Okay, so this is not an STD. Testing semen is not an accurate way to test for STDs, and I'm guessing they are testing your semen for fertility testing?
So this is not my area, but this is what I found - and you should absolutely ask the doctor about it to confirm anything I say here -
Dysbacteriosis - https://en.wikipedia.org/wiki/Dysbiosis
Mixed etiology means more than one cause.
The things detected are all different bacteria. A quick google tells me that some aren't harmful, and some may cause infection.
Lacking normal microflora means that your body is lacking in the things that help keep everything in check. We all have good and bad bacteria in our bodies to help keep our systems going - even good bacteria can overgrow and cause problems, but it's all like a big checks and balances system.
Your body, especially your reproductive tract, may be lacking in that balance.
I don't know how that's treated, or if you are going through fertility testing, if that affects fertility. Again - not my area.
These are not STD bacteria, though.
If you need to test specifically for STDs, make sure they tested you specifically for things like gonorrhea, chlamydia, syphilis, herpes, etc. Those are not done on semen.