We believe that the universe is not self caused. But how do we then explain the asexual reproduction of a bacteria that makes more copies of itself?
Interesting question!
A further answer from a different perspective:
The universe is a closed system and therefore caused by something outside itself (it is not something from nothing).
However, a bacterium is not a closed system - it takes in energy and material from the outside, and uses this to reproduce. So therefore it a different situation.
If it could originate itself or reproduce infinitely without feeding or requiring any materials or energy, this would be an example of self-causing its existence. (Thanfully this does not happen, or it we would be overwhelmed!)