We report the genome sequence of
Staphylococcus aureus
PS/BAC/169/17/W, which was isolated in 2017 from a contaminated platelet concentrate at the National Health Service Blood and Transplant. Assessment of the genome sequence of this strain showed the presence of a 2,753,746-bp chromosome and a plasmid of 2,762 bp.
We present the genome sequence of
Staphylococcus aureus
CI/BAC/25/13/W, which was isolated in 2013 as a contaminant of a platelet concentrate with abnormal clotting at the National Health Service Blood and Transplant. Assessment of the genome sequence showed the presence of one chromosome (2,719,347 bp) and one plasmid (1,533 bp).
Background and Objectives
Staphylococcus aureus is a predominant contaminant of platelet concentrates (PCs) that can evade detection during screening with culture methods. Importantly, S. aureus produces staphylococcal enterotoxins (SEs) during PC storage, which are linked to slow growth and enhanced biofilm formation. This study investigated timing of SE production during PC storage and feasibility of SE detection as a PC safety strategy.
Materials and Methods
Genomic and transcriptomic data of transfusion‐relevant S. aureus PS/BAC/169/17/W, PS/BAC/317/16/W, CI/BAC/25/13/W and CBS2016‐05 were used to determine the presence and differential expression of exotoxin genes in PCs. Trypticase soy broth (TSB) and PCs were inoculated with 1.0E+06 cfu/mL of S. aureus PS/BAC/169/17/W and CBS2016‐05. Expression of SEs at different growth phases was confirmed with Western blotting. PCs were inoculated with 30 cfu/unit of the same strains, and SE detection during PC storage was optimized with a sandwich dot‐ELISA assay.
Results
S. aureus genomes contain multiple exotoxin genes including those encoding for SEs. Transcriptome data revealed significant upregulation (0.5–6.7‐fold, p < 0.05) of SE genes in PCs versus TSB. Western blots demonstrated SE production at all growth phases. Notably, dot‐ELISA detected clinically relevant concentrations of SEs (~0.2 μg/mL) at 32 h of PC storage when S. aureus PS/BAC/169/17/W and CBS2016‐05 counts were 1.8E+04 and 1.4E+04 cfu/mL, respectively.
Conclusion
Genomic analyses revealed that staphylococcal exotoxins are widely distributed and highly conserved among transfusion‐relevant S. aureus isolates. Furthermore, SEs are significantly upregulated in PCs and detected at 30 h of PC storage. Therefore, bacterial toxin detection could supplement mitigation strategies to enhance PC safety.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.