Background Ixodes ricinus ticks are commonly encountered in either natural or urban areas, contributing to Lyme disease agents Borreliella [(Borrelia burgdorferi (sensu lato)] spp. and Borrelia miyamotoi enzootic cycles in cities. It is an actual problem whether urbanization affects pathogen circulation and therefore risk of infection. The aim of the study was to evaluate main tick-borne disease risk factors in natural, endemic areas of north-east (NE) Poland (Białowieża) and urban areas of central Poland (Warsaw), measuring tick abundance/density, prevalence of infection with spirochaetes and diversity of these pathogens in spring-early summer and late summer-autumn periods between 2012 and 2015.MethodsQuesting I. ricinus ticks were collected from three urban sites in Warsaw, central Poland and three natural sites in Białowieża, NE Poland. A total of 2993 ticks were analyzed for the presence of Borreliella spp. and/or Borrelia miyamotoi DNA by PCR. Tick abundance was analyzed by General Linear Models (GLM). Prevalence and distribution of spirochaetes was analyzed by Maximum Likelihood techniques based on log-linear analysis of contingency tables (HILOGLINEAR). Species typing and molecular phylogenetic analysis based on the sequenced flaB marker were carried out.ResultsOverall 4617 I. ricinus ticks were collected (2258 nymphs and 2359 adults). We report well established population of ticks in urban areas (10.1 ± 0.9 ticks/100 m2), as in endemic natural areas with higher mean tick abundance (16.5 ± 1.5 ticks/100 m2). Tick densities were the highest in spring-early summer in both types of areas. We observed no effect of the type of area on Borreliella spp. and B. miyamotoi presence in ticks, resulting in similar prevalence of spirochaetes in urban and natural areas [10.9% (95% CI: 9.7–12.2%) vs 12.4% (95% CI: 10.1–15.1%), respectively]. Prevalence of spirochaetes was significantly higher in the summer-autumn period than in the spring-early summer [15.0% (95% CI: 12.8–17.5%) vs 10.4% (95% CI: 9.2–11.6%), respectively]. We have detected six species of bacteria present in both types of areas, with different frequencies: dominance of B. afzelii (69.3%) in urban and B. garinii (48.1%) in natural areas. Although we observed higher tick densities in forests than in maintained parks, the prevalence of spirochaetes was significantly higher in the latter [9.8% (95% CI: 8.6–11.0%) vs 17.5% (95% CI: 14.4–20.5%)].ConclusionsSurprisingly, a similar risk of infection with Borreliella spp. and/or B. miyamotoi was discovered in highly- and low-transformed areas. We suggest that the awareness of presence of these disease agents in cities should be raised.Electronic supplementary materialThe online version of this article (10.1186/s13071-017-2391-2) contains supplementary material, which is available to authorized users.

BackgroundThe bacteria of the genus Bartonella are obligate parasites of vertebrates. Their distribution range covers almost the entire world from America, Europe, Asia to Africa and Australia. Some species of Bartonella are pathogenic for humans. Their main vectors are blood-sucking arthropods such as fleas, ticks and blood-feeding flies. One such dipteran able to transfer vector-borne pathogens is the deer ked (Lipoptena cervi) of the family Hippoboscidae. This species acts as a transmitter of Bartonella spp. in cervid hosts in Europe.MethodsIn the present study, 217 specimens of deer ked (Lipoptena cervi) were collected from 26 red deer (Cervus elaphus) hunted in January 2014. A short fragment (333 bp) of the rpoB gene was used as a marker to identify Bartonella spp. in deer ked tissue by PCR test. A longer fragment (850 bp) of the rpoB gene was amplified from 21 of the positive samples, sequenced and used for phylogenetic analysis.ResultsThe overall prevalence of Lipoptena cervi infection with Bartonella spp. was 75.12% (163/217); 86.67% (104/120) of females and 60.82% (59/97) of males collected from red deer hunted in the Strzałowo Forest District in Poland (53°45′57.03″N, 21°25′17.79″E) were infected. The nucleotide sequences from 14 isolates (Bartonella sp. 1) showed close similarity to Bartonella schoenbuchensis isolated from moose blood from Sweden (GenBank: KB915628) and human blood from France (GenBank: HG977196); Bartonella sp. 2 (5 isolates) and Bartonella sp. 3 (one isolate) were similar to Bartonella sp. from Japanese sika deer (GenBank: AB703149), and Bartonella sp. 4 (one isolate) was almost identical to Bartonella sp. isolated from Japanese sika deer from Japan (GenBank: AB703146).ConclusionsTo the best of our knowledge, this is the first report to confirm the presence of Bartonella spp. in deer keds (Lipoptena cervi) in Poland by molecular methods. Bartonella sp. 1 isolates were most closely related to B. schoenbuchensis isolated from moose from Sweden and human blood from France. The rest of our isolates (Bartonella spp. 2–4) were similar to Bartonella spp. isolated from Japanese sika deer from Japan.Electronic supplementary materialThe online version of this article (10.1186/s13071-017-2413-0) contains supplementary material, which is available to authorized users.

Bacteria of Rickettsiaceae and Anaplasmataceae families include disease agents spread by Ixodes ricinus ticks, the most common tick vector in Europe. The aim of the study was to compare the prevalence and co-infection prevalence of particular tick-transmitted Rickettsiales members: Rickettsia spp. (further referred as Rs), Anaplasma phagocytophilum (Ap), and “ Candidatus Neoehrlichia mikurensis” (CNM) in I . ricinus ticks in two types of areas, different in terms of human impact: natural and urban. Using additional data, we aimed at investigating co-occurrence of these Rickettsiales with Borreliella spp. A total of 4189 tick specimens, 2363 from the urban area (Warsaw park and forests) and 1826 from the natural area (forests and park in the vicinity of National Parks), were tested for the presence of Rickettsiales DNA by PCRs. The prevalence of selected Rickettsiales was twice higher in urban than natural areas (13.2% vs. 6.9%, respectively). In total ticks, the prevalence of Rs, Ap, and CNM was 6.5%, 5.3%, and 3.6% in urban areas vs. 4.4%, 1.1%, and 2.1% in natural areas, respectively. Co-infections of Rickettsiales were also more prevalent in urban areas (2.6% vs. 0.3%, respectively). The most common Rs was R . helvetica ; also R . monacensis and novel “ Candidatus Rickettsia mendelii” were detected. Positive association between Ap and CNM infections was discovered. Rickettsiales bacteria occurrence was not associated with Borreliella occurrence, but co-infections with these two groups were more common in ticks in urban areas. In conclusion, three groups of Rickettsiales constituted the important part of the tick pathogen community in Poland, especially in the urbanized central Poland (Mazovia). In the Warsaw agglomeration, there is a greater risk of encountering the I . ricinus tick infected with Rickettsiales and co-infected with Lyme spirochaetes, in comparison to natural areas. This finding raises the question whether cities might in fact be the hot spots for TBDs. Electronic supplementary material The online version of this article (10.1007/s00248-018-1269-y) contains supplementary material, which is available to authorized users.