Table 1.

Bacterial strains and plasmids used in this study

Strain or plasmidGenotype and/or relevant characteristicSource or reference
Strains
A. salmonicida
  AS1102Type strain, A-layer negativeNCIMB 1102
  644RbVirulent isolate, Nalr, A-layer positive 35
  MT1326Virulent isolate, A-layer positive 3
  CB3Undefined Tn5 mutant, decreased synthesis of extracellular proteins including GCAT and serine protease 6
  644RbΔG ΔsatA::kan, serine protease, A-layer positiveThis study
  644RbΔSP ΔaspA::kan, pro-GCAT, A-layer positiveThis study
  MT1326ΔG ΔsatA::kan, serine protease, A-layer positiveThis study
  MT1326ΔSP ΔaspA::kan, pro-GCAT, A layer positiveThis study
E. coli
  HB101Δ(gpt-proA)62 leuB6 supE44 ara-14 galK2 lacY1 Δ(mcrC-mrr) rpsL20 xyl-5 mtl-1 recA13 1
  DH5α recA1gyrA relA1 Δ(lacIZYA-argF)U169 deoR[φ80dlac lacZΔM15] 1
  S17-1 thi pro hsdR hsdM+ recA [RP4 2-Tc::Mu-Km::Tn7 (TprSmr) Tra+] 32
Plasmids
 pUC18/19Cloning and sequencing 1
 pBSKBluescript SKII, cloning and sequencingStratagene
 M13mp18/19Sequencing and mutagenesis 1
 pSUP202Mobilizable suicide vector (Ampr Tetr CamrColE1 ori Mob+) 32
 pSM20Levansucrase confers sucrose sensitivity (sacRB +Ampr) 31
 pRAT1Kanamycin resistance determinant, lacking transcriptional terminator, on 1.436-kbHaeII fragment from Tn903 D. Evans, University of Reading
 pMMB66HEBroad-host-range expression vector (Ampr) 17
 pSUP202sacMobilizable suicide vector, confers Sucs (Mob+ sacRB +Tetr)This study
 pUC18G satA on 1.2-kb PstI fragment, cloned in PstI site of pUC18 in reverse orientation to plac This study
 pUC19S satA on 5.5-kb SacI fragment inSacI site of pUC19This study
 pUC19SΔGpUC19S with Kan cassette replacing an internal fragment of satA This study
 pSUP202sacΔG SacI fragment from pUC19SΔsatA::kan inserted in pSUP202sacThis study
 pBSKSP aspA cloned in pBSKThis study
 pBSKΔSPpBSKSP with Kan cassette replacing small internal fragment of ΔaspA This study
 pSUP202sacΔSPΔaspA::kanon PstI fragment from pBSKSPΔaspA::kan in PstI site of pSUP202sacThis study
 pMMBG satAsubcloned on 1.2-kb PstI fragment in PstI site of pMMB66HE, under tac controlThis study
 M13mp18G+/− satA on 1.2-kb PstI fragment in forward or reverse orientation in PstI site of M13mp18This study
 pMMBG228-AlapMMBG encoding mutation of Gly-228 to Ala-228This study