I do not know if there is an actual written requirement for swing doors or allowing the use of door knobs on processing rooms. I would suggest that you explain to management that door knobs would be a source of contamination build up. You would need to assess the level of contamination, what cleaning is needed and then continue to test to determine the frequency of cleaning. This sounds like a lot of swabbing and plating and a significant cost. I would suggest that the door knobs be placed on an operational cleaning schedule. Cleaned every 20 minutes (or maybe every time the door is opened). I bet swing doors would be paid for in a matter of weeks when you cancel the wages to clean a door knob, the cost of testing and that person doing the cleaning could be doing other valuable activities instead (like production or operational sanitation).
Swing doors also need to be cleaned if they become contaminated but I would say less likely when employees are aware of how to pass through a swing door. Butt first with clean hands or gloved hands not touching anything.
Depending on the product you are manufacturing I would also like to see handwash stations on the inside of the rooms.
Hope this helps.