TABLE 1.

Strains and plasmids used in this study

Strain or plasmidGenotype, description, and/or relevant featuresReference or source
Strains
    RdBA042; H. influenzae capsule-deficient type d89
    RdHARd ΔnrfA::hel-ha; nrfA deletion-replacement strain containing a C-terminal HA epitope fusion to the hel gene driven by the nrfA promoter, replacing nrfAThis study
    RnrfACRdHA xylAΔ4-804::nrfA; nrfA mutant complemented with nrfA expressed via the nrfA promoter from pXTnrfC, replacing xylAThis study
    RfnrRd fnr′::nptII; fnr mutant with Kmr transposon insertion in fnrThis study
    RfnrVRfnr xylAΔ4-804::tetAR; fnr mutant carrying empty Tetr vector sequence from pXT10, replacing xylAThis study
    RfnrCRfnr xylAΔ4-804::fnr; fnr mutant complemented with fnr expressed via the fnr promoter from pXTfnrC, replacing xylAThis study
    RHAfnrRdHA fnr′::nptII; Pnrf-hel-HA reporter strain and fnr mutant with Kmr transposon insertion in fnrThis study
    RHAfnrVRHAfnr xylAΔ4-804::tetAR; Pnrf-hel-HA reporter strain and fnr mutant carrying empty Tetr vector sequence from pXT10, replacing xylAThis study
    RHAfnrCRHAfnr xylAΔ4-804::fnr; Pnrf-hel-HA reporter strain and fnr mutant complemented with fnr expressed via the fnr promoter from pXTfnrC, replacing xylAThis study
    RVRd xylAΔ4-804::tetAR; parental Rd carrying a deletion of nonessential phase-variable repeats in lic1A and empty Tetr vector sequence from pXT10, replacing xylA89
    RytfeVRd ΔytfE::aacCI xylAΔ4-804::tetAR; ytfE mutant carrying empty Tetr vector sequence from pXT10, replacing xylAThis study
    RytfeCRd ΔytfE::aacCI xylAΔ4-804::ytfE; ytfE mutant complemented with ytfE expressed via ytfE promoter from pXTPytfeC, replacing xylAThis study
    NT127Nontypeable H. influenzae clinical isolateR. Husson
    NTVNT127 xylAΔ4-804::tetAR; contains Tetr vector sequence from pXT10, replacing xylAThis study
    NytfeVNT127 ΔytfE::aacCI xylAΔ4-804::tetAR; ytfE mutant carrying empty Tetr vector sequence from pXT10 replacing xylAThis study
    NytfeCNT127 ΔytfE::aacCI, xylAΔ4-804::ytfE; ytfE mutant complemented with ytfE expressed via the xylA promoter from pXTytfeC replacing xylAThis study
Plasmids
    pXT10Delivery vector for chromosomal expression at the H. influenzae xylose locus, containing xylF, xylB, xylAΔ4-804, and the tetAR tetracycline resistance cassette90
    pXTnrfCpXT10 carrying nrfA expressed from the nrfA promoterThis study
    pXTfnrCpXT10 carrying fnr expressed from the fnr promoterThis study
    pXTPytfeCpXT10 carrying ytfE expressed from the ytfE promoterThis study
    pXTytfeCpXT10 carrying ytfE expressed from the xylA promoterThis study
    pBNheltagpBR322 vector carrying the Pnrf-hel-HA reporter constructThis study