Studies on parasitic prevalence in pet birds from Punjab, Pakistan / Estudos de prevalência parasítica em pássaros de estimação de Punjab, Paquistão

During this one year study, blood and fecal samples of doves (Zenaida asiatica), ducks (Anas platyrhynchos), pigeons (Columba livia), partridges (Alectoris chukar), turkeys (Meleagris gallopavo) and goose (Chen caerulescens) were collected to assess the parasitic prevalence in these birds. The birds were kept at Avian Conservation and Research Center, Department of Wildlife and Ecology, University of Veterinary and Animal Sciences, Lahore. All these avian species were kept in separate cages and their entire body was inspected on regularly basis to record external parasites. For internal parasites, 100 blood and 100 fecal samples for each species were analyzed. During present study, two species of ectoparasites i.e. fowl ticks (Args persicus) and mite (Dermanyssus gallinae) while 17 species of endoparasites; three from blood and 14 from fecal samples were identified. Prevalence of blood parasites was Plasmodium juxtanucleare 29.3%, Aegyptinella pullorum 15% and Leucoctoyzoon simond 13%. Parasitic species recorded from fecal samples included 6 species of nematodes viz. Syngamus trachea with parasitic prevalence of 50%, Capillaria anatis 40%, Capillaria annulata 37.5%, Heterakis gallinarum 28.3%, Ascardia galli 24% and Allodpa suctoria 2%. Similarly, two species of trematodes viz. Prosthogonimus ovatus having parasitic prevalence of 12.1% and Prosthogonimus macrorchis 9.1% were also recorded from fecal samples of the birds. Single cestode species Raillietina echinobothrida having parasitic prevalence of 27% and 3 protozoan species i.e. Eimeria maxima having prevalence 20.1%, Histomonas meleagridis 8% and Giardia lamblia 5.3% were recorded. In our recommendation, proper medication and sanitation of the bird's houses and cages is recommended to avoid parasites.

Durante este estudo de um ano, amostras de sangue e fezes de pombos (Zenaida asiatica), patos (Anas platyrhynchos), pombos (Columba livia), perdizes (Alectoris chukar), perus (Meleagris gallopavo) e ganso (Chen caerulescens) foram coletados para avaliar a prevalência de parasitas nessas aves. As aves foram mantidas no Centro de Conservação e Pesquisa de Aves, Departamento de Vida Selvagem e Ecologia, Universidade de Veterinária e Ciências Animais, Lahore. Todas essas espécies de aves foram mantidas em gaiolas separadas e todo o seu corpo foi inspecionado regularmente para registrar parasitas externos. Para parasitas internos, foram analisadas 100 amostras de sangue e 100 amostras fecais de cada espécie. Durante o presente estudo, duas espécies de ectoparasitas, ou seja, carrapatos de aves (Args persicus) e ácaros (Dermanyssus gallinae), enquanto 17 espécies de endoparasitas, três de sangue e 14 de amostras fecais, foram identificadas. Os parasitas sanguíneos prevalentes foram Plasmodium juxtanucleare, 29,3%, Aegyptinella pullorum, 15%, e Leucoctoyzoon simond, 13%. As espécies parasitas registradas em amostras fecais incluíram 6 espécies de nematoides viz. Syngamus traqueia com prevalência parasitária de 50%, Capillaria anatis, 40%, Capillaria annulata, 37,5%, Heterakis gallinarum, 28,3%, Ascardia galli, 24% e Allodpa suctoria, 2%. Da mesma forma, duas espécies de trematódeos viz. Prosthogonimus ovatus com prevalência parasitária de 12,1% e Prosthogonimus macrorchis, 9,1%, também foram registrados nas amostras fecais das aves. Espécies de cestoide único Raillietina echinobothrida com prevalência parasitária de 27% e 3 espécies de protozoários, ou seja, Eimeria maxima tendo prevalência de 20,1%, Histomonas meleagridis, 8%, e Giardia lamblia, 5,3%, foram registradas. Em nossa recomendação, são indicados medicação adequada e saneamento das casas e gaiolas dos pássaros para evitar parasitas.

Recombinantly Expressed Chimeric Fibers Demonstrate Discrete Type-Specific Neutralizing Epitopes in the Fowl Aviadenovirus E (FAdV-E) Fiber, Promoting the Optimization of FAdV Fiber Subunit Vaccines towards Cross-Protection in vivo.

Vaccines against inclusion body hepatitis in chickens are complicated by the involvement of antigenically diverse fowl adenovirus types. Though immunization with fiber protein confers robust protection, type specificity of fiber antibodies is an obstacle for the desired broad coverage. In this study, we utilized information on multiple linear epitopes predicted in the Fowl Aviadenovirus E (FAdV-E) fiber head (knob) to develop chimeric fibers with an exchange between two serotypes' sequences, each containing proposed epitopes. Two consecutive segments pertaining to amino acid positions 1 to 441 and 442 to 525/523 in the fibers of FAdV-8a and -8b, types of Fowl Aviadenovirus E that cause inclusion body hepatitis, were swapped reciprocally to result in novel chimeras, crecFib-8a/8b and crecFib-8b/8a. crecFib was indistinguishable from monospecific recombinant fibers in its eactivity with different FAdV antisera in Western blotting. However, contrary to the results for monospecific fibers, crecFib induced cross-neutralizing antibodies against both serotypes in chickens. This demonstrates three nonidentical epitopes in the FAdV-E fiber, the conserved epitope detected in Western blotting and at least two epitopes participating in neutralization, being type specific and located opposite residue position 441-442. Furthermore, we supply conformational evidence for a site in the fiber knob with accessibility critical for neutralization. With such an extended neutralization spectrum compared to those of individual fibers, crecFib was anticipated to fulfill and even extend the mechanistic basis of fiber-mediated protection toward bivalent coverage. Accordingly, crecFib, administered as a single-antigen component, protected chickens simultaneously against challenge with FAdV-8a or -8b, demonstrated by up-to-complete resistance to clinical disease, prevention of target organ-related changes, and significant reduction of viral load. IMPORTANCE The control of inclusion body hepatitis, a disease of economic importance for chicken production worldwide, is complicated by an etiology involving multiple divergent fowl adenovirus types. The fiber protein is principally efficacious in inducing neutralizing and protective antibodies in vaccinated chickens; however, it faces limitations due to its intrinsic type specificity for neutralization. In this study, based on an in silico-guided prediction of multiple epitopes in the fowl adenovirus fiber head's loops, we designed chimeric proteins, swapping N- and C-distal fiber portions, each containing putative epitopes, between divergent types FAdV-8a and -8b. In in vitro and in vivo studies, the chimeric fiber displayed extended properties compared to those of individual monotype-specific fibers, allowing the number, distribution, functionality, and conformational bearings of epitopes of the fowl adenovirus fiber to be characterized in more detail. Importantly, the chimeric fiber induced cross-neutralizing antibodies and protective responses in chickens against infections by both serotypes, promoting the advancement of broadly protective subunit vaccination strategies against FAdV.

Exposure of pelagic seabirds to Toxoplasma gondii in the Western Indian Ocean points to an open sea dispersal of this terrestrial parasite.

Toxoplasma gondii is a protozoan parasite that uses felids as definitive hosts and warm-blooded animals as intermediate hosts. While the dispersal of T. gondii infectious oocysts from land to coastal waters has been well documented, transmission routes to pelagic species remain puzzling. We used the modified agglutination test (MAT titre ≥ 10) to detect antibodies against T. gondii in sera collected from 1014 pelagic seabirds belonging to 10 species. Sampling was carried out on eight islands of the Western Indian Ocean: Reunion and Juan de Nova (colonized by cats), Cousin, Cousine, Aride, Bird, Europa and Tromelin islands (cat-free). Antibodies against T. gondii were found in all islands and all species but the great frigatebird. The overall seroprevalence was 16.8% [95% CI: 14.5%-19.1%] but significantly varied according to species, islands and age-classes. The low antibody levels (MAT titres = 10 or 25) detected in one shearwater and three red-footed booby chicks most likely resulted from maternal antibody transfer. In adults, exposure to soils contaminated by locally deposited oocysts may explain the detection of antibodies in both wedge-tailed shearwaters on Reunion Island and sooty terns on Juan de Nova. However, 144 adults breeding on cat-free islands also tested positive. In the Seychelles, there was a significant decrease in T. gondii prevalence associated with greater distances to cat populations for species that sometimes rest on the shore, i.e. terns and noddies. This suggests that oocysts carried by marine currents could be deposited on shore tens of kilometres from their initial deposition point and that the number of deposited oocysts decreases with distance from the nearest cat population. The consumption of fishes from the families Mullidae, Carangidae, Clupeidae and Engraulidae, previously described as T. gondii oocyst-carriers (i.e. paratenic hosts), could also explain the exposure of terns, noddies, boobies and tropicbirds to T. gondii. Our detection of antibodies against T. gondii in seabirds that fish in the high sea, have no contact with locally contaminated soils but frequent the shores and/or consume paratenic hosts supports the hypothesis of an open-sea dispersal of T. gondii oocysts by oceanic currents and/or fish.

Pathogenic evaluation of a turkey coronavirus isolate (TCoV NC1743) in turkey poults for establishing a TCoV disease model.

Turkey coronavirus (TCoV) can cause a highly contagious enteric disease in turkeys with severe economic losses in the global turkey industry. To date, no commercial vaccines are available for control of the disease. In the present study, we isolated a field strain (NC1743) of TCoV and evaluated its pathogenicity in specific-pathogen-free (SPF) turkey poults to establish a TCoV disease model. The results showed that the TCoV NC1743 isolate was pathogenic to turkey poults with a minimal infectious dose at 106 EID50/bird. About 50 % of one-day-old SPF turkeys infected with the virus's minimal infectious dose exhibited typical enteric disease signs and lesions from 6 days post-infection (dpi) to the end of the experiment (21 dpi). In contrast, fewer than 20 % of older turkeys (1- or 2-week-old) infected with the same amount of TCoV displayed enteric disease signs, which disappeared after 15-18 dpi. Although all infected turkeys, regardless of age, shed TCoV, the older turkeys shed less virus than the younger birds, and 50 % of the 2-week-old birds even cleared the virus at 21 dpi. Furthermore, the viral infection caused day-old turkeys more body-weight-gain reduction than older birds. The overall data demonstrated that the TCoV NC1743 isolate is a highly pathogenic strain and younger turkeys are more susceptible to TCoV infection than older birds. Thus, one-day-old turkeys infected with the minimal infectious dose of TCoV NC1743 could be used as a TCoV disease model to study the disease pathogenesis, and the TCoV NC1743 strain could be used as a challenge virus to evaluate a vaccine protective efficacy.

Infection dynamics of Salmonella Infantis strains displaying different genetic backgrounds - with or without pESI-like plasmid - vary considerably.

Food-borne infections with Salmonella are among the most common causes of human diseases worldwide, and infections with the serovar Infantis are becoming increasingly important. So far, diverse phenotypes and genotypes of S. Infantis have been reported. Therefore, the present study aimed to investigate the infection dynamics of two different S. Infantis strains in broilers. For this purpose, 15 birds were infected on day 2 of life with 108 CFU/ml of a pESI+ or a pESI- S. Infantis strain, respectively. Ten uninfected birds served as in-contact birds to monitor transmission. In both groups, an increase of infection was observed from 7 days of age onwards, reaching its peak at 28 days. However, the pESI+ strain proved significantly more virulent being re-isolated from most cloacal swabs and organs by direct plating. In contrast, the pESI- strain could be re-isolated from cloacal swabs and caeca only when enrichment was applied. Although the excretion of this strain was limited, the transmission level to in-contact birds was similar to the pESI+ strain. Differences in infection dynamics were also reflected in the antibody response: whereas the pESI+ strain provoked a significant increase in antibodies, antibody levels following infection with the pESI- strain remained in the range of negative control birds. The actual findings provide for the first time evidence of S. Infantis strain-specific infectivity in broilers and confirm previous observations in the field regarding differences in persistence on farms and resistance against disinfectants.

Serum metabolomics in chickens infected with Cryptosporidium baileyi.

BACKGROUND: Cryptosporidium baileyi is an economically important zoonotic pathogen that causes serious respiratory symptoms in chickens for which no effective control measures are currently available. An accumulating body of evidence indicates the potential and usefulness of metabolomics to further our understanding of the interaction between pathogens and hosts, and to search for new diagnostic or pharmacological biomarkers of complex microorganisms. The aim of this study was to identify the impact of C. baileyi infection on the serum metabolism of chickens and to assess several metabolites as potential diagnostic biomarkers for C. baileyi infection. METHODS: Ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) and subsequent multivariate statistical analysis were applied to investigate metabolomics profiles in the serum samples of chickens infected with C. baileyi, and to identify potential metabolites that can be used to distinguish chickens infected with C. baileyi from non-infected birds. RESULTS: Multivariate statistical analysis identified 138 differential serum metabolites between mock- and C. baileyi-infected chickens at 5 days post-infection (dpi), including 115 upregulated and 23 downregulated compounds. These metabolites were significantly enriched into six pathways, of which two pathways associated with energy and lipid metabolism, namely glycerophospholipid metabolism and sphingolipid metabolism, respectively, were the most enriched. Interestingly, some important immune-related pathways were also significantly enriched, including the intestinal immune network for IgA production, autophagy and cellular senescence. Nine potential C. baileyi-responsive metabolites were identified, including choline, sirolimus, all-trans retinoic acid, PC(14:0/22:1(13Z)), PC(15:0/22:6(4Z,7Z,10Z,13Z,16Z,19Z)), PE(16:1(9Z)/24:1(15Z)), phosphocholine, SM(d18:0/16:1(9Z)(OH)) and sphinganine. CONCLUSIONS: This is the first report on serum metabolic profiling of chickens with early-stage C. baileyi infection. The results provide novel insights into the pathophysiological mechanisms of C. baileyi in chickens.

Novel Models for Chronic Intestinal Inflammation in Chickens: Intestinal Inflammation Pattern and Biomarkers.

For poultry producers, chronic low-grade intestinal inflammation has a negative impact on productivity by impairing nutrient absorption and allocation of nutrients for growth. Understanding the triggers of chronic intestinal inflammation and developing a non-invasive measurement is crucial to managing gut health in poultry. In this study, we developed two novel models of low-grade chronic intestinal inflammation in broiler chickens: a chemical model using dextran sodium sulfate (DSS) and a dietary model using a high non-starch polysaccharide diet (NSP). Further, we evaluated the potential of several proteins as biomarkers of gut inflammation. For these experiments, the chemical induction of inflammation consisted of two 5-day cycles of oral gavage of either 0.25mg DSS/ml or 0.35mg DSS/ml; whereas the NSP diet (30% rice bran) was fed throughout the experiment. At four times (14, 22, 28 and 36-d post-hatch), necropsies were performed to collect intestinal samples for histology, and feces and serum for biomarkers quantification. Neither DSS nor NSP treatments affected feed intake or livability. NSP-fed birds exhibited intestinal inflammation through 14-d, which stabilized by 36-d. On the other hand, the cyclic DSS-treatment produced inflammation throughout the entire experimental period. Histological examination of the intestine revealed that the inflammation induced by both models exhibited similar spatial and temporal patterns with the duodenum and jejunum affected early (at 14-d) whereas the ileum was compromised by 28-d. Calprotectin (CALP) was the only serum protein found to be increased due to inflammation. However, fecal CALP and Lipocalin-2 (LCN-2) concentrations were significantly greater in the induced inflammation groups at 28-d. This experiment demonstrated for the first time, two in vivo models of chronic gut inflammation in chickens, a DSS and a nutritional NSP protocols. Based on these models we observed that intestinal inflammation begins in the upper segments of small intestine and moved to the lower region over time. In the searching for a fecal biomarker for intestinal inflammation, LCN-2 showed promising results. More importantly, calprotectin has a great potential as a novel biomarker for poultry measured both in serum and feces.

Effect of blood source on vector competence of Culex pipiens biotypes for Usutu virus.

BACKGROUND: Infectious blood meal experiments have been frequently performed with different virus-vector combinations to assess the transmission potential of arthropod-borne (arbo)viruses. A wide variety of host blood sources have been used to deliver arboviruses to their arthropod vectors in laboratory studies. The type of blood used during vector competence experiments does not always reflect the blood from the viremic vertebrate hosts in the field, but little is known about the effect of blood source on the experimental outcome of vector competence studies. Here we investigated the effect of avian versus human blood on the infection and transmission rates of the zoonotic Usutu virus (USUV) in its primary mosquito vector Culex pipiens. METHODS: Cx. pipiens biotypes (pipiens and molestus) were orally infected with USUV through infectious blood meals containing either chicken or human whole blood. The USUV infection and transmission rates were determined by checking mosquito bodies and saliva for USUV presence after 14 days of incubation at 28 °C. In addition, viral titers were determined for USUV-positive mosquito bodies and saliva. RESULTS: Human and chicken blood lead to similar USUV transmission rates for Cx. pipiens biotype pipiens (18% and 15%, respectively), while human blood moderately but not significantly increased the transmission rate (30%) compared to chicken blood (17%) for biotype molestus. USUV infection rates with human blood were consistently higher in both Cx. pipiens biotypes compared to chicken blood. In virus-positive mosquitoes, USUV body and saliva titers did not differ between mosquitoes taking either human or chicken blood. Importantly, biotype molestus had much lower USUV saliva titers compared to biotype pipiens, regardless of which blood was offered. CONCLUSIONS: Infection of mosquitoes with human blood led to higher USUV infection rates as compared to chicken blood. However, the blood source had no effect on the vector competence for USUV. Interestingly, biotype molestus is less likely to transmit USUV compared to biotype pipiens due to very low virus titers in the saliva.

Antox® and Bactofort® mitigated the haematological alterations induced by a very virulent infectious bursal disease virus in chicks.

The study investigated the mitigating effects of two probiotics on blood parameters of ISA Brown chicks inoculated with a very virulent infectious bursal disease virus (vvIBDV). Two hundred chicks were assigned into four groups of 50 birds each. Groups A and B were administered Antox® in water and Bactofort® in feed daily from 1 to 42 days of age and inoculated with a vvIBDV at 28 days and C and D served as positive and negative controls, respectively. Blood samples were examined for changes in packed cell volume (PCV), haemoglobin concentration (Hb), red blood cell (RBC), total white blood cell (TWBC), heterophil and lymphocyte counts seven days post inoculation. The PCV between groups A and C differed (P < 0.05) and in group B it was higher (P < 0.05) than that of group C. The Hb concentration between groups A, B and C differed (P < 0.05). There was a difference (P < 0.05) in RBC counts between groups A, B, C. Differences in TWBC between group A and C were significant (P < 0.05) and TWBC in group B was higher (P < 0.05) than that of group C. There was a significant difference in heterophil (P < 0.05) and lymphocyte (P < 0.05) count between group A and C, and B and C. Heterophil/lymphocyte ratio was significantly higher in positive control compared to groups A, B, C. Antox® and Bactofort® mitigated the deleterious effects of vvIBDV on blood parameters and can assist in cases of IBD outbreak.

CpG-ODN induced antimicrobial immunity in neonatal chicks involves a substantial shift in serum metabolic profiles.

Synthetic CpG-ODNs can promote antimicrobial immunity in neonatal chicks by enriching immune compartments and activating immune cells. Activated immune cells undergo profound metabolic changes to meet cellular biosynthesis and energy demands and facilitate the signaling processes. We hypothesize that CpG-ODNs induced immune activation can change the host's metabolic demands in neonatal chicks. Here, we used NMR-based metabolomics to explore the potential of immuno-metabolic interactions in the orchestration of CpG-ODN-induced antimicrobial immunity. We administered CpG-ODNs to day-old broiler chicks via intrapulmonary (IPL) and intramuscular (IM) routes. A negative control group was administered IPL distilled water (DW). In each group (n = 60), chicks (n = 40) were challenged with a lethal dose of Escherichia coli, two days post-CpG-ODN administration. CpG-ODN administered chicks had significantly higher survival (P < 0.05), significantly lower cumulative clinical scores (P < 0.05), and lower bacterial loads (P < 0.05) compared to the DW control group. In parallel experiments, we compared NMR-based serum metabolomic profiles in neonatal chicks (n = 20/group, 24 h post-treatment) treated with IM versus IPL CpG-ODNs or distilled water (DW) control. Serum metabolomics revealed that IM administration of CpG-ODN resulted in a highly significant and consistent decrease in amino acids, purines, betaine, choline, acetate, and a slight decrease in glucose. IPL CpG-ODN treatment resulted in a similar decrease in purines and choline but less extensive decrease in amino acids, a stronger decrease in acetate, and a considerable increase in 2-hydroxybutyrate, 3-hydroxybutyrate, formic acid and a mild increase in TCA cycle intermediates (all P < 0.05 after FDR adjustment). These perturbations in pathways associated with energy production, amino acid metabolism and nucleotide synthesis, most probably reflect increased uptake of nutrients to the cells, to support cell proliferation triggered by the innate immune response. Our study revealed for the first time that CpG-ODNs change the metabolomic landscape to establish antimicrobial immunity in neonatal chicks. The metabolites highlighted in the present study can help future targeted studies to better understand immunometabolic interactions and pinpoint the key molecules or pathways contributing to immunity.

Serological evidence of avian HEV antibodies in apparently healthy chickens in southwest Nigeria.

Avian hepatitis E virus (aHEV) is associated with hepatitis-splenomegaly syndrome, big liver and spleen disease and hepatic rupture haemorrhage syndrome. However, the knowledge about aHEV in commercial layer chickens in Nigeria is scarce. In this study, 460 serum samples obtained from 36 apparently healthy commercial layer chicken flocks in three states (Ogun, Osun and Oyo States) of southwestern Nigeria were analysed by enzyme linked immunosorbent assay for the presence of anti-aHEV immunoglobulin Y (IgY) antibodies. In total, the overall seroprevalence of anti-aHEV antibodies was 14.6%. The serological analysis revealed that 75% of the flocks examined were positive for anti-aHEV IgY antibodies from chickens of various ages in all three states. The percentage of the seropositive chickens in the three states varied from flock to flock ranging from 60% to 88.8% and seropositive chickens were detected at any age (24-52 weeks of age) without significant differences between the age groups. This is the first report assessing the presence of aHEV antibodies in chickens from Nigeria. The detection of anti-aHEV antibodies in commercial layer chickens in this study emphasizes the importance of serosurveillance in disease monitoring due to the economic threat posed by aHEV as a result of decreased egg production and increased mortality in affected commercial layer chicken farms. However, further studies are essential to reveal the clinical implications and to assess the real burden of aHEV in Nigeria.

Detection of infectious laryngotracheitis virus (ILTV) in tissues and blood fractions from experimentally infected chickens using PCR and immunostaining analyses.

The ability of infectious laryngotracheitis virus (ILTV) to replicate in organs outside of the upper respiratory tract and conjunctiva associated-lymphoid tissues is still not well understood. This study investigated the tissue distribution of an Australian field strain of ILTV (class 9) on birds experimentally inoculated via eye-drop at 7 days of age by using quantitative PCR (qPCR) and immunohistochemistry. Tissues including conjunctiva, caecal tonsil, kidney, liver, lung, spleen, thymus, trachea and blood were collected from sham-inoculated (control group; n = 2) and ILTV-inoculated (n = 8) birds at 7 days post-inoculation (dpi). Blood was collected from 13 infected birds at 14 dpi and fractionated using ficoll-paque. At 7 dpi, the highest detection rate and genomic copies (GC) were in conjunctiva (8/8; 8.08 ± 0.48 log10 GC/mg) followed by trachea (8/8; 4.64 ± 0.48) and thymus (8/8; 4.52 ± 0.48), kidney (8/8; 3.97 ± 0.48), lung (8/8; 3.65 ± 0.48), spleen (8/8; 3.55 ± 0.48), liver (8/8; 3.51 ± 0.48), caecal tonsil (7/8; 3.76 ± 0.48) and plasma (4/8; 2.40 ± 0.48 log10 GC/ml). ILTV antigen was only detected in conjunctiva (7/8), trachea (6/8) and lung (4/8) samples. At 14 dpi, ILTV detection rate and genomic copies in buffy coat cells were 12/13 and 2.86 ± 0.39 log10 GC/mg, respectively while those of plasma were 11/13 and 4.29 ± 0.39 log10 GC/ml and red blood cell were 3/13 and 0.36 ± 0.39 log10 GC/mg. In conclusion, ILTV DNA was detected in a wide range of tissues and blood fractions but ILTV antigen was only detected in respiratory organs and conjunctiva.

Development of A recombinant nucleocapsid based indirect ELISA for the detection of antibodies to avian metapneumovirus subtypes, A, B, and C.

Nucleocapsid (N) protein is the most highly expressed of all avian metapneumovirus (aMPV) viral proteins and stimulates a substantial immune response in infected animals. Codon optimized recombinant N (rec-N) protein from aMPV subtypes A, B, and C were expressed using the baculoviral expression system in Trichoplusia ni (Tni) insect cells. A mixture of purified rec-N antigens from each subtype was used as a coating antigen and was evaluated in indirect ELISA (iELISA) to assess antibody response in serum samples collected from experimentally infected chickens and turkeys with different aMPV subtypes. Also, archived field serum samples that were collected from different poultry submissions were used. Receiver operating characteristic (ROC) analysis was performed using chicken and turkey serum samples that were confirmed by indirect fluorescent antibody (IFA) test for serostatus (positive n = 270, negative n = 610). The ROC analysis showed sensitivity and specificity of 97 % at a cut-off value of 0.25. The rec-N iELISA was compared with a commercial whole virus-based APV kit. The rec-N iELISA showed comparable results in detecting antibody response in aMPV infected chicken sera but was more sensitive in detecting early antibody response in aMPV infected turkey serum samples. Our results further confirm the presence of aMPV antibodies in Canadian domestic poultry populations. The developed aMPV-rec N iELISA offers a safe and valuable alternative to whole virus-based iELISA for serodiagnosis and seroepidemiological surveillance of the disease in domestic poultry.

Supplemental 25-hydroxycholecalciferol Alleviates Inflammation and Cardiac Fibrosis in Hens.

Broiler breeder hens with efficient feed conversion rate under restricted feed intake (R-hens) or allowed unlimited access to feed (Ad-hens) progressed with cardiac functional failure and suffered early sudden death. A supplement of 69 µg 25-hydroxycholecalciferol (25-OH-D3)/kg feed improved heart health and rescued livability in both R- and Ad-hens throughout laying stage (26-60 wks). Improvements occurred through cardiac hypertrophic remodeling, reduced arrhythmias, and pathological cues. Here, we further demonstrated consistently decreased circulating and cardiac IL-6 and IL-1ß levels in conjunction with reduced cardiac chemoattraction and leukocyte infiltration by 25-OH-D3 in Ad-hens and in R-hens at later time points (35 and 47 wks) (p < 0.05). Supplemental 25-OH-D3 also ameliorated cardiac fibrosis, endoplasmic reticulum (ER) stress, and autophagy, mostly in Ad-hens, as both collagen content and expression of COL3A1, as well as CCAAT box binding enhancer homologous protein (CHOP) and activating transcription factor 6 (ATF6), were consistently decreased, and suppression of microtubule-associated protein 1 light Chain 3 beta (LC3B) and Sequestosome 1 (SQSTM1) was rescued at 35 and 47 wks (p < 0.05). Vitamin D receptor-NF-κB signaling was shown to mediate these beneficial effects. The present results demonstrate that ER stress and autophagic processes along the sequence from inflammation to fibrotic changes contribute to pathological cardiac remodeling and functional compromise by Ad-feed intake. 25-OH-D3 is an effective anti-inflammatory and anti-fibrotic supplement to ameliorate cardiac pathogenesis in broiler breeder hens.

Influence of Eimeria spp. infection and dietary inclusion of arginine on intestine histological parameters, serum amino acid profile and ileal amino acids digestibility in broiler chicks.

Coccidiosis is considered to be one of the most important challenge in the poultry industry causes economic losses due to the destruction in the digestive tract of chicken. It disturbs amino acids profile and their digestibility, leading to weight lost and economic burden. Using dietary arginine may decrease the adverse effects of coccidiosis on chicken digestive tract. This study aimed to evaluate the effects of dietary inclusion of arginine on intestine histological parameters, serum amino acid concentration and ileal amino acid digestibility of broiler chicks infected with coccidiosis. A total number of 384 one-d-old broiler chicks (Ross 308) of mixed sex with initial weight of 42 ±â€¯2 g was allocated into 8 groups with 8 birds/pen from grower period. At 21 days of age, broiler chicks were infected with a mixture of Eimeria spp. Broiler chicks were divided into infected and un-infected groups and received arginine at recommended levels of 85, 100, 125 and 150 %. Intestinal morphology and lesions, serum amino acid concentration and ileal amino acid digestibility were evaluated. Broiler chicks infected with Eimeria spp. showed lower villus height and villus height: crypt depth ratio and also higher intestinal lesions (P < 0.05). Coccidia infection decreased the ileal amino acid digestibility for all studied amino acids and also reduced serum concentrations of amino acids, except lysine and isoleucine (P < 0.05). Dietary supplementation of arginine especially in higher levels significantly increased villus height and villus height:crypt depth ratio and decreased lesions (P < 0.05). Moreover, dietary supplementing of arginine increased the serum concentration of arginine (P < 0.05), but it did not have any significant effect on its digestibility (P > 0.05). In sum, coccidiosis decreases amino acid digestibility and serum amino acid concentration, but dietary inclusion of higher levels of arginine significantly improved histological parameters of broiler chicks infected with coccidiosis.

Research Note: Serological investigation of Ornithobacterium rhinotracheale infection in China.

Ornithobacterium rhinotracheale (ORT) has been associated with avian respiratory disease. On coinfection with other pathogens, ORT can cause serious health problems in avian species, leading to financial losses. To monitor the serologic prevalence of ORT in chicken flocks in China, 1,280 sera were collected to determine ORT antibodies among 64 flocks from 15 provinces of China using a commercial ELISA kit. The overall seroprevalence of ORT among the birds tested was 44.06%. In younger chickens, the serum positive rate was lower than that in older chickens, and with increased age, the serum positive rates increased. Older chickens had not only higher positive rates but also higher antibody levels. These data indicated that ORT infections were common in China. Because an ORT vaccine is currently not available, good disease management and biosecurity measures are required for effective disease control.

Effects of dietary Original XPC on selected blood variables in layer pullets challenged with Mycoplasma gallisepticum,.

Effects of dietary Original XPC (XPC) on 17 selected blood variables in commercial layer pullets challenged with the virulent, low-passage R strain of Mycoplasma gallisepticum (RlowMG) were investigated. Hy-Line W-36 pullets sourced from M. gallisepticum-clean layer breeders were fed a basal diet with XPC (1.25 kg/metric ton) or without from hatch until 12 wk of age (woa). At 8 and 10 woa, half of the birds in each dietary treatment were challenged with RlowMG. Blood samples were taken immediately before the initial RlowMG challenge at 8 woa and again at 12 woa (4 wk after challenge). At 8 woa, blood pH was lower and glucose concentration was higher in the preassigned challenge treatment groups. At 12 woa, the concentration of oxygen dissolved in the blood was significantly lower in the RlowMG-challenged group than the unchallenged group of birds regardless of dietary treatment. The RlowMG challenge significantly increased blood carbon dioxide partial pressure, calcium, sodium, anion gap, osmolality, glucose, and corticosterone levels but significantly decreased blood oxygen partial pressure, oxyhemoglobin concentration, concentration of oxygen dissolved in the blood, chloride, and pH levels. Because blood pH and glucose concentration at 8 woa were examined before challenge, their baseline values were biased with respect to challenge treatment before treatment was applied. However, the lack of a significant main effect due to diet at 8 woa for blood pH and glucose concentration, along with the other 15 blood variables, indicate that the baseline data with respect to dietary treatment were unbiased, allowing for real dietary effects to be accurately assessed. In conclusion, layer pullets challenged with RlowMG undergo a stress response associated with changes in various physiological blood variables, and a decrease in pH and increase in carbon dioxide partial pressure, in association with a lack of change in bicarbonate, indicates that the stress response caused by the RlowMG challenge was associated with respiratory acidosis. Nevertheless, feeding XPC did not influence the effects of challenge treatment on these postchallenge physiological blood values.

Effect of coccidial challenge and vaccination on the performance, veterinary postmortem scores, and blood biochemistry of broiler chickens.

A total of 960 male Cobb 500 broilers were used in a growth performance study to explore the effect of coccidial vaccination and/or coccidial challenge on blood biochemistry and veterinary postmortem metrics. Day-old chicks were randomly divided into one of the 4 experimental treatments. Treatments were arranged in a 2 × 2 factorial arrangement, with the factors being without or with vaccination (administered on day 1) or coccidial challenge (oral gavage on day 7). Growth performance was monitored on a weekly basis. Blood sample collection, as well as full veterinary necropsies, were carried out on days 6, 8, 13, 20, 27, and 34. Birds that did not receive the vaccination but were challenged with coccidiosis had higher feed conversion ratio, lower body weights, and higher mortality than the other experimental groups, and this effect was particularly evident from day 13 to day 20. Birds challenged with coccidiosis had lower plasma sodium and total carotenoid concentrations and higher potassium and globulin concentrations than nonchallenged birds. Significant interactions between age and experimental treatment for these blood parameters were observed, particularly on day 13. The necropsy results confirmed the effectiveness of the challenge and vaccination treatments, wherein birds that were challenged had higher coccidiosis scores on day 13 and day 27 than birds that were not challenged. These results demonstrate the potential for plasma sodium, potassium, total protein, total carbon dioxide, globulin, and carotenoid analysis for early diagnosis of coccidiosis in growing broiler chickens. Further work is necessary to establish whether the changes in blood biochemistry observed in the present study are transferable to alternative flocks of chicken and whether early diagnosis and intervention may mitigate performance losses associated with this disease.

Expression of the Campylobacter jejuni FliD protein and its reaction to chicken sera.

Campylobacter is a leading causative pathogen of acute bacterial gastroenteritis among humans. Contaminated chicken products are regarded as major sources of human infection. The flagellar capping protein (FliD), which plays important roles in colonization and adhesion to the mucosal surface of chicken ceca, is conserved among Campylobacter jejuni strains. In this study, the recombinant C. jejuni FliD protein was expressed, purified and used as a coated protein to examine the prevalence of C. jejuni antibodies in chickens. The anti-FliD antibody was prevalent among chicken serum samples taken from different farms in the diverse regions of Jiangsu province by using enzyme-linked immunosorbent assay. The Campylobacter antibody was present in culture-negative chickens. No strong dose-response relationships were observed between serum FliD antibody levels and Campylobacter cultural status. These results provide a basis for further evaluating FliD as a vaccine candidate for broiler chickens or for examining host-C. jejuni interactions, with implications for improving food safety.

Bioassay-based detection of Toxoplasma gondii in free-range chickens from Khorramabad, Iran: comparison of direct microscopy and semi-nested PCR.

This study aimed to investigate the occurrence of anti-Toxoplasma gondii antibodies in free-range chickens from Khorramabad, western Iran, and also to compare the performance of direct microscopy and semi-nested PCR in mice bioassayed with tissues from seropositive chickens. We investigated 97 serum samples from free-range chickens, using the modified agglutination test (MAT). Tissues from all seropositive chickens (MAT ≥ 1:10) were bioassayed in mice. All inoculated mice were examined by direct microscopy and a semi-nested PCR targeting the 529 bp repeat element (RE) of the parasite. Anti-T. gondii antibodies were detected in 21.6% of chicken sera. Eighteen of 21 (85.7%) seropositive chickens were positive in mouse bioassay using molecular DNA detection. However, biological forms of the parasite were isolated only from 11 (52.3%) seropositive chickens. Compared with semi-nested PCR, the sensitivity of direct microscopy was 62.1%. It can be concluded that although direct microscopy is a rapid and specific method for the detection of T. gondii, it does not detect the parasite in all experimentally infected mice. The low sensitivity of direct microscopy highlights the need for molecular techniques, such as RE-based semi-nested PCR, to increase the sensitivity of the mouse bioassay.