IDENTIFICATION OF 2 SEROLOGICAL FLAGELLAR TYPES (H1 AND H2) IN PSEUDOMONAS-SYRINGAE PATHOVARS

Flagellar antigen specificity was studied for the species Pseudomonas syringae, P. viridiflava and P. cichorii. After checking their motilit y, bacteria were reacted against six polyclonal antisera containing an ti-O (LPS) and anti-H (flagellar) antibodies by indirect immunofluores cent staining. Two distinct flagellar serotypes (H1 and H2) were descr ibed. The distribution of H1 and H2 serotypes was then determined for a collection of 88 phytopathogenic Pseudomonas strains. Serotype H1 wa s possessed by P. syringae pv. aptata (12 strains), P. s. pv. helianth i (2), P. s. pv. pisi (11), and P. s. pv. syringne (13). Serotype H2 w as possessed by P. cichorii (2), P. s. pv. delphinii (1), P. s. pv. gl ycinea (4), P. s. pv. lacrymans (1), P. s. pv. mori (1), P. s. pv. mor sprunorum (10), P. s. pv. persicae (1), P. s. pv. phaseolicola (8), P. s. pv. tabaci (10) and P. s. pv. tomato (1). P. viridiflava (5) revea led HI, H2 and untyped flagella. The following isolates were untypable by the H1/H2 system: P. corrugata (3), P. fluorescens (2), P. tolaasi i (1). H1/H2 serotypes distribution is not linked to P. syringae O-ser ogroups. On the other hand, H1/H2 distribution seems remarkably linked to the new genospecies of the P. syringae group.