# Identification of Bed Bugs from Comoros, Using Morphological, Matrix-Assisted Laser Desorption Ionisation Time-of-Flight Mass Spectrometry, and Molecular Biology Tools, and the Detection of Associated Bacteria

## TL;DR

This study confirms the presence of tropical bed bugs and Wolbachia bacteria in the Comoros using advanced identification techniques.

## Contribution

First confirmation of Cimex hemipterus and Wolbachia Clade F in the Comoros using MALDI-TOF MS and molecular methods.

## Key findings

- Cimex hemipterus was confirmed as the bed bug species in Grande Comore.
- Wolbachia endosymbiont from Clade F was detected in the bed bugs.
- MALDI-TOF MS successfully differentiated bed bug developmental stages.

## Abstract

Bed bug infestations have soared worldwide in recent years and Cimex lectularius (common in temperate regions) and Cimex hemipterus (the tropical bed bug) have been identified as the primary human parasites. Despite their prevalence, information on these species remains limited, particularly in some regions. This study analysed bed bug specimens found in residential areas of the Union of the Comoros, using MALDI-TOF MS (Bruker Daltonics, Bremen, Germany) and molecular biology to confirm their morphological identification and to detect bacteria. Notably, this study is the first confirmation of Cimex hemipterus in the Union of the Comoros, as well as the first confirmation of the presence of a Wolbachia endosymbiont from Clade F.

After virtually disappearing from domestic dwellings in the Western world at the end of the Second World War, bed bugs have re-emerged in recent years. Few studies, however, have been carried out on these insects in tropical islands. In this study, we focussed on describing bed bug specimens collected from dwellings in a high-altitude village in Grande Comore, an island in the Comoros, in the Indian Ocean. We also aimed to detect the bacteria associated with them. Using MALDI-TOF MS coupled with molecular biology, we were able to confirm that the C. hemipterus species (the tropical bug) was the bug infesting these homes. Interestingly, the results also show that MALDI-TOF MS can differentiate between the developmental stages of bed bugs (immature and adult). Screening for bacteria was carried out using qPCR, regular PCR, and sequencing, with only Wolbachia DNA being found. Widespread surveys throughout the country are needed to ascertain the level of bed bug infestation, with a view to implementing appropriate control measures.