BACKGROUND: Calcific aortic stenosis is a major public health problem in the United States. The mechanism of calcification remains unclear. The hypothesis that low grade chronic or recurrent bacterial endocarditis with specific calcifiable bacteria is a cause of calcification of the aortic valves was investigated using an animal model. Such bacteria are typically present as part of the normal human oral flora. METHODS: Forty New Zealand white rabbits were divided into four groups: group 1, control (1 ml of normal saline); group 2, Corynebacterium matruchotti 100,000 colonies; group 3, Streptococcus sanguis II 10 colonies; and group 4, C matruchotti 100,000 colonies plus S sanguis II 10 colonies. Animals were inoculated with bacteria through a flexible catheter placed through the aortic valve through a right carotid cut down. Inoculations were repeated every 3 days the first 2 weeks and then twice a week thereafter. At postmortem examination the aortic valves were harvested, embedded in paraffin, and stained with von Kossa stain. They were also examined by scanning and transmission electron micrography. RESULTS: Group 4 had 93.3% large calcifications (confluent calcium densities that are easily recognized with minimal magnification) and 6.6% small microcalcifications (dustlike microscopic particles requiring a compound microscope to appreciate) of the aortic valves. Group 3 exhibited large calcification in 20% and small in 40% of the aortic valves. Group 1 and group 2 had no evidence of calcification. CONCLUSIONS: These results suggest that recurrent low-grade endocarditis from calcifying oral bacteria, particularly when occurring with synergistic strains, may be one cause of calcific aortic stenosis.
BACKGROUND:Calcific aortic stenosis is a major public health problem in the United States. The mechanism of calcification remains unclear. The hypothesis that low grade chronic or recurrent bacterial endocarditis with specific calcifiable bacteria is a cause of calcification of the aortic valves was investigated using an animal model. Such bacteria are typically present as part of the normal human oral flora. METHODS: Forty New Zealand white rabbits were divided into four groups: group 1, control (1 ml of normal saline); group 2, Corynebacterium matruchotti 100,000 colonies; group 3, Streptococcus sanguis II 10 colonies; and group 4, C matruchotti 100,000 colonies plus S sanguis II 10 colonies. Animals were inoculated with bacteria through a flexible catheter placed through the aortic valve through a right carotid cut down. Inoculations were repeated every 3 days the first 2 weeks and then twice a week thereafter. At postmortem examination the aortic valves were harvested, embedded in paraffin, and stained with von Kossa stain. They were also examined by scanning and transmission electron micrography. RESULTS: Group 4 had 93.3% large calcifications (confluent calcium densities that are easily recognized with minimal magnification) and 6.6% small microcalcifications (dustlike microscopic particles requiring a compound microscope to appreciate) of the aortic valves. Group 3 exhibited large calcification in 20% and small in 40% of the aortic valves. Group 1 and group 2 had no evidence of calcification. CONCLUSIONS: These results suggest that recurrent low-grade endocarditis from calcifying oral bacteria, particularly when occurring with synergistic strains, may be one cause of calcific aortic stenosis.
Authors: Qingchun Zeng; Rui Song; David A Fullerton; Lihua Ao; Yufeng Zhai; Suzhao Li; Dov B Ballak; Joseph C Cleveland; T Brett Reece; Timothy A McKinsey; Dingli Xu; Charles A Dinarello; Xianzhong Meng Journal: Proc Natl Acad Sci U S A Date: 2017-01-30 Impact factor: 11.205
Authors: Carmen García-Rodríguez; Iván Parra-Izquierdo; Irene Castaños-Mollor; Javier López; J Alberto San Román; Mariano Sánchez Crespo Journal: Front Physiol Date: 2018-03-12 Impact factor: 4.566