DOI: 10.5061/dryad.34tmpg4v6
title: Ticks, and tick-borne bacterial pathogens found on hard ticks (Acari: Ixodidae) on cattle in the Central River Region of The Gambia

description: Ticks are significant vectors of pathogens affecting both animals and
 humans, with the climate in Sub-Saharan Africa providing ideal conditions
 for their growth. However, there is limited data on ticks and tick-borne
 pathogens (T&TBPs) in cattle in The Gambia. This study aimed to
 identify tick species on cattle and conduct molecular screening for
 T&TBPs. A total of 92 ticks were collected from 306
 indigenous cattle. Ticks were first identified morphologically using
 taxonomic keys and then confirmed molecularly through DNA sequencing. DNA
 was extracted from the right fourth leg of six representative ticks for
 species confirmation, while 77 whole adult ticks were used for screening
 T&TBPs. Screening PCR assays targeted Anaplasma marginale msp1β
 gene, Ehrlichia spp. dsb gene, and hemotropic Mycoplasma spp. 16S rRNA
 gene. Ehrlichia-positive samples underwent additional assays targeting the
 sodB, 16S rRNA, and groEL genes, followed by Sanger sequencing and
 phylogenetic analyses. A total of 92 (53 M, 37 F, and two nymphs)
 ticks were collected from 30/306 (9.8%; 95% CI: 5.6 - 12.2 %) cattle with
 a mean of 3.1 ticks per animal. Adult ticks were identified as Hyalomma
 marginatum (73/92; 79.3%; 45 M and 28 F), Amblyomma variegatum (eight/92;
 8.7%; eight M), Hyalomma rufipes (four/92; 4.3%; four F), and
 Rhipicephalus evertsi (1/92; 1.1%; one F). The 16S rRNA sequences of six
 (four engorged females and two nymphs) ticks showed 98.6–100% identity
 with reference sequences from Rhipicephalus geigyi. Twelve out of 77
 (15.6%) ticks tested positive for at least one TBP. Eight H. marginatum
 (six M, two F) (10.4%) were positive for Ehrlichia spp. dsb gene, three H.
 marginatum (two M and one F) (3.9%) for A. marginale, and two (one H.
 marginatum F and one A. variegatum M) (2.6%) for hemotropic Mycoplasma
 spp. All Ehrlichia-positive samples showed 100% detection for the 16S rRNA
 gene and 62.5% for the sodB gene. BLASTn analysis revealed 99.3–99.7%
 identity with Ehrlichia sp. from Brazil and 98.2-99.3% identity with E.
 minasensis from Panama and Pakistan. Phylogenetic analysis grouped the
 sequences from this study with Ehrlichia spp. and E. minasensis from ticks
 in the Czech Republic and Brazil. This study identified various
 tick species and pathogens in cattle from The Gambia, including the first
 report of E. minasensis, A. marginale, and hemotropic Mycoplasma spp. in
 the country. These findings highlight the importance of ongoing
 surveillance and research on tick-borne diseases in the region.
description: # Ticks, and tick-borne bacterial pathogens found on hard ticks (Acari:
 Ixodidae) on cattle in the Central River Region of The Gambia Access this
 dataset on Dryad: DOI: 10.5061/dryad.34tmpg4v6 ## Description: Our data
 contains one file: Data\_Ticks\_from\_Gambia.xlsx Data Structure and
 Potential Use: This dataset is organized in an Excel spreadsheet format
 with separate sheets and clearly labeled columns to facilitate ease of
 use. ### Sheet 1: Identified ticks Tick Metadata Sample ID: Unique
 identifier for each tick. Host Animal ID: Identifier linking the tick to
 the individual cattle host. Tick Species: Determined using morphological
 keys (e.g., *Hyalomma marginatum*, *Amblyomma variegatum*, etc.). Sex
 & Life Stage: Recorded as male (M), female (F), or nymph. ### Sheet 2:
 TBPs analysed PCR Results Sample ID: Cross-referenced with Sheet 1.
 Pathogen Target Gene: Indicates which gene was tested (e.g., dsb, 16S
 rRNA, sodB for Ehrlichia spp.). PCR Result: Positive or negative. Pathogen
 Identified: Name of the pathogen detected, if any. ### Glossary This
 includes explanations of technical terms and acronyms for non-specialists:
 PCR: Polymerase Chain Reaction - a method to amplify DNA. qPCR
 (Quantitative PCR), also called real-time PCR, this technique quantifies
 the amount of target DNA present in a sample, providing both detection and
 approximate load (if standards are used). Results are often expressed as
 Ct values (cycle threshold). dsb gene: A target for detecting *Ehrlichia*
 spp. 16S rRNA gene: A universal marker for bacterial identification. sodB
 and groEL: Genes used to characterize *Ehrlichia* and related organisms.
 ### Notes Explanation of "n/a" Values in the dataset: The label
 "n/a" is used in this dataset to indicate instances where data
 are either not available or not applicable, depending on the context.
 Below is a breakdown of how this applies to different parts of the data:
 Unsequenced Samples (Positive and Negative): "n/a" is used for
 both positive and negative samples that were not sequenced. Sequencing was
 performed only on a subset of PCR-positive samples due to resource
 constraints, limitations, and prioritization of the representative. qPCR
 Results -- Cq Values: Cq (cycle quantification) values are only generated
 for qPCR-positive samples. Negative samples do not have valid Cq values
 and are marked as "n/a" in the corresponding columns. Gene
 Characterization -- Only Performed on Positives: Downstream gene-specific
 PCR assays (e.g., sodB, msp1a, groEL) were conducted only on samples that
 tested positive in initial screenings. Therefore, samples that were
 negative in screening assays are marked "n/a" in those columns
 to indicate that these tests were not applicable.