Marta Kołodziej-Sobocińska

Kinetics of specific humoral immune response of mice infected with low doses of Trichinella spiralis, T. britovi, and T. pseudospiralis larvae

SummaryThe specific humoral immune response of the host (mouse) to the infection with low doses of larvae of encapsulating (Trichinella spiralis, T. britovi) and non-encapsulating (T. pseudospiralis) species was studied. Mice were experimentally infected with 10 muscle larvae of the parasite to simulate natural conditions of the infection in rodents, important reservoirs of trichinellosis. The low infective dose of T. spiralis and T. britovi did not evoke an increased specific IgM response, which is typical for the acute infection. Only T. pseudospiralis induced a higher specific IgM level in the intestinal phase of the infection, till day 30 p.i. The low infective dose of T. spiralis larvae stimulated a specific IgG1 production from day 20 p.i. with a strong increase on day 45 p.i., but T. britovi infection on day 60 p.i. Specific IgG1 antibodies were not detected in T. pseudospiralis infection. The production of IgG2a and IgG2b antibodies was again earlier and more expressive in T. spiralis infection from day 45 p.i., in contrast to T. britovi, where these antibodies were increased on day 60 p.i. Only IgG2b isotype was detected in T. pseudospiralis infection on days 45 and 60 p.i., however in very low values in comparison with encapsulating species.Results conclude the low infective dose of T. spiralis, T. britovi, and T. pseudospiralis induced a late seroconversion in infected mice. T. spiralis caused earlier and more intensive specific antibody response, from day 45 p.i, when antigens from newborn and muscle larvae were accumulated, on the contrary to T. britovi and T. pseudospiralis, which induced specific antibody response from day 60 p.i.

Range expansion of the golden jackal (Canis aureus) into Poland: first records

The range of the golden jackal (Canis aureus) in Europe has been expanding in recent decades. We describe the first three records of golden jackal from Poland and attribute them to the natural range expansion of the species. A young male jackal was found dead on a road in western Poland, close to the German border, on 13th April 2015. Morphological examination and genetic analysis confirmed the species identification. This individual had the same mitochondrial DNA haplotype as a comparative individual from the wild population in southern Ukraine. The two other observations of jackals, confirmed from photographs, were reported in May and June 2015 from the Biebrza river valley and the Polesie region, both in eastern Poland. The records suggest a natural expansion of the species into Poland, probably from different source populations, and indicate the urgent need to determine the status of the golden jackal in this part of Europe.

The first report of sparganosis (Spirometra sp.) in Eurasian badger (Meles meles).

Spirometra sp. is a diphyllobothriid cestode which reproduces mainly in cat-like carnivores and canids. Several animal species that are not definitive hosts function as paratenic hosts, in which plerocercoids migrate to other tissues causing sparganosis. In this paper we describe the first case of sparganosis (Spirometra sp.) in Eurasian badger (Meles meles). It was found in an adult female Eurasian badger killed on the road in the Białowieża Primeval Forest (north-eastern Poland) in April 2013. At necropsy, 128 complete and 40 fragments of plerocercoids (spargana) were found and were located subcutaneously, mainly on the hind legs and along the spine. The average length of spargana was 87±38mm. No adult Spirometra sp. tapeworms were found in the animal intestine, indicating that the investigated badger was a paratenic host for Spirometra sp. Analysis of 18S rRNA gene sequences combined with morphological examination confirmed affiliation of the concerned plerocercoids to genus Spirometra.

Does the blood-sucking nematode Ashworthius sidemi (Trichostrongylidae) cause deterioration of blood parameters in European bison (Bison bonasus)?

European bison (Bison bonasus), after extinction in the wild at the beginning of twentieth century, were reintroduced in over 30 free-ranging populations in central and eastern Europe. Major threats to this species include disease and parasites. In the last decades, the highly pathogenic blood-sucking nematode Ashworthius sidemi (Trichostrongylidae) has been found in high infection intensity and prevalence within the abomasa of free-living European bison. We investigated the impact of this invasion on blood parameters associated with the red blood cell system in 64 bison (53 free-living and 11 captive) which were culled in two neighbouring populations in north-eastern Poland between 2008 and 2015. We observed a significant decrease in red blood cell count, haemoglobin and haematocrit relative to the intensity of A. sidemi infection. Furthermore, the same parameters were significantly lower, and the percentage of reticulocytes was increased in highly infected free-living bison compared to captive individuals. Studies indicate the urgent need to change the conservation management of herds because traditional management that includes supplementary feeding causes a large concentration of bison in winter feeding areas. This causes an increase in parasitic load which ultimately impacts on their condition. The reservoir of this parasite in wildlife may also adversely affect livestock grazing on pastures used by bison.

Trichinella spiralis reinfection: changes in cellular and humoral immune response in BALB/c mice

SummaryTrichinella spiralis infection induces a host cell-mediated and humoral response. The role of T and B lymphocytes in the immune response of mice reinfected with 2 × 400 T. spiralis larvae was studied in relation to the parasite burden. BALB/c mice were infected on days 0 and 60 and immunological parameters were examined within a period of 180 days. In comparison with a single T. spiralis infection, T- and B-lymphocytes in reinfected mice responded by a significant increase in the proliferative activity during 10 days after reinfection. At the same time, the percentages of CD4+ T-cells of reinfected mice were also increased. In contrast, the CD8+ T-cell numbers were significantly reduced almost 30 days after reinfection. High concentration of serum IFN-γ lasted till the end of the experiment. The IL-5 level was increased only for 2 weeks after reinfection, followed by its decrease. Kinetics of specific anti-Trichinella immunoglobulins IgG2a was not affected with reinfection, but specific antibodies IgG1 significantly increased after reinfection and persisted elevated till the end of the experiment. Lower numbers of adults (69.2 % reduction) in the small intestine and 72.3 % reduction in muscle larvae were found after reinfection. Stimulation of the host immune response — the increased activity of CD4+ T lymphocytes and high levels of IFN-γ and specific IgG1 after reinfection, contributed to the reduction of the parasite burden.

Occurrence of Echinococcus multilocularis in red foxes from the Carpathian Regions of Slovakia and Poland

The extensive distribution of Echinococcus multilocularis cestode from endemic alpine areas to the parts of Central Europe has been recorded in recent years. The first confirmed finding of E. multilocularis in Slovakia was recorded in 1999 in the area adjacent to the Polish border. At present, this serious zoonosis occurs almost across the whole territory of Slovakia. The occurrence of these tapeworms in red foxes (Vulpes vulpes) at the border regions of Slovakia and Poland has been monitored. In these districts, out of 152 faecal samples examined, 36.2% were positive for the coproantigen-ELISA. With the sedimentation and counting technique the prevalence of E. multilocularis in red foxes was up to 38.8%. The examination of foxes from neighbouring districts revealed worm burden ranging from 1–15,000 specimens, but the majority of animals harboured medium number of tapeworms. In the Small Carpathian and Sub-Carpathian regions of Poland, out of 65 samples examined, 13.8% were coproantigen positive. Using the small intestine scraping method only 6.1% prevalence of E. multilocularis in red foxes was determined, mostly with a high worm burdens over 1,000 specimens. The results suggest possible transborder transmission of E. multilocularis, the causative agent of serious alveolar echinococcosis.

An invasive species as an additional parasite reservoir: Trichinella in introduced American mink (Neovison vison).

The American mink (Neovison vison Schreber, 1777) is one of the most invasive alien mammal species which has been introduced to many countries in Europe, Asia and South America. As a predator which feeds on various prey, American mink carry many endoparasites; however, data about infection rate and prevalence of different parasites in mink are limited, especially concerning Trichinella spp. The aim of our study was to evaluate the role of American mink in the circulation of Trichinella species in its introduced range. In total, 812 muscle samples of mink from six feral populations and three farms in Poland were examined for presence of Trichinella muscle larvae using the artificial HCl-pepsin digestion method. Muscle larvae were found in 27 out of 812 individuals (3.3%) from six localities in western and north-eastern Poland. The intensity of infection varied from 0.1 to 274.8 LPG. The majority of Trichinella-positive individuals - 15 (55.6%) were infected with T. britovi, one with T. spiralis, and one with T. pseudospiralis. Two animals harboured T. britovi and T. spiralis in co-infection and this data confirmed the first report of a mixed Trichinella infection in American mink.

Sparganosis in wild boar (Sus scrofa) – Implications for veterinarians, hunters, and consumers

From February to March 2016 we found plerocercoids of Spirometra sp. in four wild boar hunted in Białowieża Primeval Forest, north-eastern Poland. Plerocercoids were located subcutaneously and in muscle tissue. A sequence of a nuclear 18S rRNA gene was used for genetic specification of the samples. The analyzed gene fragment showed 100% identity with the Spirometra erinacei sequence. Thus, the emerge of human sparganosis due to consumption of undercooked or smoked wild boar meat is likely in the areas where wild boar is an approved food source, especially in the absence of routine guidelines for vets. It has become a priority to inform the public about possibilities and consequences of this zoonosis.

Influence of management and biological factors on parasitic invasions in the wild – Spread of the blood-sucking nematode Ashworthius sidemi in European bison (Bison bonasus)

The full course of new parasite introductions in wild animals is difficult to accurately trace. We documented and analysed the invasive blood-sucking nematode Ashworthius sidemi (Trichostrongylidae) introduction and spread in European bison (Bison bonasus) from the initial phase of its progression. In the Polish part of the Białowieża Primeval Forest (BPF) the parasite was first found in 2000. From 2002 to 2015, 165 culled bison were investigated. The prevalence and intensity of A. sidemi Schulz, 1933 infection increased over the following years, reaching 100% of investigated bison four years after introduction and a maximal median intensity of 8200 nematodes per animal in the winter of 2008/2009. Afterwards, a significant decline of median infection intensity was observed to the minimum value of 410 nematodes per animal. Between 2011 and 2014 prevalence varied from 89 to 100%. Among the factors analysed, the number of years since introduction, herd size, age and sex proved to significantly influence infection intensity. A higher infection intensity was recorded in sub-adults compared to juveniles and adults. Males had significantly lower infection intensity than females, but this was the case for adults only. The highest infection intensities were recorded in the biggest bison herds, where the winter supplementary feeding of bison is intense. Moreover, the longer the parasite was present in the host population, the more important herd size became as a factor. Our study indicates that it is not solely biological factors that determine the spread of a newly detected parasite in wildlife, but that management practices can also have a strong influence. This is especially important in endangered species under intensive human care as the management practices may pose a threat to the species.

In vivo inhibition of inducible nitric oxide synthase by aminoguanidine influences free radicals production and macrophage activity in Trichinella spiralis infected low responders (C57BL/6) and high responders (BALB/c) mice

SummaryThe influence of aminoguanidine (AG) — inhibitor of inducible nitric oxide synthase (iNOS), on macrophage activity and free radicals level was examined during Trichinella spiralis infection in two strains of mice: C57BL/6 and BALB/c. AG was administered either between 1–5 days post infection (dpi) for intestinal phase examinations or between 16–29 dpi for muscle phase examinations. The number of peritoneal macrophages and level of nitric oxide NO) and hydrogen peroxide (H2O2) in biological fluids were determined in both strains after infection or infection together with AG treatment as well as in control uninfected mice. The performed studies have proved, that free radicals play role in host immune response during intestinal and muscle phase of T.spiralis infection in mice. Inflammatory response in peritoneal cavity was delayed during infection in low responders C57BL/6 mice in comparison with high responders BALB/c mice. C57BL/6 mice are Th-1 like strain and react stronger to AG in contrary to BALB/c being Th-2 like strain. It was manifested as changes and fluctuations of free radicals levels and in the number of peritoneal macrophages after AG treatment in C57BL/6 mice. A weak or no reaction on AG injection in BALB/c mice is responsible for more stable and more effective defense response of the host to T. spiralis infection.