Indestructibility and -1/-1 counters

[travolter]

Hector reported:

Creatures with -1/-1 counters (but not at 0 toughness) on them do not benefit from indestructibility ability. They get destroyed by lethal spell/combat damage and destroy effects.

I have tried counters with Contagion Clasp'ed, persisted, withered and infected creatures.

One peculiarity is that withered and infected creatures do benefit from indestructibility the turn they get wither/infect counters. But after that turn they can be destroyed by lethal damage/destroy effects like creatures with -1/-1 counters from other types of sources.

Contagion Clasp
Color= Artifact Type= Artifact Cost= 2 SOM(U)
Text (SOM): When ~this~ enters the battlefield, put a -1/-1 counter on target creature. ; 4, Tap: Proliferate