Old zoonotic agents and novel variants of tick-borne microorganisms from Benguela (Angola), July 2017

Abstract

Background Ticks and tick-borne diseases constitute a real threat for the livestock industry, which is increasing in Angola. In addition, ticks are vectors of zoonoses of public health concern, and scarce information is available from this country. In an effort to contribute to the prevention of zoonotic infectious diseases affecting humans and animals, the molecular screening of certain tick-related microorganisms collected on cattle in Angola was performed under a ‘One Health’ scope. Methods Ticks collected from cattle in Cubal (Benguela Province, Angola) in July 2017 were analysed in pools using specific PCR assays for bacteria (Rickettsia, Anaplasmataceae, Borrelia, Coxiella and Spiroplasma) and protozoa (Theileria and Babesia) detection. Results A total of 124 tick specimens were grouped in 25 pools (two Amblyomma variegatum, three Hyalomma truncatum, 16 Rhipicephalus decoloratus, two Rhipicephalus duttoni, one Rhipicephalus evertsi mimeticus and one Rhipicephalus sp.). The amplified microorganisms were (pools): Rickettsia africae (two A. variegatum and one R. decoloratus), Rickettsia aeschlimannii (three H. truncatum), Ehrlichia spp. (six R. decoloratus), Coxiella spp. (all but H. truncatum), Francisella sp. (one H. truncatum), Spiroplasma sp. closely related to Spiroplasma ixodetis (three R. decoloratus), Babesia bigemina (two R. decoloratus) and Babesia spp. (two A. variegatum). The obtained nucleotide sequences from Ehrlichia spp., two Coxiella genotypes (from R. duttoni and Rhipicephalus sp.), Francisella sp. and Babesia spp. (from A. variegatum) reached low identities with known genetically characterized species. Conclusions This study demonstrates the circulation in Angola of the pathogen R. aeschlimannii and potential novel tick-related microorganisms belonging to Ehrlichia, Coxiella, Francisella, Spiroplasma and Babesia spp. and corroborates the presence of R. africae and B. bigemina. Our results should be considered in developing protocols for the management of fever of unknown origin and for veterinary practices. Further studies are required to evaluate the risk of tick-borne diseases in Angola. Graphical Abstract

Molecular detection of Ehrlichia spp. in ticks parasitizing wild lagomorphs from Spain: characterization of a novel Ehrlichia species

“…In addition, the nucleotide sequences at the 16S rRNA partial gene showed a percentage identity ranging from 99.4 to 99.7% when compared to several deposited sequences of uncultured Ehrlichia spp . (AF311968, AY309970, KJ410257, KX987325, KX577724, KY046298, MH250197, MT258392 and OK481113) from different species of Hyalomma , Rhipicephalus and Haemaphysalis from African and Asian countries, including Angola [ 27 ], China [ 28 , 29 ], Japan [ 30 , 31 ], Malaysia [ 32 ], Niger [ 33 ] and Pakistan [ 34 ]. The degree of similarity between the Ehrlichia species at the 16S rRNA gene could indicate that it is not an appropriate gene for discriminating between species of this genus, similar to previous conclusions for other bacterial genera [ 35 ].…”

Molecular Detection and Characterization of Rickettsia Species in Ixodid Ticks from Selected Regions of Namibia

“…Within the southern African region, various tick species have been shown to harbor Rickettsia species at varying prevalence levels, and these include Hyalomma marginatum rufipes, Hyalomma trancatum, Rhipicephalus appendiculatus, Rhipicephalus decoloratus, and Rhipicephalus evertsi evertsi [24,27,37,46,47]. Our current study, however, did not specify the ticks sampled; thus, we recommend that future studies in the country show the prevalence of different tick species, as this will allow for a better understanding of the epidemiology of Rickettsia species in the region.…”

Distribution and Prevalence of Anaplasmataceae, Rickettsiaceae and Coxiellaceae in African Ticks: A Systematic Review and Meta-Analysis

“…The following supporting information can be downloaded at: , Table S1: PRISMA checklist and additional checklist based on Migliavaca et al, 2020, guidelines; Table S2: List of papers excluded during full-text examination and relevant exclusion criteria; Table S3: Details of qualitative analysis; Table S4: Details of critical appraisal. References [ 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 , 126 , 127 , 128 , 129 , 130 , 131 , 132 , 133 , 134 , 135 , 136 , 137 , 138 , 139 , 140 , 141 , 142 , 143 , 144 , 145 , 146 ,…”