Is microbial diversity of bovine mammary ecosystem correlated to mastitis susceptibility
Résumé
Inflammation and infection of bovine mammary glands, commonly known as mastitis, cause significant losses in the milk industry worldwide. To date, antibiotic treatment is the most common method to treat bovine mastitis. However it has a low cure rate during lactation for many mastitis pathogens, frequently resulting in chronic and recurrent infections. Our group explores new strategies to fight against mastitis. In the recent years, the concept of biological control has emerged as an interesting and sustainable alternative to antibiotics. The MEUH project (Milk Ecosystem and Udder Health) aims at describing bovine mammary microbiota in relation to mastitis sensitivity in cows. Cows were grouped according to their sanitary status over the past 3 years, as defined upon somatic cell counts in milk and clinical examinations. Three groups were defined: healthy, clinical mastitis sensitive, and subclinical mastitis sensitive cows. Samples (foremilk and swab) corresponding to the teat canal microbiota were collected on eight cows for each group. These samples are subjected to metagenomic pyrosequencing of bacterial 16S rRNA genes (ongoing, plateforme GEF, Rennes). We also plan to include a functional characterization of the bovine mammary microbiota through Illumina sequencing. Expected results include i) the determination of the composition of mammary microbiota according to the sanitary status (identification and proportion of each OTU), ii) the definition of a balanced versus unbalanced microbiota, and iii) the identification of marker species and functions correlated to mastitis susceptibility. These marker species will be further evaluated as candidates for the development of bovine mammary probiotics.