in the literature, there are several studies of the gut virome and microbiome, for instance Reyes et al. on Nature (https://www.nature.com/articles/nature09199?error=cookies_not_supported&code=f5201dbe-3cda-4e09-ba17-688d0352ef81). Now, it makes sense to find bacteria (hence phages) in stools. However, there are other studies reporting bacteria from tissue, for instance Kostic et al. on Genome res ( Article Genomic analysis identifies association of Fusobacterium wit... ). In this specific case, the identified bacterium (Fusobacterium nucleatum) is an endocellular parasite and has virulence factors that allows it to penetrate tissues. But my question is more general: Would be normal to identify bacteria and bacteriophages INSIDE human tissues? In particular, would whole genome sequencing metagenomic experiments be likely to identify bacteria genome from human tissues? And if yes, how can we explain the presence of bacteria inside loci that are supposed to be sterile? Thank you
NERVES and BRAIN
After chickenpox infection, some Herpes viruses travel along the nerves and may remain dormant in the dorsal root ganglia of the spinal nerves...they can be activated later and cause shingles.
According to (jvi.asm.org):
Herpes simplex virus 1 (HSV-1) establishes latency in neurons of the brains and sensory ganglia of humans and experimentally infected mice.
Our findings further validated the presence of low-virulence anaerobic bacteria in degenerated IVDs, and P. acnes was the most frequent bacterium.