Erwinia and Pseudomonas bacteria can be reliably screened by an improved serological agglutination test.
The sensitivity of a modified agglutination test for the detection of Erwinia amylovora and Pseudomonas syringae pv. pisi antisera was examined. The bacterial polyclonal antisera were sensitized by Staphylococcus aureus bacteria. These antisera enhanced the sensitivity of the agglutination test by 2 or 3 times. The modification of the agglutination test described is recommended for the detection of E. amylovora in plant sap and in bacterial slime of hawthorns (Crataegus sp.) attacked by E. amylovora.