Vibrio parahaemolyticus is frequently isolated from environmental and seafood
samples and associated with gastroenteritis outbreakes in American, European,
Asian and African countries. To distinguish between different lineages of V.
parahaemolyticus various genotyping techniques have been used, incl.
multilocus sequence typing (MLST). Even though some studies have already
applied MLST analysis to characterize V. parahaemolyticus strain sets, these
studies have been restricted to specific geographical areas (e.g. U.S. coast,
Thailand and Peru), have focused exclusively on pandemic or non-pandemic
pathogenic isolates or have been based on a limited strain number. To generate
a global picture of V. parahaemolyticus genotype distribution, a collection of
130 environmental and seafood related V. parahaemolyticus isolates of
different geographical origins (Sri Lanka, Ecuador, North Sea and Baltic Sea
as well as German retail) was subjected to MLST analysis after modification of
gyrB and recA PCRs. The V. parahaemolyticus population was composed of 82
unique Sequence Types (STs), of which 68 (82.9%) were new to the pubMLST
database. After translating the in-frame nucleotide sequences into amino acid
sequences, less diversity was detectable: a total of 31 different peptide
Sequence Types (pSTs) with 19 (61.3%) new pSTs were generated from the
analyzed isolates. Most STs did not show a global dissemination, but some were
supra-regionally distributed and clusters of STs were dependent on
geographical origin. On peptide level no general clustering of strains from
specific geographical regions was observed, thereby the most common pSTs were
found on all continents (Asia, South America and Europe) and rare pSTs were
restricted to distinct countries or even geographical regions. One lineage of
pSTs associated only with strains from North and Baltic Sea strains was
identified. Our study reveals a high genetic diversity in the analyzed V.
parahaemolyticus strain set as well as for geographical strain subsets, with a
high proportion of newly discovered alleles and STs. Differences between the
subsets were identified. Our data support the postulated population structure
of V. parahaemolyticus which follows the 'epidemic' model of clonal expansion.
Application of peptide based AA-MLST allowed the identification of reliable
relationships between strains.
600 Technik, Medizin, angewandte Wissenschaften::630 Landwirtschaft
Population analysis of Vibrio parahaemolyticus originating from different
geographical regions demonstrates a high genetic diversity
BMC Microbiology. - 14 (2014), 1, S.59-73
Institut für Lebensmittelsicherheit und -hygiene
Deutsche Forschungsgemeinschaft (DFG)