Some bacterial infections don't necessarily require an adaptive immunity response. Our innate immunity cells have receptors that recognize common pathogens. We even have a system that is just an elegant sequence of proteins being modified to create a pore in bacteria. This is just kicked off by sugars on the outside of the bacteria cell wall (although one such pathway is initiated by antibodies). In fact, certain organs are "immune privileged" and (mostly) do not allow T cells and B cells to infiltrate. But in all cases the invaders are destroyed by the immune system and the debris will find its way (whether or not it goes to the spleen first) to the liver or kidneys and get excreted like any other waste.