Evaluation of methods for the determination of Q and K antigens of an 02:K1(L) strain of Escherichia coli.
Tests made on ten colonies from a strain of Escherichia coli O2:K1 demonstrated that bacterial agglutination tests were reliable for identifying the O antigen of serogroup O2 but were unreliable for identifying the K1 antigen. The granular nature of K agglutination was not a reliable characteristic of the L type of K antigen. In contrast, indirect haemagglutination, immunodiffusion and immunoelectrophoresis tests with bacterial extracts gave consistent results with all colonies. The polysaccharide K1 antigen formed a long anodic precipitation line with two peaks, indicating its heterogenous nature, and partial fusion of this line with the O-antigen precipitation line suggested the presence of common serological determinants. In addition, a heat-labile protein antigen, possibly another K antigen, was identified by indirect haemagglutination tests and may have produced a short anodic precipitation line. The results also showed that the K1 antigen was still produced after storage of a culture for 12 years on Dorset-egg medium.
D000372:Agglutination Tests; D000942:Antigens, Bacterial / Q000032:analysis*; D000939:Epitopes; D004926:Escherichia coli / Q000276:immunology*; D005069:Evaluation Studies as Topic; D006386:Hemagglutination Tests; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D012698:Serologic Tests / Q000379:methods*
D000942:Antigens, Bacterial; D000939:Epitopes