Table 1 Bacterial strains and plasmids used in this study

 pQK663

Asd⁺ vector, p15A ori, spec^r

Derived from pYA3332 [26]

 pQK163

Insertion of crp into pQK663

This work

 pET-32a-crp

For the expression of P. multocida Crp

This work

 pMC-Express

A broad host-range shuttle vector derived from pMIDG100, chloramphenicol^r

[27]

 pYA4278

pRE112 derivative, sacB mobRP4 R6K ori Cm⁺

[29]

 pQK174

pYA4278-Δcrp

This work

 pQK175

pYA4278-Δcrp::kan, for deletion of crp in P. multocida 0818

This work

 pQK176

Insertion of crp into pMC-Express

This work

 S184

S. Typhimurium Δasd66

Lab collection

 S411

S. Typhimurium Δasd66 Δcrp89

Lab collection

  P. multocida 0818

Wild-type and virulent. Capsular serotype A:1.

Lab collection

 S416

P. multocida 0818 Δcrp::kanR

This work

 χ7232

E.coli K-12, endA1 hsdR17 (r_K-, m_K +) glnV44 thi-1 recA1 gyrA relA1 Δ(lacZYA-argF)U169 λpir deoR (ϕ80dlac Δ(lacZ)M15)

[30]

 χ7213

E.coli K-12, thi-1 thr-1 leuB6 glnV44 fhuA21 lacY1 recA1 RP4-2-Tc::Mu λpir ∆asdA4 ∆zhf-2::Tn10

[30]