(R)-2-((R)-((Z)-2-(2-aminothiazol-4-yl)-2-(((2-carboxypropan-2-yl)oxy)imino)acetamido)(carboxy)methyl)-5-(pyridin-1-ium-1-ylmethyl)-3,6-dihydro-2H-1,3-thiazine-4-carboxylate