Detection of antibodies to Staphylococcus aureus Toxic Shock Syndrome Toxin-1 using a competitive agglutination inhibition assay.
OBJECTIVE
To develop a competitive agglutination inhibition assay (CAIA) for the detection of anti-Toxic Shock Syndrome Toxin-1 (TSST-1) antibody in serum samples using a commercially available reverse passive agglutination assay (RPLA) kit.


RESULTS
TSST-1 toxin and sera were incubated together, so that anti-toxin IgG would complex with the toxin. Latex particles sensitized with rabbit IgG anti-TSST-1 were added to test for un-complexed toxin. The sensitivity and specificity of the CAIA assay was determined relative to positive and negative ELISA results. The sensitivity (proportion of positive ELISA sera which tested positive by CAIA) was 66% whilst the specificity (proportion of ELISA negative sera which tested negative by CAIA) was 75%. Seven sera (14%) were negative by ELISA but positive for CAIA and 12 (18.8%) were positive for ELISA but negative for CAIA, suggesting some interference with the assays. Statistical analysis showed no significant difference between the methods in terms of the numbers of individuals testing positive (chi2, P = 0.04).


CONCLUSIONS
The CAIA assay allowed detection of anti-TSST-1 within 18 h and was simple to read visually.


CONCLUSIONS
The method is a useful test for individual serum samples and a preliminary investigation for medical screening of suspected toxic shock syndrome and is applicable in situations where antibody assays are not routinely used for anti-TSST-1 and also where sophisticated equipment (e.g. microtitre plate reader) is not available.
Javid Khojasteh
V
V
Biosciences Research Institute, School of Environment and Life Sciences, University of Salford, Salford, Lancs M5 4WT, UK.
Rogan
M T
MT
Edwards-Jones
V
V
Foster
H A
HA
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D001427:Bacterial Toxins; D002648:Child; D002675:Child, Preschool; D004768:Enterotoxins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007841:Latex Fixation Tests; D011817:Rabbits; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*; D012772:Shock, Septic / Q000175:diagnosis*; D013203:Staphylococcal Infections / Q000175:diagnosis; D013211:Staphylococcus aureus / Q000276:immunology* / Q000378:metabolism; D018089:Superantigens
D000907:Antibodies, Bacterial; D001427:Bacterial Toxins; D004768:Enterotoxins; D011933:Reagent Kits, Diagnostic; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal