Prevalence of pigeon rotavirus infections: animal exhibitions as a risk factor for pigeon flocks

Retrospective detection and whole genome sequencing identify the first local case of Pigeon Rotavirus A infection in Taiwan from 2018

In 2018, pigeon Rotavirus A G18P[17] was identified in Australia as the causative agent of a disease outbreak presenting as vomiting and diarrhea, reminiscent of the young pigeon disease syndrome. This virus has subsequently been detected in several other countries, including Belgium, Denmark, Germany, Great Britain, Poland, and the United States. This study was conducted to determine the presence of pigeon Rotavirus A among archived samples collected in Taiwan, and to subsequently characterize the whole genome of a local isolate. Two hundred twenty-five pigeon liver samples collected from 2018 to 2023 were tested for the presence of pigeon rotavirus A RNA using PCR. A sample from 2018 tested positive, and the successful rescue of infective virions was achieved. The first coding-complete genome of this virus from Taiwan was successfully sequenced, revealing that isolate NPUST-001 belongs to genotype G18P[17]-I4-R4-C4-M4-A4-T4-N4-E19-H4. To date, this is the earliest known rotavirus A isolate with this exact genotype constellation recovered from a domestic pigeon sample in the Asian region. Phylogenetic analysis of the VP6 segment showed that isolate NPUST-001 belongs to a distinct lineage of pigeon Rotavirus A which comprises of several other strains reported from mainland China and the USA. Although no recent cases were detected, active surveillance for rotaviral infection among suspected cases is recommended to gather more information on the epidemiology of this virus locally.

Rotaviruses in Pigeons With Diarrhea: Recovery of Three Complete Pigeon Rotavirus A Genomes and the First Case of Pigeon Rotavirus G in Europe

Rotaviruses are well-recognized pathogens responsible for diarrhea in humans and various animal species, with Rotavirus A the most often detected and most thoroughly described. Rotaviral disease is an important concern in pathology of pigeons as well, as pigeon rotavirus A was proven to play a major role in young pigeon disease (YPD). However, rotaviruses of other groups have been so far understudied in birds. This paper describes the first finding of Rotavirus G in domestic pigeon in Europe, as well as the recovery of three complete genomes of pigeon rotavirus A with Oxford Nanopore Sequencing. Quantification of pigeon rotavirus A genetic material with droplet digital polymerase chain reaction (PCR) in pigeons suffering from diarrhea and in asymptomatic pigeons was also performed in the frameworks of this study and resulted in determination of statistically highly significant differences between the groups in both detection rate and shedding of the virus. Phylogenetic analysis revealed the close relationship of acquired strains with those originating from pigeons from Europe, North America, Asia, and Australia, indicating a broad geographical spread of pigeon rotaviruses. Results of our research shed more light on occurrence and diversity of Rotavirus species in pigeons.

Designing and development of efficient multi-epitope-based peptide vaccine candidate against emerging avian rotavirus strains: A vaccinomic approach

BACKGROUND

Enteric avian rotavirus (ARV) is the etiological agent of several health problems that pose a global threat to commercial chickens. Therefore, to avoid these widespread epidemics and high mortality rates, only vaccine and strict biosecurity are required.

METHOD

The present study employs computational techniques to design a unique multi-epitope-based vaccine candidate that successfully activates immune cells against the ARV by combining adjuvant, linker, and B and T-cell epitopes. Starting, homologous sequences in the various ARV serotypes were revealed in the NCBI BLAST database, and then the two surface proteins (VP4 and VP7) of the ARV were retrieved from the UniprotKB database. The Clustal Omega server was then used to identify the conserved regions among the homologous sequences, and the B and T-cell epitopes were predicted using IEDB servers. Then, superior epitopes-2 MHC-1 epitopes, 2 MHC-2 epitopes, and 3B-cell epitopes-were combined with various adjuvants to create a total of four unique vaccine candidates. Afterward, the designed vaccine candidates underwent computational validation to assess their antigenicity, allergenicity, and stability. The vaccine candidate (V2) that demonstrated non-antigenicity, a high VaxiJen score, and non-allergenicity was ultimately chosen for molecular docking and dynamic simulation.

RESULTS

Although the V2 and V4 vaccine candidates were highly immunogenic, V2 had a higher solubility rate. The predicted values of the aliphatic index and GRAVY value were 30.4 and 0.417, respectively. In terms of binding energy, V2 outperformed V4. Being successfully docked with TLRs, V2 was praised as the finest. After adaptation, the sequence's 50.73 % GC content outside of the BglII or ApaI restriction sites indicated that it was equivalently safe to clone. The chosen sequence was then inserted into the pET28a(+) vector within the BglII and ApaI restriction sites. This resulted in a final clone that was 4914 base pairs long, with the inserted sequence accounting for 478 bp and the vector accounting for the remainder.

CONCLUSIONS

The immune-mediated simulation results for the selected vaccine construct showed significant response; thus, the study confirmed that the selected V2 vaccine candidate could enhance the immune response against ARV.

The course of Rotavirus A (RVA) infection in young racing pigeons during the racing season

BACKGROUND

Pigeon Rotavirus A (RVA) infection has been confirmed in pigeons in the last decade as a cause of Young Pigeon Disease (YPD). Although YPD has been known for many years to date, no studies have been conducted to track the spread of RVA infection in pigeons during the racing season. The presented research aims to determine the course of RVA infection during the flights of young racing pigeons in the summer season, in one of the districts in the Mazovian Voivodeship in Poland.

RESULTS

Faecal samples of pigeons collected from transport baskets in vehicles transporting pigeons to the starting point were tested. The quantitative RT-PCR (qRT-PCR) was used to detect the genetic material of RVA. Samples taken during 6 flights were analysed. The study showed a percentage increase in infections up to the fourth flight of pigeons, and then their decrease. With Cq values below 20, breeders did not participate in the next flight and/or reported disease in the flock. With positive Cq values of 20 to 30, clinical signs of disease were not reported. Of the 76 breeders participating in the races, at least one positive result was found in 46 (60.5%). Including the occurrence of the disease during the racing season was reported by 11 breeders (14.4%). The main clinical signs in sick pigeons were vomiting, diarrhea and stowed crop. The tested pigeons were not vaccinated against RVA.

CONCLUSIONS

During training and racing of pigeons, it is not possible to avoid exposing them to pathogens, including RVA, regardless of whether pigeons from different breeders are placed in the same baskets or are in separate baskets. However, after four flights the number of new cases of the disease decreases which indicates the development of immunity. The qRT-PCR test is useful in the diagnosis and differentiation of clinical (Cq below 20) and subclinical RVA infections in racing pigeons.

Columbiform Pediatrics

Pigeons have been bred by humans for thousands of years as a source of food and feathers, as messengers, but also for their beauty, and more recently for sport. Pediatric medicine of pigeons has risen in importance given the interest at stake during international competitions. Young pigeons have a unique development and an increased sensitivity to both infectious and nutritional disorders compared with adults. Preventive medicine is of paramount importance and relies on measures targeting parents before breeding and chicks after hatching. Vaccination has been especially studied in pigeons.

Airborne methicillin-resistant Staphylococcus aureus, other bacteria, fungi, endotoxin, and dust in a pigeon exhibition

Pigeon breeding is associated with exposure to airborne microorganisms and endotoxin and with symptoms of the airways. Antibiotic resistance is a threat to human health. Some pigeons participate in national and international indoor exhibitions. This study aims to obtain knowledge about the potential human exposure to dust, endotoxin, fungi, and bacteria including the methicillin-resistant Staphylococcus aureus (MRSA) in a pigeon exhibition in Denmark. In walking areas for visitors, airborne microorganisms in different size fractions able to enter the airways were sampled and following identified. The average concentrations were: 5000 cfu fungi/m³, 1.8 × 10⁴ cfu bacteria/m³, 37 endotoxin units/m³, and 0.18 mg dust/m³ air with the highest concentrations in-between rows with pigeon cages. The fungal species Wallemia sp. and Aspergillus versicolor and the bacterial species S. equorum and S. aureus were found in high concentrations. MRSA spa type t034 described to be associated with livestock was found in the air. Most of the S. aureus was present in the size fraction of 1.1-2.1 μm, which are particles able to enter the human terminal bronchi. In conclusion, fungi, bacteria, and endotoxin, respectively, were found in concentrations 10, 2000, and 200 times higher than outdoor references. The airborne bacteria in the exhibition were mainly species found previously in pigeon coops showing that the pigeons are the sources of exposure. The presence of airborne MRSA in the pigeon exhibition highlights the importance of also considering this environment as a potential place of exchange of resistant bacteria between animals and between animals and humans.

Pigeon Rotavirus A as the cause of systemic infection in juvenile pigeons (young pigeon disease)

Recent investigations suggested pigeon associated Rotavirus Typ A genotype G18P[17] (RVA) as a causative agent of the classical 'young pigeon disease' (YPD). YPD was first described in the late 1980 s as an acute, mainly seasonally recurring disorder of mostly juvenile domestic pigeons (Columba livia) with clinical signs such as anorexia, dairrhea, vomiting, congested crops, weight loss and occasionally mortality. Various studies in the past indicated a multifactorial nature of YPD. Several pathogens, such as pigeon circovirus 1, avian adenoviruses and Escherichia coli were also suggested, but none of these could reproduce the disease experimentally. However, the impact of other pathogens on the clinical development of YPD cannot be excluded and requires further investigation. This present review summarizes available information on RVA-induced disease in pigeons, its association with YPD, the transmission, and diagnosis of the infection, and on prophylactic strategies to prevent RVA outbreaks.

Pigeon Circovirus over Three Decades of Research: Bibliometrics, Scoping Review, and Perspectives

The pigeon circovirus (PiCV), first described in the literature in the early 1990s, is considered one of the most important infectious agents affecting pigeon health. Thirty years after its discovery, the current review has employed bibliometric strategies to map the entire accessible PiCV-related research corpus with the aim of understanding its present research landscape, particularly in consideration of its historical context. Subsequently, developments, current knowledge, and important updates were provided. Additionally, this review also provides a textual analysis examining the relationship between PiCV and the young pigeon disease syndrome (YPDS), as described and propagated in the literature. Our examination revealed that usages of the term 'YPDS' in the literature are characterizations that are diverse in range, and neither standard nor equivalent. Guided by our understanding of the PiCV research corpus, a conceptualization of PiCV diseases was also presented in this review. Proposed definitions and diagnostic criteria for PiCV subclinical infection (PiCV-SI) and PiCV systemic disease (PiCV-SD) were also provided. Lastly, knowledge gaps and open research questions relevant to future PiCV-related studies were identified and discussed.

Genome Sequence of Rotavirus A from a Florida Racing Pigeon (Columba livia domestica)

The complete coding sequence of a rotavirus A strain was determined from a dead racing pigeon in Florida. It was found to be most closely related to a rotavirus A strain isolated from a dead racing pigeon in California.

Health Status and Stress in Different Categories of Racing Pigeons

Simple Summary

Corticosterone is the most important “stress” hormone in birds. Stress response is influenced by different factors, such as phylogeny, feed supply, age, body condition, health status, climate, predators. Pigeon races over long distances, 500 km or more, can lead to the “exploitation” of animals if not strictly regulated and observed, jeopardizing their welfare status. Animals should be in good health and body condition, and health monitoring must be implemented. In stressful situations such as races, the possibility of infection increases. Clinically asymptomatic infections can flare up later in the breeding season and can cause high offspring mortality. For example, infections with circoviruses are particularly important because of their ability to weaken the immune system. The purpose of this work is to identify the critical stress points during the active training season of racing pigeons for the improvement of their condition and the preservation of their welfare during races. The aim of our study was to determine the serum corticosterone levels in different categories of racing pigeons exposed to severe stress factors. At the time of racing, some parameters of stress, including environmental factors, or the presence of infectious diseases or parasites, were recorded. It was found that participation in the race significantly increased serum corticosterone levels and remained high even one month after the race. Therefore, training and races should be properly managed and planned.

Abstract

The influence of different stress parameters in racing pigeon flocks, such as the presence of diseases and environmental conditions at the time of the races, were described. A total of 96 racing pigeons from 4 pigeon flocks were examined, and health monitoring was carried out. No helminth eggs and coccidia were found. Trichomonas sp. was confirmed in subclinical form. Paramyxoviruses and avian influenza viruses were not confirmed, but circovirus infections were confirmed in all flocks. Chlamydia psittaci was confirmed in one flock. Blood samples were collected, and HI antibody titers against paramyxoviruses before and 25 days after vaccination were determined. To improve the conditions during racing and the welfare of the pigeons, critical points were studied with regard to stress factors during the active training season. Serum corticosterone levels were measured in the blood serum of four different categories of pigeons from each flock. Corticosterone levels were almost twice as high in pigeons from the category that were active throughout the racing season, including medium- and long-distance racing, compared to the other three categories that were not racing actively. Within five hours of the finish of a race, the average serum corticosterone level was 59.4 nmol/L in the most physically active category. The average serum corticosterone level in this category remained at 37.5 nmol/L one month after the last race.