Author(s)

Abir Maalaoui^1,2, Abdesselem Trimeche², Pierre Guy Marnet³, Yann Demarigny^4*

¹Institut Supérieur Agronomique de Chott Mariem, Université de Sousse, Sousse, Tunisie.
²Laboratoire de gestion de la santé et de la qualité des productions animales, Ecole Nationale de Médecine Vétérinaire de Sidi Thabet, Université de La Manouba, Manouba.
³Department of Animal Science and Production, AGROCAMPUS OUEST, Rennes, France.
⁴Bioengineering and Microbial Dynamic at Food Interfaces (Associated team n°3733 (BioDyMIA), University of Lyon 1-ISARA Lyon), Isara-Lyon, Agrapole-23 rue Jean Baldassini, F-69364 Lyon Cedex 07, France.

Bovine mastitis affects the udder health and thus causing significant economic losses. Probiotic products based on the use of lactic acid bacteria (LAB) to limit pathogens multiplication and pre-infection risks can be an interesting alternative to post infection allopathic treatment with antibiotics. Lactococcus lactis is one of the most important bacteria used in dairy technology. In this work, a total of 21 Lactococcus lactis subsp. Lactis strains, 20 from goat milk whey and one strain from cow milk were used to evaluate their antibacterial activity against four pathogenic germs responsible for mastitis: Escherichia coli, Staphylococcus aureus, Streptococcus uberis and Streptococcus agalactiae. The nisin-producing cow milk strain was active against St. uberis and Str. Agalactiae using the well diffusion method. For the strains isolated from goat milk whey, no antimicrobial effect was observed against these pathogens. However, a different approach based on the growth of pathogenic bacteria interacting with the Lactococcus lactis strains in a minimum medium was used to study the barrier effect of LAB. The Lactococcus lactis strains S1 and S2 from goat milk whey depleted the growth of Sa. aureus, St. uberis and E. coli during 8 h and stopped the development of St. agalactiae.

Lactococcus lactis, Minimal Medium, Pathogenic Bacteria, Antibacterial Activity, Barrier Effect

Maalaoui, A. , Trimeche, A. , Marnet, P. and Demarigny, Y. (2020) Use of Lactococcus lactis Subsp. Lactis Strains to Inhibit the Development of Pathogens. Food and Nutrition Sciences, 11, 98-112. doi: 10.4236/fns.2020.112009.