Evaluation of enzyme-linked immunosorbent assay for detection of Salmonella typhi antigen and antibodies.
Enteric fever is considered a major health problem in developing countries. The need for a rapid, accurate and conclusive method for diagnosis is important for adequate and proper treatment. The usefulness and reliability of the ELISA test in detection of S. typhi O antigen and specific IgG and IgM antibodies were assessed using sera obtained from 63 subjects clinically suspected to have enteric fever, 22 febrilenon-enteric subjects and 20 normal subjects. ELISA detection of S. typhi somatic antigen was positive in 75% of subjects with positive clot cultures. IgG and IgM antibodies to S. typhi lipopolysaccharide (LPS) were detected in sera from 83% and 88% of enteric fever subjects, respectively. While anti-LPS IgM was negative in all sera from febrile non-enteric subjects, 9% were positive for anti-LPS-IgG. The use of an ELISA for detection of anti-S. typhi LPS antibody in combination with the Widal test and/or the O antigen detection ELISA would provide a useful (95.8% sensitivity) adjunct to standard culture methods and allow for an earlier and more rapid diagnosis of enteric fever.
el Fattah
M M
MM
Microbiology Department, Faculty of Medicine for Girls, AL-Azhar University.
Hassan
E M
EM
Shaheen
H
H
Awad
R A
RA
Girgis
N
N
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D007136:Immunoglobulins; D008070:Lipopolysaccharides / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D019081:O Antigens; D011135:Polysaccharides, Bacterial / Q000097:blood*; D012680:Sensitivity and Specificity; D014435:Typhoid Fever / Q000097:blood* / Q000453:epidemiology
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D008070:Lipopolysaccharides; D019081:O Antigens; D011135:Polysaccharides, Bacterial; C042866:antilipopolysaccharide antibodies