RT Journal Article SR Electronic(1) A1 Mignacca, Sebastian Alessandro A1 Dore, Simone A1 Spuria, Liliana A1 Zanghì, Pietro A1 Amato, Benedetta A1 Duprè, Ilaria A1 Armas, Federica A1 Biasibetti, Elena A1 Camperio, Cristina A1 Lollai, Stefano A. A1 Capucchio, Maria Teresa A1 Cannas, Eugenia Agnese A1 Di Marco Lo Presti, Vincenzo A1 Marianelli, CinziaYR 2017 T1 Intramammary infusion of a live culture of Lactococcus lactis in ewes to treat staphylococcal mastitis JF Journal of Medical Microbiology, VO 66 IS 12 SP 1798 OP 1810 DO https://doi.org/10.1099/jmm.0.000641 PB Microbiology Society, SN 1473-5644, AB Purpose. Alternatives to antibiotic therapy for mastitis in ruminants are needed. We present an evaluation, in two trials, of the efficacy of an intramammary infusion of a live culture of Lactococcus lactis for the treatment of subclinical and clinical mastitis in ewes. Methodology. In total, 67 animals were enrolled: 19 lactating ewes (study 1), including healthy (N=6) and coagulase-negative staphylococci (CNS)-infected ewes (N=13); and 48 lactating ewes (study 2) with either CNS mastitis (N=32), or Staphylococcus aureus mastitis (N=16), for a total of 123 mammary glands. Intramammary infusions were performed with either L. lactis or PBS for 3 (study 1) or 7 (study 2) consecutive days. Antibiotic-treated and untreated control glands were included. Milk samples for microbiology, somatic cell analysis and milk production were collected before and after treatment. Results/Key findings. L. lactis rapidly activated the mammary glands' innate immune response and initiated an inflammatory response as evidenced by the recruitment of polymorphonuclear neutrophils and increased somatic cell counts. But while leading to a transient clearance of CNS in the gland, this response caused mild to moderate clinical cases of mastitis characterized by abnormal milk secretions and udder inflammation. Moreover, S. aureus infections did not improve, and CNS infections tended to relapse. Conclusion. Under our experimental conditions, the L. lactis treatment led to a transient clearance of the pathogen in the gland, but also caused mild to moderate clinical cases of mastitis. We believe it is still early to implement bacterial formulations as alternatives in treating mastitis in ruminants and further experimentation is needed., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000641