What Causes Penis Swab To Test Positive For Enterococcus?

Hello I had a penis swab taken and it came back positive for Enterococcus. My doctor put me on anti biotics but the problem has still persisting with lower back back and redness around my penis. I have had tests done for sexual diseases e.g. clamydia, herpes etc and they all came back negative. What does this mean regarding the Enterococcus??