Wow, this guy looks desperate - he left you five negative feedbacks without any reference. I don't believe that he are doing it without any reason. Maybe in past you reported him or his alt as scammer and he is angry at you.
He isn't DT member, so his feedbacks doesn't affect your trust score. But this red color definitely doesn't looks goid on your profile. Unfortunately, not much can be done, because trust aren't moderated on Bitcointalk. I'm not sure, maybe some DT members can red tag him for leaving fake trust.