A within-host mathematical model of H9N2 avian influenza infection and type-I interferon response pathways in chickens.

Chickens infected with avian influenza virus (AIV) transmit the virus via respiratory and cloacal shedding. While previous mathematical models have shown that the innate immune response is necessary for the early suppression of virus production in infected respiratory cells, the different pathways by which the innate immune response can affect cloacal viral shedding have not been studied in chickens. The present study aims to evaluate the sensitivity of H9N2 low pathogenic AIV shedding in chicken gastrointestinal cells to different type-I interferon (IFN) response pathways, and to determine the impact of a cellular eclipse phase (latent period) on the time to peak virus shedding using a mathematical model describing within host viral kinetics. Our model results demonstrate that a mechanistic model that incorporates 1) the intracellular antiviral effects of type-I IFN on virus production, 2) destruction of infected cells by type-I IFN activated Natural Killer cells, and 3) an eclipse phase is most consistent with experimental cloacal virus shedding data. These results provide a potential mechanistic explanation for the delay to peak cloacal virus shedding observed in experimental studies conducted in chickens, as well as an improved understanding of the primary type-I IFN pathways involved in the control of cloacal virus shedding, which may lead to the development of more targeted vaccine candidates.

Significant genomic introgression from grey junglefowl (Gallus sonneratii) to domestic chickens (Gallus gallus domesticus).

BACKGROUND: Chicken is one of the most numerous and widely distributed species around the world, and many studies support the multiple ancestral origins of domestic chickens. The research regarding the yellow skin phenotype in domestic chickens (regulated by BCO2) likely originating from the grey junglefowl serves as crucial evidence for demonstrating the multiple origins of chickens. However, beyond the BCO2 gene region, much remains unknown about the introgression from the grey junglefowl into domestic chickens. Therefore, in this study, based on whole-genome data of 149 samples including 4 species of wild junglefowls and 13 local domestic chicken breeds, we explored the introgression events from the grey junglefowl to domestic chickens. RESULTS: We successfully detected introgression regions besides BCO2, including two associated with growth trait (IGFBP2 and TKT), one associated with angiogenesis (TIMP3) and two members of the heat shock protein family (HSPB2 and CRYAB). Our findings suggest that the introgression from the grey junglefowl may impact the growth performance of chickens. Furthermore, we revealed introgression events from grey junglefowl at the BCO2 region in multiple domestic chicken breeds, indicating a phenomenon where the yellow skin phenotype likely underwent strong selection and was retained. Additionally, our haplotype analysis shed light on BCO2 introgression event from different sources of grey junglefowl into domestic chickens, possibly suggesting multiple genetic flows between the grey junglefowl and domestic chickens. CONCLUSIONS: In summary, our findings provide evidences of the grey junglefowl contributing to the genetic diversity of domestic chickens, laying the foundation for a deeper understanding of the genetic composition within domestic chickens, and offering new perspectives on the impact of introgression on domestic chickens.

Pharmacokinetics of Danofloxacin in Gushi Chickens after Single Oral and Intravenous Administration.

This study aimed to determine the pharmacokinetics of danofloxacin in Gushi chickens after a single oral (PO) and intravenous (IV) dose at 5 mg/kg body weight (BW). Thirty-two Gushi chickens, aged 20 weeks, were selected and divided into two groups at random, with each group consisting of 16 chickens, evenly distributed between males and females. Following danofloxacin administration, blood samples were taken at predetermined time intervals and the plasma was separated. The concentrations of danofloxacin in plasma were quantified by HPLC with a fluorescence detector. Then the concentrations versus time data were subjected to non-compartmental analysis (NCA) using Phoenix software (version: 8.1.0). After administering danofloxacin orally at a dose of 5 mg/kg BW to Gushi chickens, our results demonstrated that the peak concentration reached 0.53 µg/mL at 4 h. The half-life of absorption (t1/2ka) was determined to be 2.37 ± 1.60 h, and the bioavailability (F) was calculated as 40.12 ± 15.83%. For both oral and intravenous administration, the area under the concentration-time curve (AUC0-∞) was determined to be 4.72 ± 1.86 and 11.76 ± 3.25 h·µg/mL, respectively. The corresponding elimination half-life (t1/2λz) was measured as 11.24 ± 3.90 and 10.17 ± 3.72 h. Moreover, the mean residence time (MRT) was calculated as 10.20 ± 2.47 and 7.05 ± 1.97 h for these respective routes. Based on the calculated AUC/MIC ratio values, it can be inferred that the 5 mg/kg BW dosage of danofloxacin, whether administered orally or intravenously, is expected to effectively treat Escherichia coli and Pasteurella multocida infections in Gushi chickens.

Nanopore MinION Sequencing Generates a White Spot Syndrome Virus Genome from a Pooled Cloacal Swab Sample of Domestic Chickens in South Africa.

White spot syndrome virus is a highly contagious pathogen affecting shrimp farming worldwide. The host range of this virus is primarily limited to crustaceans, such as shrimps, crabs, prawns, crayfish, and lobsters; however, several species of non-crustaceans, including aquatic insects, piscivorous birds, and molluscs may serve as the vectors for ecological dissemination. The present study was aimed at studying the faecal virome of domestic chickens (Gallus gallus domesticus) in Makhanda, Eastern Cape, South Africa. The cloacal swab specimens (n = 35) were collected from domestic chickens in December 2022. The cloacal swab specimens were pooled-each pool containing five cloacal swabs-for metagenomic analysis using a sequence-independent single-primer amplification protocol, followed by Nanopore MinION sequencing. While the metagenomic sequencing generated several contigs aligning with reference genomes of animal viruses, one striking observation was the presence of a White spot syndrome virus genome in one pool of cloacal swab specimens. The generated White spot syndrome virus genome was 273,795 bp in size with 88.5% genome coverage and shared 99.94% nucleotide sequence identity with a reference genome reported in China during 2018 (GenBank accession: NC_003225.3). The Neighbour-Joining tree grouped South African White spot syndrome virus genome with other White spot syndrome virus genomes reported from South East Asia. To our knowledge, this is the first report of a White spot syndrome virus genome generated from domestic chickens. The significance of White spot syndrome virus infection in domestic chickens is yet to be determined.

Therapeutic efficacy of n-Docosanol against velogenic Newcastle disease virus infection in domestic chickens.

Introduction: The control of Newcastle disease virus (NDV) infection depends solely on vaccination which in most cases is not sufficient to restrain the consequences of such a highly evolving viral disease. Finding out substances for preparing an efficient anti-ND drug would be of high value. n-Docosanol is a saturated fatty alcohol with an inhibitory effect against many enveloped viruses. In this study, we evaluated the therapeutic effect of n-docosanol on NDV infection and shedding in chickens. Methods: Chickens infected with a highly virulent NDV were treated with low to high concentrations of n-docosanol (20, 40, and 60 mg/kg body weight) for 4-successive days, once they showed the disease symptoms. Survival and curative rates, virus load, histopathological scoring, and virus shedding were defined. Results: Symptoms development was found to discontinue 24-72 hours post-treatment. Survival rate in the NDV-infected chickens raised 37.4-53.2% after the treatment. n-Docosanol treatment was also found to significantly reduce virus load in the digestive (26.2-33.9%), respiratory (38.3-63%), nervous (26.7-51.1%), and lymphatic (16.4-29.1%) tissues. Histopathological scoring of NDV lesions revealed prominent rescue effects on the histology of different tissues. Importantly, n-docosanol treatment significantly reduced virus shedding in oropharyngeal discharge and feces thereby allowing the restriction of NDV spread. Conclusion: Our findings suggest n-docosanol as a promising remedy in the control strategy of Newcastle disease in the poultry industry.

Learning and motor inhibitory control in crows and domestic chickens.

Cognitive abilities allow animals to navigate through complex, fluctuating environments. In the present study, we tested the performance of a captive group of eight crows, Corvus corone and 10 domestic chickens, Gallus gallus domesticus, in the cylinder task, as a test of motor inhibitory control and reversal learning as a measure of learning ability and behavioural flexibility. Four crows and nine chickens completed the cylinder task, eight crows and six chickens completed the reversal learning experiment. Crows performed better in the cylinder task compared with chickens. In the reversal learning experiment, species did not significantly differ in the number of trials until the learning criterion was reached. The performance in the reversal learning experiment did not correlate with performance in the cylinder task in chickens. Our results suggest crows to possess better motor inhibitory control compared with chickens. By contrast, learning performance in a reversal learning task did not differ between the species, indicating similar levels of behavioural flexibility. Interestingly, we describe notable individual differences in performance. We stress the importance not only to compare cognitive performance between species but also between individuals of the same species when investigating the evolution of cognitive skills.

Molecular characterization of Oxyspirura mansoni and Philophthalmus gralli collected from the eyes of domestic chickens in Bangladesh.

A variety of helminths have been found in domestic chickens in Bangladesh, but little is known about their gene sequences. Here, parasitic nematodes and trematodes were collected from the eyes of domestic chickens and analyzed for their morphological and morphometric characteristics, and characterized molecularly. The helminths were identified as Oxyspirura mansoni and Philophthalmus gralli. The ITS1 and ITS2 sequences of O. mansoni were 532 bp and 306 bp in length, respectively, and showed low identity (50.7-62.7%) with those of O. petrowi and O. conjunctivalis. Furthermore, the O. mansoni CO1 sequences (393 bp) showed five haplotypes (97.5-99.5% similarity) that formed a monophyletic clade. With respect to P. gralli, the ITS1 (452 bp) and ITS2 (736 bp) sequences showed 100% similarity with the reference sequences in GenBank. Both the ND1 and CO1 phylograms showed that P. gralli from Bangladesh, Costa Rica and Peru form a monophyletic clade, distinct from the clades of P. lucipetus and P. lacrymosus. Our data show that, Philophthalmus gralli isolates from Bangladesh, Costa Rica and Peru are genetically close to each other.

Prevalence of Eimeria species in domestic chickens in Anhui province, China.

Prevalence studies can adequately assist in the design of prophylaxis strategies for disease control. Here, the prevalence of Eimeria species in chickens was investigated in Anhui province, China, from July to September 2016. A total of 171 samples were tested by microscopic examination and molecular methods. The prevalence of coccidiosis in Anhui province was found to be 87.75% (150/171). Eimeria tenella was the most prevalent species (80.67%, 121/150), and Eimeria necatrix, Eimeria mitis, Eimeria maxima, Eimeria brunetti and Eimeria acervulina were 68% (102/150), 55.33% (83/150), 54.67% (82/150), 44.67% (67/150) and 2.67% (4/150), respectively. Eimeria praecox was not detected at all. The most common combinations are E. tenella, E. maxima, E. necatrix, E. brunetti and E. mitis (26.67%, 40/150), followed by E. tenella, E. maxima and E. necatrix (19.33%, 29/150). Eimeria necatrix exhibited the highest participation in multiple infections. The results of the present study suggested that Eimeria infection is mixed, severe and widespread in chickens, Therefore, integrated strategies should be performed to prevent and control coccidial infection in chickens in Anhui province.