Spotted fever group rickettsiae in ticks of migratory birds in Romania

Abstract

BackgroundBirds are important hosts and dispersers of parasitic arthropods and vector-borne zoonotic pathogens. Particularly migratory species may carry these parasites over long distances in short time periods. Migratory hotspots present ideal conditions to get a snapshot of parasite and pathogen diversity of birds migrating between continents. The aim of this study was to investigate the presence and diversity of Rickettsia spp. in ticks collected from birds at a migratory hot-spot in the Danube Delta, Romania, eastern Europe.MethodsDNA was extracted from ticks that were collected from migratory birds in the Danube Delta during migratory seasons in 2011–2012. Two 360 bp fragments of the 16S ribosomal RNA gene and a 381 bp fragment Gene gltA were PCR amplified and analyzed by sequence analysis (performed at Macrogen Europe, Amsterdam, The Netherlands). Nucleotide sequences were compared to reference sequences available in the GenBank database, using Basic Local Alignment Search Tool.ResultsFour hundred ticks of four different species were found on 11 bird species. The prevalence of Rickettsia spp. infection was 14 % (56/400, CI: 11.7–29.1), with significantly more nymphs hosting rickettsial infection compared to larvae (48 vs 7; P < 0.001). Significantly more ticks in nymphal stage were hosting Rickettsia spp. infection in spring, than in autumn. Four different genospecies were found: R. monacensis (29 ticks), R. helvetica (13), R. massiliae (3) and R. slovaca (2). The seasonal distribution of different Rickettsia spp. was heterogeneous; with most of the R. monacensis-infected ticks were found in spring, while more R. helvetica were found in autumn than spring. R. massiliae was found only in autumn and R. slovaca was found only in spring.ConclusionThis study has shown that birds migrating through eastern Europe may carry ticks infected with a high diversity of rickettsial pathogens, with four Rickettsia spp. recorded. Migratory direction was important for pathogen burden, with seasonal differences in the occurrence of individual Rickettsia species. Here we report the first individual records of different Rickettsia spp. in H. concinna (R. monacensis), I. arboricola (R. helvetica, R. massiliae) and I. redikorzevi (R. helvetica) and also the first geographical record of occurrence of R. massiliae in Romania, representing the easternmost observation on the continent.

The Potential Role of Migratory Birds in the Rapid Spread of Ticks and Tick-Borne Pathogens in the Changing Climatic and Environmental Conditions in Europe

“…These included: Ixodes acuminatus [56], Ixodes arboricola [14,42,45,[57][58][59] Ixodes canisuga [40], Ixodes eldaricus [42,60], Ixodes festai [61], I. frontalis [13,14,27,38,42,44,52,56,[61][62][63] Ixodes hexagonus [40], Ixodes lividus [27,40,64], Ixodes persulcatus [50], and Ixodes redikorzevi [45,57,58,61] as well as representatives of Haemaphysalis, i.e., Ha. concinna [27,58,61], Haemaphysalis punctata [14,45,61,63], Haemaphysalis parva [57], Haemaphysalis sulcata [61], and Hy. marginatum group [56,57,65,66].…”

“…For example, in Romania, the DNA of various Rickettsia species was detected in several tick species, i.e., Ha. concinna (R. monacensis), I. arboricola (R. helvetica, R. massiliae), and I. redikorzevi (R. helvetica) [58]. In Northern Spain, B. turdi spirochetes were identified in I. frontalis, Ha.…”

“…The prevalence of Borrelia spirochetes in bird-infesting ticks varies largely depending on the area (Figure 1), season, and year of study. In addition to Borrelia spirochetes, immature I. ricinus ticks collected from birds usually transmit rickettsia of the genus Rickettsia, mainly Rickettsia helvetica [37,41,43,44,51,54,58,71,72]. Noteworthy,…”

Broad-range survey of vector-borne pathogens and tick host identification of Ixodes ricinus from Southern Czech Republic

“… 2016 ; Mărcuţan et al. 2016 ). Both these Rickettsia species are considered generally non-pathogenic and have rarely been identified in association with human disease cases with variable in severity (Fournier et al.…”

Letea Virus: Comparative Genomics and Phylogenetic Analysis of a Novel Reassortant Orbivirus Discovered in Grass Snakes (Natrix natrix)

“…As one of Europe's largest wetlands, the Danube Delta Biosphere Reserve (DDBR) located in the southeast of Romania, is a very biodiverse and heterogeneous complex of ecosystems [10]. The region is a major hub for bird migration along main African-Eurasian fly corridors, with ecoclimatic conditions suitable for abundant and diverse populations of arthropod vectors [11][12][13][14], which may allow pathogen import and maintenance [15][16][17][18].…”