INTRACELLULAR KILLING OF MASTITIS PATHOGENS BY PENETHAMATE HYDRIODIDE FOLLOWING INTERNALIZATION INTO MAMMARY EPITHELIAL CELLS

摘要

Research from our laboratory has shown that several mastitis pathogens adhere to and internalize into bovine mammary epithelial cells (1-3). We hypothesize that adherence and internalization are important virulence attributes of mastitis pathogens. Adherence is important for mastitis pathogens once they gain entrance inside the udder. Otherwise bacteria would be removed quite easily by fluid flow during milking. Internalization of mastitis pathogens into the cytoplasm of mammary epithelial cells allows pathogens an opportunity to reach the intracellular microenvironment. Once internalized, mastitis pathogens could infect deeper regions of the affected mammary gland resulting in the development of chronic intramammary infections. Following internalization, components of the immune system such as polymorphonuclear neutrophils, macrophages and antibodies; nonspecific antibacterial factors present in bovine milk; and antibiotics that do not cross mammary epithelial cell membranes are essentially ineffective. Therefore, it would appear that central to the control of several mastitis pathogens is the ability of antibiotic preparations used in the treatment of mastitis to penetrate into host cells and kill intracellular bacteria within the cytoplasm of mammary epithelial cells.