Don't Let the Bed Bugs Bite

The common bed bug (Cimex lectularius), a human pest for centuries, now persistently infests homes and hotels. Often a nuisance, it can also transmit Trypanosoma cruzi experimentally.

Two groups have recently published DNA and RNA sequencing of Cimex at various stages of development. Both place Cimex genetically close to Pediculus humanas (the cause of pediculosis) and Acyrthosiphon pisum (the pea aphid). As a curious feature, Cimex requires endosymbiosis with Wolbachia bacteria for necessary micronutrients, including vitamin B group compounds. Accordingly, Wolbachia was identified within the microbiome of Cimex.

Not surprisingly, the Cimex genome shows specialized adaptations for blood meal acquisition and processing, including anticoagulants and aquaporins for removing water from whole blood. Transcriptional responses to first blood meal ingestion between the first and second nymph stages were the most extensive of any comparisons between stages, and there was a coordinated Cimex and Wolbachia transcriptional response to blood meal ingestion. Pyrethroid insecticide resistance is thought to be conferred by mutations in target sodium channels, cuticle proteins, cytochrome p450 enzymes, and ATP-dependent ABC transporters, all of which were observed to be expressed.

Rosenfeld and colleagues performed a metagenomics analysis of over 1000 samples taken across the five New York City boroughs, demonstrating that geographic proximity predicted more-closely-related bed bugs and that each borough had distinct populations.