Candidate genes for this activity include mig-14 , virK and somA because inactivation of these PhoP-activated genes results in strains displaying increased susceptibility to polymyxin B ( Brodsky et al. , 2002 ; Detweiler et al. , 2003 ) .
These regulated genes included induction of PhoP-activated genes ( pags ) pagCDPOK , virK , mgtBC , and pgtE , and repression of sopBD2 and the PhoP-repressed genes ( prgs ) prgHIJK .
These regulated genes included induction of PhoP-activated genes -LRB- pags -RRB- virK .
Methods -- The TLC plates were covered by a staining solution containing agar , Luria-Bertani medium , 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside ( X-gal ) , kanamycin and a S. typhimurium strain that harbours a reporter transcriptional lacZ-fusion to an archetypal PhoP-activated gene virK .
( a ) Bioautography carried out with the S. typhimurium strain that harbours a reporter transcriptional lacZ-fusion to a PhoP-activated gene virK .
After development the solvent was removed and the plate was revealed by bioautography with a S. Typhimurium strain that harbours a reporter transcriptional lacZ-fusion to a PhoP-activated gene virK as described in the Methods section .
The overlay was prepared in a Falcon tube in conditions of sterility by mixing sterile LB-medium ( 20 mL ) containing agar ( 0.12 g ) at ca. 42 °C , with 20 mg/mL solution of X-gal ( 333 μL ) , 50 μg/mL solution of kanamycin ( 20 μL ) and 1 × 10 CFU/mL 8 of the S. typhimurium strain ( 100 μL ) that harbours reporter transcriptional lacZ-fusions to either the archetypal PhoP-activated gene virK ( 14028 virK : : lacZ ) or to a gene activated by the OmpR -- EnvZ two-compo-nent system , tppB ( 14028 tppB : : MudI ) .
Inhibitory activity was detected by overlaying the plate with an aqueous solution of soft agar containing X-gal and a homogeneous suspension of the S. typhimurium strain that harbours a reporter transcriptional lacZ-fusion to an archetypal PhoP-activated gene virK .
of the S. typhimurium str in that harbours reporter transcriptional lacZ-fusions to either the archetypal PhoP-activated gene virK or to a gene activated by the O