Immunocytochemical demonstration of Actinomyces species and Arachnia propionica in periapical infections

Abstract

Immunocytochemical methods were used for the demonstration of Actinomyces israelii, Actinomyces naeslundii and Arachnia propionica in bacterial colonies found in 7 routine biopsies from periapical inflammatory lesions. All 3 species were found in one specimen, both A. israelii and A. propionica in 3 specimens, and one of each species in the remaining 3 biopsies. Specificity controls by enzyme immunoassay showed that antiserum to A. israelii reacted also with A. odontolylicus, and that to A. naeslundii with A. viscosus, while antiserum to A. propionica did not show any cross‐reactions with Actinomyces species. The results indicate that immunocytochemical methods can be used for the diagnosis of periapical actinomycosis at the species level. Actinomyces and Arachnia species seem to have an important role in the pathogenesis of complicated periapical infections.

Fluorescence in situ hybridization (FISH) for direct visualization of bacteria in periapical lesions of asymptomatic root-filled teeth

“…The defence systems mobilized by periapical inflammation are believed first to eliminate the bacteria that invade the periapex. In long-standing infections with a more or less permanently established microflora in the root canal, the host defences appear to be less effective, and findings have been made suggesting that micro-organisms can survive outside the root canal system, on the root surface and/or in the periapical lesions of asymptomatic root-filled teeth (Happonen et al, 1985;Tronstad et al, 1987Tronstad et al, , 1990Iwy et al, 1990;Wayman et al, 1992;Gatti et al, 2000;Sunde et al, 2000a, b). Since tissue invasion is considered a major virulence factor of endodontic bacteria and complete Abbreviations: CLSM, confocal laser scanning microscopy; DAPI, 49,69-diamidino-2-phenylindole; FISH, fluorescence in situ hybridization; FITC, fluorescein isothiocyanate.…”

Synergistic Pathogenicity of Porphyromonas gingivalis and Fusobacterium nucleatum in the Mouse Subcutaneous Chamber Model

“…Survival in such a hostile environment should be less favorable than and different from bacterial survival in the sanctuary of a necrotic root canal. Mechanisms that allow bacterial evasion of phagocytosis are most likely necessary for bacteria to either survive in this niche as a true extraradicular infection (1)(2)(3)(4) or to simply survive extraradicularly for a period long enough to be sampled as viable bacteria (5); Porphyromonas gingivalis and Fusobacterium nucleatum are among the most frequently isolated bacterial species from both chronic suppurative apical periodontitis and abscesses of dental origin (6 -9, 10). They are commonly encountered together in mixed infections associated with these conditions.…”

Building biofilms in vital host tissues: a survival strategy of Actinomyces radicidentis

“…Traditionally, a diagnosis of actinomycosis in tissue sections has been reached on the basis of demonstration of typical "ray-fungus" colonies (1,4) and by specific immunohistochemical staining of such colonies. (5,6) Since the advent of molecular methods, an unequivocal identification and typing of the organism has been achieved by molecular genetic methods, particularly by sequencing of 16s rRNA gene and by whole cell protein profiling. (7) Recently, two strains of previously not described actinomyces-like organisms were recovered in pure culture from root canals of two teeth with persistent apical periodontitis.…”