Evaluation of commercial latex reagents for identification of O157 and H7 antigens of Escherichia coli.
Agglutination reactions obtained with three commercial latex reagents for detecting Escherichia coli O157 antigen (Oxoid Diagnostic Reagents, Hampshire, England; Pro-Lab Inc., Richmond Hill, Ontario, Canada; and Remel Microbiology Products, Lenexa, Kans.) and one for detecting H7 antigen (Remel) were compared with those obtained by standard serologic methods by using the Centers for Disease Control and Prevention (CDC) reference antisera for O157 and H7 antigens. For 159 strains of E. coli and related organisms, the Oxoid, Pro-Lab, and Remel O157 latex reagents each had a sensitivity and specificity of 100% compared with the CDC reference antiserum. For 106 strains of E. coli and related organisms that were not enhanced for motility through semisolid medium, the Remel H7 latex reagent had a sensitivity of 96% and a specificity of 100% compared with the standard tube agglutination method with CDC H7 antiserum. Measures to enhance motility were needed for some strains to detect the H7 antigen. Our findings demonstrate that the commercial latex reagents are good alternatives to standard serologic methods for identifying the O157 and H7 antigens of E. coli.
Sowers
E G
EG
Diarrheal Diseases Laboratory Section, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
Wells
J G
JG
Strockbine
N A
NA
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial / Q000032:analysis*; D001431:Bacteriological Techniques; D004926:Escherichia coli / Q000276:immunology* / Q000302:isolation & purification / Q000472:pathogenicity; D005069:Evaluation Studies as Topic; D006801:Humans; D007202:Indicators and Reagents; D007840:Latex; D007841:Latex Fixation Tests / Q000379:methods*; D013045:Species Specificity
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007202:Indicators and Reagents; D007840:Latex