Lactococcus lactis subsp lactis CRL1655 and Schleiferilactobacillus perolens CRL1724 inhibit the adherence of common bovine mastitis pathogens to mammary gland cells, without causing histological changes in the mammary gland

Abstract

Aims:The present work assessed the ability of two selected lactic acid bacteria (LAB) strains (Schleiferilactobacillus perolens CRL1724 and Lactococcus lactis subsp. lactis CRL1655) to inhibit the adherence of bovine mastitis pathogens to mammary epithelial cells (MAC-T) and their effects (if any) on the structure of the gland after intramammary inoculation at dry-off. Methods and Results:Established bovine mammary epithelial cells (MAC-T) were used to assess the LAB strains' ability to inhibit the adherence of bovine mastitis pathogens. Monolayers of MAC-T cells were co-cultured with the LABs and then individual pathogen was added. Both strains prevented the adherence of S. aureus RC108, S. chromogenes, S. uberis UT102 and E. coli ATCC 35218. Adherence of the latter two pathogens was inhibited most strongly in vitro. To evaluate the effect of the LAB on the structure of the bovine udders, quarters were intramammary inoculated with the LAB mixture at dry-off. After slaughtering, the teats were dissected and histopathologically analysed. No modifications were identified post-inoculation in the structure of the epithelial, subepithelial and connective tissues of the mammary gland.Conclusions: Probiotic strains L. lactis subsp lactis CRL1655 and S. perolens CRL1724 were both able to inhibit the adherence of a number of bovine mastitis pathogens in vitro, and that the intramammary inoculation of these strains at the established dose and concentration did not cause significant alterations in the mammary epithelium nor had undesirable effects on tissues, and may therefore be considered harmless. Significance and Impact of Study:The promising findings demonstrated in this work support the potential of probiotic micro-organisms as a natural and effective alternative to prevent bovine mastitis during the dry-off period.

A Study on Differential Biomarkers in the Milk of Holstein Cows with Different Somatic Cells Count Levels

“…It is easy to survive and reproduce in a moist environment, which leads to cow mastitis [57,58]. Ma et al showed that there was a significant negative correlation between Acinetobacter_johnsonii and Lactococcus, and Lactococcus could inhibit the adhesion of common bovine mastitis pathogens to mammary gland cells and reduce the histological changes of mammary glands, so the antagonism of Acinetobacter_johnsonii and Lactococcus may indirectly aggravate the occurrence of mastitis [59,60]. Pseudomonas_aeruginosa is one of the pathogens of bovine mastitis.…”

Isolation of lactic acid bacteria from the reproductive tract of mares as potentially beneficial strains to prevent equine endometritis

“…Probiotic bacteria have been shown to signi cantly improve animal health and production, mainly due to their capacity to inhibit or control pathogens. They may do so by releasing organic acids, bacteriocins, or other antimicrobial agents; or by preventing colonization and/or the expression of virulence factors by some pathogens (Pellegrino et al 2019; Miranda and Nader-Macías 2020; Berardo et al 2022). Certain probiotics may also stimulate the host's own immune response (Pellegrino et al 2017;Berardo et al 2020;Mansilla et al 2020).…”