The importance of slaughterhouses in monitoring the occurrence of tail biting in pigs - Review.

Tail biting in pigs represents a very serious problem in modern pig farming, particularly with the intensification of the industry. It is considered a multifactorial syndrome and can be caused by various factors, leading to significant economic losses through reduced weight gain and partial or total condemnation of slaughtered carcasses due to secondary bacterial infections. The aim of this article is to summarise the current knowledge regarding tail biting in pigs, with a primary focus on the use of slaughterhouses for evaluating tail lesions and monitoring their prevalence. The introduction addresses the factors influencing the incidence of tail biting in pig farms and prevention strategies. Subsequent sections cover topics such as tail docking, the negative effects of pig tail biting, the advantages and drawbacks of examining tail lesions in slaughterhouses, and the methodical procedure for evaluating such lesions. Additionally, the article discusses the relationship between tail lesions and meat inspection findings, as well as the prevalence of tail lesions in various European countries.

No indication for SARS-CoV-2 transmission to pet ferrets, in five cities in Poland, 2021 - antibody testing among ferrets living with owners infected with SARS-CoV-2 or free of infection.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in China by the end of 2019 and was responsible for a pandemic in the human population that resulted in millions of deaths worldwide. Since the beginning of the pandemic, the role of animals as spill-over or reservoir hosts was discussed. In addition to cats and dogs, ferrets are becoming increasingly popular as companion animals. Under experimental conditions, ferrets are susceptible to SARS-CoV-2 and it appears that they can also be infected through contact with a SARS-CoV-2 positive owner. However, there is still little information available regarding these natural infections. Here, we serologically tested samples collected from pet ferrets (n = 45) from Poland between June and September 2021. Of the ferrets that were included in the study, 29% (13/45) had contact with owners with confirmed SARS-CoV-2 infections. Nevertheless, SARS-CoV-2-specific antibodies could not be detected in any of the animals, independent of the infection status of the owner. The obtained results suggest that ferrets cannot be readily infected with SARS-CoV-2 under natural conditions, even after prolonged contact with infected humans. However, due to the rapid mutation rate of this virus, it is important to include ferrets in future monitoring studies.

Staphylococcus aureus from Subclinical Cases of Mastitis in Dairy Cattle in Poland, What Are They Hiding? Antibiotic Resistance and Virulence Profile.

Bovine mastitis is a common disease worldwide, and staphylococci are one of the most important etiological factors of this disease. Staphylococcus aureus show adaptability to new conditions, by which monitoring their virulence and antibiotic resistance mechanisms is extremely important, as it can lead to the development of new therapies and prevention programs. In this study, we analyzed Staphylococcus aureus (n = 28) obtained from dairy cattle with subclinical mastitis in Poland. The sensitivity of the isolated strains to antibiotics were confirmed by the disc diffusion method. Additionally, minimum inhibitory concentration values were determined for vancomycin, cefoxitin and oxacillin. Genotyping was performed by two methods: PCR melting profile and MLVF-PCR (multiple-locus variable-number tandem-repeat fingerprinting). Furthermore, the presence of antibiotic resistance and virulence genes were checked using PCR reactions. The analyzed strains showed the greatest resistance to penicillin (57%), oxytetracycline (25%) and tetracycline (18%). Among the analyzed staphylococci, the presence of 9 of 15 selected virulence-related genes was confirmed, of which the icaD, clfB and sea genes were confirmed in all staphylococci. Biofilm was observed in the great majority of the analyzed bacteria (at least 70%). In the case of genotyping among the analyzed staphylococci (combined analysis of results from two methods), 14 patterns were distinguished, of which type 2 was the dominant one (n = 10). This study provides new data that highlights the importance of the dominance of biofilm over antibiotic resistance among the analyzed strains.

Does Aleutian Disease Occur among Domestic Ferrets in Poland? Results of Preliminary Studies Conducted in Two Regions of Poland.

Although ferrets are becoming increasingly popular as companion animals, their population in households is still far lower compared to cats or dogs. This results in a much smaller number of ferret specialists, and thus poorer diagnosis of various diseases, including the Aleutian disease. Aleutian disease is a slowly progressing viral disease which can cause different symptoms in these animals. The virus can also cause symptoms in different species of animals, but in the case of ferrets, there is relatively less information on about both the prevalence and symptoms of this disease. Therefore, the aim of this study was to determine the presence of antibodies and the virus itself in ferrets from two regions of Poland. Blood samples and rectal swabs were obtained from 61 domestic ferrets from Mazowieckie and Dolnoslaskie voivodships. The presence of antibodies was determined using serological methods and real-time PCR analysis was performed to determine presence of viral DNA. Serological analyses demonstrated that 49% (n = 30) of the ferrets had antibodies against Aleutian disease virus (ADV). No relationship was observed between the prevalence of antibodies and age, sex, habitual residence or origin of ferrets. The real-time PCR did not confirm DNA of the ADV in any of the blood and rectal swab samples. Obtained results suggest that ADV circulates in the analyzed population of ferrets, therefore further studies in this direction should be carried out.

High Seroprevalence against SARS-CoV-2 among Dogs and Cats, Poland, 2021/2022.

The coronavirus SARS-CoV-2 is responsible for a pandemic in the human population that has unfolded since the beginning of 2020 and has led to millions of deaths globally. Apart from humans, SARS-CoV-2 has been confirmed in various animal species, including felines, canines, mustelids, and primates. Of these species, dogs and cats are the most popular companion animals worldwide. Several seroprevalence studies have already been performed in these animal species; however, the results vary depending on the location and especially the time of sampling. Here, serum samples were collected from a total of 388 dogs and 243 cats from three veterinary clinics in two cities (Gdansk and Olsztyn) in Poland between October 2021 and February 2022, when the country was in the midst of the fourth wave of viral spread. All sera were tested for antibodies against SARS-CoV-2 by a multispecies ELISA based on the receptor-binding domain and by an indirect immunofluorescence assay (iIFA). Overall, 18.9% of the feline sera and 16.0% of the canine sera tested positive using ELISA and iIFA. This relatively high seroprevalence among randomly selected animals is most likely related to the high case numbers in the human population and indicates a continuous occurrence of transspecies virus transmissions from infected owners to their pets. Hence, dogs and cats should be included in monitoring studies and/or outbreak investigations for a better understanding of the epidemiology of this virus.

In Vivo Bacteriophages' Application for the Prevention and Therapy of Aquaculture Animals-Chosen Aspects.

To meet the nutritional requirements of our growing population, animal production must double by 2050, and due to the exhaustion of environmental capacity, any growth will have to come from aquaculture. Aquaculture is currently undergoing a dynamic development, but the intensification of production increases the risk of bacterial diseases. In recent years, there has been a drastic development in the resistance of pathogenic bacteria to antibiotics and chemotherapeutic agents approved for use, which has also taken place in aquaculture. Consequently, animal mortality and economic losses in livestock have increased. The use of drugs in closed systems is an additional challenge as it can damage biological filters. For this reason, there has been a growing interest in natural methods of combating pathogens. One of the methods is the use of bacteriophages both for prophylactic purposes and therapy. This work summarizes the diverse results of the in vivo application of bacteriophages for the prevention and control of bacterial pathogens in aquatic animals to provide a reference for further research on bacteriophages in aquaculture and to compare major achievements in the field.

The effect of synbiotics and probiotics on the growth performance, gastrointestinal function and health status of turkeys.

The aim of this study was to evaluate the growth performance, gastrointestinal function and health status of turkeys fed diets supplemented with synbiotic preparations, as compared with commercial probiotic feed additives. The experiment lasted for 15 weeks. The research material comprised 600 female BIG 6 turkeys (6 treatments, 5 replicates, 20 birds per replicate). The turkeys from the control group (I) received a diet without additives. Groups II and III received a basal diet with the addition of probiotic BioPlus 2B or Cylactin at 0.4 g/kg diet, respectively. In groups IV, V and VI turkeys were fed diets with synbiotic preparations S1 (L. reuteri, L. plantarum, L. pentosus, S. cerevisiae + inulin), S2 (L. reuteri, L. plantarum, L. pentosus, S. cerevisiae, L. rhamnosus + inulin) and S3 (L. reuteri, L. plantarum, L. pentosus, S. cerevisiae, L. rhamnosus, L. paracasei + inulin) at 0.5 g/kg diet, respectively. The following parameters were monitored: growth performance, carcass quality, the chemical composition of meat, the structure (length, weight, villus height, crypt depth) and functional parameters (pH, viscosity) of selected segments of the gastrointestinal tract, and the health status of birds (lysozyme, gamma-globulins, ceruloplasmin and total protein). Dietary supplementation with probiotics and synbiotics contributed to an increase in the final body weights of turkeys, a decrease in the feed conversion ratio and an increase in values of the European Production Efficiency Factor (p ≤ 0.05). Synbiotics improved the immune status of birds by increasing serum gamma-globulin levels and decreasing ceruloplasmin activity at 8th week of age (p ≤ 0.05). Synbiotics and probiotics also contributed to a decrease in crop and caecal pH (p ≤ 0.05). The analysed additives had no effect on carcass dressing percentage, carcass quality characteristics or the chemical composition of breast muscles. The tested synbiotics as well as commercial probiotics can be valuable feed additives, improving the growth performance and immune status of turkeys.

Influence of Infectious Pancreatic Necrosis Virus and Yersinia ruckeri Co-Infection on a Non-Specific Immune System in Rainbow Trout (Oncorhynchus mykiss).

BACKGROUND: The IPNV is one of the most common viral pathogens of rainbow trout (Oncorhynchus mykiss), while Y. ruckeri infections are widespread among bacterial agents. The current study aimed to determine the influence of IPNV and Y. ruckeri co-infection on a non-specific immune response. METHODS: Two experiments were conducted. The first experiment determined the changes in non-specific immunity parameters upon the simultaneous occurrence of IPNV and Y. ruckeri infection. In the second experiment, infection with the IPNV was performed two weeks before Y. ruckeri infection. The level of total protein, gamma globulins, the activity of lysozyme and ceruloplasmin, as well as the metabolic activity and potential killing activity of phagocytes were measured: 0, 24 h, 72 h, 7 days, 14 days, and 21 days after co-infection. RESULTS: A differentiated effect on the parameters of the non-specific immune response was shown between single infections with the IPNV and Y. ruckeri as well as co-infection with these pathogens. CONCLUSIONS: The immune response in the course of a co-infection depended on the time between infections. IPNV infection causes lysozyme activity suppression, which may lead to secondary bacterial infections.

The Brain-gut Axis-where are we now and how can we Modulate these Connections?

A traumatic brain injury (TBI) initiates an inflammatory response with molecular cascades triggered by the presence of necrotic debris, including damaged myelin, hemorrhages and injured neuronal cells. Molecular cascades prominent in TBI-induced inflammation include the release of an excess of proinflammatory cytokines and angiogenic factors, the degradation of tight junctions (TJs), cytoskeletal rearrangements and leukocyte and protein extravasation promoted by increased expression of adhesion molecules. The brain-gut axis consists of a complex network involving neuroendocrine and immunological signaling pathways and bi-directional neural mechanisms. Importantly, modifying the gut microbiome alters this axis, and in turn may influence brain injury and neuroinflammatory processes. In recent years it has been demonstrated that the activity and composition of the gastrointestinal (GI) microbiome population influences the brain through all of above-mentioned pathways affecting homeostasis of the central nervous system (CNS). The GI microbiome is involved in the modulation of cellular and molecular processes which are fundamental to the progression of TBI-induced pathologies, including neuroinflammation, abnormal blood brain barrier (BBB) permeability, immune system responses, microglial activation, and mitochondrial dysfunction. It has been postulated that interaction between the brain and gut microbiome occurs mainly via the enteric nervous system and the vagus nerve through neuroactive compounds including serotonin or dopamine and activation by bacterial metabolites including endotoxin, neurotransmitters, neurotrophic factors, and cytokines. In recent years the multifactorial impact of selected immunomodulatory drugs on immune processes occurring in the CNS and involving the brain-gut axis has been under intensive investigation.

Effect of Different Routes of Vaccination against Aeromonas salmonicida on Rearing Indicators and Survival after an Experimental Challenge of Pikeperch (Sander lucioperca) in Controlled Rearing.

Bacterial diseases are a significant problem in the controlled rearing of fish. Furunculosis (Aeromonas sp.), flavobacteriosis (Flavobacterium sp.), and pseudomonadosis (Pseudomonas sp.) are currently the most frequently identified diseases in recirculating aquaculture systems of various fish species. Such a situation is also observed in pikeperch rearing. Due to the emerging difficulties of effective prophylaxis using commercial vaccines, interest in the use of autovaccinations is increasing, not only in ichthyopathology but also in other veterinary fields. Our research aimed to assess the effect of the vaccination method on the overall condition of the fish and survival after the experimental infection with Aeromonas salmonicida. Pikeperch were vaccinated by (1) bath, (2) a single i.p. injection, or (3) feed. The fish were measured and weighed on day 0 and after 28 and 56 days of the experiment. Specific growth rate, daily growth rate, condition factor, and feed conversion ratio were calculated. On days 7, 14, 21, and 28 of the experiment, ceruloplasmin and lysozyme levels were rated. In addition, a challenge test was performed. The obtained results showed that the method of vaccination is important and affects the growth of fish, the overall condition of fish, and survival after experimental infection.

Growing Trend of Fighting Infections in Aquaculture Environment-Opportunities and Challenges of Phage Therapy.

Phage therapy, a promising alternative to antimicrobial treatment of bacterial diseases, is getting more and more popular, especially due to the rising awareness of antibiotic resistance and restrictions in antibiotics' use. During recent years, we observed a growing trend of bacteriophages' application in aquaculture, which in each year reports high losses due to bacterial diseases. This review provides an update of the status of bacteriophage therapy for the treatment and prevention of infections in the aquatic environment. As it is still mostly in the scientific stage, there are a few constraints that may prevent effective therapy. Therefore, specific characteristics of bacteriophages, that can act in favor or against their successful use in treatment, were described. We underlined aspects that need to be considered: specificity of phages, bacterial resistance, safety, immune response of the host organism, formulation, administration and stability of phage preparations as well as bacteriophages' influence on the environment. The biggest challenge to overcome is finding the right balance between the desired and problematic characteristics of bacteriophages. Finally, regulatory approval challenges may be encountered by bacteriophage manufacturers. Even though there are still some technical constraints connected with the global use of bacteriophage therapy, it was concluded that it can be successfully applied in aquaculture.

Antiviral effects of nisin, lysozyme, lactoferrin and their mixtures against bovine viral diarrhoea virus.

BACKGROUND: Bovine viral diarrhoea virus (BVDV), an enveloped, single-stranded, positive-sense RNA virus from the Flaviviridae family, is a globally distributed bovine pathogen. BVDV infection in cattle, despite having a wide range of clinical manifestations, is invariably responsible for significant economic losses. To counteract these losses, various schemes to control and eradicate BVDV have been implemented, although safe drugs effectively inhibiting the replication of the virus are still lacking. The purpose of this study was to characterize the antiviral effect of naturally occurring proteins and peptide, such as bovine lactoferrin, chicken egg lysozyme, and nisin from Lactococcus lactis, used both individually and in combination, against the cytopathic NADL strain of BVDV in vitro. After determining the cytotoxicity level of each protein or peptide to MDBK cells, its antiviral effects were evaluated using virucidal, cytopathic effect inhibition and viral yield reduction assays. In addition, the influence of the tested compounds on the intracellular viral RNA level was determined. RESULTS: The highest efficacy among the single treatments was achieved by bovine lactoferrin, which was effective both at the early stages of viral infection and during its entire course, although the effect weakened over time. Nisin and lysozyme were effective at later stages of infection, and the intensity of their effect did not diminish with time. Nisin+lactoferrin and lysozyme+lactoferrin combinations demonstrated stronger antiviral effects than did the single substances. The nisin+lactoferrin mixture present during the whole period of infection produced the strongest anti-BVDV effect in our entire research on both the extracellular viral titre (titre reduction up to 2.875 log ≈ 99.9%) and the intracellular viral RNA level (reduction up to 89%), and this effect intensified over the incubation time. CONCLUSIONS: The tested substances could be applied in bovine viral diarrhoea prevention and therapy, especially when used in combination.

The effects of radio-frequency radiation (RFR) exposure on the analgesic efficacy of morphine in healthy rats and rats with inflammation.

OBJECTIVES: The aim of this study, conducted at the Military Institute of Hygiene and Epidemiology in Warsaw in 2017, was to evaluate the effects of a single (15 min) and repeated (5 times for 15 min) radio-frequency radiation (RFR) exposure of 1800 MHz frequency on the analgesic efficacy of morphine in healthy rats and rats with complete Freund's adjuvant (CFA) induced inflammation. MATERIAL AND METHODS: Rats were injected intraperitoneally with morphine (MF) in the dose of 8 mg/kg or drug vehicle 15 min before RFR exposure. The authors used the plantar analgesia meter and the radiant heat paw-withdrawal test to assess the pain threshold. RESULTS: A single RFR exposure slightly influenced paw withdrawal latency (PWL) in healthy rats in the single exposure baseline group, and influenced PWL, 30 and 60 min after morphine or vehicle injection, in the repeated exposure group. There were differences between the sham-exposed groups (vehicle), 30, 60 and 90 min after injection, both in the single and repeated RFR-exposure groups. The antinociceptive effect of morphine in healthy rats was slightly decreased by RFR exposure at 60 and 90 min, both in the single and repeated exposure groups. The PWL was slightly decreased, both in the single and repeated exposure groups with inflammation (CFA and CFA/MF), at 30, 60 and 90 min, and PWL was increased in the sham-exposed groups (CFA and CFA/MF), both in the single and repeated exposure groups, at 30, 60 and 90 min. The antinociceptive effect of morphine in healthy rats was significantly increased by RFR exposure at 30 min after drug injection in the single exposure group, and increased at 30 and 60 min in the repeated exposure group. CONCLUSIONS: The authors observed a minor influence of RFR exposure on the antinociceptive effects of morphine in healthy rats after repeated exposures and a statistically significant influence of repeated exposure on morphine mediated antinociceptive effects in the inflammation group. Int J Occup Med Environ Health. 2019;32(4):465-74.

Bacteriophage-based cocktail modulates selected immunological parameters and post-challenge survival of rainbow trout (Oncorhynchus mykiss).

Recently, a rapid increase in the resistance of pathogenic bacteria to antibiotics and chemotherapeutics admitted for use in aquaculture has been observed. This happens especially often in intensive breeding. The use of drugs in closed circuits is problematic because it can damage biological filters. Therefore, in recent years, there has been a growing interest in natural methods of combating pathogens. These include bacteriophages. The aim of the study was to determine the safety of the new BAFADOR® bacteriophage-based preparation, its effect on selected immunological parameters and the effectiveness of prophylactic and therapeutic use after experimental infections with pathogenic bacteria Aeromonas hydrophila and Pseudomonas fluorescens. The use of BAFADOR® increased the activity of lysozyme, total protein level and immunoglobulin level. The level of ceruloplasmin in the rainbow trout serum remained unchanged regardless of the route of administration of the preparation. Potential killing activity and metabolic activity of spleen phagocytes and proliferation of pronephros lymphocytes were higher compared to the control group. Both therapeutic and prophylactic application of the preparation after mixed experimental infection of A. hydrophila and P. fluorescens limited the mortality of rainbow trout.

Cell cycle and transmembrane mitochondrial potential analysis after treatment with chromium(iii), iron(iii), molybdenum(iii) or nickel(ii) and their mixtures.

The aim of this study was to examine the effect of chromium(iii), iron(iii), molybdenum(iii) and nickel(ii) and their combinations on the cell cycle and mitochondrial transmembrane potential (MTP) in BALB/3T3 and HepG2 cells. A statistically significant dose related decrease of the percentage of cells in the G0/G1 and S phases was observed. However, a statistically significant dose related increase of the percentage of cells in the G2/M phase after exposure to chromium(iii), nickel(ii) or molybdenum(iii) at 200-1000 µM concentrations in both cell lines was observed. Moreover, an increase of the percentage of cells in the subG1 phase was observed. In both cell lines a statistically significant dose related decrease of the percentage of cells in the G2/M phase after exposure to iron(iii) at 200-1000 µM concentrations was observed. However, a statistically significant dose related increase of the percentage of cells in the G0/G1 phase after exposure to iron(iii) at 200-1000 µM concentrations was observed. A concentration dependent statistically significant decrease in the level of the MTP was observed in both cell lines after exposure to chromium(iii), iron(iii), nickel(ii) and molybdenum(iii). The results obtained from both cell lines show that HepG2 cells are more sensitive when compared to BALB/3T3 cells. Additions of Cr(iii) at 200 µM plus Fe(iii) at 1000 µM showed a synergistic effect on the cell cycle and MTP. In the case of Cr(iii) at 200 µM plus Mo(iii) at 1000 µM, an antagonistic effect was observed in both analyses. In the case of Cr(iii) at 1000 µM plus Mo(iii), Ni(ii) and Fe(iii) at 200 µM, no changes in the percentage of cells in all phases were observed in both cell lines in both analyses.

In vitro immunomodulatory effect of nisin on porcine leucocytes.

Nisin, a lantibiotic bacteriocin, has been used for years as a natural food preservative. In addition to its antimicrobial activity, nisin also shows immunomodulatory properties, and the nisin-producing Lactococcus lactis strain has been successfully tested as a probiotic in weaned piglets. However, the impact of nisin on porcine immune cells has not yet been explored. The objective of the present study was to examine the in vitro immunomodulatory effect of nisin on porcine peripheral blood leucocytes. The whole heparinized blood samples or freshly isolated peripheral blood mononuclear cells (PBMCs) were incubated with different nisin concentrations (0, 1.56, 3.125, 6.25, 12.5, 25 or 50 µg/ml) for 1, 24, 48 or 72 hr. Escherichia coli bacteria were used to stimulate blood phagocytes, while concanavalin A and lipopolysaccharide from E. coli were used as mitogens. Control cells remained unstimulated. MTT colorimetric assay was used to evaluate PBMCs viability and mitogenic response. Phagocyte activity and T-cell proliferation were measured by flow cytometry. Flow cytometer was also used for immunophenotyping of T cells. Cytokine levels in the culture media were determined using commercial immunoassay (ELISA) kits. The highest concentration of nisin exhibited proliferative activity (p Ë‚ 0.05), stimulated interleukin-1 beta (IL-1ß) and interleukin-6 (IL-6) production (both at p Ë‚ 0.001), and increased the percentage of CD4+ CD8+ T cells (p Ë‚ 0.001) among unstimulated leucocytes. After cell stimulation, however, the highest nisin concentration showed antiproliferative activity (p Ë‚ 0.05), decreased phagocytic functions (p Ë‚ 0.05) and inhibited the synthesis of IL-6 (time- and concentration-dependent effect). As a typical bacterial product, nisin had a stronger impact on innate immune cells, and its effect on T cells was likely a consequence of the modulation of the activity of antigen-presenting cells. Nisin may be a good candidate as an immunomodulator in pig breeding.

Complete genome sequences of Aeromonas and Pseudomonas phages as a supportive tool for development of antibacterial treatment in aquaculture.

BACKGROUND: Aquaculture is the fastest growing sector of food production worldwide. However, one of the major reasons limiting its effectiveness are infectious diseases among aquatic organisms resulting in vast economic losses. Fighting such infections with chemotherapy is normally used as a rapid and effective treatment. The rise of antibiotic resistance, however, is limiting the efficacy of antibiotics and creates environmental and human safety concerns due to their massive application in the aquatic environment. Bacteriophages are an alternative solution that could be considered in order to protect fish against pathogens while minimizing the side-effects for the environment and humans. Bacteriophages kill bacteria via different mechanisms than antibiotics, and so fit nicely into the 'novel mode of action' concept desired for all new antibacterial agents. METHODS: The bacteriophages were isolated from sewage water and characterized by RFLP, spectrum of specificity, transmission electron microscopy (TEM) and sequencing (WGS). Bioinformatics analysis of genomic data enables an in-depth characterization of phages and the choice of phages. This allows an optimised choice of phage for therapy, excluding those with toxin genes, virulence factor genes, and genes responsible for lysogeny. RESULTS: In this study, we isolated eleven new bacteriophages: seven infecting Aeromonas and four infecting Pseudomonas, which significantly increases the genomic information of Aeromonas and Pseudomonas phages. Bioinformatics analysis of genomic data, assessing the likelihood of these phages to enter the lysogenic cycle with experimental data on their specificity towards large number of bacterial field isolates representing different locations. CONCLUSIONS: From 11 newly isolated bacteriophages only 6 (25AhydR2PP, 50AhydR13PP, 60AhydR15PP, 22PfluR64PP, 67PfluR64PP, 71PfluR64PP) have a potential to be used in phage therapy due to confirmed lytic lifestyle and absence of virulence or resistance genes.

Pro- and antioxidant activity of chromium(III), iron(III), molybdenum(III) or nickel(II) and their mixtures.

The aim of this study was to examine the effect of chromium(III), iron(III), molybdenum(III) and nickel(II) and their combinations on pro- and antioxidant activity in mouse embryo fibroblasts and liver cancer cells. The present study shows that chromium(III), iron(III), nickel(II) and molybdenum(III) induce oxidative stress. In the case of chromium(III), nickel(II) and molybdenum(III) the intracellular ROS were dominant. However, in the case of iron(III) MDA was dominant - the end product of lipid peroxidation. Antioxidant activity of superoxide dismutase and catalase increased in low concentration of chromium(III); however, they decreased in higher concentrations. The same enzymes decreased after iron(III), nickel(II) and molybdenum(III) treatment in dose dependent manner. The activity of glutathione peroxidise decreased in dose dependent manner in all used microelements. Additions of Cr(III) at 200 µM plus Fe(III) at 1000 µM showed synergistic effect in ROS production and in lowering antioxidant activity. The same type of interaction in pairs Cr(III) at 1000 µM plus Fe(III) or Ni(II) or Mo(III) at concentration of 200 µM was observed. The protective effects of Cr(III) in antioxidant activity and in lowering intracellular ROS production in pairs of Cr(III) at 200 µM and Ni(II) or Mo(III) at concentration of 1000 µM were observed.

Influence of bacteriophages cocktail on European eel (Anguilla anguilla) immunity and survival after experimental challenge.

Inland fishery belongs to those branches of animal production that use very large amounts of chemotherapeutics, in particular antibiotics. The accumulation of chemotherapeutic agents in bottom sediments is a direct threat to the aquatic environment and directly affects the condition and health of the fish. Finding a preparation that could be used both prophylactically to increase the resistance of fish and therapeutically in case of infection with pathogenic bacteria, without side effects for fish and aquatic environment could be a great solution to this problem. Our aim was to determine influence of BAFADOR® the new bacteriophage-based preparation on European eel immunity and survival after experimental challenge. Application of BAFADOR® increased total protein level, immunoglobulin level, lysozyme activity and ceruloplasmin level in European eel serum. Potential killing activity and metabolic activity of spleen phagocytes as well as pronephros lymphocyte proliferation of was higher compared to control. The preparation also reduced mortality after experimental infections with the pathogenic bacteria Aeromonas hydrophila and Pseudomonas fluorescens. Our results showed that preparation BAFADOR® is well tolerated by the fish organism causing stimulation of cellular and humoral immunity parameters and reduces the mortality of the European eel after experimental challenge.

Influence of trans-resveratrol on macrophage and lymphocyte activity in rainbow trout (Oncorhynchus mykiss) - in vitro study.

The objective of this study was to investigate the effect of trans-resveratrol, a potent antioxidant with anti-inflammatory and chemopreventive properties, naturally occurring in many fruits and plants on lymphocytes proliferation and also on macrophages metabolic and phagocytic activity. The aim of this study was to demonstrate the immunomodulatory effects of the compound on fish immunocompetent cells and determine the type of this interaction (immunosuppression or immunostimulation). Proliferative activity of lymphocytes was studied by MTT assay, and the respiratory burst was evaluated using the respiratory burst activity (RBA) test. Phagocytic killing was tested using the PKA test. The experiment have shown that trans-resveratrol suppressed blood B cells, while there was no significant influence on blood T lymphocytes. However, insignificant stimulatory effect occurred at the lowest concentration. In addition, the compound inhibited proliferation of T and B lymphocytes isolated from the organs. Importantly, trans-resveratrol caused stimulation of blood and organs macrophages phagocytic killing, and also increased the respiratory burst of macrophages isolated from organ. These results suggest a potential use of trans-resveratrol as an immunomodulator of innate immunity in fish. This is particularly important, as this kind of resistance plays leading role in protecting the body against infection. In comparison, adaptive immunity is slower and also much less precise.