Philip Ward

Publications (2)8.24 Total impact

• Source

  Available from: Duncan Maskell

  Article: Evidence for niche adaptation in the genome of the bovine pathogen Streptococcus uberis.

  Philip N Ward, Matthew T G Holden, James A Leigh, Nicola Lennard, Alexandra Bignell, Andy Barron, Louise Clark, Michael A Quail, John Woodward, Bart G Barrell, Sharon A Egan, Terence R Field, Duncan Maskell, Michael Kehoe, Christopher G Dowson, Neil Chanter, Adrian M Whatmore, Stephen D Bentley, Julian Parkhill
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  ABSTRACT: Streptococcus uberis, a Gram positive bacterial pathogen responsible for a significant proportion of bovine mastitis in commercial dairy herds, colonises multiple body sites of the cow including the gut, genital tract and mammary gland. Comparative analysis of the complete genome sequence of S. uberis strain 0140J was undertaken to help elucidate the biology of this effective bovine pathogen. The genome revealed 1,825 predicted coding sequences (CDSs) of which 62 were identified as pseudogenes or gene fragments. Comparisons with related pyogenic streptococci identified a conserved core (40%) of orthologous CDSs. Intriguingly, S. uberis 0140J displayed a lower number of mobile genetic elements when compared with other pyogenic streptococci, however bacteriophage-derived islands and a putative genomic island were identified. Comparative genomics analysis revealed most similarity to the genomes of Streptococcus agalactiae and Streptococcus equi subsp. zooepidemicus. In contrast, streptococcal orthologs were not identified for 11% of the CDSs, indicating either unique retention of ancestral sequence, or acquisition of sequence from alternative sources. Functions including transport, catabolism, regulation and CDSs encoding cell envelope proteins were over-represented in this unique gene set; a limited array of putative virulence CDSs were identified. S. uberis utilises nutritional flexibility derived from a diversity of metabolic options to successfully occupy a discrete ecological niche. The features observed in S. uberis are strongly suggestive of an opportunistic pathogen adapted to challenging and changing environmental parameters.
  BMC Genomics 02/2009; 10:54. · 4.07 Impact Factor
• Article: Generation and Characterization of a Defined Mutant of Streptococcus suis Lacking Suilysin

  Andrew G Allen, Steven Bolitho, Heather Lindsay, Shahid Khan, Clare Bryant, Pam Norton, Philip Ward, James Leigh, Jeremy Morgan, Helen Riches, Sarah Eastty, Duncan Maskell
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  ABSTRACT: A defined allelic-replacement mutant of the sly gene, encoding a thiol-activated cytolysin, from a European isolate of Streptococcus suis serotype 2 was generated and characterized. Unlike the parental strain, it is nonhemolytic, noncytotoxic for cultured macrophage-like cells, avirulent in a mouse infection model, yet only slightly attenuated in a porcine model of systemic infection.
  Infection and Immunity 05/2001; · 4.16 Impact Factor