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Virulence related sequences; insights provided by comparative genomics of Streptococcus uberis of differing virulence

Hossain, Maqsud; Emes, Richard; Coffey, Tracey; Egan, Sharon; Ward, Philip N; Wilson, Ray; Leigh, James A


Maqsud Hossain

Richard Emes

Professor of Sustainable Livestock Production

Philip N Ward

Ray Wilson



Streptococcus uberis, a Gram-positive, catalase-negative member of the family Streptococcaceae is an important environmental pathogen responsible for a significant proportion of subclinical and clinical bovine intramammary infections. Currently, the genome of only a single reference strain (0140J) has been described. Here we present a comparative analysis of complete draft genome sequences of an additional twelve S. uberis strains.


Pan and core genome analysis revealed the core genome common to all strains to be 1,550 genes in 1,509 orthologous clusters, complemented by 115-246 accessory genes present in one or more S. uberis strains but absent in the reference strain 0140J. Most of the previously predicted virulent genes were present in the core genome of all 13 strains but gene gain/loss was observed between the isolates in CDS associated with clustered regularly interspaced short palindromic repeats (CRISPRs), prophage and bacteriocin production. Experimental challenge experiments confirmed strain EF20 as non-virulent; only able to infect in a transient manner that did not result in clinical mastitis. Comparison of the genome sequence of EF20 with the validated virulent strain 0140J identified genes associated with virulence, however these did not relate clearly with clinical/non-clinical status of infection.


The gain/loss of mobile genetic elements such as CRISPRs and prophage are a potential driving force for evolutionary change. This first “whole-genome” comparison of strains isolated from clinical vs non-clinical intramammary infections including the type virulent vs non-virulent strains did not identify simple gene gain/loss rules that readily explain, or be confidently associated with, differences in virulence. This suggests that a more complex dynamic determines infection potential and clinical outcome not simply gene content.


Hossain, M., Emes, R., Coffey, T., Egan, S., Ward, P. N., Wilson, R., & Leigh, J. A. (2015). Virulence related sequences; insights provided by comparative genomics of Streptococcus uberis of differing virulence. BMC Genomics, 16, 1-13.

Journal Article Type Article
Acceptance Date Apr 8, 2015
Publication Date Apr 23, 2015
Deposit Date May 23, 2018
Publicly Available Date Nov 19, 2018
Electronic ISSN 1471-2164
Publisher Springer Verlag
Peer Reviewed Peer Reviewed
Volume 16
Article Number 334
Pages 1-13
Public URL
Publisher URL
PMID 00035417


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