The innate immune modulators staphylococcal complement inhibitor and chemotaxis inhibitory protein of Staphylococcus aureus are located on beta-hemolysin-converting bacteriophages.
Two newly discovered immune modulators, chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS) and staphylococcal complement inhibitor (SCIN), cluster on the conserved 3' end of beta-hemolysin (hlb)-converting bacteriophages (betaC-phis). Since these betaC-phis also carry the genes for the immune evasion molecules staphylokinase (sak) and enterotoxin A (sea), this 8-kb region at the 3' end of betaC-phi represents an innate immune evasion cluster (IEC). By PCR and Southern analyses of 85 clinical Staphylococcus aureus strains and 5 classical laboratory strains, we show that 90% of S. aureus strains carry a betaC-phi with an IEC. Seven IEC variants were discovered, carrying different combinations of chp, sak, or sea (or sep), always in the same 5'-to-3' orientation and on the 3' end of a betaC-phi. From most IEC variants we could isolate active bacteriophages by mitomycin C treatment, of which lysogens were generated in S. aureus R5 (broad phage host). All IEC-carrying bacteriophages integrated into hlb, as was measured by Southern blotting of R5 lysogens. Large quantities of the different bacteriophages were obtained by mitomycin C treatment of the lysogens, and bacteriophages were collected and used to reinfect all lysogenic R5 strains. In total, five lytic families were found. Furthermore, phage DNA was isolated and digested with EcoR1, revealing that one IEC variant can be found on different betaI-phis. In conclusion, the four human-specific innate immune modulators SCIN, CHIPS, SAK, and SEA form an IEC that is easily transferred among S. aureus strains by a diverse group of beta-hemolysin-converting bacteriophages.
van Wamel
Willem J B
WJ
Eijkman-Winkler Institute, Room G04-614, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands. w.j.b.vanwamel@azu.nl
Rooijakkers
Suzan H M
SH
Ruyken
Maartje
M
van Kessel
Kok P M
KP
van Strijp
Jos A G
JA
D024509:3' Flanking Region; D001426:Bacterial Proteins / Q000235:genetics*; D001427:Bacterial Toxins / Q000378:metabolism*; D050577:Complement C3-C5 Convertases / Q000037:antagonists & inhibitors* / Q000235:genetics*; D004279:DNA, Viral / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005798:Genes, Bacterial / Q000235:genetics; D006460:Hemolysin Proteins; D006801:Humans; D007113:Immunity, Innate; D005810:Multigene Family; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism*; D013203:Staphylococcal Infections / Q000382:microbiology; D013204:Staphylococcus Phages / Q000235:genetics* / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000235:genetics* / Q000276:immunology
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004279:DNA, Viral; D006460:Hemolysin Proteins; C493134:chemotaxis inhibitory protein, Staphylococcus aureus; D013108:Sphingomyelin Phosphodiesterase; C029878:hlb protein, Staphylococcus aureus; D050577:Complement C3-C5 Convertases