RT Journal Article SR Electronic T1 Discovery of genes encoding a Streptolysin S-like toxin biosynthetic cluster in a select highly pathogenic methicillin resistant Staphylococcus aureus JKD6159 strain JF bioRxiv FD Cold Spring Harbor Laboratory SP 752204 DO 10.1101/752204 A1 Trevor Kane A1 Katelyn E. Carothers A1 Yunjuan Bao A1 Won-Sik Yeo A1 Taeok Bae A1 Claudia Park A1 Francisco R. Fields A1 Henry M. Vu A1 Daniel E. Hammers A1 Jessica N. Ross A1 Victoria A. Ploplis A1 Francis J. Castellino A1 Shaun W. Lee YR 2019 UL http://biorxiv.org/content/early/2019/08/31/752204.abstract AB Background Staphylococcus aureus (S. aureus) is a major human pathogen owing to its arsenal of virulence factors, as well as its acquisition of multi-antibiotic resistance. Here we report the identification of a Streptolysin S (SLS) like biosynthetic gene cluster in a highly virulent community-acquired methicillin resistant S. aureus (MRSA) isolate, JKD6159. Examination of the SLS-like gene cluster in JKD6159 shows significant homology and gene organization to the SLS-associated biosynthetic gene (sag) cluster responsible for the production of the major hemolysin SLS in Group A Streptococcus.Results We took a comprehensive approach to elucidating the putative role of the sag gene cluster in JKD6159 by constructing a mutant in which one of the biosynthesis genes (sagB homologue) was deleted in the parent JKD6159 strain. Assays to evaluate bacterial gene regulation, biofilm formation, antimicrobial activity, as well as complete host cell response profile and comparative in vivo infections in Balb/Cj mice were conducted.Conclusions Although no significant phenotypic changes were observed in our assays, we postulate that the SLS-like toxin produced by this strain of S. aureus may be a highly specialized virulence factor utilized in specific environments for selective advantage; studies to better understand the role of this newly discovered virulence factor in S. aureus warrant further investigation.