In a warm climate, ventilation, indoor temperature and outdoor relative humidity have significant effects on Campylobacter spp. colonization in chicken broiler farms which can occur in only 2 days.

A longitudinal study was conducted in five conventional broiler farms during a 2-year period to determine the dynamics of Campylobacter infection in a warm climate region (north-eastern Spain). Weekly sampling of 63 flocks was performed upon one-day-old chick placement, including animal and environmental samples. Campylobacter spp.

Assessment of laying-bird welfare following acaricidal treatment of a commercial flock naturally infested with the poultry red mite (Dermanyssus gallinae).

The poultry red mite (PRM), Dermanyssus gallinae, a potential vector of pathogens to animals and humans, causes impaired bird welfare. A study investigated changes in behavioural variables, physiological biomarkers, and health parameters following acaricidal treatment of PRM infestation of laying hens on a commercial farm. Mite traps determined the challenge to 12,700 hens before and after drinking water administration of the acaricide, fluralaner (Exzolt®, 0.

Evaluation of a Phylogenetic Marker Based on Genomic Segment B of Infectious Bursal Disease Virus: Facilitating a Feasible Incorporation of this Segment to the Molecular Epidemiology Studies for this Viral Agent.

Background: Infectious bursal disease (IBD) is a highly contagious and acute viral disease, which has caused high mortality rates in birds and considerable economic losses in different parts of the world for more than two decades and it still represents a considerable threat to poultry. The current study was designed to rigorously measure the reliability of a phylogenetic marker included into segment B. This marker can facilitate molecular epidemiology studies, incorporating this segment of the viral genome, to better explain the links between emergence, spreading and maintenance of the very virulent IBD virus (vvIBDV) strains worldwide.

Assessment of two different types of sample for the early detection and isolation of thermophilic Campylobacter in broiler farms.

In order to assess the optimal method for the early detection and isolation of thermophilic Campylobacter in broilers at farm level, two types of samples were compared: caecal contents obtained by necropsy and cloacal swabs transported in charcoal Amies medium. The study was conducted in five batches of broilers from five different farms, where weekly samples (caecal contents and cloacal swabs) from 30 birds were obtained. Samples were plated onto selective agar (modified charcoal cefoperazone desoxycholate agar, mCCDA) for Campylobacter isolation.

Pathobiology of avian influenza virus infection in minor gallinaceous species: a review.

Susceptibility to avian influenza viruses (AIVs) can vary greatly among bird species. Chickens and turkeys are major avian species that, like ducks, have been extensively studied for avian influenza. To a lesser extent, minor avian species such as quail, partridges, and pheasants have also been investigated for avian influenza.

The NS segment of H5N1 avian influenza viruses (AIV) enhances the virulence of an H7N1 AIV in chickens.

Some outbreaks involving highly pathogenic avian influenza viruses (HPAIV) of subtypes H5 and H7 were caused by avian-to-human transmissions. In nature, different influenza A viruses can reassort leading to new viruses with new characteristics. We decided to investigate the impact that the NS-segment of H5 HPAIV would have on viral pathogenicity of a classical avian H7 HPAIV in poultry, a natural host.

Spatiotemporal Phylogenetic Analysis and Molecular Characterisation of Infectious Bursal Disease Viruses Based on the VP2 Hyper-Variable Region.

Background: Infectious bursal disease is a highly contagious and acute viral disease caused by the infectious bursal disease virus (IBDV); it affects all major poultry producing areas of the world. The current study was designed to rigorously measure the global phylogeographic dynamics of IBDV strains to gain insight into viral population expansion as well as the emergence, spread and pattern of the geographical structure of very virulent IBDV (vvIBDV) strains.

Methodology/principal Findings: Sequences of the hyper-variable region of the VP2 (HVR-VP2) gene from IBDV strains isolated from diverse geographic locations were obtained from the GenBank database; Cuban sequences were obtained in the current work.

Pathobiology and transmission of highly and low pathogenic avian influenza viruses in European quail (Coturnix c. coturnix).

European quail (Coturnix c. coturnix) may share with Japanese quail (Coturnix c. japonica) its potential as an intermediate host and reservoir of avian influenza viruses (AIV).

Phylogeographic distribution of very virulent infectious bursal disease virus isolates in the Iberian Peninsula.

Viral population dynamics of very virulent infectious bursal disease virus (vvIBDV) field strains isolated in the Iberian Peninsula since the first outbreak in the 1990s have been analysed. Low levels of genetic variability and a global purification selection pattern were reported in 480 base pairs of the hypervariable region of the VP2 gene, indicating a lack of a selection-driven immune escape in the evolutive pathway of the virus. The viral population structure of vvIBDV strains in the Iberian Peninsula showed a strong relationship between geography and phylogeny, with two main groups observed.

Highly (H5N1) and low (H7N2) pathogenic avian influenza virus infection in falcons via nasochoanal route and ingestion of experimentally infected prey.

An experimental infection with highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) viruses was carried out on falcons in order to examine the effects of these viruses in terms of pathogenesis, viral distribution in tissues and viral shedding. The distribution pattern of influenza virus receptors was also assessed. Captive-reared gyr-saker (Falco rusticolus x Falco cherrug) hybrid falcons were challenged with a HPAI H5N1 virus (A/Great crested grebe/Basque Country/06.

New insights on infectious bronchitis virus pathogenesis: characterization of Italy 02 serotype in chicks and adult hens.

Infectious bronchitis (IB) is a worldwide disease affecting chickens of all ages and causing important economic losses in poultry industry. Despite being one of the predominant IB virus (IBV) serotype in several European countries, slightly is known about pathogenesis and pathogenicity of Italy 02 serotype. In this study chicks and old hens were infected by oculo-nasal route with Italy 02 serotype.

Neuropathogenesis of a highly pathogenic avian influenza virus (H7N1) in experimentally infected chickens.

In order to understand the mechanism of neuroinvasion of a highly pathogenic avian influenza virus (HPAIV) into the central nervous system (CNS) of chickens, specific pathogen free chickens were inoculated with a H7N1 HPAIV. Blood, cerebrospinal fluid (CSF), nasal cavity and brain tissue samples were obtained from 1 to 4 days post-inoculation (dpi) of infected and control chickens. Viral antigen topographical distribution, presence of influenza A virus receptors in the brain, as well as, the role of the olfactory route in virus CNS invasion were studied using different immunohistochemistry techniques.

Pathogenesis of highly pathogenic avian influenza A virus (H7N1) infection in chickens inoculated with three different doses.

To study the pathogenesis of a H7N1 highly pathogenic avian influenza virus strain, specific pathogen free chickens were inoculated with decreasing concentrations of virus: 10(5.5) median embryo lethal dose (ELD(50)) (G1), 10(3.5) ELD(50) (G2) and 10(1.

Pathogenesis and transmissibility of highly (H7N1) and low (H7N9) pathogenic avian influenza virus infection in red-legged partridge (Alectoris rufa).

An experimental infection with highly pathogenic avian influenza virus (HPAIV) and low pathogenic avian influenza virus (LPAIV) was carried out in red-legged partridges (Alectoris rufa) in order to study clinical signs, gross and microscopic lesions, and viral distribution in tissues and viral shedding. Birds were infected with a HPAIV subtype H7N1 (A/Chicken/Italy/5093/1999) and a LPAIV subtype H7N9 (A/Anas crecca/Spain/1460/2008). Uninoculated birds were included as contacts in both groups.

Molecular characterization of Newcastle disease viruses in Ostriches (Struthio camelus L.): further evidences of recombination within avian paramyxovirus type 1.

Newcastle disease virus (NDV) strains isolated from ostriches have been genotyped for the first time by partial sequencing of the F gene to determine the epidemiologic role that this species can play within ND outbreaks. Fifteen additional NDV strains, mostly isolated from chickens but also from pigeons and penguins, were also included in the study to determine genetic relationships with ostriches NDV isolates. High genetic diversity was demonstrated in ostrich NDV isolates, as the 10 isolates were grouped in four distinct NDV genotypes.

Persistence of highly pathogenic avian influenza virus (H7N1) in infected chickens: feather as a suitable sample for diagnosis.

Selection of an ideal sample is a vital element in early detection of influenza infection. Rapid identification of infectious individuals or animals is crucial not only for avian influenza virus (AIV) surveillance programmes, but also for treatment and containment strategies. This study used a combination of quantitative real-time RT-PCR with an internal positive control and a cell-titration system to examine the presence of virus in different samples during active experimental AIV infection and its persistence in the infected carcasses.

Applying phylogenetic analysis to viral livestock diseases: moving beyond molecular typing.

Changes in livestock production systems in recent years have altered the presentation of many diseases resulting in the need for more sophisticated control measures. At the same time, new molecular assays have been developed to support the diagnosis of animal viral disease. Nucleotide sequences generated by these diagnostic techniques can be used in phylogenetic analysis to infer phenotypes by sequence homology and to perform molecular epidemiology studies.

The VG/GA strain of Newcastle disease virus: mucosal immunity, protection against lethal challenge and molecular analysis.

The Villegas-Glisson/University of Georgia (VG/GA) strain of Newcastle disease virus (NDV) isolated from the intestine of healthy turkeys has been proposed to replicate in the respiratory and intestinal tract of chickens. In the present study, the virus distribution, the mucosal and systemic immune response, the efficacy against lethal challenge and the full genome sequence of the VG/GA strain were compared with the La Sota strain of NDV. The VG/GA strain was detected at different time points in the respiratory and intestinal tract of chickens with a preferential tropism for the latter.

Molecular epidemiology and evolution of avian infectious bronchitis virus in Spain over a fourteen-year period.

An in-depth molecular study of infectious bronchitis viruses (IBV) with particular interest in evolutionary aspects of IBV in Spain was carried out in the present study based on the S1 gene molecular characterization of twenty-six Spanish strains isolated over a fourteen-year period. Four genotypes were identified based on S1 gene sequence analyses and phylogenetic studies. A drastic virus population shift was demonstrated along time and the novel Italy 02 serotype was shown to have displaced the previous predominant serotype 4/91 in the field.

Antigenic and molecular characterization of isolates of the Italy 02 infectious bronchitis virus genotype.

As part of an epidemiological surveillance of infectious bronchitis virus (IBV) in Spain, four Spanish field isolates showed high S1 spike sequence similarities with an IBV sequence from the GenBank database named Italy 02. Given that little was known about this new emergent IBV strain we have characterized the four isolates by sequencing the entire S1 part of the spike protein gene and have compared them with many reference IBV serotypes. In addition, cross-virus neutralization assays were conducted with the main IBV serotypes present in Europe.