GAS-J, a User-Friendly Browser Application for Genome Assembly, emm-Typing, MLST Typing, and Virulence Factor Gene...

Clinical isolates of Streptococcus pyogenes are usually classified using emm and multilocus sequence typing (MLST). Recently, whole genome sequencing (WGS) has been employed for emm typing and MLST analysis. WGS data provides additional information on the presence of virulence factor genes. To enable researchers unfamiliar with bioinformatics to analyze WGS data of S. pyogenes, we opened an online tool named GAS-J, which automatically outputs emm types, sequence types (STs), carriage of virulence factor genes, and phylogenetic trees. The tool accepts raw short-read data as inputs, since it includes the velvet assembler. In all isolates, the emm typing results from this tool were identical to those obtained by conventional PCR and Sanger sequencing, even in cases where isolates had pseudo-emm (emm-like) genes. STs are determined by performing a BLAST search using seven alleles as references. To detect S. pyogenes virulence factor genes, we prepared a new data set containing 620 related proteins. Users may choose which isolates to include in SNP-based phylogenetic tree from a pool of 406 isolates with epidemiological data. The data set includes isolates whose symptoms (STSS or non-STSS) were diagnosed based on the STSS criteria of the Japan Communicable Disease Prevention Law. GAS-J application is available at http://gasj.ncgm.go.jp. The data of isolates are going to be updated in the future.