Pulsed-Field Gel Electrophoresis (PFGE): Application in Population Structure Studies of Bovine Mastitis-Causing Streptococci

Part of the Methods in Molecular Biology book series (MIMB, volume 1247)


Pulsed-field gel electrophoresis (PFGE) separates large DNA molecules by the use of an alternating electrical field, such that greater size resolution can be obtained when compared to normal agarose gel electrophoresis. PFGE is often employed to track pathogens and is a valuable typing scheme to detect and differentiate strains. Particularly, the contour-clamped homogeneous electric field (CHEF) PFGE system is considered to be the gold standard for use in epidemiological studies of many bacterial pathogens. Here we describe a PFGE protocol that was applicable to the study of bovine streptococci, namely, Streptococcus agalactiae (group B Streptococcus, GBS), Streptococcus dysgalactiae subsp. dysgalactiae (group C Streptococcus, GCS), and Streptococcus uberis—which are relevant pathogens causing mastitis, a highly prevalent and costly disease in dairy industry due to antibiotherapy and loss in milk production.

Key words

Bovine mastitis Streptococcus agalactiae Streptococcus dysgalactiae subsp. dysgalactiae Streptococcus uberis Molecular typing Molecular epidemiology Pulsed-field gel electrophoresis PFGE Alternating electrical field CHEF 



The PFGE data mentioned in this chapter were obtained by Márcia Rato as part of her research leading to Ph.D. thesis. Fundação para a Ciência e a Tecnologia (FCT) is acknowledge for the financial support for the accomplishment of Márcia Rato Doctoral Project (SFRH/BD/32513/2006). The work was supported by the grants Pest-OE/BIA/UI0457/2011-CREM (Centro de Recursos Microbiológicos) and PROC 60839, funded by Fundação para a Ciência e Tecnologia, Portugal and Fundação Calouste Gulbenkian, Portugal (respectively).


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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.Faculdade de Ciências e Tecnologia (FCT), Centro de Recursos Microbiológicos (CREM) and Research Unit on Applied Molecular Biosciences (UCIBIO, REQUIMTE)Universidade Nova de Lisboa (UNL)Caparica, LisbonPortugal
  2. 2.Faculdade de Ciências (FC), Centro de Biodiversidade, Genómica Integrativa e Funcional (BioFig)Universidade de Lisboa (UL)LisbonPortugal

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