Inducible Transcription Acts as a Sensor for Envelope Stress of .

infects a broad range of host animals, and zoonostic infection threatens both public health and the livestock and meat processing industries. Many antimicrobials have been developed to target envelope that performs essential bacterial functions; however, there are very few analytical methods that can be used to validate the efficacy of these antimicrobials. In this study, to develop a potential biosensor for envelope stress, we examined the transcription of the serovar gene, the ortholog of which in encodes Spy (spheroplast protein y). Spy is a chaperone protein expressed and localized in the periplasm of during spheroplast formation, or by exposure to protein denaturing conditions. expression in was examined by constructing a transcriptional fusion. transcription was strongly induced during spheroplast formation, and also when exposed to membrane-disrupting agents, including ethanol and the antimicrobial peptide polymyxin B. Moreover, induction required the activity of regulator proteins BaeR and CpxR, which are part of the major envelope stress response systems BaeS/BaeR and CpxA/CpxR, respectively. Results suggest that monitoring transcription may be useful to determine whether a molecule particularly cause envelope stress in .