The passage of viable bacteria from the gastrointestinal tract to extra-intestinal sites, such as the mesenteric lymph node complex, liver, spleen, kidney, and blood. Factors that promote bacterial translocation include overgrowth with gram-negative enteric bacilli, impaired host immune defenses, and injury to the intestinal mucosa resulting in increased intestinal permeability. bacterial translocation from the lung to the circulation is also possible and sometimes accompanies MECHANICAL ventilation.