Cross-reactions between Erwinia amylovora and other bacteria in immunofluorescence staining using different antisera.
The results of a comparative study with indirect fluorescence antibody staining (IFAS) between E. amylovora and several selected bacteria (other Erwinia spp., Citrobacter spp., Pseudomonas fluorescens and 2 unidentified spp.), using 2 or 3 dilutions of antisera from 5 different European laboratories, are tabulated. Even though the antisera varied in specificity, results reveal the existence of cross-reactions. Consequently IFAS must be used with great caution in detecting E. amylorova in plant tissues, especially in the absence of symptoms.