A glimpse of the bacteriome of Hyalomma dromedarii ticks infesting camels reveals human Helicobacter pylori pathogen

Abstract

Introduction: The tick Hyalomma dromedarii is predominant in camels of Saudi Arabia and harbor multiple pathogens causing disease in humans and animals. Knowing the bacterial community of ticks is crucial for surveillance of known and newly emerging pathogens. Yet, the bacteriome of H. dromedarii remain unexplored to date.
 Methodology: In a cross-sectional survey, we used V3-V4 region of 16S rRNA to characterize the bacteriome of 62 whole H. dromedarii tick samples collected from camels found in Hofuf city in Saudi Arabia.
 Results: Sequencing results yielded 217 species incorporated into 114 genera, which in turn belong to the dominant phylum Proteobacteria (98%) followed by Firmicutes (1.38%), Actinobacteria (0.36%), Bacteroidetes (0.17%), meanwhile the phyla Cyanobacteria, Verrucomicrobia and unclassified bacteria were rarely detected. Francisella endosymbiont dominated the bacteriome of H. dromedarii ticks with average abundance of 94.37% and together with Salincoccus sp. accounted for 94.51% of the average sequences. The remaining bacteriome consisted of low abundance of potential pathogens and environmental bacteria. Of these pathogens, we found Helicobacter pylori in the tick H. dromedarii for the first time. Notably, Anaplasma, Ehrlichia and Rickettsia pathogens known to be found in H. dromedarii ticks were not detected.
 Conclusion: This first preliminary study advances our knowledge about the bacterial community of H. dromedarii ticks and provides a basis for pathogen surveillance and studying the influences of symbionts on vector competence. Presence of pathogens in ticks, raise concerns about potential transmission of these agents to humans or animals.

Microbial communities associated with the camel tick, Hyalomma dromedarii: 16S rRNA gene-based analysis

“…Bacillus , Escherichia , Siccibacter and Acinetobacter were the other predominant genera at different locations in 2019 samples. The genus Francisella was confirmed previously in H. dromedarii ticks from Palestine 47 and Saudi Arabia 48 .…”

“…Therefore, the genus level identifications presented in the current study are provided as preliminary baseline data, which may require further confirmation. Our results indicated that Acinetobacter and Corynebacterium were the two most abundant genera detected in the microbiota of H. dromedarii from all locations with high sequence ratios 47 and Saudi Arabia 48 . We found significant associations between Acinetobacter, Escherichia and Francisella and between these three genera and several other genera.…”

“…The patterns of bacterial phyla in the current study were consistent with findings of Elbir et al . 48 where the Proteobacteria was the most abundant followed by Firmicutes and Actinobacteria . In addition, they were consistent with the results of Thapa et al .…”

“…Nonetheless, so far there are no published records on the microbial communities in H. dromedarii ticks in the UAE. Two studies, one from West Bank, Palestine 47 , and second from Saudi Arabia 48 investigated microbial communities in H. dromedarii . The objectives of this study were to (i) characterize the microbiota associated with H. dromedarii ticks in the UAE and (ii) determine temporal patterns of richness and evenness in microbial communities in H .…”

Description of microbial diversity associated with ticks Hyalomma dromedarii (Acari: Ixodidae) isolated from camels in Hail region (Saudi Arabia) using massive sequencing of 16S rDNA

“…In the DNA-pool 2, more than 66 genera were identified with a percentage of distribution ranging from 0.87% to 0.01%. These genera include among others: [36]. This approach facilitates the identification of more microorganisms as compared to the PCR-based techniques targeting specific known pathogens.…”