V. aporrectodeae[1] V. eiseniae[1] Verminephrobacter is a genus of Gram-negative bacteria that colonize the nephridia of earthworms within the family Lumbricidae.
[4] While the function of the bacteria inside the nephridia remains unknown, several lines of evidence suggest this association as a stable symbiosis.
Chiefly among them is the vertical transmission of the bacteria, meaning that the bacteria are deposited by the parent earthworm inside the egg-capsule, and colonize the developing embryo via specialized anatomical features.
[6] DNA belonging to members of the genus has not been recovered from surveys of soil samples even in the presence of high densities of earthworms, suggesting that Verminephrobacter species are confined to their earthworm hosts.
Observations for comparative analyses of the genome sequence of V. eiseniae suggest that this organisms shares features associated with the transition from a free-living to a host-associated lifestyle.