Common Bed Bugs: Non-Viable Hosts for Trypanosoma rangeli Parasites

Sanam Meraj; Phillip Phung; Kelvin Lau; Carl Lowenberger; Gerhard Gries

doi:10.3390/cells13242042

Common Bed Bugs: Non-Viable Hosts for Trypanosoma rangeli Parasites

Cells. 2024 Dec 11;13(24):2042. doi: 10.3390/cells13242042.

Authors

Sanam Meraj¹, Phillip Phung¹, Kelvin Lau¹, Carl Lowenberger¹, Gerhard Gries¹

Affiliation

¹ Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.

Abstract

The hemoflagellate parasite Trypanosoma rangeli is transmitted by triatomine kissing bugs and may co-infect humans together with its Chagas disease-causing congener T. cruzi. Using real-time quantitative polymerase chain reaction (RT-qPCR) and antimicrobial assays, we studied (i) the temporal and spatial distribution of T. rangeli in common bed bugs, Cimex lectularius, following oral ingestion and hemocoelic injection of T. rangeli, and (ii) the immune responses of bed bugs induced by T. rangeli infections. Irrespective of infection mode, no live T. rangeli were present in the bed bugs' hemolymph, salivary glands, or feces. On day 1 following infection, the bed bugs strongly upregulated the antimicrobial peptide CL-defensin. Following hemocoelic injection of T. rangeli, live parasites were absent in any bed bug tissues examined throughout the 10-day study period. The ingestion of T. rangeli-infected blood had no significant effect on bed bug survival. Our findings indicate that bed bugs disable the development of T. rangeli within their body, in stark contrast to triatomine kissing bugs, which allow the development and transmission of T. rangeli. Our findings help unravel the intricate relationships between bed bugs and trypanosomes, and they contribute to our understanding of vector biology.

Keywords: Chagas disease; Cimex lectularius; Trypanosoma cruzi; Trypanosoma rangeli; defensins; immune response; parasite–host interactions; prolixicins; vector competence.

MeSH terms

Animals
Bedbugs*
Hemolymph / parasitology
Host-Parasite Interactions
Trypanosoma rangeli*

Grants and funding

The author(s) declare financial support for the research reported in this article. The research was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) CGS D Doctoral Scholarship, an Entomological Society of British Columbia Graduate Student Scholarship, a Philip & Marian McClelland Scholarship, and an Entomological Society of Canada Postgraduate Scholarship to Sanam Meraj. The research was further supported by NSERC-Discovery Grants to Gerhard Gries and Carl Lowenberger and by an NSERC-Industrial Research Chair to Gerhard Gries, with funding from BASF Canada Inc. and Scotts Canada Ltd. as the industrial sponsors of the NSERC Chair. The funders were not involved in the study design, collection, analysis, or interpretation of data, the writing of this article, or the decision to submit it for publication.