Beyond the chromosome: the prevalence of unique extra-chromosomal bacteriophages with integrated virulence genes in pathogenic Staphylococcus aureus.

Autor: Bryan Utter, Douglas R Deutsch, Raymond Schuch, Benjamin Y Winer, Kathleen Verratti, Kim Bishop-Lilly, Shanmuga Sozhamannan, Vincent A Fischetti
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: PLoS ONE, Vol 9, Iss 6, p e100502 (2014)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0100502
Popis: In Staphylococcus aureus, the disease impact of chromosomally integrated prophages on virulence is well described. However, the existence of extra-chromosomal prophages, both plasmidial and episomal, remains obscure. Despite the recent explosion in bacterial and bacteriophage genomic sequencing, studies have failed to specifically focus on extra-chromosomal elements. We selectively enriched and sequenced extra-chromosomal DNA from S. aureus isolates using Roche-454 technology and uncovered evidence for the widespread distribution of multiple extra-chromosomal prophages (ExPΦs) throughout both antibiotic-sensitive and -resistant strains. We completely sequenced one such element comprised of a 43.8 kbp, circular ExPΦ (designated ФBU01) from a vancomycin-intermediate S. aureus (VISA) strain. Assembly and annotation of ФBU01 revealed a number of putative virulence determinants encoded within a bacteriophage immune evasion cluster (IEC). Our identification of several potential ExPΦs and mobile genetic elements (MGEs) also revealed numerous putative virulence factors and antibiotic resistance genes. We describe here a previously unidentified level of genetic diversity of stealth extra-chromosomal elements in S. aureus, including phages with a larger presence outside the chromosome that likely play a prominent role in pathogenesis and strain diversity driven by horizontal gene transfer (HGT).
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