Diphyllobothrium sp. and Other Parasites of Migrating and Rare Fish Species in the Southern Baltic Sea and Coastal Waters, Poland

The present study is the first to analyse the parasite fauna of sole Solea solea, dab Limanda limanda, hake Merluccius merluccius, whiting Merlangius merlangus, and plaice Pleuronectes platessa in the Pomeranian Bay, as well as saithe Pollachius virens from the Szczecin Lagoon (Poland). The aim of this study was to determine the occurrence of parasites in migrating and rare fish in the Pomeranian Bay and the Szczecin Lagoon and to determine the composition of the diet of these fish. The fish for analysis were obtained in the years 2010-2019. The typical marine nematode Capillaria (Procapillaria) gracilis, rarely recorded in Poland, was found, in addition to the following parasites: Ichthyophonus hoferi, Trichodina jadranica, Diphyllobothrium sp., Dichelyne (Cucullanellus) minutus, Raphidascaris acus, Anisakis simplex, Contracaecum osculatum, Hysterothylacium aduncum, Pseudoterranova decipiens, and Echinorhynchus gadi. Because the fish species analysed in the study are not typically present in the Baltic (with the exception of plaice), and because we do not know how long they feed while they are in the Baltic, we cannot be certain which parasites they acquired in the water bodies analysed in the study and which were introduced during the migration of fish. Although these fish are outside of their normal geographic range (except for plaice), in the new environment, there were enough suitable intermediate hosts for the parasites of these fish to complete their life cycle and survive.

Tick-borne pathogens in questing adults Dermacentor reticulatus from the Eastern European population (north-eastern Poland)

Dermacentor reticulatus is tick species with an expanding geographical range in Europe, which creates the possibility of spreading microorganisms of significant veterinary and medical importance. The study aimed to investigate the prevalence and genetic diversity of Rickettsia spp., Babesia spp., Borrelia spp. and Anaplasma phagocytophilum in adult D. reticulatus ticks from the Eastern European population in the urban and the natural biotopes of north-eastern Poland. Microorganisms were detected by PCR and identified by DNA sequencing. The overall infection rate of at least one of the pathogens was 29.6%. The predominantly was Rickettsia spp. (27.1%) (with R. raoultii-9.1%) followed by Babesia spp. (2.4%) with B. canis (1.5%) as the most frequent. Based on 18S rRNA gene sequence, three B. canis genotypes were revealed. The prevalence of R. raoultii and B. canis was significantly higher in ticks from natural biotopes. The infection rates of B. afzelii and A. phagocytophilum were determined at 0.9% and 0.3%, respectively. Co-infections were detected in 3.8% of infected ticks. In diagnosing tick-borne diseases in humans, tick-borne lymphadenopathy should not be excluded. The prevalence of different genotypes of B. canis suggests differences in the clinical picture of canine babesiosis in the area.

Effect of Selected Entomopathogenic Fungal Species on Embryonic Development of Ascaris suum (Nematoda)

The aim of the study was to evaluate the potential of using five selected species of entomopathogenic fungi (Beauveria bassiana, B. brongniartii, Conidiobolus coronatus, Isaria fumosorosea, and Metarhizium robertsii) in the bioregulation of the dispersive stages of the parasitic nematode-Ascaris suum. Experimental cultures of each of the selected entomopathogenic fungi, as well as a control culture without fungi, were incubated with A. suum eggs at 26 °C for 28 days. Development of the A. suum eggs was observed using a light microscope on the 7th, 14th, 21st, and 28th days of incubation. The API-ZYM® test was used to determine, semiquantitatively, the activity of 19 hydrolytic enzymes from the entomopathogenic fungi. The cytotoxicity of the fungi was determined using tetrazole salt MTT. It was found that none of the five tested strains of entomopathogenic fungi showed an ovicidal effect, and none of them colonized the A. suum egg shells. However, ovistatic activity was observed mainly until the 14th day of incubation by I. fumosorosea, M. robertsii, and B. bassiana. In the MTT test, M. robertsii showed moderate cytotoxicity, while the other species showed low cytotoxicity. Among the strains tested, I. fumosorosea showed the highest spectrum of hydrolase production (13 out of 19 enzymes gave a positive reaction from 3 to 5; 20-40 nM or more). The absence of morphological changes in the A. suum egg shells suggests that the antagonistic effect of the studied entomopathogenic fungi may be due to their cytotoxicity, associated with the production of secondary metabolites-toxins (M. robertsii) and enzymatic activity (I. fumosorosea).

The Relationship between Complement Components C1R and C5 Gene Polymorphism and the Values of Blood Indices in Suckling Piglets

The main mechanism of innate immunity is the complement system. Its components include the protein products of the C1R and C5 genes, which are involved in the classical activation pathway as well as the inflammatory and cytolytic immune responses, respectively. The aim of this study was to determine the relationship between PCR-restriction fragment length polymorphism in C1R (726T > C) and C5 (1044A > C) genes, and the values of hematological and biochemical blood indices in suckling crossbred (Polish Large White × Polish Landrace × Duroc × Pietrain) piglets (n = 473), considering their age (younger, 21 ± 3 days, n = 274; older, 35 ± 3 days, n = 199) and health status. The frequencies of the C5 genotypes deviated from the Hardy-Weinberg expectations. Younger piglets, healthy piglets, piglets that deviated from physiological norms and older piglets with the C1R TT genotype all had lower white and red blood cell indices. In piglets with the C5 CC genotype, younger piglets, piglets that deviated from physiological norms and older piglets, a greater number and/or percentage of monocytes were recorded in the blood. Older piglets also showed an increase in the number of leukocytes and granulocytes, along with a tendency for a decrease in the percentage of lymphocytes in their blood. We concluded that a polymorphism in the C1R gene may exhibit a functional association or genetic linkage with other genes involved in the process of erythropoiesis. Furthermore the relationship between the C5 gene polymorphism and the number and/or percentage of monocytes in the blood may modify the body's defense abilities. Piglets with the CC genotype, having an increased number/proportion of these cells in their blood, probably display a weakened immune response to pathogens or a chronic stimulation of the immune system.

Abundance of Ixodes ricinus Ticks (Acari: Ixodidae) and the Diversity of Borrelia Species in Northeastern Poland

Monitoring the abundance of ticks and the prevalence of pathogens in ticks is an important activity in assessing the risk of tick-borne diseases and helps to develop preventive measures. This study aimed to estimate the density of Ixodes ricinus, the prevalence of Borrelia species, and their diversity in northeastern Poland. The overall mean I. ricinus density was 9.7 ticks/100 m². There were no differences between years, subregions, or habitats of study. The Borrelia infection rate was higher in females (22.6%) and males (14.3%) than in nymphs 5.5% (MIR). The most infected ticks came from the eastern subregion (10.1%) where the incidence of borreliosis among the inhabitants was over 20% higher than in the other subregions. In the infected ticks, B. afzelii (38.3%) and B. garinii (34.5%) were predominant. B. bavariensis was confirmed in I. ricinus in Poland for the first time. The most polymorphic was B. garinii. B. miyamotoi (belonged to the European type) was identified as a mono-infection in 0.9% of ticks and in 1.5% as a co-infection with B. afzelii and with B. garinii. Besides the risk of borreliosis and co-infections with different Borrelia species, physicians should also be aware of B. miyamotoi infections among patients.

The Risk of Exposure to Ticks and Tick-Borne Pathogens in a Spa Town in Northern Poland

The aim of this study was to determine the potential risk of human exposure to tick-borne infection in a recreation areas in a spa town located in northern Poland. Questing Ixodes ricinus and Dermacentor reticulatus ticks were collected in the spring of 2018. Tick-borne microorganisms were detected by PCR. Species were identified based on RFLP and the sequencing of DNA. In total, 38.3% of the ticks (34.6% of I. ricinus and 48.6% of D. reticulatus) were infected. The prevalence was 14.9% for Borrelia spp., 10.6% for Babesia spp. and 17.7% for Rickettsia spp. No Anaplasma phagocytophilum was detected. Spirochaetes B. afzelii, B. garinii and B. burgdorferi s.s. were detected only in I. ricinus ticks (20.2%). The differences in the infection rates of Babesia spp. between I. ricinus (7.7%) and D. reticulatus (18.9%) were not significant. DNA of B. canis and B. venatorum were identified in both tick species. B. microti were detected in D. reticulatus ticks. The prevalence of Rickettsia spp. was significantly higher in D. reticulatus (37.8%) than that in I. ricinus (10.6%). R. raoultii was identified only in D. reticulatus and R. helvetica in I. ricinus. Co-infections of at least two pathogens were recognized in 13% of positive ticks.

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

Simple Summary

The presence of intestinal parasites such as nematodes, cestodes, and trematodes is a serious problem for programmes for the conservation of partridges and pheasants, mainly involving the breeding of these birds and their release into the natural environment. These parasites can cause disease in these birds, whether farmed or free-living. The aim of this study was to describe the morphology of parasitic worms in the partridge, native to Poland, and the introduced pheasant, and to determine the level of infection of these birds with intestinal parasitic worms. The study showed that partridges are infected with several helminth species that had not previously been recorded in this species in Poland. Pheasants are more often infected by intestinal nematodes than are partridges. These worms can negatively affect the condition of partridges and increase their risk of infection with pathogenic protozoa. The results of parasitological examination should be used to develop programmes for diagnosis and monitoring of parasitic infections in order to keep flocks free of parasites.

Abstract

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.

Prevalence, subtypes and risk factors of Blastocystis spp. infection among pre- and perimenopausal women

Background

Blastocystis spp. are considered pathogenic or commensal organisms, although the majority of researchers suggest that these are neglected pathogens. The main aim of this study was to determine the prevalence and subtype distribution of Blastocystis spp. in pre- and perimenopausal women, with respect to socio-demographic (age and place of residence), and epidemiological factors, as well as drinking tap water, contact with domestic animals, traveling abroad, health status, and presence of gastrointestinal symptoms. Additionally, the objective was to compare hematological and biochemical parameters of Blastocystis spp. infected and uninfected women.

Methods

The study included 425 women aged 45–60. Their stool samples were examined microscopically and analyzed by a conventional polymerase chain reaction (cPCR).

Results

Blastocystis spp. were detected in 6.1% of pre- and perimenopausal women. Molecular analysis of the stool samples identified seven Blastocystis subtypes (ST1–ST4, ST6, ST7, and ST9). Blastocystis subtypes 2 and 3 were the most prevalent. The presence of Blastocystis spp. was not significantly related to socio-demographic and epidemiological factors. There were also no significant associations between Blastocystis spp. and blood parameters, or gastrointestinal symptoms.

Conclusion

This study complements the limited available data on the prevalence of Blastocystis spp. in pre- and perimenopausal women. It is also the first report showing the presence of Blastocystis subtype 9 in Poland.

PREVALENCE OF BLASTOCYSTIS SUBTYPES IN HEALTHY VOLUNTEERS IN NORTHEASTERN POLAND

Blastocystis is a common enteric protist that is linked to intestinal and extra-intestinal diseases. At least 24 subtypes (STs) have been described, with the main colonization of ST1-ST4 in humans. In our attempt to determine the distribution of Blastocystis STs in Olsztyn and surroundings in northeastern Poland, 319 stool samples from volunteers were subjected to copro-ELISA and PCR testing. Positive findings were identified in 77, 48, and 46 of the samples via copro-ELISA, PCR, and sequencing, respectively. Blastocystis colonization was not associated with gender or dwelling place but was statistically higher in people age 60-69 yr (32.6%). Five STs (ST1-ST4, ST7) were identified, in which ST3 (37%) was most prevalent, followed by ST2 (19.6%), ST1 (17.4%), ST4 (13%), and ST7 (8.7%). The current study revealed a similar rate of microorganism colonization in Polish volunteers compared to other developed countries, without significant differences in gender and dwelling place. Significant statistical differences were found in different age groups, where Blastocystis was highly detected in elderly people. In the current study, PCR was the most plausible method based on the sequencing results.

Increased PACAP- and DβH-Positive Hepatic Nerve Fibers after Bisphenol A Exposure

Bisphenol A (BPA) is an endocrine-disrupting compound (EDC) that can be found nearly everywhere in our polluted world. BPA has been correlated with pathophysiologies that include psychological disorders, especially in children. This study used juvenile porcine models to investigate the effects of BPA on the liver of developing vertebrates in order to determine the effects of BPA on innervated hepatic samples with the use of double-labeled immunofluorescence. This study specifically investigated the sympathetic nervous system (SNS) colocalized with a specific neural marker (PACAP) that has previously been correlated with specific pathophysiologies in the literature. In the liver, it was observed that there were significantly increased nerve fibers in the SNS colocalized with the neural marker PACAP after exposure to BPA at concentrations considered to be “safe” with the same or more profound effects at higher exposure levels. The implications of childhood exposure to BPA are then discussed with regard to several correlation studies that have linked BPA exposure to behavioral/psychological disorders. It is possible that BPA exposure in childhood may upregulate the SNS and PACAP levels, thereby contributing to the correlations in the literature.

Influence of Proton Pump Inhibitors and Histamine Receptor 2 Antagonists on Blastocystis ST3 and Selected Microorganisms of Intestinal Microbiota In Vitro

INTRODUCTION

Proton pump inhibitors (PPIs) and histamine receptor 2 (H2) antagonists are commonly prescribed medications. Association between PPIs and alteration of the gut microbiota has been reported. Blastocystis, the most common intestinal protozoan worldwide, occurs in both healthy and symptomatic people with gastrointestinal or cutaneous disorders, with controversial pathogenicity. The current study was aimed to investigate the influence of PPIs and H2 blockers on the in vitro proliferation of selected intestinal bacteria, fungi, and protozoa.

METHODS

Cultures of Lactobacillus rhamnosus, Escherichia coli, Enterococcus faecium, Candida albicans, and Blastocystis subtype 3 were treated with different concentrations of respective medications in vitro, and the numbers of microorganisms were quantified and compared.

RESULTS

Pantoprazole and esomeprazole exerted a significant inhibition on Blastocystis and C. albicans, especially at higher concentrations, which were even more effective than metronidazole. On the other hand, treatment with pantoprazole caused an increase in proliferation of L. rhamnosus and E. coli. There was no influence of H2 blockers on the examined microorganisms.

DISCUSSION

PPIs, such as pantoprazole, can be a potential treatment in the prophylaxis or eradication of Blastocystis and C. albicans.

Dermatological and Molecular Evidence of Human Cercarial Dermatitis in North-Eastern Poland

Swimmer's itch or human cercarial dermatitis (HCD) appears as a skin rash caused by an allergic reaction to larval (cercariae) flatworm parasites of the family Schistosomatidae. In our study, two cases of HCD were analyzed; both of them were reported in people swimming in Lake Pluszne. In the summer of 2018, a sample of 397 snails was collected at swimming sites in that area. Five Lymnaea stagnalis (1.9%) were found to host cercariae of bird schistosomes. Positive samples were selected by amplification of the Internal Transcribed Spacers (ITS) gene region. Sequence analysis confirmed that they were homologous with European isolates of Trichobilharzia szidati. The cases reported in this article are the first confirmed cases of HCD in this lake. This study demonstrates that there is a rationale for conducting screening studies of regions with a high recreational potential.

Changes in the Population Size of Calbindin D-28k-Immunoreactive Enteric Neurons in the Porcine Caecum under the Influence of Bisphenol A: A Preliminary Study

Calbindin D-28k (CB) is a calcium-binding protein widely distributed in living organisms that may act as a calcium buffer and sensory protein. CB is present in the enteric nervous system (ENS) situated in the gastrointestinal tract, which controls the majority of activities of the stomach and intestine. The influence of various doses of bisphenol A (BPA)—a chemical compound widely used in plastics production—on the number and distribution of CB-positive enteric neuronal cells in the porcine caecum was investigated with an immunofluorescence technique. The obtained results showed that low dosages of BPA resulted in an increase in the number of CB-positive neuronal cells in the myenteric (MP) and inner submucous (ISP) plexuses, whereas it did not alter the number of such neuronal cells in the outer submucous plexus (OSP). High dosages of BPA caused the increase in the amount of CB-positive perikarya in all the above-mentioned kinds of the caecal neuronal plexuses. These observations strongly suggest that CB in the ENS participates in the processes connected with the toxic activity of BPA. Most likely, the changes noted in this experiment result from the adaptive and protective properties of CB.

Epidemiology of scabies in relation to socio-economic and selected climatic factors in north-east Poland

INTRODUCTION

Scabies is a contagious parasitic disease, a skin infestation caused by Scaroptes scabieri, tiny mites that burrow under the skin. Outbreaks of scabies can be difficult to control and require the implementation of appropriate control programme.

OBJECTIVE

The purpose of the study was to analyze the epidemiology of scabies in north-east Poland, considering socio-economic and selected climatic factors.

MATERIAL AND METHODS

The analysis was based on data reports (n=26,362) obtained from the Polish National Health Fund (NFZ) for the period 2007-2014. Monthly climate data were collected from the Institute of Meteorology and Water Management/National Research Institute (IMGW-PIB) in Warsaw, including data on temperature and relative humidity. Additionally, the influence of socio-economic factors on the prevalence of scabies was analyzed. Data on population size, medical staff, and unemployment rate were obtained from the Central Statistical Office (GUS) in Warsaw, and analyzed using SPSS Statistics 24.0 programme.

RESULTS

The age group of 10-19 years showed the highest infestation rates. Seasonality of scabies was demonstrated. The highest numbers of cases were reported during the autumn and winter months. There was a significant negative correlation (rho = -0.499; p<0.001) between air temperature and the incidence of scabies, and a positive correlation (r = 0.532; p<0.001) between relative humidity and the number of cases reported. A rise in the unemployment rate also caused an increase in the scabies incidence rate (r = 0.294; p<0.001).

CONCLUSIONS

The results suggest that an improvement of socio-economic conditions may contribute to a reduction in the number of scabies infections. The possibility should be considered of monitoring the parameters, such as air temperature and humidity, particularly when scabies outbreaks occur.

The Ovistatic Effect of Saprotrophic Soil Fungi on Ascaris suum Eggs

The aim of the study was to evaluate the potential use of selected species of soil fungi (Fusarium oxysporum, F. sulphureum, F. verticillioides, and Penicillium expansum) for the bioregulation of the dispersive stages of a parasitic nematode – the large roundworm of pig (Ascaris suum). Experimental cultures containing A. suum eggs with soil fungi and control cultures without fungi were incubated at 26°C for 28 days. Microscopic observations of the developmental stages of the A. suum eggs (zygote, 2-8 blastomeres, morula/blastula, gastrula, and larva) were performed at 7, 14, 21, and 28 days. The API-ZYM test was used to semi-quantitatively determine the activity of 19 hydrolytic fungal enzymes. The cytotoxicity of the fungi was determined with a tetrazole salt MTT assay. Microscopic observations of A. suum eggs incubated in the presence of fungi up to day 28 did not show any signs of destruction to egg shells and/or penetration of the fungi into the eggs. The ovistatic effect of all tested fungi (F. sulphureum, P. expansum, F. verticillioides, and F. oxysporum; p<0.05) was seen only on the 7th day of incubation, whereas on the 14th day, only F. verticillioides and F. oxysporum showed an inhibitory effect on the embryogenesis of A. suum, and by the 28th day, only P. expansum. The API-ZYM test showed differences in the hydrolytic activity of the tested strains, while the MTT assay showed the high cytotoxicity of F. sulphureum, the moderate cytotoxicity of F. verticillioides and P. expansum, and the low cytotoxicity of F. oxysporum. Among the fungal strains studied, F. sulphureum showed the highest ovistatic effect, which may be related to its enzymatic activity and cytotoxicity.

Questing Ixodes ricinus ticks (Acari, Ixodidae) as a vector of Borrelia burgdorferi sensu lato and Borrelia miyamotoi in an urban area of north-eastern Poland

Green areas located within large cities, as natural ecotypes, are a convenient habitat for ticks and their use as recreational areas is associated with the potential risk of acquiring tick-borne diseases. This study estimated the I. ricinus tick density, prevalence of infection with Borrelia species and the diversity of these bacteria in a green urban area (Olsztyn) of north-eastern Poland, an endemic region of tick-borne diseases. The ticks were collected during spring and autumn of 2015, at sites differing in the degree of human pressure and habitat. Borrelia species detection, typing and a molecular phylogenetic analysis were carried out based on the sequenced flaB gene. The overall mean abundance of I. ricinus was 2.0 ± 1.55 ticks per 100 m². The density of I. ricinus did not vary significantly between sites. According to semi-qualitative tick abundance categories, the collection sites were classified as 'very low' and 'low' tick abundance category. The overall infection rate of I. ricinus with Borrelia spirochaetes was 27.4%. The infection rate of adult ticks (42.0%) was three times higher than with nymphs (14.3%). Based on the restriction patterns and sequencing, B. afzelii (93.1%; 27/29), B. valaisiana 3.5% (1/29) and B. miyamotoi (3.5%; 1/29), related to the relapsing fever (RF) spirochaetes, were detected. No co-infections were found. Borrelia miyamotoi, detected for the first time in ticks in the north-eastern urban areas of Poland, was identical to isolates described as European-type. The Borrelia spirochaete infection rate of I. ricinus ticks in an urban area indicated a high risk of LB. Physicians should also be aware of B. miyamotoi infections among patients with a history of tick-bites in north-eastern Poland.

Using scanning electron microscopy (SEM) to study morphology and morphometry of the isolated haptoral sclerites of three distinct diplozoid species

Diplozoidae infects the gills of cyprinid fishes in Africa, Europe, and Asia. Traditionally the hardened internal structures, crucial for identification of diplozoid species, are studied using light microscopy. Recently, the sclerotised haptoral structures of an African diplozoid, Paradiplozoon vaalense, were successfully isolated and visualised using scanning electron microscopy (SEM). In this paper, the haptoral sclerites of three diplozoid species are compared using SEM for the first time. Paradiplozoon ichthyoxanthon and Paradiplozoon vaalense occur on Labeobarbus and Labeo species, respectively, in the Vaal River system, South Africa, while Diplozoon paradoxum is widely-distributed in Europe and Asia, infecting several host species. Diplozoon paradoxum is a well-studied species, as well as being the type species of the family and ideal for inclusion in an exploratory study for comparative purposes. SEM study of D. paradoxum and P. ichthyoxanthon provided valuable information regarding surface morphology of the attachment structures hitherto not observed. Elaborate morphometric study of the haptoral hooks were incorporated, adding 12 point-to-point measurements to current morphometric characteristics. The results were analysed statistically, and significant differences support absolute separation (100.00%) of the three species following discriminant analysis. These point-to-point measurements could also be used for light microscopical study in the future and aid species delimitation within the Diplozoidae.

The influence of probiotic bacteria and human gut microorganisms causing opportunistic infections on Blastocystis ST3

BACKGROUND

Blastocystis subtype 3 is an intestinal protist present in humans throughout the world with a controversial pathogenic potential. It has been suggested that probiotic bacteria inhibit the multiplication of gut protozoans, while others are beneficial for their development. This study aimed to evaluate the efficacy of the lactic acid bacteria Lactobacillus rhamnosus, Lactococcus lactis and Enterococcus faecium in Blastocystis ST3 eradication and the relevance of the intestinal microorganisms Escherichia coli, Candida albicans and Candida glabrata in protozoan proliferation. Blastocystis xenic and axenic culture was co-incubated with the above-mentioned microorganisms and their cell free supernatants at different concentrations in vitro. The number of protozoan cells was counted every day.

RESULTS

Both experiments, with xenic and axenic cultures, showed Blastocystis inhibition by L. rhamnosus and L. lactis and their supernatants from the 2nd day of co-incubation. Furthermore, co-incubation with both E. faecium and E. coli showed a beneficial influence on Blastocystis during the first 2 days. Only after 3 days did the above-mentioned bacteria start to inhibit Blastocystis growth in both cultures. The supernatant containing the metabolites of E. coli was effective to a lesser degree. Compared to the control samples, co-incubation with both C. albicans and C. glabrata showed a faster decrease in Blastocystis proliferation, but this was not statistically significant.

CONCLUSIONS

This study has shown the potential of using L. rhamnosus and L. lactis, as well as E. faecium as a prophylactic treatment against Blastocystis colonization or as an additional treatment regimen in combination with standard drugs.

Dermacentor reticulatus ticks (Acari: Ixodidae) distribution in north-eastern Poland: an endemic area of tick-borne diseases

Dermacentor reticulatus is the second most important tick species in Poland. Although the north-eastern region of Poland is considered typical for D. reticulatus and is treated as a contiguous area of Eastern populations of the meadow ticks, the occurrence of this tick species in this region to date has been recorded as separate foci. The present report supplements data on the geographical distribution of D. reticulatus in urban and natural biotopes of north-eastern Poland (Warmia and Mazury province). In 2015-2017 (during the springtime activity of ticks) adult questing D. reticulatus were found in 13 of 25 monitored localities. Six sites are located in urbanized areas, within the administrative borders of the city of Olsztyn and seven sites are in natural biotopes in the central part of Warmia and Mazury. A total of 398 adult D. reticulatus ticks, including 257 females and 141 males, were collected. A comparison of data grouped according to urban and natural type of area revealed no statistical differences between them. Taking into account the habitat type, the mean tick density was the highest in open landscapes. The identification of new foci D. reticulatus in the endemic areas of Lyme borreliosis, tick-borne encephalitis and canine babesiosis is crucial for determining the risk of diseases transmitted by ticks and taking proper preventive measures.

Immunohistochemical characteristics of porcine intrahepatic nerves under physiological conditions and after bisphenol A administration

BACKGROUND

The neurochemistry of hepatic nerve fibres was investigated in large animal models after dietary exposure to the endocrine disrupting compound known as bisphenol A (BPA).

MATERIALS AND METHODS

Antibodies against neuronal peptides were used to study changes in hepatic nerve fibres after exposure to BPA at varying concentrations using standard immunofluorescence techniques. The neuropeptides investigated were substance P (SP), galanin (GAL), pituitary adenylate cyclase activating polypeptide (PACAP), calcitonin gene regulated peptide (CGRP) and cocaine and amphetamine regulated transcript (CART). Immunoreactive nerve fibres were counted in multiple sections of the liver and among multiple animals at varying exposure levels. The data was pooled and presented as mean ± standard error of the mean.

RESULTS

It was found that all of the nerve fibres investigated showed upregulation of these neural markers after BPA exposure, even at exposure levels currently considered to be safe. These results show very dramatic increases in nerve fibres containing the above-mentioned neuropeptides and the altered neurochemical levels may be causing a range of pathophysiological states if the trend of over-expression is extrapolated to developing humans.

CONCLUSIONS

This may have serious implications for children and young adults who are exposed to this very common plastic polymer, if the same trends are occurring in humans.

Endosymbiosis and its significance in dermatology

Proposed at the beginning of the twentieth century to explain the origin of eukaryotic organelles from prokaryotes, endosymbiosis is now medically defined by various interaction patterns between microorganisms and their residing hosts, best exemplified by the bacterial endosymbiont Wolbachia identified in arthropods and filarial nematodes, which can influence normal development, reproduction, survival and transmission of the hosts. Based on the transmission modes, vertical or horizontal, and the function of the endosymbionts, the host-symbiont dependence can be divided into primary or secondary. In dermatology, the role of endosymbionts in skin ectoparasitosis has aroused great interests in the past years. Riesia pediculicola is a primary bacterial endosymbiont in body lice Pediculus humanus, and supplement their hosts with vitamin B, especially pantothenic acid. In cimicosis, the Gram-negative Wolbachia can synthesize biotin and riboflavin, which are crucial for the growth and reproduction of the bedbug Cimex lectularius. In human demodicosis and rosacea, further study is required to prove the pathogenic role of the Gram-negative bacteria Bacillus oleronius or the Gram-positive bacteria Bacillus cereus demonstrated in the Demodex mites. The high infection rate of adult female ticks Ixodes ricinus with the Gram-negative bacteria Midichloria mitochondrii present in the mitochondria in diverse ovarian cells, with the high seroprevalence rate in tick-exposed subjects, raises the possibility that this non-pathogenic endosymbiont may play a role in immune response and successful transmission of the tick-borne pathogen. The anaerobic protozoan Trichomonas vaginalis and bacteria Mycoplasma hominis are two obligate parasites in the urogenital epithelium, with partially overlapping symptoms. Intracellular localization of Mycoplasma hominis can avoid host immune response and penetration of antibiotics, while Trichomonas vaginalis infected with Mycoplasma hominis seems to have a higher cytopathic activity and amoeboid transformation rate. Further study on the biology and pathogenesis of different endosymbionts in dermatological parasitosis will help for the development of new treatment modalities.

Enterobiasis epidemiology and molecular characterization of Enterobius vermicularis in healthy children in north-eastern Poland

Enterobiasis is a human intestinal parasitic disease caused by human pinworm, Enterobius vermicularis. Despite being the most prevalent nematode infection in Europe and North America, predominantly among in school aged children, the data concerning infection rate and knowledge of genetic variability of pinworms are incomplete. The aim of the study was the estimation of prevalence and molecular typing of Enterobius vermicularis among healthy children in north-eastern Poland. In 2013 – 2015, 296 individuals (aged 2 – 18 years) from 12 kindergartens, schools and orphanages were examined by the adhesive cellophane tape method. Data on socio-demographic status were collected using a questionnaire. Molecular analysis was performed using the DNA of adult female pinworms and primers targeting the region of cytochrome oxidase I gene. The overall prevalence of enterobiasis was 10.1 %. Enterobius vermicularis infection rates were 3.9 % in children living in families and 32.8 % among the orphans (OR=0.08; 95 % CI: 0.04 – 0.19; p<0.001). There were no associations between distribution of enterobiasis and gender, pets possession and the season of examination. In 43.3 % of the infected children enterobiasis was asymptomatic. Based on a molecular marker three different haplotypes of pinworm were identified. All sequences clustered within type B, together with human E. vermicularis isolates from Denmark, Germany, Greece, and Japan. This paper provides complementary data on the occurrence and intraspecific variability of E. vermicularis in human population in Europe.

Blastocystis: how do specific diets and human gut microbiota affect its development and pathogenicity?

Blastocystis is an enteric parasite that inhabits the gastrointestinal tract of humans and many animals. This emerging parasite has a worldwide distribution. It is often identified as the most common eukaryotic organism reported in human fecal samples. This parasite is recognized and diagnosed more often than ever before. Furthermore, some strains develop resistance against currently recommended drugs, such as metronidazole; therefore, the use of natural remedies or special diets has many positive aspects that may address this problem. The goal of this review is to compare natural treatments and various diets against the efficacy of drugs, and describe their influence on the composition of the gut microbiota, which affects Blastocystis growth and the occurrence of symptoms. This article reviews important work in the literature, including the classification, life cycle, epidemiology, pathogenesis, pathogenicity, genetics, biology, and treatment of Blastocystis. It also includes a review of the current knowledge about human gut microbiota and various diets proposed for Blastocystis eradication. The literature has revealed that garlic, ginger, some medical plants, and many spices contain the most effective organic compounds for parasite eradication. They work by inhibiting parasitic enzymes and nucleic acids, as well as by inhibiting protein synthesis. The efficacy of any specific organic compound depends on the Blastocystis subtype, and, consequently, on its immunity to treatment. In conclusion, the article discusses the findings that human gut microbiota composition triggers important mechanisms at the molecular level, and, thus, has a crucial influence on the parasitic pathogenicity.

An ultrastructural study of the surface and attachment structures of Paradiplozoon homoion (Bychowsky & Nagibina, 1959) (Monogenea: Diplozoidae)

Background

Species of Diplozoon Palombi, 1949 (Monogenea: Diplozoidae) are blood-feeding ectoparasites mainly parasitising the gills of cyprinid fishes. Although these parasites have been the subject of numerous taxonomic, phylogenetic and ecological studies, the ultrastructure of the surface and haptor attachment structures remains almost unknown. In this study, we used transmission electron microscopy to examine the ultrastructure of attachment clamps and neodermal surface of Paradiplozoon homoion (Bychowsky & Nagibina, 1959), family Diplozoidae Palombi, 1949, thereby broadening our knowledge of platyhelminth biology.

Results

The hindbody surface of P. homoion is distinctly ridged, each ridge being supported by several muscle fibers and equipped with scales on the surface plasma membrane. Such structures have not been recorded previously in species of the family Diplozoidae. Comparisons of the surface structure of different body parts revealed slight differences in the thickness and number of organelles. Each of the clamps has a flattened bowl-like structure composed of sclerites, movable skeletal-like structures that are anchored by robust, radially oriented muscle bundles. The base of the posterior median plate sclerites is equipped with glandular cells possessing secretory vesicles.

Conclusion

This study brings detailed ultrastructural data for the surface and haptoral attachment clamps of P. homoion and provides new insights into the ultrastructure of Diplozoidae. Glandular cells at the base of the attachment clamps responsible for sclerite development in diplozoid species were observed for the first time. Our findings support the hypothesis that the structure of particular neodermal compartments is similar within the Platyhelminthes. On the other hand, the diplozoid glandular system and the mechanism of sclerite development clearly merits further attention.

The prevalence of Trichomonas vaginalis infections in the population of Warmińsko-Mazurskie voivodeship (North-Eastern Poland)

INTRODUCTION

Trichomonas vaginalis is considered to be the most common non-viral sexually transmitted infection. Trichomoniasis is not a reportable disease and due to this fact only estimates can be made about its incidence

AIM OF THE STUDY

The aim of the study was to determine the prevalence of T. vaginalis in the female population of north-eastern Poland as well as to conduct an epidemiological analysis on the basis of the data from the years of 2009 – 2015 derived from the registers of the National Health Fund

MATERIALS AND METHODS

In this study 300 women aged 19 – 50 were examined. Two vaginal swabs were taken from each patient. The first swab was used to prepare microscope slides, and stained with Giemsa stain. The second swab was used for a diagnostic immunochromatographic rapid test (OSOM Trichomonasis test). Each woman was also asked to complete a questionnaire. Additionally, on the basis of the data from the National Health Fund, epidemiological analysis was conducted. Statistical analysis was performed with SPSS Statistics ver. 24 using Fisher test

RESULTS

T. vaginalis infection was confirmed in two women. The diagnosis of trichomoniasis was confirmed as a result of T.vaginalis antigen detection with the use of immunochromatographic diagnostic test (OSOM Trichomonas test). The data from the National Health Fund show that 160 cases of trichomoniasis were reported, of which women accounted for 135 (84%), and men for 25 (16%). The highest infection rate was found in women aged 50 – 59 and those over 60 years old

CONCLUSIONS

Our results show that the prevalence of T. vaginalis infection remains low, the infection occurs mainly in elderly women. However, one should pay attention to the differences in the detection of T. vaginalis connected with a particular method used. Conducting screen tests on a larger scale using more advanced tests would allow a more accurate assessment of the scale of the problem in our country

The Effect of an Eextremely Low Frequency Magnetic Field on Larvae Production in the Parasite-Host System: Fasciola hepatica-Galba truncatula: a Preliminary Study

The aim of this study was to determine the effect of an extremely low-frequency magnetic field (ELFMF) on the production of liver fluke larvae in a parasite-host system: Fasciola hepatica--Galba truncatula. Both F. hepatica eggs and F. hepatica-infected snails were exposed to an ELFMF (50 Hz, 2.0 mT) for 14 days and 36 days, respectively. F. hepatica-infected snails were divided into 4 groups, 10 specimens each. The snails of groups I and II were infected with F. hepatica larvae--miracidia obtained from control cultures, while the snails of groups III and IV were infected with miracidia reared from eggs that had been incubated in an ELFMF. After infection, the snails of groups II and IV were placed in an ELFMF, while those of groups I (control) and III were housed outside the ELFMF. At 36 days post-infection (dpi) there were no statistically significant differences between the number of F. hepatica larvae--cercariae and metacercariae, obtained from G. truncatula snails in the control group (group I) and the snail groups exposed to ELFMF (groups II, III and IV). However, a statistically significant difference between the average number of F. hepatica larvae in snail groups III and IV may indicate that the duration of exposure to ELFMF, i.e. embryogenesis period vs. the entire larval development, played a role in the production of F. hepatica larvae, and resulted in a reduction of their number.

Mysterious chronic urticaria caused by Blastocystis spp.?

Species of the genus Blastocystis, which are single-cell, intestinal protozoan parasites of humans and animals, remain mysterious, with unclear clinical and epidemiologic significance. In recent years, many researchers have suggested a possible connection between Blastocystis spp. infection and chronic urticaria. In the present article, we review the literature and discuss the possible associations between the clinical symptomatology and pathogenicity of this organism in terms of its subtypes, morphologic forms, genetic diversity, and interactions with other intestinal microbiota.

Ultrastructure of the digestive tract of Paradiplozoon homoion (Monogenea)

Paradiplozoon homoion is a representative of blood-feeding ectoparasites from the family Diplozoidae (Polyopisthocotylea, Monogenea). Although these worms have been the subject of numerous taxonomical, phylogenetic and ecological studies, the ultrastructure of the alimentary system and related structures, as well as the mechanisms of essential processes like fish blood digestion, remain mostly unknown. Our observation of P. homoion using a transmission electron microscopy (TEM) revealed two main types of digestive cells-U-shaped haematin cells and connecting syncytium. Particular structures such as mouth cavity with specialised receptors, two oval-shaped muscular buccal suckers, pharynx surrounded with the glandular cells, oesophagus, the intestinal caeca with intact erythrocytes in the lumen, the apical pinocytotic fibrous surface complex and haematin vesicles of U-shaped cells have been shown in detail. According to our results, the P. homoion is degrading the blood components predominantly intracellularly.

The prevalence of intestinal parasites in children in preschools and orphanages in the Warmia-Masuria province (North-Eastern Poland)

OBJECTIVE

A comparison of the prevalence of intestinal parasites (IP) in preschoolers and orphans in the Warmia-Masuria province (Poland).

MATERIAL AND METHODS

Between 2003-2006 fecal samples and perianal swabs from 1052 preschoolers and 859 orphans were tested on the basis of direct saline and iodine mount, decantation test and the adhesive cellophane tape method.

RESULTS

10.8% of preschoolers and 46,3% of orphans were infected with IP. Among the six detected IP species the E. vermicularis was the most common. Infections of E. vermicularis were diagnosed in 9.5% of preschoolers and 36,7% of orphans. There were statistically significant differences in the distribution of IP between males and females in preschools. IP infections were the most frequent among 7-year-old children, 19.1% in preschools and 65.7% in orphanages, respectively. In preschools, the prevalence of IP was higher among preschoolers from the rural area (17.3%) than from the urban area (10.3%).

CONCLUSION

Orphans and children from rural areas, especially at the age of 7, should be covered by systematic screening with parasitic tests throughout all of Poland. In this group of children, enterobiasis is the main health problem. The promotion of the awareness of IP infections and their prevention among parents and educational staff is required.

Seroprevalence of Lyme disease and genospecies of Borrelia burgdorferi sensu lato in patients diagnosed with borreliosis in the Province of Warmia-Masuria in north-eastern Poland

Between 2009-2010, a group of 259 patients suspected of contracting Lyme disease were examined in the Provincial Sanitary-Epidemiological Station in Olsztyn for the presence of IgM and IgG against specific Borrelia burgdorferi sensu lato (s.l.) genospecies antigens by immunoblot. A total of 27.4% and 29.0% of the blood serum samples showed positive and uncertain results for IgM and IgG antibodies. The majority of positive and uncertain results were found in patients aged 30-40 years (30%) for IgM, and people aged 50 and over (35.8%) for IgG. Significantly more positive results for IgG were found in males (40.2%) then females (19.7%). In both groups, similar proportions of positive results for IgM anti-Borrelia were recorded (26.1% of females and 29% of males. In 71.5% of patients, IgM against flagellin protein (p41) of B. burgdorferi sensu stricto (s.s.) was found. For IgG, the most frequently detected antibodies were found against the p41 protein of B. burgdorferi s.s. (64.8%) and the recombinant variable surface antigens (VlsE) (49%). Among all the analysed antigens those of B. burgdorferi s.s. were the most frequent cause of immunological reaction, followed by antigens of B. afzelii and B. garinii. Reaction to antigens of B. spielmanii was rarely detected.

[Serological confirmation of the prevalence of tick-borne encephalitis virus among patients with neurological infections in the Warmia-Masuria province in 2006-2010]

The aim of the study was to analyze of tick-borne encephalitis (TBE) in the Warmia-Masuria province on the basis of serological testing of 878 patients with symptoms of neurological infections, diagnosed in 2006-2010 in the Voivodeship Sanitary-Epidemiological Station in Olsztyn. Specific IgM and IgG antibodies against the TBE virus were detected in serum and cerebrospinal fluid samples by ELISA method. Percentage of persons with serologically confirmed TBE was 15.5%. This confirms contact with TBE virus and its role as the suspected cause of neurological infections in patients in the Warmia-Masuria province. Men and people over 46 years of age were more commonly seropositive. Among examined patients the percentage of seropositive men was 18.1% and the proportion of seropositive women was - 12.9%. Most positive results were found in patients between 46 and 50 years of age (20.7%) and in those aged 56-60 years (19.5%). Seasonal patterns were detected, with highest proportion of seropositive results in July, August and October.

Actitis hypoleucos (L., 1758)--new Polish host of the trematodes: Plagiorchis nanus (Rudolphi, 1802) and Leucochloridium perturbatum Pojmańska, 1969

In July-August of 2005-2008, 47 digenean trematodes were examined from 7 specimens of the common sandpiper, Actitis hypoleucos (L., 1758). The digeneans were collected during a study on the food composition of the common sandpiper. The research was conducted near Lisewo Malborskie (near Tczew, Zuławy Wiślane, Gdańsk sea-coast), at a resting site on the birds' migration route. The foods ingested were extracted from live birds by draining their alimentary tracts with a nasogastric tube. Two digenean species were identified: Plagiorchis nanus Rudolphi, 1802 (Plagiorchiidae) and Leucochloridium perturbatum Pojmańska, 1969 (Leucochloridiidae). Actitis hypoleucos is the host for these new records in Poland. The P. nanus individuals isolated from A. hypoleucos differed in terms of the visible uterus and the extent of the vitellaria in the posterior part of the body.

A checklist of fish monogeneans from Poland

This paper lists 127 monogenean species belonging to 2 subclasses, 3 orders, 6 families and 13 genera reported from Polish freshwater and marine fishes. This checklist provides information also on the hosts, distribution in Poland and respective literature sources.

The Gyrodactylidae fauna of rainbow trout Oncorhynchus mykiss Walbaum 1792 in the Rogg breeding pound in Bavaria, Germany

In July 2005, 107 rainbow trout in age 1+ from a salmonid farm in Southern Germany situated in the southern tributary area of the Danube river were examined. The aim of this study was to determine the gyrodactylid species found on rainbow trout and to identify their location on the host's body. In total, 291 specimens from genus Gyrodactylus were collected. The most abundantly occurring species was Gyrodactylus truttae (181 specimens), whilst the others were less abundant. For the first time in Germany, Gyrodactylus teuchis and Gyrodactylus derjavinoides on rainbow trout were found. Most parasites occurred on the pectoral and ventral fins. Few specimens were found on the anal or caudal fins, in the oral cavity or on the gills. The only uninfected place was the nasal cavity.

[Host and topic specificity of Monogenea--parasites of Polish fish and amphibians]

This paper presents the distribution of Monogenea among Polish fish and amphibians as well as their location on the host body. Out of 127 Monogenea species recorded in Poland, 126 were found in fish, and only one in amphibians. Dactylogyridae were found in 3, Diplozoidae in 2, whereas Ancyrocephalidae in 6, and Gyrodactylidae in 9 fish families. Most Monogenea are closely attached to their location (topospecificity). Some species of fish parasites are found on gills, where they may occupy various microhabitats, while others (especially Gyrodactylidae) were found on fins, skin, gills, and rarely in the oral or nasal cavity.

Invalidity of three Palaearctic species of Triaenophorus tapeworms (Cestoda: Pseudophyllidea): evidence from morphometric analysis of scolex hooks

A comparative study of the scolex hook morphology of five species of tapeworms of the genus Triaenophorus Rudolphi, 1793 (Cestoda: Pseudophyllidea), parasites of pikes (Esox lucius L. and E. reichertii Dybowski) in the Palaearctic Region, was carried out. Measurements of scolex hooks of 81 plerocercoids and 492 adults from different hosts and regions were compared using basic statistics and forward stepwise linear discriminant analysis. The shape of the scolex and that of tridental hooks were found to be suitable only for differentiation of the taxa with a similar shape of hooks, i.e. Triaenophorus nodulosus (Pallas, 1781) from T. amurensis Kuperman, 1968, and T. crassus Forel, 1868 from T. meridionalis Kuperman, 1968 and T. orientalis Kuperman, 1968, respectively. In contrast, discriminant analysis did not enable reliable separation of specimens of individual taxa of these two morphological groups due to high intraspecific variability and overlaps between species. This was reflected in low classification efficiencies (average 83%) of all species of the T. crassus group, whereas all T. amurensis specimens were misidentified as T. nodulosus. The new data also considerably enlarge (up to twofold) the size range of the species described by Kuperman in 1968, which invalidates suitability of the most important discriminant characteristic, the width of the basal plate, for delimitation of Triaenophorus species. Based on the present data, all Kuperman's taxa are considered to represent only distinct geographical populations of T. nodulosus and T. crassus. As a result, T. anmurensis is synonymized with T. nodulosus, whereas T. orientalis is considered to be a synonym of T. crassus. Previous synonymisation of T. ineridionalis with T. crassus, first proposed by Dubinina (1987), is also accepted.

Fish monogeneans from a shallow, eutrophic Oświn Lake in Poland

BACKGROUND

A study was carried out in a shallow, eutrophic Oświn Lake, within Seven Islands Reserve (north-eastern Poland), in order to determine the infection of fish with monogeneans as sensitive indicators of water quality. This paper presents comparative analysis of the occurrence of Monogenea in fishes from two, distinctly separated pools of the lake, differing in environmental conditions. The impact of fish size and sampling season on the infection parameters was also analyzed.

MATERIAL AND METHODS

In 1998 and 1999, a total of 1091 fish representing 8 dominant species were examined. Samples were collected four times a year (in May, July, August, and October) simultaneously from the eastern and western parts of the lake.

RESULTS

16 species of Monogenea (and some unidentified specimeus) occurred in the fish examined, most of them from the Dactylogyridae family: Dactylogyrus sphyrna, D. auriculatus, D. intermedius, D. anchoratus, D. falcatus, D. tincae, D. wunderi, D. zandti, D. difformis, D. nanus, D. distinguendus, D. crucifer, D. caballeroi. Furthermore, Tetraonchus monenteron (Tetraonchidae), Gyrodactylus elegans (Gyrodactylidae), and Paradiplozoon megan (Diplozoidae) were detected. Monogenea occurred abundantly on the gills of pike, roach, rudd, white bream, carp bream and crucian carp, but rather sporadically in tench and perch. The highest species variety and diversity of monogenean guilds were detected in carp bream and roach. It was proved that D. crucifer and D. difformis were significantly more abundant in the western pool compared to the eastern one. Infection of fish with Dactylogyridae was season-dependent, contrary to the infection of pike with T. monenteron. Intensity of infection of white bream with D. sphyrna and roach with D. crucifer increased with fish body length; such a relationship did not appear for the other monogeneans and their hosts.

CONCLUSION

Presence of common Monogenea in the fish examined, lack of rare species, poor diversity of monogenean guilds and relatively low infection rate could be connected with the low stability of the lake environment. Location-dependent occurrence of D. crucifer and D. difformis indicated that the exchange between fish groups from the eastern and western parts of the lake is limited.

Effect of different contents of proteins and vitamin B2 in the feed on the prevalence and infection intensity of Ascaridia galli in chickens

A group of 10-day-old chickens was experimentally infected with a dose of 500 infective eggs of Ascaridia galli (Schrank, 1788) (Nematoda). Forty-nine days post infection the chickens were necropsied and the infection intensity and prevalence were determined. The group maintained on the feed containing 11% of protein showed higher infection intensity and prevalence compared to the chickens fed a diet containing 19% of protein. The addition of vitamin B2 to the feed containing 11% protein resulted in lower intensity and prevalence of the infection. In both series of experiments no effect of Zn-bacitracin or vitamin B2 on infection intensity or prevalence was observed for chickens fed feed containing 19% of protein.

Deformations of the attachment organ in Diplozoidae (Palombi, 1949) (Monogenea)

This work consisted in studying the frequency of deformations of the attachment organ in specimens representing the family Diplozoidae, occurring in roach, common bream, and white bream from five different water bodies. These water bodies differed in morphometric parameters, levels of eutrophication, and character of their pollution. The presence of three types of deformation was stated. The most common were deformations of type II (morphological changes of clamps, such as sclerite deformation, incomplete sclerite separation or sclerites missing altogether in a clamp), while less frequent were those of types I (changes in the size of clamps not associated with the structural changes) and III (missing clamps in a set). Most frequently anomalies of the attachment organ were stated in polluted Lyna River, polluted Wulpińskie Lake, and in dystrophic Warniak Lake. Less frequent were anomalies in less eutrophied lakes Dgal Wielki and Ukiel. Also the prevalence values of those parasites were the highest in the polluted water bodies. The present study supports believes of other authors, that both infection parameters of Diplozoidae affecting fishes and deformations of monogeneans' attachment apparatus can be treated as indicators of environmental pollution.

Occurrence of Trichodina pediculus Ehrenberg, 1838 in Dgal Wielki Lake

Parasitological investigation were performed in Dgal Wielki, occurrence T. pediculus Ehrenberg 1838 on the roach gills were recorded. On the 277 examined roach in 9 roach specimens T. pediculus were found. Prevalence of roach infection was 3.25%, mean intensity 3.5 and abundance 0.11 parasite per number of fish examined. T. pediculus were found on fish in May and June.

The effect of infestation with Diplostomum sp. on growth rate of Siberian sturgeon fry Acipenser baeri brandt

The objective of the experiment was to compare the growth rate in two groups of Siberian sturgeon fry, one of which was infested with metacercariae of Diplostomum, the infestation degree was from 1 to 160/fish. The fish fed on natural as well as artificial food; the latter was given at the rate sufficient to cover 50% of the fish requirements. The average initial body weight in the control group was 16.8 +/- 1.9g, and in the group with Diplostomum - 28.4 +/- 3.6 g. During the period of favorable temperatures, viz. for about 90 days, the fry was showed satisfactory growth, but the growth rate became inhibited as the temperatures decreased to below 12 degrees C, so that throughout the wintering period the fish weight decreased by some 10%. Fish from the control group showed a higher growth rate than the infested ones, and by the end of the experiment the controls weighted 7.5% more than the infested group in spite of their lower initial weight.

Trichodina pediculus Ehrenberg, 1838 in roach Rutilus rutilus (L.), metric and meristic data

During the parasitological studies in Dgał Wielki Lake 32 specimens of Trichodina pediculus were collected from roaches (Rutilus rutilus). T. pediculus were subjected to the metric and meristic measurements. High correlation factors significance was obtained between the following data: body diameter and adhesive disc diameter with border membrane, adhesive disc diameter without border membrane, denticulate ring diameter, height of denticle. However no correlation significance between body diameter and number of denticles was found.

[Leeches (Hirudinea: Piscicolidae and Glossiphonidae) infecting lake fish in the Ukiel, Warniak and Wulpińskie. Preliminary study]

The aim of the study was to determine leeches found on the lake fishes. From the lake Ukiel, 213 roaches (R. rutilus) and from the lake Wulpińskie 202 were examined between Nov. 1988 and Dec. 1999. From the Warniak 258 roaches and 9 tenches (Tinca tinca) were examined between May 1998 and Nov. 1999. Warniak on roach (R. rutilus) 4 Piscicola geometra and Hemiclepis marginata on the fish body were found, tench (Tinca tinca) P. geometra were found on gills. Ukiel on roach Piscicola pojmanskae on gills were found. Wulpińskie on roach P. pojmanskae and Piscicola sp. as well as 2 Caspiobdella fadejewi on gills were found. Prevalence and intensity of fish infection with leeches was low in all lakes. C. fadejewi and P. pojmanskae are the first recorded on the lake fishes. Further investigations are necessary since they can result in informations concerning inhabitation of new microhabitants with P. geometra gills.

[Occurrence of metacerkariae Diplostomum sp. in the Siberian turgeon fry (Acipenser baeri Brandt)--preliminary study]

Siberian sturgeon fry coming from three different ponds has been examined. 1. "Dgał" - fish culture conerete-terrestrial pond beloning to D.O.Z. Dgał Inland Fisheries Institute in Olsztyn supplied with fresh water from Great Dgał Lake; 2. "Grzmieca" - fish culture pond terrestrial, natural belonging to fishing farm Grzmieca near Brodnica; 3. "Konin" - fish culture pond near Konin supplied with water utilized by near heat and power generating plant. Total of 80 sturgeons fry with parameters: length 17.5 cm - 38.5 cm, weight 21 g - 134 g, age 0+1+ has been examined. The examinated group of sturgenos had metacercariae Diplostomum sp. in their lenses. Prevalence of infection of sturgeon with metacercariae Diplostomum sp. was high in all this three ponds. Intensity of infection was also high in ponds "Dgal" and "Grzmieca", but low in "Konin". In ponds "Dgal" and "Konin" we have obtained high positive correlation ("Dgal" - r = 0,606, p < 0,05; "Konin" - r = 0,743, p < or = 0,01) between number of metacercariae in sturgeon and temperature of water. Our study confirmed observations other authors susceptibility sturgeon fry on the Diplostomum sp. invasion.