Detection of relapsing fever Borrelia spp., Bartonella spp. and Anaplasmataceae bacteria in argasid ticks in Algeria

Abstract

BackgroundArgasid ticks (soft ticks) are blood-feeding arthropods that can parasitize rodents, birds, humans, livestock and companion animals. Ticks of the Ornithodoros genus are known to be vectors of relapsing fever borreliosis in humans. In Algeria, little is known about relapsing fever borreliosis and other bacterial pathogens transmitted by argasid ticks.Methodology/Principal findingsBetween May 2013 and October 2015, we investigated the presence of soft ticks in 20 rodent burrows, 10 yellow-legged gull (Larus michahellis) nests and animal shelters in six locations in two different bioclimatic zones in Algeria. Six species of argasid ticks were identified morphologically and through 16S rRNA gene sequencing. The presence and prevalence of Borrelia spp., Bartonella spp., Rickettsia spp. and Anaplasmataceae was assessed by qPCR template assays in each specimen. All qPCR-positive samples were confirmed by standard PCR, followed by sequencing the amplified fragments. Two Borrelia species were identified: Borrelia hispanica in Ornithodoros occidentalis in Mostaganem, and Borrelia cf. turicatae in Carios capensis in Algiers. One new Bartonella genotype and one new Anaplasmataceae genotype were also identified in Argas persicus.ConclusionsThe present study highlights the presence of relapsing fever borreliosis agents, although this disease is rarely diagnosed in Algeria. Other bacteria of unknown pathogenicity detected in argasid ticks which may bite humans deserve further investigation.

Inventory and update on argasid ticks and associated pathogens in Algeria

“…In Algeria, only few epidemiologic studies in the interest of these vectors have been conducted, as previously described, listing nine species of argasid ticks and several associated pathogens [4] , [5] , [6] , [7] . Nowadays, the argasid species on Algerian territory comprise nine species in different localities: Ornithodoros erraticus, Ornithodoros sonrai, Ornithodoros rupestris, Ornithodoros costalis, Ornithodoros occidentalis, Ornithodoros marocanus, Ornithodoros normandi, Ornithodoros capensis s.s. and Argas persicus.…”

“…in humans [13] . Each of the tick vectors collected is mostly geographically restricted in its habitat and is considered to be a specific vector of different pathogens, as previously described [4] , [5] , [6] , [7] ; they colonize peridomestic settings and burrows, caves, and cavities under outcroppings. Ornithodoros capensis s.l., a soft tick of seabirds, infests the nests of the yellow-legged gull ( Larus michahellis ) along the coasts of Algeria [5] , [7] .…”

“…has been found in ( Ornithodoros capensis s.s., Ornithodoros rupestris, Ornithosoros erraticus ) [5] and the last series of bacterial agents ( Borrelia spp., Bartonella spp., Anaplasma spp.) has been detected in argasid ticks collected from different localities [6] . However, further investigation should be carried out to clarify this situation.…”

“…The nests were placed in individual bags to avoid parasite loss, and soft ticks were collected [5] . From poultry, ticks were collected from inside wall cracks with entomologic forceps [6] .…”

“…( Ornithodoros capensis s.s., Ornithodoros erraticus, Ornithodoros rupestris ) [5] , the detection of relapsing fever Borrelia spp., Bartonella spp. and Anaplasmataceae bacteria [6] and the first report of Ornithodoros capensis s.s. in Algiers [7] . Knowledge about soft ticks in Algeria is currently incomplete.…”