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. 2019 Mar 26;12(1):136.
doi: 10.1186/s13071-019-3396-9.

Transmission of Anaplasma phagocytophilum (Foggie, 1949) by Ixodes ricinus (Linnaeus, 1758) ticks feeding on dogs and artificial membranes

Josephus J Fourie  1 , Alec Evans  2 , Michel Labuschagne  3 , Dionne Crafford  3 , Maxime Madder  3 , Matthias Pollmeier  4 , Bettina Schunack  4
Affiliations

Transmission of Anaplasma phagocytophilum (Foggie, 1949) by Ixodes ricinus (Linnaeus, 1758) ticks feeding on dogs and artificial membranes

Josephus J Fourie et al. Parasit Vectors. .

Abstract

Background: The interplay of speed of activity of acaricidal products and tick-borne pathogen transmission time is the major driver for disease prevention. This study aimed to investigate the time required for transmission of Anaplasma phagocytophilum by adult Ixodes ricinus ticks in vivo on dogs, and to confirm the time required for transmission observed in vivo, in vitro.

Methods: Nymphs of I. ricinus were experimentally infected with an A. phagocytophilum strain of canine origin. Dogs were allocated to 6 groups of 3 dogs each. Groups 1-5 were infested with 50 A. phagocytophilum-infected female adult ticks on Day 0. Ticks were removed post-infestation at 3, 6, 12, 24 and 48 h. Dogs in Group 6 were infested with 60 A. phagocytophilum-infected female adult ticks (left on dogs until engorged). Dogs were observed daily for general health and clinically examined on Day 0, and weekly from Day 14. Blood was collected for qPCR and serological analysis on Day 0 (pre-challenge) and weekly thereafter. In the in vitro study each artificial feeding chamber was seeded with 10 adult ticks (5 male/5 female), attachment assessed, and blood pools sampled for qPCR at 6 h intervals up to 72 h after first tick attachment.

Results: Anaplasma phagocytophilum specific antibodies and DNA were detected in all 3 dogs in Group 6. No A. phagocytophilum-specific antibodies or DNA were detected in any dogs in Groups 1-5. All dogs remained healthy. Female tick attachment in 60 artificial feeding chambers over 72 h ranged between 20-60%. Anaplasma phagocytophilum DNA was detected in the blood collected from 5% of chambers sampled at 6 h, with the highest number of positive samples (16.3%) observed at 36 h.

Conclusions: Transmission of A. phagocytophilum by I. ricinus ticks starts within a few hours after attachment but establishment of infections in dogs is apparently dependent on a minimum inoculation dose that was only observed when ticks attached for greater than 48 h. These findings highlight the need for acaricidal products to exert a repellent and/or rapid killing effect on ticks to forestall transmission and subsequent disease.

Keywords: Anaplasma phagocytophilum; Dogs; In vitro; In vivo; Ixodes ricinus; Transmission.

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Conflict of interest statement

JF and AE are employed by Clinvet and DC, ML and MM by Clinglobal, the organizations that performed the study for Bayer Animal Health (sponsor company who funded the study). MP and BS are employed by Bayer Animal Health GmbH.

Figures

Fig. 1
Fig. 1
Schematic diagram of the feeding chambers used (as per Kröber & Guerin [23])
Fig. 2
Fig. 2
Example of feeding units in 6-well plates containing bovine blood in an incubator. Note the net covered stopper to preclude tick escape
Fig. 3
Fig. 3
Ticks on the artificial membrane within the feeding unit after removal from the 6-well plate containing bovine blood (visible in the background). Also note the bovine hair clippings in the feeding unit
Fig. 4
Fig. 4
A tick hypostome as viewed from beneath the artificial membrane of the feeding unit after removal from a culture plate well containing cattle blood warmed to 37 °C
Fig. 5
Fig. 5
Phylogenetic tree based on amplification of the ank gene and sequencing of the PCR product
Fig. 6
Fig. 6
Percentage of blood samples in which Anaplasma phagocytophilum DNA was detected (out of total number tested) at each of the respective time points during the in vitro experiment
See this image and copyright information in PMC

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References

    1. Greig B, Asanovich KM, Armstrong PJ, Dumler JS. Geographic, clinical, serologic, and molecular evidence of granulocytic ehrlichiosis, a likely zoonotic disease, in Minnesota and Wisconsin dogs. J Clin Microbiol. 1996;34:44–48. - PMC - PubMed
    1. Poitout FM, Shinozaki JK, Stockwell PJ, Holland CJ, Shukla SK. Genetic variants of Anaplasma phagocytophilum infecting dogs in western Washington State. J Clin Microbiol. 2005;43:796–801. doi: 10.1128/JCM.43.2.796-801.2005. - DOI - PMC - PubMed
    1. Kohn B, Galke D, Beelitz P, Pfister K. Clinical features of canine granulocytic ehrlichiosis in 18 naturally infected dogs. J Vet Intern Med. 2008;22:1289–1295. doi: 10.1111/j.1939-1676.2008.0180.x. - DOI - PubMed
    1. Johansson KE, Pettersson B, Uhlén M, Gunnarsson A, Malmqvist M, Olsson E. Identification of the causative agent of granulocytic ehrlichiosis in Swedish dogs and horse by direct solid phase sequencing of PCR products. Res Vet Sci. 1995;58:109–112. doi: 10.1016/0034-5288(95)90061-6. - DOI - PubMed
    1. Chirek A, Silaghi C, Pfister K, Kohn B. Granulocytic anaplasmosis in 63 dogs: clinical signs, laboratory results, therapy and course of disease. J Small Anim Pract. 2018;59:112–120. doi: 10.1111/jsap.12787. - DOI - PubMed

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