Comparison of MST and UPGMA The geographic dependency found in UPGMAs but not in MSTs could be explained by the different approaches of sequence-based versus allelic profile-based comparison. Sequences with fewer differences are grouped close together in the UPGMA whereas in MSTs all sequences which differ in at least one nucleotide have the same distance to each
selleck chemical other. Thus the UPGMA seems to be more suitable for showing geographical relationships between strains of highly diverse populations. The CCs identified by goeBURST were grouped together also in UPGMA analysis. Similarly Yan et al. observed the grouping of CCs identified by eBURST in high monophyletic clades of UPGMA analysis . Conclusions The generated data reveal a high genetic diversity
for all V. parahaemolyticus strain subsets analyzed, with a high proportion of new alleles and STs discovered, typical for environmental strain collections. Clusters of strains on nucleotide level contained mainly strains originating from one continent, but no exclusive clusters for the distinct continents were identified. STs and pSTs were either supra-regionally distributed or exclusively present in one region. Using AA-MLST instead of MLST in the goeBURST analysis allowed reliable identification of closely related strains (pSTs were SLVs), independent of their geographic origin. In contrast the application of MLST is more useful to recognize relationships in an epidemiological context by creating distinct CCs. In general AZD1480 pubMLST database reflects only the diversity of so far S63845 purchase analyzed strains, and may not represent the natural diversity of the V. parahaemolyticus population as also indicated by our rarefaction analysis. Further analysis of strains of diverse origins may help to complete the database and to keep pace with new evolving genotypes. Availability of supporting data The data sets and additional figures supporting the results of this article are included in Additional files 1, 2, 3, 4 and 5. Acknowledgements We acknowledge Kathrin Oeleker for assistance in performing PCR and strain cultivation. The Montelukast Sodium project was funded by
the German Ministry of Education and Research (BMBF) within the VibrioNet project. Electronic supplementary material Additional file 1: Table S1: Characteristics and allelic profiles of V. parahaemolyticus strains included within this study. (PDF 151 KB) Additional file 2: Tables S2: AA-MLST profiles and properties of each allele on peptide level (numbers, sequences and frequencies). (XLSX 42 KB) Additional file 3: Figure S1: Population snapshot based on MLST profiles of pubMLST dataset. Coloring depends on geographical origin of isolates: Asia (red), South America (light green), North America (dark green), Africa (yellow) and Europe (blue). Size of circles represents number of isolates with the corresponding ST. STs that differ in one allele are connected via black lines.