Table 1 Strains and plasmids used in this study.

Strains

E. coli DH5αZ1

Δ(argF-lac)169 ϕ80Δlac Z58(M15) gln V44 (AS) rfb D1 gyr A96 (Nal^R) rec A1 end A1 spo T1 thi-1 hsdR1 7 Z1(lacR tetR Sp^R)

[36]

S. aureus RN4220

Avirulent mutant of NCTC 8325-4 that accepts foreign DNA

[43]

S. aureus RN6390

Laboratory virulent strain derived from NCTC 8325

[43]

S. aureus COL

Highly methicillin resistant clinical isolate

[44]

S. aureus Newman

Virulent strain containing a high level of Clumping Factor

[45]

S. aureus RN4220 hfq

RN4220, Δhfq::cat, Cm^R

This work

S. aureus RN6390 hfq

RN6390, Δhfq::cat, Cm^R

This work

S. aureus COL hfq

COL, Δhfq::cat, Cm^R

This work

S. aureus Newman hfq

Newman, Δhfq::cat, Cm^R

This work

Plasmids

PMAD

Thermosensitive plasmid in S. aureus derived from pRN5101 and containing the bgaB gene, Ery^R, Amp^R

[38]

pMADΔhfq::cat

pMAD containing up- and downstream regions from hfq gene cloned on either side of the Cm cassette (cat); used for construction of the S. aureus RN4220 hfq mutant, Ery^R, Amp^R, Cm^R, bgaB

This work