Following infection with Ostertagia circumcincta there was considerable variation in worm burdens, worm size and number of inhibited larvae even among sheep matched for age, sex, breed, farm of origin and history of parasite exposure. There was also substantial variation among sheep in the concentration of mast cells, globule leucocytes, eosinophils, IgA-positive plasma cells and parasite-specific IgA in the abomasal mucosa. With the exception of faecal egg counts over time, the parasitological and immunological traits were all continually distributed among animals and sheep did not fall into discrete high and low-responder categories. The responses were correlated. Sheep with more mast cells also had more globule leucocytes, more eosinophils, more IgA plasma cells and greater amounts of parasite-specific IgA in the abomasal mucosa. Female worm length was strongly and positively correlated with the number of eggs in utero. Faecal egg counts were associated with variation in worm number and with variation in the number of eggs in utero. The worm burden was negatively correlated with the number of globule leucocytes in the abomasal mucosa, suggesting that worm numbers are regulated by immediate hypersensitivity reactions. Decreased female worm length was associated with an increased local IgA response to fourth stage larvae. The number of inhibited larvae was positively associated with the size of the local IgA response and positively associated with the size of the worm burden. The results suggest that variation among mature sheep in faecal egg counts is due, at least in part, to variation in local IgA responses which regulate worm fecundity and to variation in local immediate hypersensitivity reactions which regulate worm burdens.

The major histocompatibility complex (MHC) genes code for the proteins responsible for pathogen recognition. The MHC class II DRB gene is multiplicated in the bank vole, Myodes glareolus, with different numbers of loci found in different individuals. Possessing large numbers of loci should increase the probability of pathogen recognition, but according to the optimality hypothesis, there is a cost of possessing too many MHC alleles. Using 454 technology, we determined the individual DRB allelic diversity and related it to the load of intestinal parasites in voles collected from three sites separated by a distance of 12 to 27 km. The analysis of six microsatellite loci revealed significant population structure (F ST = 0.07). The sites differed significantly in the prevalence and abundance of nematode species as well. We found two significant associations between MHC alleles and the intensity of the infection with the most prevalent nematode, Aspiculuris tetraptera. One of these associations was population-specific. This result suggests that the directions of selection can differ between populations connected by a low level of gene flow, which may contribute to the maintenance of high DRB allele diversity. In accordance with the optimality hypothesis, individuals with an intermediate number of alleles carried the lowest number of nematode species and had the lowest prevalence of A. tetraptera. However, the intensity of infection with A. tetraptera was linearly and negatively associated with the number of alleles.

(2001) Variation in the helminth community structure in bank voles (Clethrionomys glareolus) from three comparable localities in the Mazury Lake District region of Poland. Parasitology, 123 (4 A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. We tested the null hypothesis that populations of hosts trapped in isolated neighbouring locations showing comparable habitat quality, should support similar helminth parasite communities. The study was undertaken in a 2-week period in late summer in NE Poland in a single year, thereby eliminating seasonal and between-year variation in parasite burdens. A total of 139 Clethrionomys glareolus (bank vole) were sampled from 3 forest sites of similar habitat quality. Total species richness was 11 (6 nematodes and 5 cestodes) with 85n6 % of the voles carrying at least 1 species and an overall mean species richness of 1n4. At the component community level, the fewest species of helminths were recorded from site 2 (n l 6, compared with 9 at each of the other sites), but site 3 had the lowest Berger-Parker Dominance Index and the highest Simpson 's Index of Diversity. At the infracommunity level, site 3 had the highest mean no. of helminth species\vole, the highest mean Brillouin 's Index of Diversity but the lowest mean no. of helminths\vole. Voles from sites 1 and 3 differed in the nematodes that were most common (site 1, Heligmosomum mixtum -95 % ; site 3, Heligmosomoides glareoli -79n3 %). At site 2 no species exceeded 50 % but prevalence of Syphacia petrusewiczi was higher than at the other sites. The prevalence of cestodes was too low to test reliably (12n9 %), but the highest prevalence of adult cestodes was recorded at site 1 (22n5 % compared with 4n9 and 1n7 % for sites 2 and 3 respectively). Host sex did not influence infection, but mean species richness increased with age. The different sites were responsible for most of the variation in our data, and the intrinsic factors (sex and age) were less important in shaping the component community structure of helminths. We conclude that even locations in relative close proximity to one another (13-25 km), selected on the basis of similar habitat quality, have rodent populations that differ in their helminth parasite communities, although for reasons other than the factors quantified in the present study.

Bartonella infections from wild mice and voles (Apodemus flavicollis, Mi. oeconomus, Microtus arvalis and Myodes glareolus) were sampled from a forest and old-field habitats of eastern Poland; a complex network of Bartonella isolates, referrable to B. taylorii, B. grahamii, B. birtlesii and B. doshiae, was identified by the sequencing of a gltA fragment, comparable to previous studies of Bartonella diversity in rodents. Nested clade analysis showed that isolates could be assigned to zero- and one-step clades which correlated with host identity and were probably the result of clonal expansion; however, sequencing of other housekeeping genes (rpoB, ribC, ftsZ, groEl) and the 16S RNA gene revealed a more complex situation with clear evidence of numerous recombinant events in which one or both Bartonella parents could be identified. Recombination within gltA was found to have generated two distinct variant clades, one a hybrid between B. taylorii and B. doshiae, the other between B. taylorii and B. grahamii. These recombinant events characterised the differences between the two-step and higher clades within the total nested cladogram, involved all four species of Bartonella identified in this work and appear to have played a dominant role in the evolution of Bartonella diversity. It is clear, therefore, that housekeeping gene phylogenies are not robust indicators of Bartonella diversity, especially when only a single gene (gltA or 16S RNA) is used. Bartonella clades infecting Microtus were most frequently involved in recombination and were most frequently tip clades within the cladogram. The role of Microtus in influencing the frequency of Bartonella recombination remains unknown.

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.