• Administration of a live culture of Lactococcus lactis DPC 3147 into the bovine mammary gland stimulates the local host immune response, particularly IL-1β and IL-8 gene expression

      Beecher, Christine; Daly, Mairead; Berry, Donagh; Klostermann, Katja; Flynn, James; Meaney, William J; Hill, Colin; McCarthy, Tommie V; Ross, R Paul; Giblin, Linda; et al. (Cambridge University Press: Published for the Institute of Food Research and the Hannah Research Institute, 18/05/2009)
      Mastitis is one of the most costly diseases to the dairy farming industry. Conventional antibiotic therapy is often unsatisfactory for successful treatment of mastitis and alternative treatments are continually under investigation. We have previously demonstrated, in two separate field trials, that a probiotic culture, Lactococcus lactis DPC 3147, was comparable to antibiotic therapy to treat bovine mastitis. To understand the mode of action of this therapeutic, we looked at the detailed immune response of the host to delivery of this live strain directly into the mammary gland of six healthy dairy cows. All animals elicited signs of udder inflammation 7 h post infusion. At this time, clots were visible in the milk of all animals in the investigation. The most pronounced increase in immune gene expression was observed in Interleukin (IL)-1b and IL-8, with highest expression corresponding to peaks in somatic cell count. Infusion with a live culture of a Lc. lactis leads to a rapid and considerable innate immune response.
    • Molecular Characterisation of Bacteriophage K Towards Applications for the Biocontrol of Pathogenic Staphylococci

      O'Flaherty, Sarah; Flynn, James; Coffey, Aidan; Fitzgerald, Gerald F; Meaney, William J; Ross, R Paul (Teagasc, 01/01/2006)
      The aim of this work was to characterise staphylococcal bacteriophage (a bacterial virus) and to assess their potential as therapeutic agents against pathogenic strains of Staphylococcus aureus, particularly mastitis-causing strains. The project included the use of two newly isolated phage CS1 and DW2, and an existing polyvalent phage. The new phage were isolated from the farmyard and characterised by electron microscopy and restriction analysis. Both phage were shown to belong to the Siphoviridae family and were lytic for representatives of all three clonal groups of Irish mastitis-associated staphylococci. A cocktail of three phage (CS1, DW2 and K) at 108 (plaque forming units) PFU/ml was infused into cows teats in animal trials. The lack of an increase in somatic cell counts in milks indicated strongly that the phage did not irritate the animal. In addition, the most potent phage used in this study, phage K, was further studied by genome sequencing, which revealed a linear DNA genome of 127,395 base pairs, which encodes 118 putative ORFs (open reading frames).