f "Candidatus Neoehrlichia mikurensis" (Anaplasmataceae) is an emerging pathogen transmitted by Ixodes ticks. Conventional PCR and the newly developed high-resolution melt PCR were used to detect and discriminate "Candidatus Neoehrlichia mikurensis" and Anaplasma phagocytophilum. Both bacterial species were frequently found in Ixodes ricinus and Ixodes hexagonus but virtually absent from Dermacentor reticulatus. In rodents, "Candidatus N. mikurensis" was significantly more prevalent than A. phagocytophilum, whereas in cats, only A. phagocytophilum was found. Pathogenic Anaplasmataceae of the genera Anaplasma, Ehrlichia, and Neoehrlichia are transmitted by ixodidae. Anaplasma phagocytophilum, the agent of human, equine, canine, and feline granulocytic anaplasmosis (GA) and tick-borne fever of ruminants, occurs throughout central and northern Europe (1). Anaplasma phagocytophilum genotypes in North America and Europe apparently differ in host tropisms and clinical symptoms, with ruminant tick-borne fever and equine GA found predominantly in Europe and human GA predominantly in North America (1). Although human GA is often asymptomatic, 7% of diagnosed clinical cases require intensive medical care and 0.6% of the cases are fatal (2). Anaplasma phagocytophilum is transmitted by Ixodes species. In Eurasia, vector competence has not been experimentally established for any tick species, but the bacterium was detected in many different Ixodes species (1), including Ixodes ricinus (3, 4) and Ixodes hexagonus (1, 5).Recently, "Candidatus Neoehrlichia mikurensis" was identified as a new member of the Anaplasmataceae. This emerging pathogen is also transmitted by Ixodes ticks and can cause severe disease in humans (6-8) and dogs (9). It was first identified in Ixodes ovatus and Rattus norvegicus in Japan (10). Bacterial DNA was detected in liver, heart, and spleen tissue, and intracellular bacteria were found in splenic endothelial cells. In two human cases, the pathogen occurred in granulocytes (11). Previously, very closely related 16S rRNA gene sequences were reported as the Schotti variant of Ehrlichia-like bacteria in the Netherlands (12) and Ehrlichia sp. "Rattus Strain" in China (13). "Candidatus Neoehrlichia mikurensis" appears to be one of the most prevalent pathogens in I. ricinus in Europe (14-17), suggesting the possibility that many subclinical human infections occur. Therefore, the aim was to develop a real-time high-resolution melt PCR (HRM-PCR) assay discriminating A. phagocytophilum and "Candidatus Neoehrlichia mikurensis."Six rodent species were trapped in 2010 and 2011 at four different sites in Berlin (Table 1). Spleen samples were collected during necropsy from cats from animal shelters in Berlin (2006Berlin ( to 2008. Host-associated, nonengorged, or partially engorged I. ricinus and I. hexagonus ticks were collected from dogs in Berlin and Brandenburg by their owners and sent to the Small Animal Clinic, Freie Universität Berlin, Berlin, Germany. Questing Dermacentor reticulatus ticks were collected ...

No abstract

BackgroundTick-borne diseases are a major health risk for humans and dogs. In addition to collection and analysis of questing ticks, analysis of host-associated ticks for the presence of pathogens is a valuable method to gain insight into transmission patterns of tick-borne diseases.MethodsTicks were collected from dogs living in the Berlin/Brandenburg area. The three tick species Ixodes ricinus, Ixodes hexagonus and Dermacentor reticulatus were examined for the presence of Babesia spp., Borrelia spp., Rickettsia spp. and Anaplasmataceae. Conventional PCR followed by sequencing was used for pathogen detection and characterization.ResultsBabesia spp. were found in 2.5% and 3% of I. ricinus and I. hexagonus, respectively. Sequencing revealed the presence of Babesia microti, Babesia capreoli and Babesia venatorum. D. reticulatus were free of Babesia canis. Rickettsia spp. were detected in 61% of I. ricinus, 44% of I. hexagonus and 39% of D. reticulatus. Specifically detected were Rickettsia raoulti in D. reticulatus and I. hexagonus, Rickettsia helvetica in I. ricinus and I. hexagonus and Rickettsia monacensis in I. hexagonus. Anaplasma phagocytophilum and Candidatus Neoehrlichia mikurensis have been reported previously in I. ricinus (6.5% and 4.3%, respectively) and I. hexagonus (3.9% and 5.9%). Borrelia spp. were found in 11.6% of I. ricinus and 11.2% of I. hexagonus. Subsequent genospecies analysis revealed Borrelia afzelii, Borrelia garinii, Borrelia burgdorferi sensu stricto and Borrelia miyamotoi. Simultanous presence of more than one pathogen was found in 20% of I. ricinus and in 59% of I. hexagonus whereas the total frequency of any pathogen was 65% in I. ricinus, 59% in I. hexagonus and 64% in D. reticulatus. Ticks in which A. phagocytophilum was detected had a significantly increased risk of also containing Rickettsia. Ticks harbouring a pathogen had significantly higher scutal indices than ticks without presence of any pathogen.ConclusionsFrequencies of potential human or canine pathogens in ticks were considerable and DNA of all four groups of pathogens was detected. Differences in scutal indices might suggest that pathogens are frequently taken up by ticks when feeding on dogs in Berlin/Brandenburg.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-014-0535-1) contains supplementary material, which is available to authorized users.

Frequencies of potential human or canine pathogens in ticks were considerable and DNA of all four groups of pathogens was detected. Differences in scutal indices might suggest that pathogens are frequently taken up by ticks when feeding on dogs in Berlin/Brandenburg.

No abstract