Comparison of two commercial ELISA kits for serological monitoring of avian encephalomyelitis in a reproductive turkey flock.

Avian encephalomyelitis (AE) is a viral disease of poultry. Although the disease has a milder clinical course in turkeys than in chickens, reproductive flocks of turkeys are vaccinated against AE. Commercial AE ELISA kits are specifically designed for chickens, which makes it difficult to implement these tests in serological monitoring of turkey flocks. The aim of the study was to compare the AE serological results provided by two ELISA kits from different producers when testing an AE-vaccinated flock of turkey hens and their progeny. We detected differences in the sensitivity of the ELISAs for testing specific anti-AE antibody levels in turkey serum samples.

Relationship between chicken proventricular necrosis virus prevalence and transmissible viral proventriculitis in broiler chickens in Poland.

Transmissible Viral Proventriculitis (TVP) is a disease of chickens which contributes to significant production losses. Recent reports indicate the role of chicken proventricular necrosis virus (CPNV) in the development of TVP. However, the relationship between CPNV and TVP is inconclusive and it has been addressed in just a few reports. Given the above, a study was conducted to identify the relationship between TVP and CPNV prevalence in broiler chickens in Poland. The study was carried out on 35 proventriculi samples sent for histopathological (HP) examination to the Faculty of Veterinary Medicine in Olsztyn between 2017 and 2019. After HP examination, TVP positive samples were processed for CPNV identification by RT-PCR. TVP was the most common pathological condition of proventriculi (23 cases). CPNV was identified in 10 out of those 23 cases. The average HP score, and the average necrosis and infiltration score for CPNV-positive samples was significantly higher than in CPNV-negative ones. The average age of the CPNV-positive chickens was significantly lower than in CPNV-negative birds. Our study confirms the role of CPNV in TVP pathogenesis and it seems that preservation of the proventriculi in the early stages of the disease, when the lesions are more pronounced, should result in a greater probability of CPNV detection.

Evaluation of Lactobacillus spp. and yeast based probiotic (Lavipan) supplementation for the reduction of Salmonella Enteritidis after infection of broiler chickens.

The number of human cases of salmonellosis in the EU was 94,625 in 2015. Considering the source of these infections, Salmonella spp. was most frequently detected in broiler chicken meat and Salmonella Enteritidis (SE) was the most commonly reported serovar. The efficacy of probiotics in limiting Salmonella spp. infection in poultry has been demonstrated in numerous papers. The administration of probiotics at the level of primary production reduces the risk of contamination of poultry food products with Salmonella spp. A study was carried out in order to determine the potential for reducing the Salmonella spp. population in broiler chickens with the use of the Lavipan (JHJ, Poland) probiotic that comprised selected stains of lactic acid bacteria and Saccharomyces cervisae. Salmonella spp.-free broiler chickens were divided into two groups and received the same feed with (group L) or without (group C) the probiotic throughout the experiment. All day-old chickens were infected per os with SE. Samples of cecum content were collected 2, 4, and 6 weeks after SE infection and pectoral muscles were collected 6 weeks following SE infection for the evaluation of the SE population number. Serum samples for serological examinations were collected 6 weeks after infection. Six weeks after infection, the number of SE-positive cecal samples was lower in the L group (12.5% positive) in comparison to the C group (87.5%). Similar results were demonstrated for the muscle samples (25% in contrast to 87.5%). At the same time, in both cases, the SE CFU/g was significantly lower in the L group. The results of our study indicate that Lavipan was capable of reducing the population of SE in the gastrointestinal tract, which eventually improved the hygienic parameters of the pectoral muscles. Four weeks after infection, SE was not detected in any of the experimental groups. In both groups, no specific anti-SE antibodies were detected.

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

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.

Differentiation of infectious bronchitis virus vaccine strains Ma5 and 4/91 by TaqMan real-time PCR.

The aim of this study was to develop rapid molecular assays for differentiating vaccine strains Ma5 and 4/91 of the infectious bronchitis virus (IBV). Specific primers and probes for S1 and N genes were designed based on the nucleotide sequences of both vaccine strains. Cross-reactivity was not observed. Assay sensitivity was 2.373 × 103 copies of the Ma5 strain, and 3.852 x 103 copies of the 4/91 strain. Samples belonging to a known genotype demonstrated that the designed assays supported rapid and sensitive detection of Ma5 and 4/91 vaccine strains of IBV.

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.

Three-step Anti-aMPV IgA Expression Profile Evaluation in Turkeys of Different Immunological Status after TRT Vaccination.

Maternally derived antibodies (MDA) don not protect turkeys against rhinotracheitis (TRT) but high MDA influences upper respiratory tract (URT) immunity stimulation after avian Metapneumovirus (aMPV) vaccination. Humoral immunity can not be considered as an indicator of protection against TRT, but specific antibodies inhibit aMPV replication and alleviate the course of TRT. Scarce reports indicate the role of IgA in protection against TRT. The aim of our study was to investigate the impact of MDA on stimulation, antigen specificity acquisition of B lymphocytes, and the production of specific IgA after TRT vaccination of turkeys. The results of our study indicate that MDA on the day of TRT vaccination causes disturbances at different levels of specific humoral immunity expression including antigen specificity acquisition of B IgA+ lymphocytes as well as production and secretion of IgA. Vaccine immunity against aMPV associated with sIgA is well expressed in birds not possessing MDA on the day of TRT vaccination, whereas it is inhibited in MDA+ birds. These results corroborate our previous findings and indicate that MDA could be responsible for TRT vaccination failure. These findings could explain the observed frequency of TRT field outbreaks despite aMPV vaccination of turkey flocks.

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.

Valence and lowest Rydberg electronic states of phenol investigated by synchrotron radiation and theoretical methods.

We present the experimental high-resolution vacuum ultraviolet (VUV) photoabsorption spectra of phenol covering for the first time the full 4.3-10.8 eV energy-range, with absolute cross sections determined. Theoretical calculations on the vertical excitation energies and oscillator strengths were performed using time-dependent density functional theory and the equation-of-motion coupled cluster method restricted to single and double excitations level. These have been used in the assignment of valence and Rydberg transitions of the phenol molecule. The VUV spectrum reveals several new features not previously reported in the literature, with particular reference to the 6.401 eV transition, which is here assigned to the 3sσ/σ(∗)(OH)←3π(3a″) transition. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of phenol in the earth's atmosphere (0-50 km).

Dissociative electron attachment to the radiosensitizing chemotherapeutic agent hydroxyurea.

Dissociative electron attachment to hydroxyurea was studied in the gas phase for electron energies ranging from zero to 9 eV in order to probe its radiosensitizing capabilities. The experiments were carried out using a hemispherical electron monochromator coupled with a quadrupole mass spectrometer. Diversified fragmentation of hydroxyurea was observed upon low energy electron attachment and here we highlight the major dissociation channels. Moreover, thermodynamic thresholds for various fragmentation reactions are reported to support the discussion of the experimental findings. The dominant dissociation channel, which was observed over a broad range of energies, is associated with formation of NCO(-), water, and the amidogen (NH2) radical. The second and third most dominant dissociation channels are associated with formation of NCNH(-) and NHCONH2 (-), respectively, which are both directly related to formation of the highly reactive hydroxyl radical. Other ions observed with significant abundance in the mass spectra were NH2 (-)/O(-), OH(-), CN(-), HNOH(-), NCONH2 (-), and ONHCONH2 (-).

Epidemiological situation of turkey coryza (bordetellosis) in Poland.

The present study investigated the prevalence of Bordetella avium (BA) infections in turkey flocks of different production type in Poland, based on serological examination of blood samples collected between 2012 and 2014. The results of our study indicate that BA infections are very common in turkey flocks, they are possible during the whole production cycle and that probability of the past infection increases with age. This situation is causing high level of specific anti-BA maternally derived antibody transfer to hatching poults.

Valence and Ionic Lowest-Lying Electronic States of Isobutyl Formate Studied by High-Resolution Vacuum Ultraviolet Photoabsorption, Photoelectron Spectroscopy, and Ab Initio Calculations.

The highest resolution vacuum ultraviolet photoabsorption spectrum of isobutyl formate, C5H10O2, yet reported is presented over the energy range 4.5-10.7 eV (275.5-118.0 nm) revealing several new spectral features. Valence and Rydberg transitions and their associated vibronic series observed in the photoabsorption spectrum have been assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. Calculations have also been carried out to determine the ionization energies and fine structure of the lowest ionic state of isobutyl formate and are compared with a newly recorded photoelectron spectrum (from 9.0 to 27.0 eV). The value of the first ionization energy was determined to be 10.508 eV (adiabatic) and 10.837 eV (vertical). New vibrational structure is observed in the first photoelectron band, predominantly resulting from C-O and C═O stretches of the molecule. The photoabsorption cross sections have been used to calculate the photolysis lifetime of isobutyl formate in the upper stratosphere (20-50 km), indicating that the hydroxyl radical processes will be the main loss process for isobutyl formate.

Valence and ionic lowest-lying electronic states of ethyl formate as studied by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy, and ab initio calculations.

The highest resolution vacuum ultraviolet photoabsorption spectrum of ethyl formate, C2H5OCHO, yet reported is presented over the wavelength range 115.0-275.5 nm (10.75-4.5 eV) revealing several new spectral features. Valence and Rydberg transitions and their associated vibronic series, observed in the photoabsorption spectrum, have been assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. Calculations have also been carried out to determine the ionization energies and fine structure of the lowest ionic state of ethyl formate and are compared with a newly recorded He(I) photoelectron spectrum (from 10.1 to 16.1 eV). New vibrational structure is observed in the first photoelectron band. The photoabsorption cross sections have been used to calculate the photolysis lifetime of ethyl formate in the upper stratosphere (20-50 km).

Effect of whole wheat feeding on selected immune parameters in growing male turkeys.

The objective of this study was to determine the effect of whole wheat feeding on selected parameters of humoral and cell-mediated immunity in growing turkeys. A total of 210 one-day-old heavy-type Hybrid Converter male turkeys were randomly divided into three different dietary treatment groups, each consisting of 7 replicate pens of 10 birds per pen. Until 4 wk of age, all birds were fed a commercial diet formulated to meet nutrient requirements. From 5 to 12 wk of age, diets were composed of wheat (ground-pelleted or whole grain) and protein-fat-mineral-vitamin concentrate. The total wheat concentration in diets was 500 or 600 g/kg in the feeding periods of 5-8 and 9-12 wk of birds' age, respectively. Whole grain wheat had a 0, 50 or 100% share of the total wheat amount in the daily ration in treatment groups W0, W50 or W100, respectively. Commercial vaccines against ND (Newcastle disease) and TRT (Turkey rhinotracheitis) were administered to turkeys via the drinking water on days 20 and 30, respectively. Over the entire experiment, a significant linear decrease was observed in body weight gains (BWG) with increasing dietary levels of whole grain wheat. As a result the BWG of control turkeys (W0) were significantly higher than the BWG of group W100 birds (P = 0.002). A significant linear increase in feed conversion ratio (FCR) was observed with increasing dietary levels of whole grain wheat (P < 0.001). The levels of antibodies against TRT and ND viruses after immunization were significantly higher in both the W50 and W100 group, in comparison to group W0 (P = 0.006 and P = 0.001, respectively). Turkeys from group W50, in comparison to those from groups W0 and W100, had a significantly higher percentage of CD4+ T cell subpopulation within the lymphocytes isolated from blood and ileal mucosa, as well as CD4+ CD8+ and CD8+ T cell subpopulations within the blood immunocompetent cells (P = 0.022, P = 0.029, P = 0.009 and P = 0.011, respectively). In the cecal tonsils, the percentage of CD8+ T cell subpopulation was significantly lower in group W50 than in groups W0 and W100 (P = 0.014). The results of our study indicate that diluting diets with whole grain wheat stimulates the non-specific cell-mediated defense mechanisms of the gastrointestinal immune system in turkeys, thus positively affecting humoral response after vaccination.

Antimicrobial resistance in bacteria isolated from pigeons in Poland.

The present study investigated the drug-resistance to the selected antibiotics in Escherichia coli, Salmonella typhimurium and beta-haemolytic coagulase-positive staphylococci isolated from pigeons bred in Poland. In the case of E. coli, tetracyclines and amoxicillin were least effective. In the staphylococci, the highest resistance was detected for oxytetracycline and quinolones and 5% were resistant to methicillin. The lowest drug-resistance was reported for Salmonella typhimurium.

Epidemiological investigation of selected pigeon viral infections in Poland.

Due to a lack of data in regard to the spread of viral infections in Polish pigeon populations, studies were undertaken to assess the frequency of adeno-, circo- and herpesvirus infections in flocks of pigeons across the entire country. In total, 107 flocks were examined, of which 61 per cent consisted of racing and 39 per cent of fancy pigeons. The flocks were divided into groups according to breed (racing and fancy pigeons) as well as physical condition (healthy and sick). In the studied pigeon flocks, the pigeon circovirus (PiCV) genetic material was the most frequently detected (44.5-100 per cent depending on the group), pigeon herpesvirus genetic material was second in frequency (0-30 per cent depending on the group), while genetic material of pigeon adenovirus was found only in two flocks of young birds with clinical symptoms of Young Pigeon Disease Syndrome (YPDS). The presence of fowl adenovirus (FAdV) genetic material was not detected in any of the studied flocks. Results obtained demonstrate a wide spread of circovirus in pigeon flocks in Poland, and substantiate earlier theories proposed by other authors, that immunosuppression evoked by PiCV infection is one of the main causative agents of YPDS.

Effect of infection of turkeys with haemorrhagic enteritis adenovirus isolate on the selected parameters of cellular immunity and the course of colibacillosis.

The aim of the study was to determine the effect of a Polish low-virulence isolate of haemorrhagic enteritis adenovirus (HEV) on the immune system in turkeys and on the course of colibacillosis in birds infected under laboratory conditions. Turkeys were infected per os with HEV at the dose of 10(4.3)EID50/mL and with E. coli (APEC) (serotypes 078:K80:H9) at the dose of 4x10(9)CFU/mL by injection to the thoracic air sac. The birds infected with the HEV were infected with the APEC either simultaneously or after 5 days. Five days after HEV infection, the percentages of subpopulations of the CD3+CD4+ and CD3+CD8alpha+ T cells and the IgM+ B cells were determined in blood and spleens of the HEV-infected turkeys and in the control (uninfected) birds. The course of colibacillosis was more severe in turkeys infected with the APEC 5 days after infection with the HEV than in those infected with the HEV and APEC simultaneously and than in those infected only with APEC. Five turkeys out of the 18 infected with the APEC 5 days after infection with HEV, died. Their body weights were statistically significantly lower with higher FCR values 41 days after the infection in comparison to turkeys in the other groups. A considerable decrease in the percentage of the T and B cells subpopulations in the blood were found in turkeys infected with the HEV and while the percentage of CD3+CD4+ T cells subpopulation in the spleen increased significantly, the contribution of the CD3+CD8alpha+ T cells and IgM+ B cells subpopulations were decreased. These changes in the immune system of turkeys, occurring 5 days after infection with the HEV, made them more susceptible to infection with the APEC.

The perspective of immunoprophylaxis and selected immunological issues in the course of the turkey rhinotracheitis.

This review article presents immunological issues in the course of the turkey rhinotracheitis (TRT) emphasizing local immunity mechanisms, both humoral and cell-mediated, in the upper respiratory system. Studies on the influence of the humoral immunity in the course of infection and vaccinations against TRT have revealed many times the absence of correlation between the titre of specific IgY anti-aMPV (avian Metapneumovirus) antibodies in the serum and in the upper respiratory washings and the immunity against the occurrence of the clinical form of the TRT. Considering the above, T cells are increasingly often regarded as the main factor involved in the upper respiratory immunity against the TRT. However, there have been just a few reports on the role of the T cells in the local immunity processes in the infection with aMPV in turkeys. Additionally, studies of the T-cell-associated immunity against the TRT have given ambiguous results. Immunoprophylaxis issues against the aMPV infections are a significant part of the work where the authors confront current vaccination programmes against the perspectives of use of the future vaccines against the TRT. Future vaccines should face the following criteria: absence of the risk of immunosuppressive effect and reversion of vaccine strains virulence, ease-of-use combined with the possibility of administration of the vaccine to the large numbers of turkeys. The leading role in future vaccination programs for birds against the TRT is likely to be played by the in ovo technique and the recombinant vaccines. Great hopes are also linked with the development of subunit vaccines against the aMPV.

Limonene: electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, electron scattering, He(I) photoelectron spectroscopy and ab initio calculations.

Electronic state spectroscopy of limonene has been investigated using vacuum ultraviolet photoabsorption spectroscopy in the energy range 5.0-10.8 eV. The availability of a high resolution photon beam (~0.075 nm) enabled detailed analysis of the vibrational progressions and allowed us to propose, for the first time, new assignments for several Rydberg series. Excited states located in the 7.5-8.4 eV region have been studied for the first time. A He(I) photoelectron spectrum has also been recorded from 8.2 to 9.5 eV and compared to previous low resolution works. A new value of 8.521 ± 0.002 eV for the ground ionic state adiabatic ionisation energy is proposed. Absolute photoabsorption cross sections were derived in the 10-26 eV range from electron scattering data. All spectra presented in this paper represent the highest resolution data yet reported for limonene. These experiments are complemented by new ab initio calculations performed for the three most abundant conformational isomers of limonene, which we then used in the assignment of the spectral bands.