Is there a specific type of semen culture that provides quantitative results about enterococcus, in order to see medication effectiveness?

Go see your doctor: You shouldn't have enterococcus in your semen so however diagnosis was made, you can ask your doctor to repeat it to prove that you're cured. Typically, we identify bacterial organism via culture & sensitivity. That tells us what antibiotics the organism is sensitive to. If you can finish appropriate antibiotics as directed by sensitivities, then usually no need for test of cure.