A legitimately sick bottomset spot? (NL50)

[CalledDownLight]

The minraise behind me followed by a coldcall from the guy that limp/called preflop does not look good to me at all. There are no flush draws and while overpairs are possible I think its unlike that I'm up against 2 overpairs and 55 and 77 still have 10 and 6 clean outs respectively. Both players appear taggy in the two orbits I've been at the table. Haven't seen either of them have a pot go past the flop. Never played with either player before this session. What do you guys think the best line here is?

PokerStars No-Limit Hold'em, $0.50 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

saw flop|<font color="#C00000">saw showdown</font>

UTG+1 ($149.20)
<font color="#C00000">Hero ($50)</font>
MP2 ($67.20)
<font color="#C00000">MP3 ($54.80)</font>
CO ($29.20)
Button ($35.95)
SB ($9.50)
BB ($50)
<font color="#C00000">UTG ($61)</font>

Preflop: Hero is MP1 with 3[img]/images/graemlins/diamond.gif[/img], 3[img]/images/graemlins/heart.gif[/img].
UTG calls $0.50, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to $2.5</font>, <font color="#666666">1 fold</font>, MP3 calls $2.50, <font color="#666666">4 folds</font>, UTG calls $2.

Flop: ($8.25) 6[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/club.gif[/img], 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
UTG checks, <font color="#CC3333">Hero bets $5.5</font>, <font color="#CC3333">MP3 raises to $11</font>, UTG calls $11, Hero does not like this spot at all. Obviously fold is not an option at this point so its shove or call and then either call or fold to a turn shove or shove myself.