Wolbachia Infections in the Cimicidae: Museum Specimens as an Untapped Resource for Endosymbiont Surveys

Abstract

Wolbachia spp. are obligate maternally inherited endosymbiotic bacteria that infect diverse arthropods and filarial nematodes. Previous microscopic and molecular studies have identified Wolbachia in several bed bug species (Cimicidae), but little is known about how widespread Wolbachia infections are among the Cimicidae. Because cimicids of non-medical importance are not commonly collected, we hypothesized that preserved museum specimens could be assayed for Wolbachia infections. For the screening of museum specimens, we designed a set of primers that specifically amplify small diagnostic fragments (130 to 240 bp) of the Wolbachia 16S rRNA gene. Using these and other previously published primers, we screened 39 cimicid species (spanning 16 genera and all 6 recognized subfamilies) and 2 species of the sister family Polyctenidae for Wolbachia infections using museum and wild-caught material. Amplified fragments were sequenced to confirm that our primers were amplifying Wolbachia DNA. We identified 10 infections, 8 of which were previously undescribed. Infections in the F supergroup were common in the subfamily Cimicinae, while infections in the A supergroup were identified in the subfamilies Afrocimicinae and Haematosiphoninae. Even though specimens were degraded, we detected infections in over 23% of cimicid species. Our results indicate that Wolbachia infections may be common among cimicids and that archived museum material is a useful untapped resource for invertebrate endosymbiont surveys. The new screening primers listed in this report will be useful for other researchers conducting Wolbachia surveys with specimens with less-than-optimum DNA quality.

Bed Bugs: Clinical Relevance and Control Options

“…They are not passed by bed bugs through blood feeding and do not infect humans. The majority of bed bugs are naturally infected with Wolbachia as well as other endosymbionts (68,154,265). Considerable research has recently focused on various Wolbachia species, notably those that infect the dengue virus mosquito vector, Aedes aegypti (322).…”

Wolbachia Are Present in Southern African Scorpions and Cluster with Supergroup F

“…Wolbachia strains belonging to supergroup F have thus far been found in several species of termites [13], filarial nematodes of the genus Mansonella [6], two species of bush crickets [17], several species of cimicids [24], three species of lice, and one species of louse-fly [9]. In terms of geographical distribution, F-strains have thus far been found in host species from North America (U.S. states of AL, CA, MD, MS), South America (Venezuela), Europe (Italy), Africa (Kenya, Ethiopia, Namibia, and South Africa), Japan, Indonesia, and Australia.…”

How Diverse Is the GenusWolbachia? Multiple-Gene Sequencing Reveals a Putatively NewWolbachiaSupergroup Recovered from Spider Mites (Acari: Tetranychidae)

“…For example, supergroup F was described in 2002 (34), yet the known diversity and geographic range of host species infected with the supergroup is rapidly expanding. It has been detected in both nematodes and several major arthropod orders (in Chelicerata, scorpions (6,19,20,34,38,45). Other host taxa for which there is evidence of infection by supergroup F are cockroaches (Blattodea) and ant lions (Neuroptera) (22,54).…”