English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

P. multocida  is the causative agent of a wide range of diseases of animals, including fowl cholera in poultry and wild birds. Fowl cholera isolates of  P. multocida  generally express a capsular polysaccharide composed of hyaluronic acid. There have been reports of spontaneous capsule loss in  P. multocida , but the mechanism by which this occurs has not been determined. In this study, we identified three independent strains that had spontaneously lost the ability to produce capsular polysaccharide. Quantitative RT-PCR showed that these strains had significantly reduced transcription of the capsule biosynthetic genes, but DNA sequence analysis identified no mutations within the capsule biosynthetic locus. However, whole-genome sequencing of paired capsulated and acapsular strains identified a single point mutation within the  fis  gene in the acapsular strain. Sequencing of  fis  from two independently derived spontaneous acapsular strains showed that each contained a mutation within  fis . Complementation of these strains with an intact copy of  fis , predicted to encode a transcriptional regulator, returned capsule expression to all strains. Therefore, expression of a functional Fis protein is essential for capsule expression in  P. multocida . DNA microarray analysis of one of the spontaneous  fis  mutants identified approximately 30 genes as down-regulated in the mutant, including  pfhB_2 , which encodes a filamentous hemagglutinin, a known  P. multocida  virulence factor, and  plpE , which encodes the cross protective surface antigen PlpE. Therefore these experiments define for the first time a mechanism for spontaneous capsule loss in  P. multocida  and identify Fis as a critical regulator of capsule expression. Furthermore, Fis is involved in the regulation of a range of other  P. multocida  genes including important virulence factors.

Fis Is Essential for Capsule Production in Pasteurella multocida and Regulates Expression of Other Important Virulence Factors