(7aR,7R)-7-{[(4Z)-5-{5-[({[({3-[(4Z)-6-{[(7aR,7R)-4-carboxylato-3-{[4-(1-methylpyridin-1-ium-4-yl)-1,3-thiazol-2-yl]sulfanyl}-6-oxo-2,6,7,7a-tetrahydroazeto[2,1-b][1,3]thiazin-7-yl]amino}-6-oxo-4-aza-3-oxahex-4-en-5-yl]-1,2,4-thiadiazol-5-yl}amino)(hydroxy)(oxo)-λ5-phosphanyl]oxy}(hydroxy)(oxo)-λ5-phosphanyl)amino]-1,2,4-thiadiazol-3-yl}-6-oxo-4-aza-3-oxahex-4-en-6-yl]amino}-3-{[4-(1-methylpyridin-1-ium-4-yl)-1,3-thiazol-2-yl]sulfanyl}-6-oxo-2,6,7,7a-tetrahydroazeto[2,1-b][1,3]thiazine-4-carboxylate