Molecular Detection of Black-Pigmented Bacteria in Infections of Endodontic Origin

Abstract

A 16S rDNA-directed polymerase chain reaction method was used to assess the occurrence of four black-pigmented anaerobic rods in root canal infections. Samples were obtained from 54 infected teeth. Ten cases were diagnosed as acute periradicular abscesses. DNA was extracted from the samples and analyzed using a polymerase chain reaction-based identification assay. The method allowed detection of black-pigmented bacteria anaerobes in 59.3% of the examined teeth. Twelve cases yielded more than one black-pigmented species. In general Porphyromonas endodontalis was found in 42.6%, Porphyromonas gingivalis in 27.8%, Prevotella nigrescens in 7.4%, and Prevotella intermedia in 5.6% of the cases. P. endodontalis was found in 70% of the pus samples, P. gingivalis in 40%, and P. intermedia in 10%. P. gingivalis was always found associated with P. endodontalis in abscessed teeth. P. nigrescens was not found in any pus sample. The high prevalence of P. endodontalis and P. gingivalis suggests that they can play an important role in the pathogenesis of periradicular diseases.

Comparison of 16S rDNA-based PCR and checkerboard DNA–DNA hybridisation for detection of selected endodontic pathogens

“…In recent years, molecular methods have also been used to investigate the microbiota associated with infected root canals and with acute periapical abscesses [2,[9][10][11][12][13][14][15][16][17][18][19][20]. These methods have provided significant additional knowledge regarding the composition of the endodontic microbiota.…”

“…Furthermore, other fastidious bacterial species, such as Por. endodontalis [13,18], Slackia exigua [11], Mogibacterium timidum [11] and Eubacterium saphenum [11], have been reported in endodontic infections in higher prevalence values when molecular methods were used.…”

Bioactive Chitosan Nanoparticles and Photodynamic Therapy Inhibit Collagen Degradation In Vitro

“…In collagen gels treated with CSnp alone, there was increased resistance to collagenase-mediated degradation of collagen, as reported earlier (35). CSnp exhibit electrostatic attraction to collagen that is dependent on local environmental conditions, including the relative proximity of the carboxyl groups of collagen (-COO -) to the amino (-NH 3 + ) groups of chitosan and by chitosan associations mediated by hydrogen bonding (35).…”

“…CSnp exhibit electrostatic attraction to collagen that is dependent on local environmental conditions, including the relative proximity of the carboxyl groups of collagen (-COO -) to the amino (-NH 3 + ) groups of chitosan and by chitosan associations mediated by hydrogen bonding (35). The spatial co-localization between CSnp and collagen fibrils and stabilized collagen ultrastructure was noted in the scanning electron microscopy.…”

“…Collagenase is a potential virulence factor expressed by pathogenic bacteria associated with endodontic disease (28,35). The presence of collagenase gene prtC was confirmed in Porphyromonas gingivalis (29).…”