Beliavskaia, Alexandra and Tan, Kim -Kee and Sinha, Amit and Husin, Nurul Aini and Lim, Fang Shiang and Loong, Shih Keng and Bell-Sakyi, Lesley and Carlow, Clotilde K. S. and AbuBakar, Sazaly and Darby, Alistair C. and Makepeace, Benjamin L. and Khoo, Jing Jing (2023) Metagenomics of culture isolates and insect tissue illuminate the evolution of Wolbachia, Rickettsia and Bartonella symbionts in Ctenocephalides spp. fleas. Microbial Genomics, 9 (7). ISSN 2057-5858, DOI https://doi.org/10.1099/mgen.0.001045.
Full text not available from this repository.Abstract
While fleas are often perceived simply as a biting nuisance and a cause of allergic dermatitis, they represent important disease vectors worldwide, especially for bacterial zoonoses such as plague (transmitted by rodent fleas) and some of the rickettsioses and bartonelloses. The cosmopolitan cat (Ctenocephalides felis) and dog (Ctenocephalides canis) fleas, as well as Ctenocephalides orientis (restricted to tropical and subtropical Asia), breed in human dwellings and are vectors of cat-scratch fever (caused by Bartonella spp.) and Rickettsia spp., including Rickettsia felis (agent of flea -borne spotted fever) and Rickettsia asembonensis, suspected pathogen. These Rickettsia spp. are members of a phylogenetic clade known as the `transitional group', which includes both human pathogens and arthropod-specific endosymbionts. The relatively depauperate flea microbiome can also contain other endosymbionts, including a diverse range of Wolbachia strains. Here, we present circularized genome assemblies for two C. orientis- derived pathogens (Bartonella clarridgeiae and R. asembonensis) from Malaysia, a novel Wolbachia strain (wCori), and the C. orientis mitochondrion; all were obtained by direct metagenomic sequencing of flea tissues. Moreover, we isolated two Wolbachia strains from Malaysian C. felis into tick cell culture and recovered circularized genome assemblies for both, one of which (wCfeF) is newly sequenced. We demonstrate that the three Wolbachia strains are representatives of differ-ent major clades ('supergroups'), two of which appear to be flea-specific. These Wolbachia genomes exhibit unique combina-tions of features associated with reproductive parasitism or mutualism, including prophage WO, cytoplasmic incompatibility factors and the biotin operon of obligate intracellular microbes. The first circularized assembly for R. asembonensis includes plasmid with a markedly different structure and gene content compared to the published plasmid; moreover, this novel plasmid was also detected in cat flea metagenomes from the USA. Analysis of loci under positive selection in the transitional group revealed genes involved in host-pathogen interactions that may facilitate host switching. Finally, the first B. clarridgeiae genome from Asia exhibited large -scale genome stability compared to isolates from other continents, except for SNPs in regions predicted to mediate interactions with the vertebrate host. These findings highlight the paucity of data on the genomic diversity of Ctenocephalides- associated bacteria and raise questions regarding how interactions between members of the flea microbiome might influence vector competence.
| Item Type: | Article |
|---|---|
| Funders: | UK Department of Business, Energy and Industrial Strategy (BEIS), Ministry of Higher Education, Malaysia, for niche area research under the Higher Institution Centre of Excellence programme 332192305, European Union under the Marie Sklodowska Curie grant, Malaysian Industry- Government Group for High Technology (MIGHT) [Grant No: MO002- 2019 ; BB/P024378/1 ; BB/P024270/1 ; 223743/Z/21/Z ; H2020 MSCA ITN 2015 675752] |
| Uncontrolled Keywords: | Fleas; Symbionts; Wolbachia; Rickettsia; Bartonella; Metagenomics |
| Subjects: | Q Science > QR Microbiology |
| Divisions: | Deputy Vice Chancellor (Research & Innovation) Office > Tropical Infectious Diseases Research and Education Centre |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 10 Nov 2025 01:45 |
| Last Modified: | 10 Nov 2025 01:45 |
| URI: | http://eprints.um.edu.my/id/eprint/49734 |
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