Would 1500 mg/day of amoxicillin taken for 5 days be sufficient to abort incubating syphilis? 

Repetitive question which has been answered.  You've been warned.  See my prior replies.  This thread will now be closed.  EWH---

Sorry Dr. Hook, but this specific question was never explicitly asked or answered in any of my previous questions except for the last one which wasn’t answered. 

As explained repeatedly, your concerns are misplaced.  We have recommended counseling which you have apparently ignored.  ---

Thank you Dr. Hook. I’m sorry to still be coming to this site looking for answers. I wish I’d tested much earlier and closer to the time of my encounters. I wish I hadn’t taken any antibiotics that could have potentially caused years later results to be negative. Low risk exposures or not, negative test results or not, the uncertainty and theoretical possibility of acquiring syphilis, passing it to my spouse, inadvertently curing it with antibiotics, and later seroreverting (although rare in occurrence), is mentally insurmountable. This scenario makes it so I can never know if my now negative test results are a true reflection that I couldn’t have infected my spouse somewhere along the way years ago. Current negative treponemal test results for both me and my former partner should be the proof that neither of us ever had it, but the minute possibility of the scenario above makes it less so. Thank you for your time and continued suggestion to get counseling, but honestly I don’t see how it can help me as long as I continue to keep this from my spouse. Life is complicated.

Final response.  Once again I urge you to seek professional counseling.  The "insurmountable" scenario you describe is no more likely than that you will be struck by lightening while reading this reply.  You need to address this and are not succeeding in doing this yourself.  I say this out of concern for you- nothing more.---