Virulence genetic profile of Escherichia coli and Klebsiella pneumoniae obtained from cows with clinical mastitis and expression of cytokines in infected epithelial cells.

Abstract

Bovine mastitis is an inflammation of the mammary glands, which could be caused by multiple etiologies and has difficult control. Mastitis causing pathogens may be of contagious or environmental origin, and the inflammation may manifestates with different degrees of severity, according to the type of the causing pathogen. It's a disease that causes great economic losses in the dairy industry and potential risks to public health, once these microorganisms can carry antimicrobial resistance genes against antimicrobials used in the treatment of diseases of animals and humans. Furthermore, some strains of microorganisms that cause mastitis produce enterotoxins and other virulence factors, which results in incresed risk of outbreaks of infections and foodborne toxins in humans. Escherichia coli and Klebsiella pneumoniae are among the main pathogens causing environmental bovine mastitis, whose pathogenesis involves multiple virulence factors that hinder the host's immune response. The present study aims to evaluate the pathogenic potential and inflammatory response of E. coli and K. pneumoniae, isolated from clinical cases of ten high yielding dairy farms located in the States of São Paulo and Minas Gerais. After the whole genome sequencing of 18 isolates (9 of the E. coli and 9 of the K. pneumoniae), it will be obtained information about virulence factors, antimicrobial resistance, and phylogenetic relationships, such as MLST. In order to better understand how these pathogens may influence the immune response of the host, the expression of cytokines TNF±, IL-1±, IL-1ß, IL-4, IL-6, IL-8, IL-10, IL-17 will also be evalutated by immunoassay (Milliplex) and by transcriptome in bovine mammary gland epithelial cell culture.