Rickettsiaceae and Anaplasmataceae infections in Ixodes ricinus ticks from urban and natural forested areas of Poland

Abstract

BackgroundIxodes ricinus is a major vector for a range of microbial pathogens and the most prevalent and widely distributed tick species on the European continent, occurring in both natural and urban habitats. Nevertheless, little is known about the relative density of ticks in these two ecologically distinct habitats and the diversity of tick-borne pathogens that they carry.MethodsWe compared densities of questing I. ricinus nymphs and adults in urban and natural habitats in Central and Northeastern Poland, assessed the prevalence and rate of co-infection with A. phagocytophilum, Rickettsia, Ehrlichia and ‘Ca. Neoehrlichia spp.’ in ticks, and compared the diversity of tick-borne pathogens using molecular assays (PCR).ResultsOf the 1325 adults and nymphs, 6.2% were infected with at least one pathogen, with 4.4%, 1.7% and less than 0.5% being positive for the DNA of Rickettsia spp., A. phagocytophilum, Ehrlichia spp. and Ca. N. mikurensis, respectively. Although tick abundance was higher in natural habitats, the prevalence of the majority of pathogens was higher in urban forested areas.ConclusionWe conclude that: (i) zoonotic genetic variants of A. phagocytophilum are widely distributed in the Polish tick population, (ii) although the diversity of tick borne pathogens was higher in natural habitats, zoonotic species/strains were detected only in urban forests, (iii) and we provide the first description of Ca. N. mikurensis infections in ticks in Poland.

Extensive genetic diversity of Rickettsiales bacteria in multiple mosquito species

“…High levels of genetic diversity in Rickettsiales have been identified in both ticks and vertebrates61436, including multiple infection by distinct bacteria in a single tick species1837. Our phylogenetic analysis revealed the co-circulation of nine documented and five tentative species bacteria, as well as three symbionts/endosybionts in five species of mosquitoes.…”

“…Strikingly, although the mosquito Anaplasma bacteria (ZJARSA-8, WHANSL-27–1, JXARSA-29, WHAEAL-17-2, JXANSA-19, WHARSL-30, WHAEAP-26) were most closely related to A. platys bacteria in both the rrs and groEL trees, in the gltA tree they grouped with strain Anaplasma sp. clone SY124 previously identified in ticks from Shenyang of China36. Further studies are needed to determine whether these bacteria belong to A. platys or represent co-infection (and/or recombinant event).…”

Asymptomatic “Candidatus Neoehrlichia mikurensis” Infections in Immunocompetent Humans

“…The DNA sequences amplified from our human "Ca. Neoehrlichia mikurensis" isolates were also identical to those obtained from ticks and bank voles collected in Warmiń sko-Mazurskie province in our previous studies (5). However, the phylogenetic tree of the partial groESL operon sequences showed that two European "Ca.…”

Infections with the tick-borne bacterium Candidatus Neoehrlichia mikurensis

“…It has been detected in Mongolia [12], China [6,12,13], Japan [1,14], Russia [4,5,15,16], the Czech Republic [9,17,18], Slovakia [19][20][21], Moldova [22], Hungary [23][24][25], Austria [18,26], Germany [11,[27][28][29][30][31][32], Switzerland [33][34][35][36][37], Poland [38,39], Romania [40], France [28,41,42], Belgium [43], Italy [44][45][46], Spain [47], The Netherlands [3,42,43,48], and the Scandinavian countries [2,…”