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What is With regard to surgical site infection, what is it called if bacteria are dividing and have invaded wound surface and explain in detail?
Contamination
Bacteria are on the wound surface. No division occurring


Colonization 
Bacteria are dividing


Tropical infection (Critical colonization)
Bacteria are dividing and have invaded the wound surface. There may be an increasing variety of bacteria present ; Biofilm may be present


Local infection
Bacteria and  / or their products have invaded the local tissue