Draft genome sequence of a multidrug-resistant Salmonella enterica serotype Kentucky ST198 with chromosomal integration of blaCTX-M-14b isolated from a poultry slaughterhouse in China

Abstract Objectives The aim of this study was to characterize the draft genome sequence of a multidrug-resistant (MDR) Salmonella enterica serotype Kentucky strain XJ9S isolated from a poultry slaughter house in China. Methods The genome was sequenced using an Illumina HiSeq platform and assembled by SPAdes_3.12.0. The CGE Bacterial Analysis Pipeline was used to identify the sequence type as well as the presence of antimicrobial resistance genes and plasmids in XJ9S. The gaps among contigs that carried MDR Salmonella genomic island 1 (SGI1) fragments were filled in by PCR linkage and sequencing. Results The draft genome of strain XJ9S was assembled into 54 contigs, and the total assembly size was 4,785,059 bp. XJ9S belonged to ST198 and harboured five acquired antimicrobial resistance genes, blaCTX-M-14b, sul1, tetA(A), aacCA5 and aadA7. blaCTX-M-14b gene was located on a 2,849-bp ISEcp1-mediated translocatable unit that was inserted into the chromosomal sequence. The other four acquired antimicrobial resistance genes were carried by a new variant of SGI1 (SGI1-XJ9S, 38,593 bp in size) belonging to SGI1-K group. Besides, point mutations in QRDR were found at positions 83 and 87 for GyrA, and at position 80 for ParC. Conclusion A new SGI1 variant, SGI1-XJ9S, was characterized in this study for the first time. The draft genome sequence of S. Kentucky ST198 strain XJ9S isolated from poultry slaughter house provides valuable information for tracing the potential spread of this MDR clone from poultry products processing to consumption, even to humans.