title: The Pasteurella multocida nrfE gene is upregulated during infection and is essential for nitrite reduction but not for virulence.
abstract: Pasteurella multocida is the causative agent of a range of diseases with economic importance in production animals. Many systems have been employed to identify virulence factors of P. multocida, including in vivo expression technology (IVET), signature-tagged mutagenesis, and whole-genome expression profiling. In a previous study in which IVET was used with P. multocida, nrfE was identified as a gene that is preferentially expressed in vivo. In Escherichia coli, nrfE is part of the formate-dependent nitrite reductase system involved in utilizing available nitrite as an electron accepter during growth under anaerobic conditions. In this study, we constructed an isogenic P. multocida strain that was unable to reduce nitrite under either aerobic or anaerobic conditions, thereby demonstrating that P. multocida nrfE is essential for nitrite reduction. However, the nrfE mutant was still virulent in mice. Real-time reverse transcription-PCR analysis indicated that nrfE was regulated independently of nrfABCD by an independent promoter that is likely to be upregulated in vivo.
authors.affiliation: Australian Research Council Centre for Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Victoria 3800, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Boucher
authors.forename: Ben
authors.initials: B
authors.lastname: Adler
authors.forename: John D
authors.initials: JD
authors.lastname: Boyce
mesh_terms: D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D005260:Female; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009572:Nitrite Reductases / Q000096:biosynthesis / Q000235:genetics*; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D010326:Pasteurella Infections / Q000382:microbiology; D016979:Pasteurella multocida / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D015854:Up-Regulation; D014774:Virulence / Q000235:genetics
chemical_list: D009573:Nitrites; D009572:Nitrite Reductases