Research at Warwick: Mastitis in ewes Selin n Coope per r and - - PowerPoint PPT Presentation

Research at Warwick: Mastitis in ewes

Selin n Coope per r and Emma ma Monagha aghan

Determining the organisms and pathways of infection leading to mastitis in sheep

Selin Cooper

E-mail: Selin.cooper@Warwick.ac.uk Research Page http://go.warwick.ac.uk/ep/pg/lsrgbd

Mastitis: an overview

Definition

• Mastitis occurs when a bacterial infection in the udder causes inflammation
• It can be caused by a variety of bacteria

Identification

• Identified by the somatic cell count (SCC) in the milk, bacteriology and/or

clinical signs

Loss of half ↓ Yield

↓ LWG

Loss of half

Mastitis research at Warwick

• Understand the development of mastitis in the

udder from bacterial colonisation to the diseased state

• Understand the natural microbial community in the udder
• How this changes with time and age of ewe

DGGE MLST

Mastitis research at Warwick

PCR DNA sequencing Traditional culturing techniques Mass spectrometry PFGE Multilevel multivariable modelling

• Investigate the development of mastitis, from colonisation

with an infecting strain to development of disease

• Determine links between environmental strains of bacteria and

the intramammary infections they cause

• Identify management and environmental factors that are

associated with a ewe’s risk of developing mastitis

Mastitis research at Warwick

Same/different species/strains Same strains

Ewes with no clinical mastitis Ewes with clinical mastitis

Mastitis research at Warwick

Flock

• 100 pedigree Texel ewes

Number of samples

• 28 milk samples from ewes with clinical mastitis
• 5 milk samples from ewes without clinical mastitis
• 14 swabs

Sample storage

• Milk stored at -80°C with glycerol
• Swabs stored at -80°C in BHI and glycerol

Mastitis research at Warwick

Methods to use

• Culture and sterile streak all isolates identified
• Use MALDI-TOF-MS to identify species from the majority of samples
• Use species information to decide on which isolates to strain type
• Use PFGE to strain type
• Use statistical analyses to investigate links between isolates

Mastitis research at Warwick

Mastitis research at Warwick

Mastitis research at Warwick

Select a colony Prepare onto a MALDI target plate Generate MALDI-TOF profile spectrum

Identified species!

Data interpretation Unknown microorganism Mastitis research at Warwick

Strain A Strain B Strain A Strain B Strain B Strain B Strain B Masti titis tis Strain A Strain B Strain C

Milk Udder skin

Lambing Drying off Lambing

Laboratory testing  Milk Swabs Statistical analyses Multilevel modelling

Mastitis research at Warwick

http://go.warwick.ac.uk/ep/pg/lsrgbd This study

• Explore statistical correlaions between isolates
• Cluster identified and unidentified isolates
• Use PFGE to strain type selected isolates

Future studies

• Use similar techniques on larger longitudinal sample (samples already collected)
• Identify management and environmental risk factors based on a cross sectional study of

372 farms (data already collected)