Impact of tick-borne Anaplasma phagocytophilum infections in calves of moose (Alces alces) in southern Norway

The Gram-negative, obligate intracellular tick-transmitted pathogen Anaplasma phagocytophilum can cause acute febrile diseases in humans and domestic animals. The expansion of the tick Ixodes ricinus (Linnaeus, 1758) in northern Europe due to climate change is of serious concern for animal and human health. The aim of the present study was to investigate the impact of A. phagocytophilum infection in moose Alces alces (Linnaeus) calves by evaluating the carcass weights of infected and non-infected animals and examining animal tissues samples for co-infections with either species of Babesia Starcovici, 1893 or bacteria of the genus Bartonella. The carcasses of 68 free-ranging moose calves were weighed by hunters during the hunting seasons from 2014 to 2017 in two regions in southern Norway and spleen samples were collected. Anaplasma phagocytophilum was detected in moose sampled from locations infected with ticks with a prevalence of 82% (n = 46). The carcass weights of A. phagocytophilum-infected calves (n = 46) and non-infected (n = 22) calves were compared. Although the average weight of infected calves (45.6 kg) was lower than that of non-infected calves (46.5 kg), the difference was not statistically significant. Three different variants of the bacterium 16S rRNA gene were identified. The average weight of animals infected with variant I was 49.9 kg, whereas that of animals infected with variant III was 42.0 kg, but the difference was not statistically significant (p = 0.077). Co-infections of A. phagocytophilum with Bartonella spp. or with Babesia spp. were found in 20 and two calves, respectively. A triple infection was found in two calves. Sequence analysis of the 18S rRNA gene of Babesia-positive samples revealed the presence of Babesia cf. odocoilei (Emerson et Wright, 1970). Strains of Bartonella closely related to Bartonella bovis (Bermond, Boulouis, Heller, Laere, Monteil, Chomel, Sander, Dehio et Piemont, 2002) were identified based on phylogenetic analysis of the gltA and rpoB genes. The loss of body mass in moose calves in the tick-infected site was probably influenced by multiple factors.

Prevalence and co-infection with tick-borne Anaplasma phagocytophilum and Babesia spp. in red deer (Cervus elaphus) and roe deer (Capreolus capreolus) in Southern Norway

Anaplasma phagocytophilum and Babesia spp. are causative agents of tick-borne infections that are increasingly considered as a threat to animal and public health. To assess the role of cervids in the maintenance of zoonotic pathogens in Norway, we investigated the prevalence of A. phagocytophilum and Babesia spp. in free-ranging roe deer and red deer. Initial screening of spleen samples of 104 animals by multiplex real-time PCR targeting the major surface protein (msp2) gene and 18S rRNA revealed the presence of A. phagocytophilum infection in 81.1% red deer (Cervus elaphus) and 88.1% roe deer (Capreolus capreolus), and Babesia spp. parasites in 64.9% red deer and 83.6% roe deer, respectively. Co-infections were found in 62.2% red deer and 79.9% roe deer. Nested PCR and sequence analysis of partial msp4 and 18S rRNA genes were performed for molecular characterization of A. phagocytophilum strains and Babesia species. A total of eleven A. phagocytophilum msp4 gene sequence variants were identified: five different variants were 100% identical to corresponding A. phagocytophilum sequences deposited in the GenBank database, while other six sequence variants had unique nucleotide polymorphisms. Sequence analysis of the 18S rRNA gene demonstrated the presence of multiple Babesia species, including Babesia capreoli, Babesia divergens, Babesia venatorum and Babesia odocoilei/Babesia cf. odocoilei. This study is the first report demonstrating the prevalence and molecular characterization of A. phagocytophilum strains and Babesia species in roe deer and red deer in Norway. The high infection and co-infection rates with A. phagocytophilum and Babesia spp. in red deer and roe deer suggest that these cervids may play an important role in the transmission of single and multiple pathogens.

Infections with Bartonella spp. in free-ranging cervids and deer keds (Lipoptena cervi) in Norway

Bartonella bacteria are arthropod-borne and can cause long-term bacteremia in humans and animals. The predominant arthropod vectors and the mode of transmission for many novel Bartonella species remain elusive or essentially unstudied. The aim of this study was to investigate the prevalence of Bartonella spp. in Norwegian cervids and deer keds (Lipoptena cervi) and to characterise the bacteria by sequencing of the partial gltA gene and 16 S-23 S rRNA intergenic spacer region (ITS) in order to evaluate a possible transmission route. A total of 260 spleen samples and 118 deer keds were collected from cervids by hunters in the Southern part of Norway. Bartonella DNA was detected in 10.5% of spleen samples of roe deer (n = 67), in 35.1% red deer (n = 37), in 35.9% moose (n = 156), and in 85% pools of adult wingless deer ked (n = 59). Two Bartonella lineages were identified based on phylogenetic analysis of the gltA gene and ITS region sequences.