Fatty acid analysis as a chemotaxonomic tool for taxonomic and epidemiological characterization of four fish pathogenic Tenacibaculum species

Abstract

In this work, fatty acid content and profiles were analysed in order to differentiate the species Tenacibaculum maritimum, Tenacibaculum gallaicum, Tenacibaculum discolor and Tenacibaculum ovolyticum that are pathogenic for cultured marine fish and to assess the potential of fatty acid profiles as a tool for epizootiological typing. The fatty acid methylesters (FAMEs) were extracted from cells grown on marine agar for 48 h at 25 degrees C and were prepared and analysed according to the standard protocol of the MIDI/Hewlett Packard Microbial Identification System. The cellular fatty acid profiles of Tenacibaculum strains tested were characterized by the presence of large amounts of branched (36.1-40.2%) and hydroxylated (29.6-31.7%) fatty acids. The FAME products from the four species significantly (P < 0.05) differed in the content of iso-C(15:0)3-OH, iso-C(16:0)3-OH, iso-C(15:1)G, summed feature 3 (a component that contains C(16:1)omega7c and/or iso-C(15:0) 2-OH), iso-C(16:0), C(17:1)omega6c, C(15:0)3-OH, iso-C(17:0)3-OH. Results of present study demonstrated the existence of differences in the fatty acids content between the T. maritimum isolates from different marine fish/geographical origin and between strains of T. maritimum, T. discolor, T. gallaicum and T. ovolyticum. Profiling of fatty acids may be a useful tool to distinguish T. maritimum from other Tenacibaculum species pathogenic for fish as well as for epizootiological differentiation of T. maritimum isolates.