Persistence of dead-cell bacterial DNA in ex vivo root canals and influence of nucleases on DNA decay in vitro

Preservation of Fusobacterium nucleatum and Peptostreptococcus anaerobius DNA after loss of cell viability

“…) and in instrumented ex vivo human root canals after 2 years (Brundin et al . ). Enterococcus faecalis is a robust gram‐positive species, and in previous studies, the cultures were killed by heat treatment, which leaves the cell wall largely intact (Kort et al .…”

“…In another long‐term study, heat‐killed E. faecalis cells were inoculated into human root canals ex vivo, and amplifiable DNA was detected by PCR 2 years after cell death (Brundin et al . ). Together, these studies showed the durability of DNA from heat‐killed E. faecalis and that the form of the DNA was an important factor in preservation of the DNA after cell death.…”

Clinical antibacterial effectiveness of the self‐adjusting file system

“…There is an obvious concern about using a DNA‐based molecular method immediately after treatment (Rôças & Siqueira ), because these methods cannot distinguish whether the detected DNA was from viable or dead cells (Brundin et al . ). A recent in vitro study using root canals of human teeth experimentally contaminated with E. faecalis demonstrated no significant differences for samples taken after treatment analysed by culture or DNA‐based qPCR (Alves et al .…”

Spirochete antigens persist near cartilage after murine Lyme borreliosis therapy

“…In humans, spirochete DNA has been detected by PCR for up to 9 months after treatment for Lyme arthritis, but its presence does not correlate with relapse or duration of arthritis (22). Microbial DNA can persist in mammalian tissues for extended periods (years) when sequestered in cellular debris even though the microbe itself is no longer viable (23,24). Some B. burgdorferi DNA could remain intact if it is sequestered in cellular debris such as the GFP deposits.…”