Prolonged repeated inseminations trigger a local immune response and accelerate aging of the uterovaginal junction in turkey hens.

Artificial insemination is a standard practice in the turkey breeder industry to ensure the production of fertile eggs. Even though hens are inseminated on a weekly basis, their fertility tends to decline after a few weeks of production. Avian species have a specialized structures called sperm storage tubules (SSTs), located in the uterovaginal junction (UVJ) of the oviduct. The ability of SSTs to store sperm is directly correlated with the fertility of the hen. The objective of the study was to examine changes in the transcriptome of the turkey hen's UVJ in response to the presence of sperm at three key stages of production. We hypothesized that repeated and prolonged exposure to sperm would alter the transcriptome of the UVJ. Samples were collected from virgin hens prior to the onset of lay, as well as from sham-inseminated (extender only) and semen-inseminated hens at early lay, peak lay, and late lay. Gene expression profiling of the UVJ was examined, and a differential expression analysis was conducted through pairwise comparisons between semen- and sham-inseminated groups at each production stage and across production stages. In the early laying stage, no significant gene expression changes were found between semen- and sham-inseminated groups. However, at peak lay, genes related to lipid biosynthesis, Wnt signaling, cell proliferation, and O-glycan biosynthesis were upregulated in the semen group, while the immune response and cytokine-cytokine receptor interaction were downregulated. In the late lay stage, the transcription pathway was upregulated in the semen group, whereas the translation pathway was downregulated. The local immune response that was suppressed during peak lay was increased at the late laying stage. In the semen-inseminated group, the UVJ exhibited advanced aging at the late laying stage, evidenced by reduced telomere maintenance and translation processes. The results from this study provide valuable insights into the alteration of the UVJ function in response to the presence of sperm at different stages of production and throughout the production cycle. Targeting the modulation of local immune response and addressing aging processes after peak production could potentially prevent or delay the decline in fertility of turkey breeder hens.

Refining the definition of the avian pathogenic Escherichia coli (APEC) pathotype through inclusion of high-risk clonal groups.

Colibacillosis in poultry is a unique disease manifestation of Escherichia coli in the animal world, as one of the primary routes of entry is via the respiratory tract of birds. Because of this, a novel extraintestinal pathogenic E. coli (ExPEC) subpathotype coined avian pathogenic E. coli (or APEC) has been described. Like other ExPEC, this pathotype has been challenging to clearly define, and in the case of APEC, its role as an opportunistic pathogen has further complicated these challenges. Using 3,479 temporally matched genomes of poultry-source isolates, we show that the APEC plasmid, previously considered a defining trait of APEC, is highly prevalent in clinical isolates from diseased turkeys. However, the plasmid is also quite prevalent among cecal E. coli isolates from healthy birds, including both turkeys and broilers. In contrast, we identify distinct differences in clonal backgrounds of turkey clinical versus cecal strains, with a subset of sequence types (STs) dominating the clinical landscape (ST23, ST117, ST131, ST355, and ST428), which are rare within the cecal landscape. Because the same clinical STs have also dominated the broiler landscape, we performed lethality assays using strains from dominant STs from clinical or cecal landscapes in embryonated turkey and chicken eggs. We show that, irrespective of plasmid carriage, dominant clinical STs are significantly more virulent than dominant cecal STs. We present a revised APEC screening tool that incorporates APEC plasmid carriage plus markers for dominant clinical STs. This revised APEC pathotyping tool improves the ability to identify high-risk APEC clones within poultry production systems, and identifies STs of interest for mitigation targets.

The Risk of Highly Pathogenic Influenza A Virus Transmission to Turkey Hen Flocks Through Artificial Insemination.

Artificial insemination is a routine practice for turkeys that can introduce pathogens into breeder flocks in a variety of ways. In this manuscript, a risk analysis on the potential transmission of highly pathogenic avian influenza (HPAI) to naïve hens through artificial insemination is presented. A case of HPAI on a stud farm where the potential transmission of the virus to susceptible hens in the 2015 H5N2 HPAI outbreak in Minnesota is described along with documentation of known and potential transmission pathways from the case. The pathways by which artificial insemination might result in the spread of HPAI to susceptible hens were determined by considering which could result in the 1) entry of HPAI virus onto a premises through semen movement; and 2) exposure of susceptible hens to HPAI as a result of this movement. In the reported case, HPAI virus was detected in semen from infected toms, however, transmission of HPAI to naïve hens through semen is unclear since the in utero infectious dose is not known. This means that the early detection of infection might limit but not eliminate the risk of hen exposure. Because of the numerous potential pathways of spread and the close contact with the birds, it is highly likely that if semen from an HPAI-infected tom flock is used, there will be spread of the virus to naïve hens through insemination. If insemination occurs with semen from stud farms in an HPAI control area, receiving hen farms should have restricted movements to prevent outbreak spread in the event that they become infected.

Artículo regular­Riesgo de transmisión del virus de la influenza A altamente patógeno a parvadas de pavos hembras mediante inseminación artificial. La inseminación artificial es una práctica de rutina para los pavos que puede introducir patógenos en las parvadas de reproductores de diversas formas. En este manuscrito, se presenta un análisis de riesgo sobre la posible transmisión de la influenza aviar altamente patógena a gallinas susceptibles mediante inseminación artificial. Un caso de influenza aviar altamente patógena en una granja de machos sementales donde se describe la posible transmisión del virus a gallinas susceptibles en el brote de influenza aviar altamente patógena H5N2 del año 2015 en Minnesota, junto con la documentación de las vías de transmisión conocidas y potenciales del caso. Las vías por las cuales la inseminación artificial podría resultar en la propagación de la influenza aviar altamente patógena a las gallinas susceptibles se determinaron considerando cuáles podrían resultar en 1) la entrada del virus de la influenza aviar altamente patógena en una granja a través del movimiento del semen; y 2) exposición de gallinas susceptibles a la influenza aviar altamente patógena como resultado de este movimiento. Sin embargo, se demostró la detección del virus de la influenza aviar altamente patógena en el semen de machos infectados. Debido a que se desconoce la dosis infecciosa del virus de la influenza aviar administrada en el útero necesaria para transmitir la influenza aviar altamente patógena a las gallinas susceptibles, está claro que la detección de la infección no puede ser la única estrategia de contención. La detección temprana de la infección puede limitar, pero no eliminar, el riesgo de exposición de las gallinas. Debido a las numerosas vías potenciales de propagación y al estrecho contacto con las aves, es muy probable que si se usa semen de una parvada de machos infectados con influenza aviar de alta patogenicidad, se propague el virus a gallinas susceptibles a través de la inseminación. Si la inseminación ocurre con semen de granjas de sementales en un área de control de influenza aviar de alta patogenicidad, las granjas de gallinas receptoras deben tener movimientos restringidos para prevenir la propagación del brote en caso de que se infecten.

Genomic diversity and molecular epidemiology of Pasteurella multocida.

Pasteurella multocida is a bacterial pathogen with the ability to infect a multitude of hosts including humans, companion animals, livestock, and wildlife. This study used bioinformatic approaches to explore the genomic diversity of 656 P. multocida isolates and epidemiological associations between host factors and specific genotypes. Isolates included in this study originated from a variety of hosts, including poultry, cattle, swine, rabbits, rodents, and humans, from five different continents. Multi-locus sequence typing identified 69 different sequence types. In-silico methodology for determining capsular serogroup was developed, validated, and applied to all genome sequences, whereby capsular serogroups A, B, D, and F were found. Whole genome phylogeny was constructed from 237,670 core single nucleotide variants (SNVs) and demonstrated an overall lack of host or capsular serogroup specificity, with the exception of isolates from bovine sources. Specific SNVs within the srlB gene were identified in P. multocida subsp. septica genomes, representing specific mutations that may be useful for differentiating one of the three known subspecies. Significant associations were identified between capsular serogroup and virulence factors, including capsular serogroup A and OmpH1, OmpH3, PlpE, and PfhB1; capsular serogroup B and HgbA and PtfA; and capsular serogroup F and PtfA and PlpP. Various mobile genetic elements were identified including those similar to ICEPmu1, ICEhin1056, and IncQ1 plasmids, all of which harbored multiple antimicrobial resistance-encoding genes. Additional analyses were performed on a subset of 99 isolates obtained from turkeys during fowl cholera outbreaks from a single company which revealed that multiple strains of P. multocida were circulating during the outbreak, instead of a single, highly virulent clone. This study further demonstrates the extensive genomic diversity of P. multocida, provides epidemiological context to the various genotyping schemes that have traditionally been used for differentiating isolates, and introduces additional tools for P. multocida molecular typing.

Genomic Landscape of Ornithobacterium rhinotracheale in Commercial Turkey Production in the United States.

Ornithobacterium rhinotracheale is a causative agent of respiratory tract infections in avian hosts worldwide but is a particular problem for commercial turkey production. Little is known about the ecologic and evolutionary dynamics of O. rhinotracheale, which makes prevention and control of this pathogen a challenge. The purpose of this study was to gain insight into the genetic relationships between O. rhinotracheale populations through comparative genomics of clinical isolates from different U.S. turkey producers. O. rhinotracheale clinical isolates were collected from four major U.S. turkey producers and several independent turkey growers from the upper Midwest and Southeast, and whole-genome sequencing was performed. Genomes were compared phylogenetically using single nucleotide polymorphism (SNP)-based analysis, and then assembly and annotations were performed to identify genes encoding putative virulence factors and antimicrobial resistance determinants. A pangenome approach was also used to establish a core set of genes consistently present in O. rhinotracheale and to highlight differences in gene content between phylogenetic clades. A total of 1,457 nonrecombinant SNPs were identified from 157 O. rhinotracheale genomes, and four distinct phylogenetic clades were identified. Isolates clustered by company on the phylogenetic tree, however, and each company had isolates in multiple clades with similar collection dates, indicating that there are multiple O. rhinotracheale strains circulating within each of the companies examined. Additionally, several antimicrobial resistance proteins, putative virulence factors, and the pOR1 plasmid were associated with particular clades and multilocus sequence types, which may explain why the same strains seem to have persisted in the same turkey operations for decades.IMPORTANCE The whole-genome approach enhances our understanding of evolutionary relationships between clinical Ornithobacterium rhinotracheale isolates from different commercial turkey producers and allows for identification of genes associated with virulence, antimicrobial resistance, or mobile genetic elements that are often excluded using traditional typing methods. Additionally, differentiating O. rhinotracheale isolates at the whole-genome level may provide insight into selection of the most appropriate autogenous vaccine strain, or groups of strains, for a given population of clinical isolates.

Environmental Sampling for Influenza A Viruses in Turkey Barns.

We have examined a variety of sampling strategies for detecting pathogens in turkey flocks undergoing infections with low pathogenicity avian influenza virus (LPAIV). We found that viral RNA was widely distributed in the barn environment of turkey flocks undergoing an active LPAIV infection and was in both water and drinker biofilm samples. Viral RNA was concentrated in drinker biofilm and sediment and was detectable using real-time reverse-transcription polymerase chain reaction (RRT-PCR) and by virus isolation. Drinker biofilm sample results correlated with concurrently collected oropharyngeal (OP) sample results from flocks on a farm with LPAI in which the two sampling strategies were directly compared. To evaluate the utility of biofilm sampling for the detection of highly pathogenic avian influenza virus (HPAIV), biofilm and OP swabs from mortality pools were collected daily from negative turkey flocks on an HPAI-positive premise. The biofilm swabs were positive 1-2 days prior to positives appearing in the OP sample pools. The drinker biofilm sampling strategy overcame the difficulty of finding a subclinical infectious bird in a population by collecting material from a large number of individuals and testing a sample in which a positive signal persists for several days to weeks. The sampling method is convenient for use in turkey barns and has been reliably used in both active and passive surveillance programs for LPAIV and HPAIV using RRT-PCR.

Muestreo ambiental para el virus de influenza A en casetas de pavos. Se han examinado una variedad de estrategias de muestreo para detectar patógenos en parvadas de pavos que sufren infecciones con el virus de la influenza aviar de baja patogenicidad (con las siglas en inglés LPAIV). Se encontró que el ARN viral se distribuyó ampliamente en el ambiente de las casetas con parvadas de pavos con infección activa por el virus de la influenza aviar de baja patogenicidad y se determinó tanto en muestras de agua como en muestras de la biopelícula de bebederos. El ARN viral se concentró en la biopelícula y en el sedimento de bebederos y se detectó mediante transcripción reversa y reacción en cadena de la polimerasa en tiempo real (RRT-PCR) y mediante el aislamiento del virus. Los resultados de la muestra de la biopelícula del bebedero se correlacionaron con los resultados de la muestra orofaríngea (OP) colectada de forma simultánea de parvadas en una granja con influenza aviar de baja patogenicidad en las que se compararon directamente las dos estrategias de muestreo. Para evaluar la utilidad del muestreo de la biopelícula para la detección del virus de la influenza aviar altamente patógena (HPAIV), se recolectaron diariamente biopelículas e hisopos orofaríngeos de grupos de mortalidad de parvadas de pavos negativas en una granja positiva para la influenza aviar de alta patogenicidad. Los hisopos de biopelículas fueron positivos de uno a dos días antes de que aparecieran resultados positivos en las muestras orofaríngeas agrupadas. La estrategia de muestreo de la biopelícula del bebedero eliminó la dificultad de encontrar un ave infectada subclínicamente en una población al recolectar material de un gran número de individuos y analizar una muestra en la que persiste una señal positiva durante varios días o semanas. El método de muestreo es adecuado para su uso en casetas de pavos y se ha utilizado de manera confiable en los programas de vigilancia activa y pasiva para el virus de influenza aviar tanto de baja como de alta patogenicidad utilizando transcripción reversa y reacción en cadena de la polimerasa en tiempo real.