Molecular characterization of Rickettsia spp., Bartonella spp., and Anaplasma phagocytophilum in hard ticks collected from wild animals in Benin, West Africa.

Tick and tick-borne pathogens constitute a growing veterinary and public health concern around the world. Ticks are considered natural reservoirs for tick-borne related pathogens and are equally responsible for the spread of infections in animals as well as humans. In this study, the presence of Rickettsia, Bartonella, and Anaplasma phagocytophilum was investigated in hard ticks collected from reptiles, birds, and wild mammalian animals. The sample collection was carried out between December 2020 and September 2021. Adult ticks (male and female) were collected from wild animals in six districts of southern Benin. Molecular analysis was used to verify the presence of pathogens in all the ticks collected from wild animals. A total of 504 ticks were collected and grouped into 115 different tick pools. The PCR analysis detected 19 out of 115 tick pools which turn out positive for Rickettsia spp. and 9/115 tick pools positive for Bartonella spp., while Anaplasma phagocytophilum DNA was not detected in any tick. Several of the tick species collected from our studied reptiles/wild mammalian animals could be potential sources of zoonotic pathogens when subjected to further investigation. Therefore, stringent attention should be established for tick infestation of reptiles/wild mammalian animals in order to put in place proper control and prevention measures for tick-borne diseases in the wild, which could serve as reservoirs in the infestation of domestic animals/humans in the event of any possible contact.

Phenotypic and genotypic characterization of dog tick Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) resistance to deltamethrin in Benin.

The aim of this study was to evaluate the phenotypic and genotypic resistance of Rhipicephalus sanguineus sensu lato to deltamethrin in dogs in the municipality of Natitingou in Benin. In this study, the collection and identification of ticks, Larval Packet Test and specific allele PCR were the main methods used. A total of 41 dogs were examined and 420 ticks were collected in six areas which includes: Tchrimina, Yokossi, Boriyoure, Berécingou, Péporiyakou and Perma. Three species of ticks were identified and they include: R. sanguineus s.l., Rhipicephalus microplus and Haemaphysalis spp. However, R. sanguineus s.l. was the most abundant tick species (9.85) and had the highest parasitic intensity (10.36). The results of the Larval Packet Test showed that the larvae of R. sanguineus s.l. developed a phenotypic resistance against deltamethrin, particularly in the Bérécingou area where resistance ratios of LC50 and LC95 of R. sanguineus s.l. compared to a susceptible strain were 1.591 (1.025-3.054) and 65.339 (20.235-579.825) respectively. The molecular study of the sodium channel gene revealed three genotypes namely the susceptible genotype (SS), the heterozygous genotype (SR) and the resistant genotype (RR), which correlates with the phenotypic results. This information is fundamental to improve monitoring and resistance management strategies of R. sanguineus s.l. ticks to pyrethroids.