Immunogenicity of toxins during Staphylococcus aureus infection.
BACKGROUND
Toxins are important Staphylococcus aureus virulence factors, but little is known about their immunogenicity during infection. Here, additional insight is generated.


METHODS
Serum samples from 206 S. aureus-infected patients and 201 hospital-admitted control subjects were analyzed for immunoglobulin (Ig) G binding to 20 toxins, using flow-cytometry based technology. Antibody levels were associated with polymerase chain reaction-defined presence of toxin genes in homologous S. aureus isolates.


RESULTS
IgG levels directed to exfoliative toxin (ET) A, ETB, gamma hemolysin B (HlgB), leukocidin (Luk) D, LukE, LukS, staphylococcal enterotoxin (SE) A, SEE, SEH, SEI, and SElM were higher in S. aureus-infected patients than in control subjects (P < .05). Furthermore, in the S. aureus-infected patient group, IgG levels were higher if genes encoding ETA, ETB, SEA, SEC, SEH, SElQ, toxic shock syndrome toxin-1 (TSST-1), or Panton-Valentine leukocidin (PVL) were present in the infectious isolate (P< .05). Levels of anti-SEA IgG increased during infections with sea-positive (median fluorescence intensity from 11,555 to 12,388; P<.05) but not sea-negative strains. In addition, anti-LukS IgG levels increased during skin and soft-tissue infections with luk-PV-positive (median fluorescence intensity from 15,231 to 15,911; P<.05) but not luk-PV-negative strains. Bacteremia was associated with sea (odds ratio, 3.4; 95% confidence interval, 1.2-10.0) and tst (odds ratio, 5.7; 95% confidence interval, 1.6-20.8). Skin and soft-tissue infections and bone and joint infections were associated with luk-PV (odds ratio, 2.5; 95% confidence interval, 1.2-5.2).


CONCLUSIONS
Many toxins are expressed in vivo and recognized by the immune system during staphylococcal infections, suggesting their involvement in S. aureus pathogenesis.
Verkaik
Nelianne J
NJ
Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, Rotterdam, the Netherlands. n.j.verkaik@erasmusmc.nl
Dauwalder
Olivier
O
Antri
Kenza
K
Boubekri
Ilhem
I
de Vogel
Corné P
CP
Badiou
Cédric
C
Bes
Michèle
M
Vandenesch
François
F
Tazir
Mohamed
M
Hooijkaas
Herbert
H
Verbrugh
Henri A
HA
van Belkum
Alex
A
Etienne
Jerome
J
Lina
Gerard
G
Ramdani-Bouguessa
Nadjia
N
van Wamel
Willem J B
WJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000276:immunology*; D001427:Bacterial Toxins / Q000235:genetics / Q000276:immunology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D018709:Statistics, Nonparametric
D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D007074:Immunoglobulin G