000235:genetics*; D013290:Streptococcal Infections / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D014774:Virulence / Q000235:genetics
D001426:Bacterial Proteins; D005098:Exotoxins; D008565:Membrane Proteins; D011749:Pyrogens; C117980:SpeA protein, Streptococcus pyogenes; D003546:Cysteine Endopeptidases; C042477:streptopain