Key T3SS-related genes identified in bovine mastitis isolates include exlA, pcrD, and hopAJ2. Additionally, a range of other virulence and secretion system genes—such as clpV1, flgC, flgG, flgK, flgL, fliC, mucA, mucB, algD, algF, algA, pilV, pilY2, pvdF, pvdS, rhlR, rhlI, rhlA, rhlB, rhlC, tssB1, tssF1, tssG1, vgrG1, as well as components of the xcp (PA3095–PA3105) and hxc (PA0677–PA0687) secretion system are regulated by phosphate availability (56). This evidence concerns the gene RHOXF1P3 and mastitis.