Sequence characteristics of O-antigen gene cluster of Vibrio parahaemolyticus O10:K4 and construction of molecular serotype database

Objective  To analyze the molecular characteristics of the O-antigen gene cluster of Vibrio parahaemolyticus O10:K4 and construct a genomic-based molecular serotype predictive database.

Methods The O-antigen gene cluster locus (OL) sequences of Vibrio parahaemolyticus were obtained from the National Center of Biotechnology Information (NCBI) Assembly database of USA. The sequence similarity and polymorphism were analyzed by using blastn, fastANI, Sourmash and pixy tools. Recombination analysis was performed by using gubbins, and a molecular serotype prediction database of Vibrio parahaemolyticus was constructed.

Results The O-antigen gene cluster (OL10V1) of Vibrio parahaemolyticus O10:K4 was significantly different from the typical O10 serotype gene cluster (OL10), but was most similar to OL4. In the 116 full-length sequences of OL10V1 in the public databases, only one single nucleotide mutation was found. The IS1634 and ISVa2 transposase genes carried by OL10V1 were widely distributed in Vibrio species, suggesting that this variant might formed through horizontal gene transfer(HGT).

Conclusion This study revealed the potential molecular mechanism for the rapid spread of Vibrio parahaemolyticus O10:K4, and the constructed molecular serotype database can provide key technical support for genomic surveillance and traceability.