Characterization of Mammary Pathogenic E. coli and S. aureus and their Interaction with Commensal Bacteria in Bovine Udder

摘要

Bovine mastitis is the costliest infection that affects dairy cows, and it is estimated that this disease causes an economic loss of 665 million CAD from the Canadian economy annually (Aghamohammadi et al., 2018). Bovine mastitis is manifested by inflammation of mammary gland and caused by colonization of bacterial pathogens. The most commonly reported contagious and environmental pathogens are Staphylococcus aureus and Escherichia coli, respectively. Despite many efforts to reduce the occurrence ofthese infections, S'. aureus still remains as the most prevalent contagious pathogen and there has been an absolute increase in the environmental mastitis caused by E. coli (Klaas & Zadoks, 2018). Recent work has shown that the bovine udder is home to adiverse and extensive commensal bacterial population, and it is likely that this population provides some defense against pathogenic bacteria through competitive exclusion, production of inhibitory molecules, or direct inter-bacterial antagonism (Kuehn et al., 2013). In this work we aim to further define and characterize the interactions that take place between the established population of commensal bacteria and incoming bacterial pathogens in the bovine udder. A better understanding of these relationships may allow future optimization of the bovine udder microbiome for pathogen resistance.