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Organisms, pathways and risks for mastitis


Mastitis is an inflammation of the mammary gland caused by an intramammary infection (IMI). It impacts on the health, welfare and productivity of sheep. In dairy sheep IMI results in a reduction in milk yield and altered milk composition. In suckler ewes (ewes suckling lambs) it can result in death, premature culling of ewes and decreased live-weight gain in lambs; all these result in economic losses. To date little research has been carried out on intramammary infections and the development of mastitis in suckler ewes.

The aim of this PhD is to improve our understanding of the development and persistence of intramammary infection and test the following hypotheses

  1. The mammary gland becomes infected with certain strains of bacteria that persist and ultimately lead to clinical disease.
  2. The skin of the ewe and/or lambs is a reservoir for some strains of bacteria that cause clinical IMI.
Transmission and persistence of strains of bacteria in the udder of suckler ewes 2010 - 2015

Different strains within a bacterial species can have varying pathogenicity, transmission and persistence characteristics. This project aims to understand where bacteria that enter the mammary gland originate from and whether they persist over time. We are focussing particularly on reservoirs of bacteria in the nose, throat and skin of ewes and lambs, and carriage of these bacteria into the udder, which might lead to mastitis.

Techniques used include traditional culturing, matrix assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-ToF-MS), and pulsed field gel electrophoresis (PFGE) in order to identify species, and differentiate strains of bacteria on sampled body sites and in ewe milk in longitudinal studies.

Risk factors for clinical mastitis in suckler ewes 2009- present

In 2009, a cross-sectional study of 372 farmers with suckler ewes was carried out. Farmers estimated that 0.1 - 5.0% of their flock were affected with clinical mastitis. We are investigating risk factors for clinical mastitis, focussing on management practices before, during and after the lambing period. This will provide hypotheses for further investigation in flock control of mastitis and eventually help farmers to manage their ewes to reduce the occurrence of clinical mastitis.


To find out more about my research background, including research projects, and my MRes, please click here.


Selin Cooper

School of Life Sciences
University of Warwick
Selin dot Cooper at warwick dot ac dot uk


Professor Laura Green Laura dot Green at warwick dot ac dot uk
Dr Kevin Purdy K dot Purdy at warwick dot ac dot uk
Dr Andrew Bradley andrew dot bradley at qmms dot co dot uk



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