Andrzej Koncicki

Biochemical and immunological responses of young turkeys to vaccination against Ornithobacterium rhinotraheale and different levels of dietary methionine.

The objective of this study was to verify the hypothesis that increasing levels of dietary methionine can stimulate the mechanisms of cell-mediated and humoral immunity in young turkeys. The blood and organs involved in cell-mediated and humoral immune responses were analyzed in 8-week-old turkeys that had been vaccinated against Ornithobacterium rhinotraheale (ORT) infection (on days 17 and 48). The birds were fed diets with a low (LM), medium (MM) and high (HM) methionine content (0.45 and 0.40%, 0.60 and 0.51%, 0.71 and 0.57% in weeks 1 - 4 and 5 - 8, respectively). Dietary methionine supplementation led to a significant increase in body weights of turkeys at 56 days of age, from 3532 g in group LM to 3720 g in group MM and 3760 g in group HM (p=0.001). A significant increase in vaccine-induced antibody titers against ORT was noted in group HM relative to group LM (p=0.006). Increasing levels of methionine had no significant effect on total serum IgG nor IgM levels and most serum biochemical parameters, TP, ALB, GLOB, GLU, AST, ALP, P and Ca. In comparison with group LM, group HM turkeys were characterized by a lower percentage of IgM⁺ B cell subpopulation in the blood and bursa of Fabricius. The percentages of CD4⁺ and CD8⁺ T cell subpopulations in the bursa of Fabricius in group HM were significantly different from those found in groups LM and MM. The highest percentages of CD4⁺ T cells and CD8⁺ T cells in the spleen were observed in groups LM (p<0.001) and HM (p=0.04), respectively. The differences were statistically significant relative to the remaining groups. Turkeys of group LM were characterized by a lower CD4⁺ T cell percentage in the thymus (p<0.001) and a lower CD8⁺ T cell percentage in the cecal tonsils (CTs) (p<0.01). Vaccination against ORT resulted in a significant increase in the percentage of CD4⁺CD8⁺ T cell subpopulation and a decrease in the percentage of CD8⁺ T cell subset in the spleen.

The epidemiology, molecular characterization and clinical pathology of circovirus infections in pigeons – current knowledge

ABSTRACT The first cases of circovirus infections in pigeons were documented less than 25 years ago. Since then, circovirus infections have been reported on nearly all continents. The specificity of pigeon breeding defies biosecurity principles, which could be the reason for the high prevalence of PiCV infections. PiCV infections in pigeons lead to atrophy of immune system organs and lymphocyte apoptosis. Infected birds could be more susceptible to infections of the respiratory and digestive tract. PiCV has been associated with the young pigeon disease syndrome (YPDS). PiCVs are characterized by high levels of genetic diversity due to frequent point mutations, recombination processes in the PiCV genome and positive selection. Genetic recombinations and positive selection play the key role in the evolution of PiCV. A protocol for culturing PiCV under laboratory conditions has not yet been developed, and traditional vaccines against the infection are not available. Recombinant capsid proteins for detecting anti-PiCV antibodies have been obtained, and these antigens can be used in the production of diagnostic tests and subunit vaccines against PiCV infections. However, YPDS has complex etiology, and it remains unknown whether immunization against PiCV alone will contribute to effective control of YPDS.

Immunological aspects of the efficiency of protectotype vaccination strategy against chicken infectious bronchitis

BackgroundOne of the most commonly applied protectotype vaccination protocol against infectious bronchitis (IB) in broiler chickens in the EU is simultaneous or alternate use of Ma5 and 4/91 vaccine strains. After IB vaccination and infection, systemic and upper respiratory tract (URT), humoral and cell-mediated immunity (CMI), are stimulated. The level of this stimulation correlates with the level of protection against IB.ResultsWe’ve investigated the development of URT and systemic, cell-mediated and humoral immunity in commercial broiler chickens vaccinated with Ma5 and/or 4/91 strains at hatch day. We’ve demonstrated that the group vaccinated with Ma5 and 4/91 strain simultaneously developed the most desirable immunity which reflects the level of CD8+ T cells stimulation in spleen and Harderian gland, as well as the level of IgA and IgY in URT washings and serum and their cross-reactivity with 7 IBV strains.ConclusionsAlthough we did not demonstrate directly why Ma5 + 4/91 protocol is so efficient it seems that it combines the benefits of monovalent vaccination with either Ma5 or 4/91 and while Ma5 seems to stimulate CMI more efficiently, the 4/91 strain generates a wider spectrum of immune system cross-reactivity and higher URT IgA production.

The influence of probiotic supplementation in broiler chickens on population and carcass contamination with Campylobacter spp. - Field study

Campylobacter spp. is a food-borne pathogen occurring all over the world. According to European Food Safety Authority, in Europe, in 2015 the number of recorded and confirmed cases of Campylobacter spp. infections in humans has reached approximately 230,000. Poultry and poultry meat are considered to be the main sources of human infection, which triggers the discussion about the possibility of imposing obligatory control of Campylobacter spp. population at the level of primary poultry production. Recently, the use of probiotics in poultry is considered as a very promising alternative that could reduce infection rate in broiler chickens with Campylobacter spp. Although, there were some approaches made in vivo, up to date, there were no studies that would evaluate those issues under field conditions. A study was carried out in order to determine the feasibility of reducing infection rate in broiler chickens with Campylobacter spp. raised at a commercial farm, by the addition of multispecies probiotic (Lavipan, JHJ, Poland) that composed of Lactococcus lactis, Carnobacterium divergens, Lactobacillus casei, Lactobacillus plantarum and Saccharomyces cerevisae to the feed. Results of our study indicate that probiotic (Lavipan) added to a feed for broiler chickens was capable to reduce the extent of Campylobacter spp. invasion in the gastrointestinal tract of birds and, resultantly, to diminish contamination level in bird environment, which eventually contributed to the improved hygienic parameters of analyzed poultry carcasses. Additionally, this probiotic displayed promising immunomodulatory properties that may improve the effectiveness of the specific prophylaxis program applied in a flock of broiler chickens.

An evaluation of the impact of aloe vera and licorice extracts on the course of experimental pigeon paramyxovirus type 1 infection in pigeons

Abstract The progressive decrease in the efficiency of synthetic drugs has prompted research into phytogenic feed additives with potentially immunomodulatory and anti‐infective properties. Complex diseases with a mixed etiology, including viral, pose a growing problem in domestic pigeons. The aim of this study was to determine the effectiveness of various doses of aloe vera and licorice extracts on the course of experimental PPMV‐1 infection in pigeons. The experiment was performed on pigeons divided into 5 groups, including one control group and 4 experimental groups, which were orally administered aloe vera or licorice extracts at 300 or 500 mg/kg BW for 7 d after experimental inoculation with PPMV‐1. On d 4, 7, and 14 after inoculation, cloacal swabs and samples of organs were collected from 4 birds in each group. The samples were analyzed to determine the copy number of PPMV‐1 RNA by TaqMan qPCR. The results indicate that licorice and aloe vera extracts inhibited PPMV‐1 replication by decreasing viral RNA copy numbers in the examined organs. The most inhibitory effect was observed in pigeons receiving aloe vera extract at 300 mg/kg BW, for which PPMV‐1 RNA copy numbers were approximately 7‐fold lower (brain), 9‐fold lower (kidneys), and 14‐fold lower (liver) than in the control group. The results of this study point to the potentially antiviral effects of aloe vera and licorice extracts in pigeons infected with PPMV‐1. To the best of our knowledge, this is the first study to investigate the antiviral properties of aloe vera and licorice extracts in domestic pigeons.

Application of pigeon circovirus recombinant capsid protein for detecting anti-PiCV antibodies in the sera of asymptomatic domestic pigeons and the potential use of a combination of serological and molecular tests for controlling circovirus infections in pigeon breeding flocks

&NA; The aim of this study was to evaluate the serologic status of domestic pigeons not infected and asymptomatically infected with the pigeon circovirus (PiCV) with the use of an enzyme‐linked assay based on PiCV recombinant capsid protein as a plate antigen. Recombinant PiCV capsid protein was produced by transforming E. coli BL21 (DE3) Rosetta colonies with expression plasmids. Blood samples and cloacal swabs were collected from 171 asymptomatic pigeons. The birds were divided into two groups (infected and not infected with PiCV) based on the results of Sybr Green real time PCR screening for the presence of PiCV genetic material. Approximately 70% of the pigeons tested positive for anti‐PiCV antibodies regardless of their infection status. Antibody levels, the coefficient of variation and standard deviation were significantly higher in the group of infected pigeons. The results indicate that ELISA is a highly useful test that complements molecular methods in evaluations of PiCV infection status in domestic pigeons. The spread of pigeon circovirus infections can be controlled by keeping breeding flocks free of PiCV, which can only be achieved by subjecting birds to real time PCR and serological tests.

Identification of Transmissible Viral Proventriculitis (TVP) in broiler chickens in Poland

The aim of the study was to investigate the possibility of Transmissible Viral Proventriculitis (TVP) occurrence in broiler chickens in Poland. In march 2016 proventriculi samples were collected from broiler chickens showing poor uniformity and decreased body weight, accompanied by enlarged proventriculi. Histopathological examination of affected proventriculi revealed typical lesions associated with TVP (vacuolar degeneration and necrosis of glandular epithelium, replacement of glandular epithelium by hyperplastic ductal epithelium and moderate to severe lymphocytic infiltration). To our best knowledge, up to date there is no report indicating the presence of TVP in Poland nor in Central and Eastern Europe.

Detection of Bordetella avium by TaqMan real-time PCR in tracheal swabs from wildlife birds

Bordetella avium, the causing agent of bordetellosis, a highly contagious infection of the respiratory tract in young poultry, causes significant losses in poultry farming throughout the world. Wildlife birds can be a reservoir of various pathogens that infect farm animals. For this reason the studies were conducted to estimate the prevalence of Bordetella avium in wildlife birds in Poland. Tracheal swab samples were collected from 650 birds representing 27 species. The bacterial DNA was isolated directly from the swabs and screened for Bordetella avium by TaqMan real-time PCR. The assay specificity was evaluated by testing DNA isolated from 8 other bacteria that can be present in avian respiratory tract, and there was no amplification from non-Bordetella avium agents. Test sensitivity was determined by preparing standard tenfold serial dilutions of DNA isolated from positive control. The assay revealed to be sensitive, with detection limit of approximately 4.07x10^2 copies of Bordetella avium DNA. The genetic material of Bordetella avium was found in 54.54% of common pheasants, in 9.09% of Eurasian coots, in 3.22% of black-headed gulls and in 2.77% of mallard ducks. The results of this study point to low prevalence of Bordetella avium infections in wildlife birds. The results also show that described molecular assay proved to be suitable for the rapid diagnosis of bordetellosis in the routine diagnostic laboratory.

Cutaneous Leiomyosarcoma with Multiple Visceral Metastases in a Domestic Pigeon

SUMMARY A clinical examination of a 4-yr-old fantail pigeon revealed a large skin tumor in the area of the left wing. The tumor had solid consistency and a single cavity filled with fluid. During necropsy, multiple tumors of varied size and diameter were found in the liver, spleen, pancreas, and kidneys. A histopathological examination of the skin tumor revealed extensive multifocal neoplasia with a tendency to infiltrate, composed of polygonal, round, oval, and elongated cells forming a solid system with cellular bands and obliteration of intercellular boundaries. Multifocal necrosis was detected in the foci of neoplastic infiltration. Similar foci were present in the liver, pancreas, and lungs. In an immunohistochemical examination, tumor cells tested positive for smooth-muscle actin and vimentin. The diagnosis was cutaneous leiomyosarcoma with an uncommon feature of visceral metastases.

Practical aspects of estimation of optimal time for vaccination of chicken against IBD with use of "Deventer formula".

One of the most commonly applied vaccination strategies against chicken infectious bursal disease (IBD) is the use of live vaccines at the optimal time estimated with the use of Deventer formula. The present study investigated the impact of different factors on maternally derived antibodies decline and therefore on the vaccination schedule against IBD. Our results suggest that blood collection from birds older than 3 days is more reliable in order to estimate the optimal date for IBD vaccination, due to disturbances in yolk sac resorption early after hatch.