In Vitro Assessment of the Probiotic Potential of Lactococcus lactis LMG 7930 against Ruminant Mastitis-Causing Pathogens

Abstract

Mastitis in dairy ruminants is considered to be the most expensive disease to farmers worldwide. Recently, the intramammary infusion of lactic acid bacteria has emerged as a potential new alternative to antibiotics for preventing and treating bovine mastitis. In this study we have investigated in vitro the probiotic potential of Lactococcus lactis LMG 7930, a food-grade and nisin-producing strain, against mastitis-causing pathogens. We have characterized its carbohydrate fermentation and antibiotic susceptibility profiles, cell surface properties and antimicrobial activity, as well as its capabilities to adhere to and inhibit the invasion of pathogens into the bovine mammary epithelial cell line BME-UV1d. We found that L. lactis LMG 7930 was sensitive to tested drugs, according to the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP), and showed an improved carbohydrate fermentation capacity compared to starter strains. Moreover, the strain exhibited antagonistic properties towards many of the pathogens tested. It presented medium surface hydrophobicity, a low basic property and no electron acceptor capability. It showed low auto-aggregation and no co-aggregation abilities towards any of the tested pathogens. The strain was one of the most adhesive to bovine mammary epithelial cells among tested bacteria, but its internalisation was low. The strain did not affect significantly pathogen invasion; however, a trend to decrease internalization of some pathogens tested was observed. In conclusion, our results suggest that this strain might be a promising candidate for the development of new strategies of mastitis control in ruminants. Future investigations are needed to evaluate its safety and efficacy under field conditions.

A Controlled Fermented Samjunghwan Herbal Formula Ameliorates Non-alcoholic Hepatosteatosis in HepG2 Cells and OLETF Rats

“…Both L. brevis and L. lactis , the two most abundant bacterial species found in our FSJH preparation, are lactic acid bacteria, which are known to include many species with probiotic properties ( Ljungh and Wadstrom, 2006 ). Additionally, several lines of evidence indicate the strain-specific probiotic activities of L. lactis ( Yadav et al, 2009 ; Han et al, 2015 ; Lee et al, 2015 ; Armas et al, 2017 ; Oliveira et al, 2017 ) and L. brevis ( Rönkä et al, 2003 ; Linsalata et al, 2004 ; Fukao et al, 2013 ; Waki et al, 2014 ). Moreover, for the past few years, a large number of studies have revealed the probiotic health effects of L. plantarum ( Seddik et al, 2017 ).…”

Mastitis treatment—Reduction in antibiotic usage in dairy cows

“…Although some approaches show great promise for future treatment methods or at least for complemental therapy, there is no contemporary alternative available for in vivo administration (Gomes & Henriques, ). Several studies investigated the application of lactic acid bacteria (LAB) as mammary probiotics to inhibit in vitro growth of MCP, prevent or compete MCP biofilm formation or reduce IMI (Armas, Camperio, & Marianelli, ; Assis et al., ; Bouchard, Rault, Berkova, Le Loir, & Even, ; Bouchard et al., ; Piccart, Vásquez, Piepers, De Vliegher, & Olofsson, ).…”

A Critical Appraisal of Probiotics for Mastitis Control

“…Criteria used for the pre-selection of probiotic strains isolated from milk samples are the production of bacteriocins or other compounds interfering with the growth or survival of mastitis pathogens, the absence of known virulence factors or wide antibiotic resistance, and sometimes surface properties as indicators of the propensity to colonize an epithelium site ( 33 ). Probiotics used to prevent bacterial spoilage of cheese were also considered as mammary probiotic candidate and the capacity of the selected strain to adhere to and invade MECs was assessed ( 98 ).…”