you are right stranger , trustport indeed uses the AVG and BITDEFENDER and NORMAN engines.
TrustPort Antivirus is certainly effective antivirus software, honing the strength of two separate scanning engines. Both the Bitdefender and AVG scanners consistently perform well, but if one misses something it’s nice to have a second opinion. You can even designate which scanning engine is the first line of defense, and specify whether to use one or both for each type of scan (on-access and on-demand). And while it is normally not ok to run two real-time antivirus scanners at the same time, it’s perfectly fine to use both from TrustPort because they’re configured to not interfere with each other.
read here :
http://anti-virus-software-review.toptenreviews.com/trustport-antivirus-review.html
the 2012 version included the GFI / VIPRE engine