Another battle in the same war: Escherichia coli, dairy cattle and antibiotics.

Extraintestinal pathogenic Escherichia coli (ExPEC) represent a major burden in the human and veterinary sectors. In the dairy industry, ExPEC are responsible for causing bovine mastitis, which is the costliest disease affecting the industry, at approximately €2 billion every year in Europe. Current measures for the treatment and prevention of mastitis rely heavily on the application of antibiotics, however this reliance promotes the development of antibiotic resistance. Not all strains of ExPEC have the potential to cause mastitis, but the ExPEC responsible for causing the disease have recently been characterised as a new class of mammary pathogenic E. coli (MPEC). Genotypic analyses have identified that the ferric citrate uptake (Fec) system of E. coli is utilised by all MPEC and serves as an appealing target for novel antimicrobial compounds designed specifically to target MPEC, without the risk of increasing antimicrobial resistance in bacteria that are not the intended target of the treatment. The aim of this project is to further characterise the role of the Fec system and to, ultimately, identify novel antimicrobial compounds to selectively inhibit the growth of MPEC in situ to prevent the onset of the disease.