▁on ▁st ain less ▁steel ▁Un like ▁co pper ▁allo ys , ▁st ain less ▁steel ▁( S 3 0 4 0 0 ) ▁does ▁not ▁exhib it ▁any ▁degree ▁of ▁b acter ic idal ▁properties ▁against ▁E . ▁col i ▁O 1 5 7 : H 7 . ▁This ▁material , ▁which ▁is ▁one ▁of ▁the ▁most ▁common ▁touch ▁surface ▁materials ▁in ▁the ▁health care ▁industry , ▁allows ▁to xic ▁E . ▁col i ▁O 1 5 7 : H 7 ▁to ▁remain ▁vi able ▁for ▁weeks . ▁Near - zero ▁b acter ial ▁counts ▁are ▁not ▁observed ▁even ▁after ▁ 2 8 ▁days ▁of ▁investigation . ▁Ep if lu ores c ence ▁photograph s ▁have ▁demonstrated ▁that ▁E . ▁col i ▁O 1 5 7 : H 7 ▁is ▁almost ▁completely ▁killed ▁on ▁co pper ▁al loy ▁C 1 0 2 0 0 ▁after ▁just ▁ 9 0 ▁minutes ▁at ▁ 2 0   ° C ; ▁whereas ▁a ▁substantial ▁number ▁of ▁path og ens ▁remain ▁on ▁st ain less ▁steel ▁S 3 0 4 0 0 . ▁ ▁MR SA ▁ ▁M eth ic ill in - res istant ▁St ap hy loc oc cus ▁a ure us ▁( MR SA ) ▁is ▁a ▁dangerous ▁b acter ia ▁stra in ▁because ▁it ▁is ▁resist ant ▁to ▁beta - la ct am ▁ant ib iot ics . ▁Rec ent ▁stra ins ▁of ▁the ▁b acter ia , ▁E MR SA - 1 5 ▁and ▁E MR SA - 1 6 ,