AUTHOR=Peng Kai , Deng Jianping , Zou Nianli , Sun Xinran , Huang Weifeng , Li Ruichao , Yang Xiaorong 

TITLE=Emergence of the fourth mobile sulfonamide resistance gene sul4 in clinical Salmonella enterica

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1242369

DOI=10.3389/fmicb.2023.1242369

ISSN=1664-302X

ABSTRACT=<p>The fourth mobile sulfonamide resistance gene <italic>sul4</italic> has been discovered in many metagenomic datasets. However, there is no reports of it in cultured bacteria. In this study, a <italic>sul4</italic> positive clinical <italic>Salmonella enterica</italic> SC2020597 was obtained by conventional <italic>Salmonella</italic> isolation methods and characterized by species identification and antimicrobial susceptibility testing. Meanwhile, the genomic DNA was sequenced using both long-read and short-read methods. Following that, the complete genome was analyzed by bioinformatic methods. The <italic>sul4</italic> gene in <italic>S. enterica</italic> SC2020597 differed from the <italic>sul4</italic> identified in metagenomic data by one amino acid and could confer full resistance to sulfamethoxazole. Genetic location analysis showed that the <italic>sul4</italic> in SC2020597 was carried by a complex chromosomally integrated hybrid plasmid. IS<italic>CR20</italic>-like was strongly associated with the mobilization of <italic>sul4</italic> by core genetic context analysis. To the best of our knowledge, this is the first report of the emergence of <italic>sul4</italic> in clinically cultured <italic>S. enterica</italic>. More important, the <italic>sul4</italic> has the potential to spread to other bacteria with the help of mobile elements.</p>