Comparisons of Iranian Strains of Pseudomonas syringae pv. Syringae from Various Hosts with Different Methods

A total of 46 strains of Pseudomonas syringae pv. syringae (Pss), including four reference strains, from different hosts and various geographical regions of Iran were compared based on their phenotypic, biochemical, serological and total protein properties. Pss strains showed similar phenotypical reactions except for aesculin hydrolysis, ice nucleation activity, syringomycin production, tyrosinase activity and utilization of adonitol, L-cysteine, formate, L-proline, raffinose and tartarate. All strains possessed a similar antibiogram profile towards 28 antibiotics tested. The strains were divided into three groups of syringomycin using Geotrichum candidium in standard bioassay. Three strains were used in antisera. preparation against Pss in rabbit for serological studies. Ouchterlony double diffusion test divided Pss strains into six serological groups, when the results of heat-treated and non-treated whole bacterial cells used were combined for analysis and into seven serological groups when heat-treated antigens were used. All three antisera were able to identify Pss strains from various hosts in dot-immunobinding assay. This technique detected as few as 10(5) Pss cells per 10 mu L reaction mixture from a pure culture. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed a significant homology in soluble protein patterns among Pss strains from stone fruits, barley and wheat except for those from sugarcane. Additional protein bands were found in strains from sugarcane. Results suggested that Pss strains from various hosts and geographical regions of Iran have adapted themselves to specific niches and hosts, acting differently with respect to utilization of carbon sources, etc. and thus belong to distinct taxonomic groups. (c) 2010 Friends Science Publishers