Detection of Treponema denticola in atherosclerotic lesions

Abstract

We examined 26 atherosclerotic lesions and 14 nondiseased aorta specimens to detect the periodontopathogenic part of the bacterial 16S rRNA locus by PCR. Treponema denticola sequence of the 16S rRNA locus was found in 6 out of 26 DNA samples (23.1%) from the formalin-fixed, paraffin-embeded atherosclerotic lesions obtained during surgery but not in any of the 14 nondiseased aorta samples from deceased persons. Utilizing immunofluorescence microscopy, we observed aggregated antigenic particles reacting with rabbit antiserum against T. denticola in thin sections of the PCR-positive samples, but we could not detect any reacting particles in the PCR-negative thin sections.

FIG. 1

Amplified bands of the T. denticola 16S rRNA. Lanes 1 to 6, DNA samples extracted from the atherosclerotic aortas obtained from surgically excised tissue of patients with vascular disease (Table 1); Lane P, positive control; lane M, positive base pair markers. Strong bands are present in lanes 1 to 4, and faint bands are present in lanes 5 and 6 at positions, corresponding to the 316-bp T. denticola 16S rRNA fragment.

FIG. 2

(1A, 2A, 3A, and 4A) Thin sections of atherosclerotic lesions, stained with hematoxylin and eosin, in which strong T. denticola DNA bands were detected (Table 1 and Fig. 1). (1B, 2B, 3B, and 4B) Thin sections corresponding to panels 1A through 4A, respectively, stained with rabbit antiserum against T. denticola. Clear immunofluorescent particles can be observed in localized areas of foam cells or between small muscles in panels 1B through 4B. Bars, 20 μm.