Mastitis remains one of the most important diseases in dairy cattle due to its negative consequences on animal welfare and productivity. Cases of clinical mastitis are generally treated without knowing the underlying cause of the disease, because current diagnostic tools are based on culture or PCR techniques, the results of which take at least one day.
More than 130 bacterial species have been associated with bovine mastitis, only 10 species or groups of species, however, are responsible for 95% of the infections. Most of these pathogens can be classified, into gram-positive (G+) or gram-negative (G-) bacteria depending on the characteristics of their cell wall. This differentiation is important to properly focus treatment, as infections caused by G- bacteria should not be treated with broad-spectrum antibiotics.