Yolkin, a Polypeptide Complex from Egg Yolk, Affects Cytokine Levels and Leukocyte Populations in Broiler Chicken Blood and Lymphoid Organs after In Ovo Administration.

Yolkin is a polypeptide complex isolated from hen egg yolk that exhibits immunomodulating properties. The aim of the present study was to determine whether in-ovo-delivered yolkin affects leukocyte populations and cytokine levels in broiler chickens. The experiment was carried out on eggs from Ross 308 broiler breeder birds. Yolkin was administered in ovo on the 18th day of incubation, once, at the following three doses: 1, 10, or 100 µg/egg. The immunological parameters were assessed in 1-, 7-, 14-, 21-, 28-, 35-, and 42-day-old birds kept under farming conditions and routinely vaccinated. The leukocyte populations were determined in the thymus, spleen, and blood. The cytokine (IL-1ß, IL-2, IL-6, and IL-10) levels were determined in the plasma of the broiler chickens. Each experimental group included eight birds. The most pronounced effect of yolkin was an increase in the population of T cells, both CD4+ and CD8+, mainly in the blood. This effect on the lymphocyte subsets may be valuable regarding chicken immune responses, mainly against T-dependent antigens, during infection or after vaccination.

The influence of age and body weight gain on enrofloxacin pharmacokinetics in turkeys-Allometric approach to dose optimization.

Enrofloxacin is a concentration-dependent antimicrobial used in bacterial infections in poultry. During a few months of a turkey's life, pharmacokinetics of drugs undergoes substantial changes which may compromise their efficacy due to variability in internal exposure (measured by area under the concentration-time curve, AUC). The aim of this study was to describe the effects of age on the pharmacokinetics of a single intravenous (i.v.) and oral administration of enrofloxacin at a dose of 10 mg/kg to turkeys. It was found that during a 2.5-month-long period of growth from 1.4 to 14.6 kg, the AUC after i.v. administration increased almost threefold due to a significant decrease in the body clearance (from a mean of 0.76-0.28 L hr-1  kg-1 ). Over the same period, the mean elimination half-life was prolonged from 2.65 to 7.03 hr. Oral administration resulted in a similar trend in pharmacokinetic parameters. For both routes, formation of the major metabolite, ciprofloxacin, was marginal. Protein binding was not age-dependent and never exceeded 50%. Body clearance, volume of distribution and elimination half-life were subjected to an allometric analysis and a novel, nonlinear dosage protocol has been proposed to improve the internal exposure to the drug in different age groups of turkeys.

PssJ Is a Terminal Galactosyltransferase Involved in the Assembly of the Exopolysaccharide Subunit in Rhizobium Leguminosarum bv. Trifolii.

Rhizobium leguminosarum bv. trifolii produces exopolysaccharide (EPS) composed of glucose, glucuronic acid, and galactose residues at a molar ratio 5:2:1. A majority of genes involved in the synthesis, modification, and export of exopolysaccharide are located in the chromosomal Pss-I region. In the present study, a ΔpssJ deletion mutant was constructed and shown to produce EPS lacking terminal galactose in the side chain of the octasaccharide subunit. The lack of galactose did not block EPS subunit translocation and polymerization. The in trans delivery of the pssJ gene restored the production of galactose-containing exopolysaccharide. The mutant was compromised in several physiological traits, e.g., motility and biofilm production. An impact of the pssJ mutation and changed EPS structure on the symbiotic performance was observed as improper signaling at the stage of molecular recognition, leading to formation of a significant number of non-infected empty nodules. Terminal galactosyltransferase PssJ was shown to display a structure typical for the GT-A class of glycosyltransferases and interact with other GTs and Wzx/Wzy system proteins. The latter, together with PssJ presence in soluble and membrane protein fractions indicated that the protein plays its role at the inner membrane interface and as a component of a larger complex.

Method for generation of peptide-specific IgY antibodies directed to Staphylococcus aureus extracellular fibrinogen binding protein epitope.

The IgY antibodies offer an attractive alternative to mammalian IgGs in research, diagnosis and medicine. The isolation of immunoglobulin Y from the egg yolks is efficient and economical, causing minimal suffering to animals. Here we present the methodology for the production of IgY antibodies specific to Staphylococcus aureus fibrinogen binding protein (Efb) and its peptidyl epitope (spanning residues 127-140). The Efb is an extracellular, adhesion protein which binds both human fibrinogen and complement C3 protein thus contributing to the high infectious potential of this pathogen. The selected epitope of Efb protein is responsible for the interaction with C3. The immunochemical characterization of both anti-Efb and epitope-specific IgY antibodies revealed their similar avidity, titer, and reactivity profile, although some differences in the hen's immune response to administered antigens is discussed.

Erysipelas Outbreaks in Flocks of Geese in Poland--Biochemical and Genetic Analyses of the Isolates.

Erysipelothrix rhusiopathiae causes erysipelas in many vertebrate species. Severe disease outbreaks have been noted in many poultry species--chickens, ducks, emus, pheasants, pigeons, and geese. This article describes the biochemical and genetic analyses of six E. rhusiopathiae strains isolated from geese for meat production. The isolates came from birds kept in different poultry houses on one farm, and were collected during two erysipelas outbreaks. We analyzed and compared the isolates by random amplified polymorphic DNA with the use of NK6 primer and pulsed-field gel electrophoresis, with the restriction enzyme SmaI. Biochemical examination was performed with API Coryne test. Analyses showed that the three strains isolated during the first outbreak differed, whereas the three isolates from the second outbreak were identical to one another, but distinct from the isolates from the first outbreak. The results of biochemical and genetic analyses of E. rhusiopathiae strains isolated from geese suggest different sources of infection for the erysipelas outbreaks.

Synthesis of novel phosphonic-type activity-based probes for neutrophil serine proteases and their application in spleen lysates of different organisms.

Neutrophils are a type of granulocyte important in the "first line of defense" of the innate immune system. Upon activation, they facilitate the destruction of invading microorganisms by the production of superoxide radicals, as well as the release of the enzymatic contents of their lysozymes. These enzymes include specific serine proteases: cathepsin G, neutrophil elastase, proteinase 3, as well as the recently discovered neutrophil serine protease 4 (NSP4). Under normal conditions, the proteolytic activity of neutrophil proteases is tightly regulated by endogenous serpins; however, this mechanism can be subverted during tissue stress, thereby resulting in the uncontrolled activity of serine proteases, which induce chronic inflammation and subsequent pathology. Herein, we describe the development of low-molecular-weight activity-based probes that specifically target the active sites of neutrophil proteases.

Hemorrhagic nephritis and enteritis in a goose flock in Poland--disease course analysis and characterization of etiologic agent.

Hemorrhagic nephritis enteritis of geese (HNEG) is an epizootic viral disease caused by infection with goose hemorrhagic polyomavirus (GHPV) that affects domestic geese. This study describes the epizootic analysis, laboratory diagnosis, and molecular characterization of GHPV isolates associated with HNEG cases in Poland. HNEG symptoms persisted in infected flocks for 2 wk with a 32% mortality rate. Primary gross lesions included hemorrhaging of the kidneys, intestines, and lungs. Histopathologic examination confirmed HNEG and identified that the causative agent was similar to other GHPV isolates and identical to the Toulouse 2008 isolate.

Impact of early posthatch feeding on the immune system and selected hematological, biochemical, and hormonal parameters in broiler chickens.

Under commercial conditions, chicks hatch within a 24 to 48 h window, a period known as the hatching window. Subsequently, they undergo various treatments before finally being transported to the broiler farm. These procedures may delay the chicks' access to food and water, sometimes receiving them as late as 72 h after hatching. Previous studies have indicated that fasting during this initial period is detrimental, leading to impaired body growth, compromised immune system response, and hindered muscle development. The objective of this study was to assess the impact of early posthatch feeding on immune system organs and selected hematological, biochemical, and hormonal parameters. The experiment utilized Ross 308 broiler eggs incubated under typical commercial hatchery conditions. The experimental group's eggs were hatched in HatchCare hatchers (HC) with immediate access to feed and water, while the control group's eggs were hatched under standard conditions (ST). Thirty chickens from each group were assessed on the 1st (D1), 7th (D7), 21st (D21), and 35th (D35) day after hatching. On D1, the HC group exhibited lower hemoglobin, hematocrit, and total serum protein values, suggesting that early access to water prevents initial dehydration in newborn chicks. Conversely, the ST group showed a stress reaction on D1 due to feed deprivation, leading to an almost 2-fold higher serum corticosterone concentration compared to the HC group. However, this increase did not result in a significant change in the heterophil/lymphocyte ratio. Furthermore, the HC group displayed an increase in triglyceride concentration and a decrease in HDL concentration on D1. On D7, the HC group exhibited an increased relative weight of the bursa and a higher CD4+ cell number in the cecal tonsil (CT), indicating a more rapid development of these organs resulting from early stimulation of the gastrointestinal tract. However, early feeding did not influence the numbers of Bu-1+, CD4+, and CD8+ cells or the germinal center (GC) areas in the spleen. In conclusion, early feeding contributes to the welfare of newborn chicks by reducing dehydration and stress levels and stimulating the development of gut-associated lymphoid tissue.

Antimicrobial Resistance of Erysipelothrix rhusiopathiae Strains Isolated from Geese to Antimicrobials Widely Used in Veterinary Medicine.

The aim of this study was to determine the antibiotic resistance of E. rhusiopathiae when isolated from clinical outbreaks of erysipelas in geese to antimicrobials commonly used in poultry production. All isolates were susceptible to amoxicillin alone or with clavulanic acid, with MIC values ranging from 0.016 to 0.125 µg/mL. Ninety-six percent of isolates were fully sensitive to penicillin G (MIC 0.125-0.5 µg/mL). All isolates were fully or moderately sensitive to erythromycin (MIC 0.125-0.5 µg/mL). Most E. rhusiopathiae isolates proved resistant to fluoroquinolones (76.6% of isolates were resistant to enrofloxacin, with MIC values ranging from 0.064 to 32 µg/mL, and 68% were resistant to norfloxacin, with MIC values ranging from 0.094 to 96 µg/mL), and tetracyclines (61.7% of isolates were resistant to doxycycline, with MIC values ranging from 0.25 to 64 µg/mL, and 63.8% were resistant to tetracycline, with MIC values ranging from 0.38 to 256 µg/mL). Point mutations in the gyrA gene (responsible for fluoroquinolone resistance) and the presence of the tetM gene (responsible for tetracycline resistance) were noted in most of the resistant isolates. Multidrug resistance, defined as resistance to at least one substance in three or more antimicrobial classes, was not observed.

Prevalence of Blastocystis in Geese Reproductive Flocks.

Blastocystis is a unicellular, anaerobic protozoan that has a low specificity for the hosts, and it could be a zoonosis. There are not many data about the occurrence of Blastocystis in bird species, and this study aimed to check the prevalence of Blastocystis infection in reproductive geese flocks. The result obtained showed that a parasite was present in 46.5% of tested flocks. The extensiveness of the Blastocystis invasion in reproductive geese flocks was low because the genetic material of parasites was found only in 7.48% of samples. There was no correlation between the infection and the bird's age or the flock size. The data obtained showed that geese could be the source of infections in humans who have contact with carriers of the infection.

Molecular Analysis of the Heterakis dispar Population in Domestic Geese Based on the ITS1-5.8rRNA-ITS2 Fragment.

Heterakidosis is a parasitic infection in birds caused by the cecal parasite Heterakis spp. The most common species in geese is H. dispar, the largest avian heterakids species. Because of a scarcity of data concerning the H. dispar population, the aim of this study was the genetic analysis of Heterakis dispar isolated from geese flocks based on the ITS1-5.8rRNA-ITS2 fragment. Among the 71 H. dispar specimens isolated from 20 geese flocks, six haplotypes were determined (A, B, C, D, E, and F). The four nucleotide substitutions were noted in both ITS fragments, and all of them were transitions between adenine and guanine, or thymine and cytosine. The most frequently noted haplotype was type A (45%), followed by type B (18.3%), type C and D (11.3%), type E (8.5%), and F (5.6%). Infection with nematodes from different haplotype groups was noted in 30% of the flocks, with type A being the most prevalent, followed by types B, D, or E to make up 100%. This study represents the first H. dispar population analysis based on the ITS1-5.8rRNA-ITS2 fragment.

Early Post-Hatch Nutrition Influences Performance and Muscle Growth in Broiler Chickens.

The poultry industry is under pressure to produce safe and good quality meat in the welfare conditions. Many areas such as genetics, biosecurity, and immunoprophylaxis were improved, and hatchery is one of the areas in which welfare could be improved for better production output. The aim of the study was to investigate the effect of early post-hatch nutrition providing body weight and muscle development in broiler chickens. The experiment involving two groups (chicken hatched with access to water and feed in the hatcher, and chicken without feed and water in hatcher) was replicated three times, and the body weights and breast-muscle index of the randomly chosen 30 chickens per group in each term were measured on the 1st, 7th, 21st, and 35th day of life. The breast-muscle sample was taken for genetic examination (the expression of the myoD, myoG, and MRF4 genes) and histological examination. The results showed that the positive effect of early nutrition was observed on the seventh day of bird life with higher expression of myoG and MRF4 and higher body weight of the birds. The positive effect of early nutrition on the diameter of the breast-muscle fibers was visible on days 21 and 35 of chicken life. The average final body weight in groups with early access to food and water was 5% higher than in groups hatched under classic conditions. Conclusions: early feeding in the hatcher improves performance and muscle growth in broiler chickens.

Tetratrichomoniasis in the Geese Flock-Case Report.

Infections caused by tetratrichomonas are commonly observed in geese. Most cases are subclinical, and the clinical form of the disease manifests itself with a greater mortality and the presence of caseous content in ceca. We describe the case of tetratrichomoniasis in a geese flock caused by Tetratrichomonas gallinarum, with the genetic analysis of the isolate being based on the fragments of 18SrRNA and ITS1-5.8rRNA-ITS2.

Biomechanics of esophageal elongation with traction sutures on experimental animal model.

Esophageal elongation is one of the methods of long gap esophageal atresia treatment. The aim of the study was to determine the best type of traction suture for esophageal lengthening on an animal model. White Pekin Duck's esophagi were used as a model (fresh-frozen and thawed). The esophagus was cut in half, then both ends were sutured together and extended on a tensiometer. Tested sutures involved simple suture, suture aided by a single or double clip, and suture aided by pledget (10 samples each). Constant and 2 methods of intermittent traction were also compared. The histological study showed similarities between duck's and newborn's esophagus. The highest maximal force was achieved with pledget suture (F = 8.59 N ± 1.45 N), then with double clip (F = 5.74 N ± 1.29 N) and the lowest with single suture (F = 3.80 N ± 0.54 N) (p < 0.001). Pledget suture also allowed for the greatest elongation (p < 0.01). Intermittent traction results in better elongation at the same breaking strength as constant traction (p < 0.05) if traction is maintained during breaks. Reinforced sutures (pledget or double clip) should be taken into consideration in internal traction. When performing traction sutures, it is worth step by step carefully tightening the sliding knot in short periods before its final binding.

Uncommon Non-Candida Yeasts in Healthy Turkeys-Antimicrobial Susceptibility and Biochemical Characteristic of Trichosporon Isolates.

The microbiota of the gastrointestinal tract of humans and animals is inhabited by a diverse community of bacteria, fungi, protozoa, and viruses. In cases where there is an imbalance in the normal microflora or an immunosuppression on the part of the host, these opportunistic microorganisms can cause severe infections. The study presented here evaluates the biochemical and antifungal susceptibility features of Trichosporon spp., uncommon non-Candida strains isolated from the gastrointestinal tract of healthy turkeys. The Trichosporon coremiiforme and Trichosporon (Apiotrichum) montevideense accounted for 7.7% of all fungi isolates. The biochemical tests showed that Trichosporon coremiiforme had active esterase (C4), esterase-lipase (C8) valine arylamidase, naphthol-AS-BI phosphohydrolase, α-galactosidase, and ß-glucosidase. Likewise, Trichosporon montevideense demonstrated esterase-lipase (C8), lipase (C14), valine arylamidase, naphthol-AS-BI phosphohydrolase, α-galactosidase, and ß-glucosidase activity. T.coremiiforme and T. monteviidense isolated from turkeys were itraconazole resistant and amphotericin B, fluconazole, and voriconazole susceptible. Compared with human isolates, the MIC range and MIC values of turkey isolates to itraconazole were in a higher range limit in both species, while MIC values to amphotericin B, fluconazole, and voriconazole were in a lower range limit. Furthermore, the obtained ITS1-5.8rRNA-ITS2 fragment sequences were identical with T. coremiiforme and T. montevideense sequences isolated from humans indicating that these isolates are shared pathogens.

Tylosin Dosage Adjustment Based on Allometric Scaling in Male Turkeys.

Turkeys' body weight (BW) increases 10-fold within only 2.5 months, leading to a change in the pharmacokinetics (PK) of drugs according to allometric principles. Thus, the same dosage may lead to age-dependent variability in efficacy, in particular, to treatment failure and/or selection for resistance. The study aimed to investigate whether a non-linear dosage based on a published allometric model for tylosin clearance, may optimize the internal exposure in growing turkeys. The single dose PK study was performed on turkeys aged 6, 9.5, 13 and 17 weeks (BW from 1.75 kg to 15.75 kg). Tylosin was administered intravenously (i.v.) or orally (p.o.) according to following protocols: Dose = 31.6 × BW0.58 or Dose = 158 × BW0.58, respectively. Plasma tylosin was measured using high-performance liquid chromatography and non-compartmental PK analysis was performed. The area under the curve (AUClast) after i.v. administration was 8.90 ± 1.01; 7.51 ± 1.11; 6.54 ± 1.20 and 8.01 ± 1.75 mg × h/L in 6-; 9.5-; 13- and 17-week-old turkeys, respectively. After p.o. administration AUClast was 4.80 ± 2.92; 4.60 ± 2.45; 3.00 ± 1.49 and 3.24 ± 2.00 mg × h/L in respective age groups indicating high variability. For i.v. administration, the non-linear dosage allowed to minimize the age-dependent variability in AUC. However, due to low oral bioavailability (8-12%) and resulting interindividual variability, the proposed approach may not improve tylosin efficacy in turkeys under farm conditions.

Prevalence of Heterakis Infection in Parental Flocks of Geese.

The prevalence of Heterakis infection in reproductive geese from 56 flocks was investigated between February 2015 and November 2019 by using both anatomopathologic and coproscopic examinations. The nematodes were microscopically examined, and 37.5% (21/56) of the flocks were infected with Heterakis nematodes, mostly with Heterakis dispar (35.7%). In one particular flock, a Heterakis gallinarum infection was noted. In two flocks, Heterakis infection was identified only during coproscopic examination. The infection susceptibility of the geese depended on the bird's age-in the first reproductive season, 50% of the flocks were positive; in the second season, 42% were positive; and in the third season, 30% were positive. The number of nematodes in each necropsied goose varied from 8 to 216 individuals. During the 5 years of epidemiologic analysis, the infection occurrence decreased from 66.7% to 11%.

E-test Determination of Antifungal Susceptibility of Candida Species Isolated from Turkeys.

INTRODUCTION: Candida species are a natural component of the intestinal tract microflora, but in favourable conditions they can cause superficial, mucosal, or even systemic candidiasis. Poultry production might be a source of human drug-resistant yeast infections, including Candida spp. The limited data concerning the antifungal susceptibility of poultry Candida isolates prompted us to carry out research to determine the susceptibility of isolates from turkey intestinal tracts. METHOD AND MATERIALS: The beak cavity, crop and cloaca were swabbed of 580 turkeys from 58 flocks in western Poland. The susceptibility tests were conducted using the E-test method with amphotericin B, fluconazole, itraconazole, and voriconazole on 52 isolates of C. albicans, C. catenulata, C. glabrata, C. palmioleophila, C. rugosa, C. krusei and C. lusitaniae. RESULTS: All isolates were susceptible to voriconazole. According to the MIC values obtained for amphotericin B and fluconazole, all Candida spp. isolates were classified as susceptible according to the described breakpoints except for C. krusei, which was the only isolate that was amphotericin B-, fluconazole- and itraconazole-resistant. The susceptibility to itraconazole varied: 11 of the Candida isolates were susceptible (21.1%), 29 were dose-dependently susceptible (55.8%), and 12 isolates were resistant (23.1%). CONCLUSION: There are few resistant strains of Candida in turkeys, and the drug resistance varies. When Candida passes from turkeys to humans, there is a wide range of antifungal treatment options.

The Prevalence of Tetratrichomonas spp. in Reproductive Geese Flocks.

Tetratrichomonas is a genus of parasites that usually inhabits the lower digestive tract, especially the cecum, of various bird species. The infection might lead to birds' death, but in many cases it could be asymptomatic or with mild clinical signs which might be not observed. Subclinical infections can be undiagnosed, leading to production losses. To investigate the prevalence of Tetratrichomonas spp. in geese, 23 cloacal swabs were taken from each of 43 flocks of reproductive geese from five major geese production provinces in Poland after first, second, or third laying season. The obtained swabs were placed in culture medium for propagation of the parasite. All cultures were screened microscopically before PCR was applied to detect the parasites' DNA. After cultivation, the presence of genetic material of Tetratrichomonas was found in 430 out of 989 samples, which correspond to 38 (88.4%) of 43 flocks. The study shows how the number of laying seasons and the size of the flock in which the birds were kept affects the distribution of protozoa of the genus Tetratrichomonas in geese reproductive flocks in Poland.

Allometric Optimization of Enrofloxacin Dosage in Growing Male Turkeys: Empirical Evidence for Improved Internal Exposure.

Rapid weight gain in turkeys causes a major change in the pharmacokinetics of drugs, leading to age-dependent variability in the internal exposure and, possibly, treatment failure and/or selection for antimicrobial resistance in young individuals. The aim of the study was to investigate whether a non-linear dosing protocol that accounts for the previously established allometric relation between enrofloxacin clearance and body weight (BW) may optimize the internal exposure to enrofloxacin in growing male turkeys. Enrofloxacin was administered four times, between the age of 5 and 16.5 weeks, when the turkeys' BW increased from 1.47 to 14.92 kg. Enrofloxacin was given intravenously (i.v.) or orally at the dose calculated as follows: Dose = 30 × BW0.59. After i.v. administration, the internal exposure to the drug-quantified as the area under the concentration-time curve (AUC)-was showing little age-related variation. The coefficient of variation (CV) for AUC in all individuals (15.7%) was only slightly higher than within the age groups (5.4-13.7%). After oral drug administration, CV for AUC in all individuals (22.1%) was similar as within the age groups (8.7-32.2%). These results show that intra-species allometric scaling may be efficiently implemented in the non-linear approach to enrofloxacin dosage in turkeys in order to obtain a precise internal exposure for the optimal antimicrobial effect.