Joanna Hildebrand

Toxocara canis, Toxocara cati and Toxascaris leonina in wild and domestic carnivores

SummaryAscarididae nematodes of genera Toxocara and Toxascaris are of significant epizootic relevance among predatory mammals from families Canidae and Felidae. Localization of these nematodes in the definitive hosts, their morphology, as well as the measurements of eggs and adult worms are similar. Recently, molecular techniques have provided alternative approaches for the identification of ascarid species. A common feature of the life cycles of these generally monoxenous nematodes is the significant participation of small rodents. In case of Toxocara spp., the rodent plays the role of paratenic host but optional intermediate host for T. leonina. Several studies indicate co-occurence of both T. canis and T. leonina in domestic and wild canids as well as T. cati and T. leonina in felids. Although the infections of humans with T. canis and T. cati are common worldwide, larvae of T. leonina has the potential to cause human disease as emerging zoonosis.

Intermediate and paratenic hosts in the life cycle of Aelurostrongylus abstrusus in natural environment

The cat lungworm Aelurostrongylus abstrusus affects the domestic cats and other felids all over the world. Feline aelurostrongylosis is of importance in clinical feline medicine. Snails and slugs are the intermediate hosts, but the cat is probably infected by eating paratenic hosts, e.g., rodents, birds, amphibians and reptiles. Herein we present the first finding of A. abstrusus in a naturally infected invasive synantropic slugs Arion lusitanicus (intermediate host) and wild living rodents Apodemus agrarius (paratenic host). The results confirm the usefulness of molecular approaches for investigating the biology, ecology and epidemiology of A. abstrusus, the agent of feline aelurostrongylosis.

Small rodents as reservoirs of Cryptosporidium spp. and Giardia spp. in south-western Poland

Cryptosporidium spp. and Giardia spp. have been detected in a range of host species, including rodents. The aim of this study was to determine the distribution of these pathogens and recognition of the reservoir role of rodents in the maintenance of these pathogens in south-western Poland. Additionally, preliminary molecular studies were conducted to elucidate the species and genotypes of Cryptosporidium and Giardia identified in this study. Stool samples (n=266) from A. agrarius, A. flavicollis and M. glareolus, were subjected for analyses. Values of prevalence were 61.7, 68.3 and 68.1%, respectively, for Cryptosporidium spp. and 41.7, 24.4 and 38.4%, respectively, for Giardia spp. There was a statistically significant correlation between host species and Giardia infection where A. agrarius was the species of the highest prevalence. Statistically significant differences were not found for comparisons made for study sites and occurrence of Giardia spp. and Cryptosporidium spp. Due to preliminary nested PCR results, specific amplifications of Cryptosporidium COWP and SSU rRNA genes were obtained for several isolates taken from rodent host species. One isolate recovered from A. agrarius (from a semi-aquatic, urban area) was identified as C. parvum and revealed 100% similarity with sequences obtained from humans. To the best of the knowledge of the authors, this is the first record of the C. parvum zoonotic species from the striped field mouse. Also recorded were the first findings of C. ubiquitum from three small rodent species.

Preliminary studies on the zoonotic importance of rodents as a reservoir of toxocariasis from recreation grounds in Wroclaw (Poland)

SummaryDue to their specific biology and behaviour, rodents could play a role as an intermediate, definitive or paratenic host for many helminth species, as well as for species of zoonotic significance such as Toxocara spp. or Echinococcus multilocularis. The aim of our preliminary study was to investigate the nematode fauna of rodents collected from recreation grounds located in the vicinity of Wroclaw, and to determine their role in the transmission of toxocariasis in this area. During a one-year period, 90 individuals belonging to three rodent species, i.e. Apodemus agrarius, A. flavicollis and Myodes glareolus, were collected. The overall prevalence of infection with nematodes amounted to 63.33 ± 10.15 % and differed between hosts. Toxocara spp. larvae were located in livers and brains of A. agrarius (12.9 %). Our results indicate a role of rodents in the circulation of toxocariasis in sub-urban areas, which serve as recreation grounds for the city of Wroclaw.

Cryptosporidium spp. and Enterocytozoon bieneusi in introduced raccoons (Procyon lotor)—first evidence from Poland and Germany

The raccoon (Procyon lotor) carnivore native to North America is a fast spreading, invasive species in the Europe now. At the moment, the highest population occupies areas near the German-Polish border. The data on the occurrence of Cryptosporidium spp. and microsporidia in raccoons is limited to North America’s territory and is totally lacking in the case of their introduction to Europe. Therefore, the objective of this study was to investigate the occurrence of microparasites, i.e., Cryptosporidium spp. and microsporidia in the introduced raccoons obtained from localities in Poland and Germany. A PCR-based approach that permitted genetic characterization via sequence analysis was applied to raccoon fecal samples (n = 49), collected during 2012–2014. All fecal samples were simultaneously tested with the use of genetic markers, and DNA of microsporidia and Cryptosporidium spp. was detected among the examined raccoons. The results of our research confirmed the presence of Cryptosporidium skunk genotype and Enterocytozoon bieneusi NCF2 genotype. The results suggest a possible role of raccoons in the contamination of the environment, including urban areas, with pathogens of zoonotic significance as well as their role in the transmission and introduction of new genotypes of microparasites in the areas where P. lotor has not been observed yet. To our knowledge, there has been no literature data on the above genotypes detected previously in humans or animals from the examined study sites so far.

Diversity of Enterocytozoon bieneusi genotypes among small rodents in southwestern Poland

Diversity of Enterocytozoon bieneusi genotypes in wild small rodent populations still remains incomplete and only few molecular studies have been conducted among these hosts. Therefore, the aim of this study was to determine whether small rodents, i.e., Apodemus agrarius, Apodemus flavicollis, Mus musculus and Myodes glareolus act as hosts of E. bieneusi and can play an important role in spore spreading in the environment of south-western Poland. Molecular analyses were conducted to determine pathogen genotypes. A total of 191 fecal and 251 spleen samples collected from 311 rodent individuals were examined for the occurrence of E. bieneusi by PCR amplifying ITS gene. The overall prevalence of E. bieneusi in rodent samples was 38.9%. The nucleotide sequences of ITS region of E. bieneusi revealed the presence a total of 12 genotypes with two being already known, i.e., D and gorilla 1 genotypes. The remaining ten are novel genotypes (WR1-WR10) which segregated into three groups in a neighbor joining phylogeny. This study reports for the first time E. bieneusi occurrence in wild living rodents in Poland and shows extensive genetic diversity within E. bieneusi isolates of rodent origin.

Heligmosomoides neopolygyrus Asakawa & Ohbayashi, 1986, a cryptic Asian nematode infecting the striped field mouse Apodemus agrarius in Central Europe

BackgroundHeligmosomoides polygyrus is a widespread gastro-intestinal nematode infecting wild Apodemus (wood mice) throughout Europe. Using molecular and morphological evidence, we review the status of Heligmosomoides from Apodemus agrarius in Poland previously considered to be an outlying clade of H. polygyrus, to further resolve the status of the laboratory model species, H. bakeri.MethodsMorphological analysis of the male bursa and the synlophe, and molecular analyses of concatenated nuclear (28S rDNA, ITS1 and ITS2) and mitochondrial (CO1 and cytb) genes, of Heligmosomoides collected from Apodemus agrarius from two sites in Poland and comparison with related heligmosomids from voles and mice in Eurasia.ResultsHeligmosomoides neopolygyrus, a heligmosomid nematode from Apodemus species from China and Japan, is recognised for the first time in western Europe infecting Apodemus agrarius in Poland. It can be distinguished from H. polygyrus by the filiform externo-dorsal rays of the male copulatory bursa and the small, equally distributed longitudinal crêtes on the body. Specimens from A. agrarius are 20% different at ribosomal (ITS1 and ITS2) nuclear loci, and 10% different at the mitochondrial cytb locus from H. polygyrus, and in phylogenetic analyses group with the vole-infecting genus Heligmosomum.ConclusionsDespite morphological similarity, H. neopolygyrus is only distantly related to H. polygyrus from western European Apodemus, and may be more closely related to vole-infecting taxa. It was brought into Europe by the recent rapid migration of the host mice. Inclusion of H. neopolygyrus in phylogenies makes it clear that Heligmosomoides is paraphyletic, with the pika-infecting Ohbayashinema and the vole-infecting Heligmosomum nesting within it. Clarification of the European status of H. neopolygyrus also allows H. bakeri, the laboratory model species, to be seen as a terminal sister clade to H. polygyrus, rather than as an internal clade of the latter taxon.

Redescription and phylogenetic relationships of the rare Lyperosomum sarothrurae Baer, 1959 (Digenea: Dicrocoeliidae).

Abstract Lyperosomum sarothrurae Baer, 1959 is a rare dicrocoeliid described based on a single specimen from Belgian Congo, now Democratic Republic of the Congo, and never reported again. The original description lacked several important details of the species morphology. This work provides morphological redescription of Lyp. sarothrurae based on specimens from Kibale National Park, Uganda which is about 200 kilometres from the type locality. Results of re-examination of the holotype are also provided. Morphology of Lyp. sarothrurae shows some characteristics intermediate between those of the species rich genus Lyperosomum Looss, 1899 and Megacetabulum Oshmarin, 1964 that includes only 3 species. Due to the lack of clear morphological differences between the two genera, Megacetabulum is considered here as a junior synonym of Lyperosomum. Molecular phylogenetic analysis including Lyp. sarothrurae and all currently available partial sequences of the nuclear ribosomal 28S RNA gene of dicrocoeliid species is also included and its results are discussed

Molecular Identification of Heterakis spumosa Schneider, 1866 (Nematoda: Ascaridida: Heterakidae) with Comparative Analysis of Its Occurrence in Two Mice Species

Abstract. Heterakis spumosa Schneider, 1866 is a typical and widespread parasite of Rattus sp. Recently published reports on its presence in rodents other than rats and house mice (e.g. Apodemus agrarius and A. flavicollis) may suggest acquisition of new host or the existence of two distinct species parasitising within the subfamily Murinae in Europe. The first aim of our study was to examine the taxonomic status of H. spumosa isolated from three host species (Rattus norvegicus, Apodemus agrarius and A. flavicollis) by analysing the partial sequence of small subunit (18S) of ribosomal DNA (rDNA). The second aim was to investigate the pattern of occurrence of H. spumosa within the two species of Apodemus. As a result of partial sequencing of 18S rDNA we obtained three sequences, 977 bp (A. agrarius), 867 bp (A. flavicollis) and 873 bp (Rattus norvegicus) long. Multiple alignment showed that the nucleotide composition of DNA from all the hosts was identical, which may suggest that the nematodes isolated from the three host species are conspecific. Parasitological and statistical analysis of H. spumosa showed a high prevalence of infection and lower degree of nematodes overdispersion in A. agrarius. Comparative analysis of aggregation level in infrapopulations and metapopulations of H. spumosa indicate that A. flavicollis is not typical host for this species. Our results showed that the factor affecting the presence of H. spumosa is the hosts age, but we did not observe any influence of the hosts sex or collecting season.

Host-dependent morphology of Isthmiophora melis (Schrank, 1788) Luhe, 1909 (Digenea, Echinostomatinae) – morphological variation vs. molecular stability

BackgroundEchinostomes are cosmopolitan digenean parasites which infect many different warm-blooded hosts. Their classification is extremely confused; the host spectrum is wide, and morphological similarities often result in misidentification. During our long-term studies on the helminth fauna of rodents and carnivores we have collected 27 collar-spined echinostomes which differ in morphology to an extent that suggests the presence of more than one species. Here, we describe this material, and the extent of host-related variation in this parasite.MethodsSpecimens of Isthmiophora isolated from four host species (badger, American mink, hedgehog, striped field mouse) were subject to morphological and molecular examination; the data were statistically analysed.ResultsOur results show that genetically all the Isthmiophora specimens obtained from all the examined hosts are conspecific and represent I. melis. On the other hand, the individuals isolated from Apodemus agrarius are morphologically distinct and, based on this criterion alone, should be described as a new species.ConclusionsThe morphological traits of Isthmiophora melis are much variable and host-dependent; without molecular analysis they would suggest a necessity to describe a new species or even genus. Such a high level of intraspecific variability may be affected by the host’s longevity.