Bacterial life as we know it here on earth is too low fidelity for an honest-to-$deity, affectable-universe-spanning civ (just look at the temporal distance between a possible paspermia event in these terms in our solar system and replicating into the next couple of star systems).
An _actual_ replicating Von Neumann probe, that we can imagine working within the laws of physics today (even if we don't yet have the engineering capacity to build) can actually clone not just a couple of DNA strands, but can bootstrap an entire new sapient civilization, including technological progress, likely all the way down to the civ's culture.
It also follows: If it is possible that one civilisation spreads itself in this manner, it is likely that we are decedents of that civilisation. Simply because there will be many more copies of the original civilisation with a penchant for spraying their seed around than other kinds of civilisation.