Molecular and phenotypic approaches to identify Pseudomonas strains

Abstract

The purpose of this study was to determine the taxonomic status of the Pseudomonas strains that were deposited in the Japan Collection of Microorganisms (JCM), RIKEN BioResource Center by Dr. R. Hugh, School of Medicine, George Washington University. A total of 49 strains were studied by partial 16S rRNA gene sequence analysis, ribotyping, and biochemical characterization. All the studied strains belonged to the genus Pseudomonas except two strains, which belonged to Shewanella algae. Among the Pseudomonas strains, 64% (30/47) were closely related to the following species, Pseudomonas aeruginosa, P. pseudoalcaligenes, P. stutzeri and P. alcaliphila. The remaining 36% (17/47) of strains could not be assigned to any validly published species of Pseudomonas. Although the 16S rRNA gene sequence analysis of the strains demonstrated very close similarities (>99%) with more than one validly published Pseudomonas species, phenotypic characterizations and ribotyping of these strains produced various results. A reliable method of identifying these microorganisms needs to be developed.