Arterial thrombosis after intravenous infusion of oral bacterium in a rat model

Oral bacteria have been detected at atherosclerotic plaque, aneurysms, and thrombosed arteries in Buerger disease. We explored a possible relationship between the oral bacterium Porphyromonas gingivalis and arterial thrombosis at proximal and distal sites in rats. Eighteen rats underwent subcutaneous placement of an infusion pump connected to the jugular vein. The Pg infusion group received a continuous infusion of P. gingivalis for 2 weeks, and the controls received normal saline. At 2 and 4 weeks, specimens were obtained from the iliac, superficial, and below-knee arteries, which were studied pathologically and by polymerase chain reaction (PCR) analysis to detect P. gingivalis-specific DNA. The Pg infusion group had thrombosis in 33.3% at 2 weeks and in 55.6% at 4 weeks, but normal arterial wall structure was preserved without any features of infection. Positive PCR findings were recognized in 73.3% and 22.2% at 2 and 4 weeks, respectively. At 4 weeks, thrombosis was observed in a higher proportion, with the below-knee specimens having an especially high thrombus rate (83.3%). No control specimen had thrombosis or positive PCR results. Bacteremia due to the oral pathogen P. gingivalis may lead to thrombus formation in the peripheral arteries, especially in small-sized arteries.