Can acinetobacter cause a sinus infection?

Yes, : An infection can be caused by any bacteria that is in a place where it's not normal flora and/ or in increased number greater than normal.

Acinetobacter: This would be an unusual bacterial cause of sinusitis, but virtually any organism can produce infection under the proper circumstances. This organism most commonly infects the sinuses when the patient is nasally intubated or has a nasogastric feeding tube in place.