It's a costly and potentially dangerous road to go down in a manufacturing facility, bearing in mind that you must hold live cultures of pathogens for positive controls.
By all ,means carry out the routine TVC etc... stay well away from the pathogens unless you have a dedicated separate facility with the required level of containment.
Don't carry out microbiology without a trained technician, there is a reason we have been trained, ..... would you let an accountant do your plumbing?
The outlay for a dedicated pathogen testing laboratory will in the end prove prohibitive I would have thought, never mind the added Quality Manuals, ring testing, proficiency testing calibrations etc...
I set up a testing laboratory in the early 90's and it was no joke, it's still going by the way....I doubt equipment has become any cheaper!!