Cystic echinococcosis in Poland: genetic variability and the first record of Echinococcus granulosus sensu stricto (G1 genotype) in the country.

Cystic echinococcosis is one of the most important zoonotic diseases affecting humans and livestock worldwide, and is endemic in Poland. A set of six isolates on larval stages of Echinococcus granulosus sensu lato tapeworms collected from three humans, two pigs and one sheep from Polish foci of CE was examined by DNA sequencing of two mitochondrial genes (cox1, rrnS). The results demonstrated the presence of E. canadensis and E. granulosus sensu stricto in the investigated hydatid cysts. The former species was found in all five isolates from pigs and humans derived from central Poland. In a sheep hydatid cyst originating from Lesser Poland Voivodeship in southern Poland, E. granulosus s. s. (G1 genotype) was identified. This is the first report of an unambiguously autochthonous infection with E. granulosus s. s. in Poland. The global distribution and host affiliations of the commonly occurring G1 microvariant with nucleotide change 56C/T in cox1, detected here in Polish sheep, are discussed. The finding that sheep harboured E. granulosus s. s. may have important consequences for developing effective hydatid control programmes in Poland due to its longer maturation rate in dogs compared with E. canadensis G7. This may lead to greater expenditures for purchasing anthelmintics to provide an appropriate dosing regime in sheep-raising areas of the country.

Modified Natural Diatomite with Various Additives and Its Environmental Potential.

Diatomite has recently been the subject of intensive scientific research aimed at its extensive use in industry, breeding and agriculture. The only active diatomite mine is in Jawornik Ruski, in the Podkarpacie region of Poland. Chemical pollution in the environment, including that from heavy metals, poses a threat to living organisms. Reducing the mobility of heavy metals in the environment through the use of diatomite (DT) has recently gained much interest. More effective immobilisation of heavy metals in the environment with DT, mainly through the modification of its physical and chemical properties by various methods, should be applied. The aim of this research was to develop a simple and inexpensive material showing more favourable chemical and physical properties compared with unenriched DT in terms of metal immobilisation. Diatomite (DT), after calcination, was used in the study, considering three grain fractions, i.e., 0-1 mm (DT1); 0-0.5 mm (DT2) and 5-100 µm (DT3). Biochar (BC), dolomite (DL) and bentonite (BN) were used as additives. The proportion of DTs in the mixtures amounted to 75%, and of the additive, 25%. The use of unenriched DTs after calcination poses the risk of releasing heavy metals into the environment. Enrichment of the DTs with BC and DL resulted in a reduction or absence of Cd, Zn, Pb and Ni in aqueous extracts. It was found that for the specific surface area values obtained, the additive used for the DTs was of crucial importance. The reduction in DT toxicity has been proven under the influence of various additives. The mixtures of the DTs with DL and BN had the least toxicity. The obtained results have economic importance, as the production of the best quality sorbents from locally available raw materials reduces transport costs and thus the environmental impact. In addition, the production of highly efficient sorbents reduces the consumption of critical raw materials. It is estimated that the savings from producing sorbents with the parameters described in the article can be significant in comparison with popular competitive materials of other origins.

Effects of Functionalized Materials and Bacterial Metabolites on Quality Indicators in Composts.

The addition of functionalized materials (biochar, zeolite, and diatomite) and lyophilized metabolic products of Pseudomonas sp. and Bacillus subtilis to composted biomass may bring many technological and environmental benefits. In this study, we verify the effects of biochar, zeolite Na-P1 (Na6Si10Al6O32·12 H2O), diatomite (SiO2_nH2O), and bacterial metabolites on the composting of biomass prepared from poultry litter, corn straw, grass, leonardite, and brown coal. The experimental design included the following treatments: C-biomass without the addition of functionalized materials and bacterial metabolites, CB-biomass with the addition of biochar, CBM-biomass with the addition of biochar and bacterial metabolites, CZ-biomass with the addition of zeolite, CZM-biomass with the addition of zeolite and bacterial metabolites, CD-biomass with the addition of diatomite, and CDM-biomass with the addition of diatomite and bacterial metabolites. Composts were analyzed for enzymatic and respiratory activities, mobility of heavy metals, and the presence of parasites. The results of this study revealed that, among the analyzed functionalized materials, the addition of diatomite to the composted biomass (CD and CDM) resulted in the most effective immobilization of Cd, Zn, Pb, and Cu. Zinc immobilization factors (IFHM) for diatomite-amended composts averaged 30%. For copper, each functionalized material was found to enhance mobilization of the element in bioavailable forms; similar observations were made for lead, except for the compost to which biochar and bacterial metabolites were added (CBM). The determined values of biochemical indicators proved the different effects of the applied functionalized materials and bacterial metabolites on the microbial communities colonizing individual composts. The dehydrogenase activity (DhA) was lower in all combinations as compared with the control, indicating an intensification of the rate of processes in the studied composts. The highest basal respiration (BR) and substrate-induced respiration (SIR) activities were determined in composts with the addition of bacterial metabolites (CBM, CZM, and CDM). The addition of functionalized materials completely inactivated Eimeria sp. in all combinations. In the case of Capillaria sp., complete inactivation was recorded for the combination with zeolite as well as biochar and diatomite without bacterial metabolites (CB, CZ, and CD).

Ashworthius sidemi Schulz, 1933 (Trichostrongylidae: Haemonchinae) in mountain ecosystems - a potential risk for the Tatra chamois Rupicapra rupicapra tatrica (Blahout, 1971/1972).

The Asian native Ashworthius sidemi is now in Europe, and several dozen years after its introduction, it is a widespread parasite of all wild cervids. For bovids, the nematode is a significant threat to the European bison (Bison bonasus) population and has also been found in mouflon (Ovis aries musimon). Our study aimed to assess the risk of infection for the endemic subspecies of northern (Alpine) chamois (Rupicapra rupicapra) - the Tatra chamois (R. r. tatrica), which has a critically endangered status. We conducted the investigation in the mountainous areas of Slovakia and Poland occupied by Tatra chamois (R. r. tatrica), Alpine chamois (R. r. rupicapra), red deer (Cervus elaphus) and roe deer (Capreolus capreolus). Animals (n = 93) shot during licensed hunting and killed in road accidents (roe deer, red deer), or which had died of natural causes (chamois) were post-mortem examined for the presence of Haemonchinae. The investigation confirmed the expansion of Ashworthius sidemi to high mountain regions via Cervidae. A. sidemi affected all of the examined roe deer and 90.0% of the red deer. As for the chamois, A. sidemi was found in one R. rupicapra originating from the Low Tatras, but not in any pure R. r. tatrica individuals living in the High and Western Tatras. Our work is the first confirmation of northern chamois infection with this alien and highly pathogenic blood-sucking nematode. Due to the important health hazard of A. sidemi infection for the Tatra chamois (R. r. tatrica), appropriate measures should be taken to reduce the possibility of parasite transmission between various cervid species living in the Tatra region, as well as the affected population of chamois and the pure Tatra chamois population inhabiting the higher parts of the mountains, constituting their natural habitat.

Intestinal Helminth Communities of Grey Partridge Perdix perdix and Common Pheasant Phasianus colchicus in Poland.

The aim of this study was to describe the morphology and means of identification of helminths in native partridges (65) and introduced pheasants (32) in Poland and to determine the level of intestinal infection of these birds by helminths using parasitological and ecological indices. The birds were acquired during the hunting season in the years 2015-2017. Nematodes, Capillaria phasianina, cestodes, Railietina friedbergeri, and one trematode, Brachylaima sp. were recorded for the first time in partridges in Poland. Our findings indicate that parasites are more prevalent in pheasants (prevalence 70.4%) than in partridges (prevalence 50.0%). The component community and infracommunity of parasites of partridges are more diverse (Simpson's diversity index: 0.63 and mean Brillouin diversity index: 0.10 ± 0.17) and less dominated by a single parasite species (Capillaria sp., Berger-Parker dominance index: 0.53) than the pheasant parasite community (Simpson's diversity index: 0.07, mean Brillouin diversity index: 0.005 ± 0.02, dominant species Heterakis gallinarum, Berger-Parker dominance index: 0.96). There were statistically significant differences between partridges and pheasants in the Brillouin diversity index and in the prevalence of Heterakis gallinarum (55.6% in pheasants vs. 19.0 in partridges). There were significant differences between wild and farmed partridges in the prevalence of infection by Capillaria sp. (4.3% vs. 37.5%) and H. gallinarum (39.1 vs. 6.2%). In conclusion, the pheasant was shown to be a reservoir, carrier, and shedder of nematodes, which may increase the risk of infection in partridges.

Morphometric and Molecular Analyses of Ostertagia leptospicularis Assadov, 1953 from Ruminants: Species Diversity or Host Influence?

Ostertagia leptospicularis Assadov, 1953 was formally described in roe deer Capreolus capreolus and has been reported in a wide range of ruminants, including other Cervidae, as well as Bovidae. Nematode specimens derived from various host species exhibit morphological similarity; however, some differences can be observed. It is unclear if this is due to the differential reaction of one nematode species in different host species (i.e., host-induced changes) or because of distinct nematode species in these hosts (i.e., species complex). This paper focuses on specimens resembling O. leptospicularis f. leptospicularis and its closely related species (Ostertagia ostertagi f. ostertagi) collected from various hosts. Morphometric and molecular techniques were applied to assess host-induced changes in nematode morphology and to clarify its systematic classification. There was an overall effect of host species on measurements of nematodes resembling O. leptospicularis (both males and females), but the distinctiveness of the specimens from cattle Bos taurus were highlighted. The results obtained may suggest that the specimens of O. leptospicularis from cattle in Germany and cervids in central Europe belong to different strains. Furthermore, nematodes from the cervid strain appear to circulate within particular host species, which can be seen in the stated morphological variations.

[The influence of Taenia taeniaeformis larval infection on morphometrical parameters of muskrat (Ondatra zibethicus)]. / Wplyw zarazenia larwami tasiemca Taenia taeniaeformis na parametry morfometryczne pizmaków (Ondatra zibethicus).

An investigation aimed to check the influence of Taenia taeniaeformis larvae on morphometrical parameters of muskrat (Ondatra zibethicus) was carried. A total of 30 animals were hunted down in upper Vistula river basin in south Poland, then measured, weighed and dissected. Statistical comparison were done using U Mann-Whitney test. T. taeniaeformis larvae--cysticercus fasciolaris was found in the liver of 24 muskrats (80%). Significant differences between infected and non infected animals are reported, as regards their body mass, total length, abdomen circumference (p < 0.01) and also in body length (total minus tail length), head length, or chest and neck circumference (p < 0.05). The effect of infection on both muskrat condition and the presence of adult cestodes in definitive hosts are discussed.

Gastrointestinal nematodes of European wild boar from distinct agricultural and forest habitats in Poland.

The study aimed to compare the gastrointestinal helminthofauna of free-ranging wild boars from arable lands and forests, which are the natural habitats for wild boar in Poland and further to investigate if wild boars living in agricultural environments could acquire helminths commonly detected in domestic pigs. In 2011-2014, a total of 57 wild boars were examined post-mortem for the presence of gastrointestinal nematodes. Altogether, all but two of the animals were infected, and seven nematode species were found. The mean infection burden was 68.9 parasites, ranging from 1 to 381 worms. In forest areas, Ascarops strongylina, Physocephalus sexalatus, and Globocephalus urosubulatus were common, whereas on arable lands, the animals were more frequently infected (P < 0.05) by Ascaris suum and Trichuris suis, which are parasites that commonly occur in domestic pigs. Oesophagostomum dentatum was observed only in wild boars on arable lands, and Bourgelatia diducta, which is alien to European suids, appeared irrespective of habitat type. These results show significant differences in parasite spectra among wild boars living in forests or arable lands in Poland and indicates the risks of parasite transfer from domestic pigs to free-ranging wild boars. Furthermore, in farmed game, organic farming, or in the case of agritourism farms, one should be aware of the risk of related animals acquiring new and alien parasite infections by being kept outdoors.

Coccidiosis ­ a problem in backyard rabbitries

This paper focuses on parasites of the genus Eimeria in rabbits kept in two backyard farms ­ from Poland (herd A) and Ukraine (herd B). The concentration McMaster technique and sporulation was applied to determine the level of infection, as well as to identify the species composition. The Eimeria sp. oocysts were present in all collected samples (prevalence = 100%), and four to nine coccidian species were identified in the herd A and B, respectively. Eimeria media was the most common species, and the presence of the most pathogenic E. intestinalis and E. flavescens was observed in both studied rabbitries. The results obtained suggest that coccidiosis may cause a serious risk for rabbits kept in backyard farms, therefore prevention guidelines in relation to the backyard breeding are crucial to be developed.

The morphological and molecular identification of the tapeworm, Taenia lynciscapreoli, in intermediate and definitive hosts in Poland.

The tapeworm Taenia lynciscapreoli is a new species of the genus Taenia described in 2016, and which remains poorly understood. The aim of the present study is to extend current knowledge regarding its, morphology and genome. Biological material was analysed from three species of wild animals: Eurasian lynx (Lynx lynx), roe deer (Capreolus capreolus) and moose (Alces alces). Twenty-four adult tapeworms and four larvae were obtained from Eurasian lynx and roe deer respectively; none were detected in the studied moose. On the basis of morphometric (hooks measurements) and molecular analysis (partial 780 bp cox 1 gene sequences), the analysed tapeworm was identified as Taenia lynciscapreoli species. The phylogenetic analysis of the obtained sequences identified two haplotypes. The obtained findings can be used to supplement the species description. To our knowledge this is the first morphological and molecular identification of T. lynciscapreoli in roe deer, intermediate host, in Poland.

[The first record of the lungworm, Metastrongylus asymmetricus (Noda, 1973), in the wild boar from Poland]. / Metastrongylus asymmetricus (Noda, 1973)--nicien plucny po raz pierwszy notowany u dzika w Polsce.

A total of 17 wild boars (Sus scrofa) shot in the Miechów hunting area (southern Poland) during two consecutive winters of 2008, were surveyed for the presence of lung nematodes of the genus Metastrongylus. The animals were necropsied, their lungs removed, divided into smaller parts and examined along the bronchial tubes. The parasites found were identified based on their morphologic characters. The prevalence of the lungworms reached 76.5%, and all of the 13 infected animals harboured two (one boar) or more parasite species. The mean number of parasites in an individual boar was 58.7, ranging from 6 to 250 specimens. Out of 250 identified lungworms, 48.8% was identified as M. pudendotectus, 32.8% were M. elongatus, and 14.0% belonged to M. salmi, whereas 4.4% (i.e. 10 females and 2 males) were M. asymmetricus. Until recently, only four Metastrongylus species have been recorded from Poland, namely M. elongatus, M. pudendotectus, M. salmi and M. confusus. The presently reported finding of M. asymmetricus constitutes the first record of this species in Poland.

[Dynamics of endoparasite infections in rabbits at different rearing regimes]. / Dynamika zarazenia królików endopasozytami w róznych warunkach chowu.

This study was intended to evaluate the occurrence and seasonality of infection of coccidian and helminth parasites, in three rabbit warrens differently managed. Mothers stayed with their offspring on deep litter (farm A, 90 dams), in boxes cleaned weekly (farm B, 30 dams) or on slatted floor (farm C, 10 females), whereas all the young after weaning (1 to 5 months of age) were kept in cages with slatted floor. Animals were fed a complete balanced pelleted feed (warrens A and B) or traditional forage (herd C). Antiparasitic treatment involved coccidiostatic drugs. Robenidine (alternately with Lerbec in farm A) was added to food in the first two farms, whilst Sulfatyf mixed with water was given once after weaning in farm C. A total of 203 individual faecal samples from females of breeding stock, and 133 pooled samples from young animals, were collected on an annual cycle during 2007-2008 (February-January), and analyzed according to a modified concentration McMaster method. Coccidians were identified based on sporulated oocysts. A number of coccidian species (Eimeria perforans, E. media, E. magna, E. irresidua, E. exiqua, E. coecicola, and E. piriformis) were observed in all farms. The most pathogenic species--E. intestinalis was found both in farm A and B, whereas E. flavescens and E. stiedae--only in the former. The level of infection was high, especially in young rabbits, with the prevalence of 94.9 to 100% and mean intensity from 11,161 to 28,871 oocysts per 1 g of faeces (OPG) in a particular warren. The highest intensity of infection was observed in May, when the mean output increased to 29,454, 56,952, and 23,815 OPG in warrens A, B, and C, respectively. A nematode, Passalurus ambiguus, was detected in all searched farms, with the prevalence from 14.1% to 27.5%, depending on a farm. The species was more often seen in the first part of year. The other helminths (Trichostrongylus retortaeformis, Graphidium strigosum, and Trichuris leporis) were found only in rabbits of warren C. In this warren, the forage of farm origin was suggested to be prepared in a proper way in order to protect it from nematode transmission. The presence of coccidia and their specific composition has been continuously monitored in all farms, to estimate the efficiency of prophylactic measures undertaken.

Heterakis isolonche Linstow, 1906 ­ a new nematode species found in ornamental pheasants in Poland

Studies were carried out on 25 pheasants belonging to 13 Phasianinae species of the Phasianidae family. The research material was collected from private breeders ­ both Polish and from abroad. The results confirm that the most frequent nematode is Heterakis gallinarum, while for the first time in the country ­ in two of the examined birds of Polish flocks ­ the occurrence of Heterakis isolonche was found.

The occurrence and diversity of flies (Diptera) related to ruminant farming in southern Poland

The aim of the study was to determine the biodiversity of flies (Diptera) occurring in livestock buildings and in their direct proximity, in various systems of ruminants rearing. Flies were collected by net sweeping during the summer, in two cowsheds (one large-scale, and one traditional farm), and one specialist sheepfold, located in the Lesser Poland region of Poland. The insects were captured ­ both inside and outside the premises ­ three times (at 10:00, 12:00 and 14:00) on selected warm and sunny days of June, July and September, when animals were assumed to be the most harassed. A total of 18365 flies belonging to 13 families were obtained. The largest relative abundance of Diptera were from the Drosophilidae family (61.4%), and dominating Muscidae species ­ Musca domestica L., 1758 (19.2%) and Stomoxys calcitrans (L., 1758) (5.7%). More than half (55.5%) of all flies were captured in the morning, and their vast majority not inside a livestock building (28.2%), but in its close proximity (71.8%). This was particularly true of the large-scale cattle farm. The smallest number of insects, although with the highest biodiversity, were collected at the sheepfold. Regardless of their particular animal preferences, the insect species found were commonly occurring in different livestock sectors.

Tarantobelus arachnicida (Nematoda: Rhabditida) invasion of exotic spiders in Poland

Nematodes of the Brevibuccidae family were stated among spiders of the Theraphosidae family (the South American species), which were bred in Poland. The first sign of infection was anorexia which led to gradually increasing lethargy progressed to a huddled posture. Additionally, a white discharge with nematodes between mouth and chelicerae was noted. All of the derived nematodes were morphologically identified and determined to the species Tarantobelus arachnicida. A molecular analysis covered amplification and sequencing of small subunit ribosomal RNA (18S rRNA). A post mortem examination demonstrated the presence of nematodes not only near the chelicerae, but also inside the intestine, hence the source of infection might be insects used as a food. The research showed that such kind of infection is an important disease, which poses a serious risk to the breeding spiders. To date there is no effective treatment, however, we demonstrated that usage of the Lugol's solution seems to be promising.

Host specificity and species diversity of the Ostertagiinae Lopez-Neyra, 1947 in ruminants: a European perspective.

BACKGROUND: Nematodes of the subfamily Ostertagiinae appear to be rather specific to a species or family of hosts, but some are observed in a wide variety of hosts. The nematode Ostertagia leptospicularis draws special attention due to its presence or absence among the same host species in different European countries. Therefore, this paper focuses mainly on the host specificity among nematodes of the subfamily Ostertagiinae. The second aim of this study is to assess the possibility of treating O. leptospicularis as an Ostertagia species complex. METHODS: Data were gathered from post-mortem examinations of domestic and wild ruminants (n = 157), as well as bibliographical references (n = 96), which were pooled and discussed. The research area was limited to European countries, hence the studied ostertagiine species are limited to native ones; likewise, the host species. Special emphasis was placed on the mean abundance values that allowed a typical host or hosts for each nematode species to be specified. Correspondence analysis was performed to confirm the stated host specificity. RESULTS: The analysis revealed that nematodes of this subfamily tend to use ruminants from a particular subfamily as their principal host. The results indicate that Ostertagia leptospicularis, similar to Teladorsagia circumcincta, may represent a potential species complex. This nematode, as the sole member of the subfamily Ostertagiinae, occurs in almost all representatives of the Bovidae subfamily, as well as in the Cervidae. CONCLUSIONS: Despite the stated narrow host specificity, the results obtained may suggest that O. leptospicularis is not strongly connected to any host or is comparably associated with a very wide and diverse group of hosts (Cervidae, Bovidae). The Ostertagia complex may have particular cryptic species or strains typical for any individual host or group of hosts. Such a conclusion requires further investigations on a wider scale.

Cephenemyia stimulator (Diptera) infection in roe deer (Capreolus capreolus) from Kraków area, southern Poland.

UNLABELLED: The aim of the study was to determine the prevalence of botfly (Diptera: Oestridae) larvae infection in roe deer populations (Capreolus capreolus) in the Kraków area on the basis of necropsy and questionnaire surveys. Hunters were surveyed about the age and sex of hunted animals, and the origin of their habitat. All parasite specimens were identified to species in the laboratory. The parasites were found in the nasal cavities, esophagus, and larynx of male roe deer aged 3-8 years, living in forest habitats. The level of infection was relatively low (13%), with the intensity ranging from 1 to 10 larvae per host. Although no fly larvae were found during the dissection of roe deer carcasses, the parasites received from the hunters were identified as Cephenemyia stimulator botflies. These findings are supported by the evidence drawn from the questionnaires completed by the hunters. KEY WORDS: parasites, Cephenemyia stimulator, Capreolus capreolus, necropsy, questionnaire study, Poland.

Endoparasites of exotic ungulates from the Giraffidae and Camelidae families kept ex situ.

Giraffes and camels are popular attractions at zoological gardens. In order to present the diversity of parasites infecting exotic ungulates from zoos, faecal samples from three giraffes and six camels from both the Silesian Zoological Garden in Chorzów, and Kraków Zoological Garden, were examined. The research was carried out over a ten-month period in 2013 and 2014. In total, 100 faecal samples from 18 animals were analysed with the use of the McMaster method. Moreover, coccidian oocysts were incubated to investigate their development and larvoscopic examination was conducted to detect the presence of nematode species. Giraffes were infected with coccidia from the genus Eimeria, and gastrointestinal nematodes from the Strongylida order, and Trichuris and Aonhotheca genera. One male giraffe was uninfected. The level of infection in giraffes was low when compared to camels kept in both of the zoos. Limited contact with other animal species contributed greatly to the lower level of infection in camels from Kraków Zoo than those from Chorzów, which were kept in the same enclosure as alpacas and Shetland ponies.

Lungworm (Nematoda: Protostrongylidae) infection in wild and domestic ruminants from Malopolska region of Poland.

The conducted study has focused on domestic, as well as wild ruminant species. The post mortem examination was carried out on 68 animals, including three wild species: roe deer (Capreolus capreolus) (25 indyviduals), red deer (Cervus elaphus) (6), fallow deer (Dama dama) (5) and two domestic: sheep (Ovis aries) (14) and cattle (Bos taurus) (18). Some of the species have also been investigated in the field by the coproscopical analyses. The faecal samples from roe deer (27), fallow deer (20), red deer (36) and moose (Alces alces) (10) were collected from the environment, while from sheep (10) and goat (Capra hircus) (10)--per rectum. Based on the obtained results the following values were calculated: prevalence, mean intensity and intensity range. The post mortem examination did not reveal pulmonary nematodes neither in domestic nor in wild ungulates, however, the larvae of aforementioned parasites were often stated in the stool samples taken from the environment. All wild species, except fallow deer were infected. Consequently, six species of lungworms have been identified. The first stage larvae of Varestrongylus capreoli occurred in 11 samples of roe deer and Varestrongylus alces in one moose. The larvae of Elaphostrongylus cervi were found in 19 red deer and Varestrongylus sagittatus in 3. Furthermore, Elaphostrongylus alces larvae were noted in 6 moose. Within domestic ruminants only one sheep and two goats were infected by Muellerius capillaris.

Benzimidazole resistance in the ovine Haemonchus contortus from southern Poland - coproscopical and molecular findings.

UNLABELLED: Anthelmintic resistance within nematodes has become a very common issue, however, the data about its occurrence in the gastrointestinal nematodes of sheep in Poland are very limited. This study was carried out in order to evaluate the presence of benzimidazole resistance in highly pathogenic Haemonchus contortus by means of parasitological and molecular techniques. The research represents the first Polish attempt to confirm the presence of a mutation at codon 200 of the ß-tubulin isotype 1 gene in H. contortus by PCR-RFLP. The occurrence of this mutation indicates the risk of ineffective benzimidazole treatment, nowadays commonly used for parasite control in Poland. The resistant parasites were detected by means of FECRT in a sheep flock (30 individuals) from southern Poland. To confirm the resistance on the molecular level, primers designed according to the sequences available in Genebank were used to detect the mutation. Unfortunately, as the PCR product was shorter than required (403 bp), further analyses are needed. The obtained results may indicate the high variability within the parasite population. Hence, it is essential to adapt the reaction conditions to our geographic strain of the nematode - and further analyses are required. KEY WORDS: Haemonchus contortus, benzimidazole resistance, PCR, Poland.