First they state this
"A variety of bacteria and fungi have been cultured from nasal polyps,
but approximately 35% have sterile cultures."
meaning most people have bacteria in their sinuses.
Then they turn around and say this
"CONCLUSIONS: This study suggests that chronic bacterial infection is
not a major component of nasal polyp etiology."

Personaly I think it is difficult to find the pathogen which may or
may not cause the polyps. It could even be irritants like allergies.
My view is wash the sinuses out with "any type of abx" and see if
polyps form after that. Nice post. btw strep in the sinuses is what I
had. That is NASTY.