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A complete genome sequence of a VG/GA -like strain of avian orthoavulavirus 1 (AOAV-1) was identified by nontargeted next-generation sequencing of an oropharyngeal swab sample collected from a carcass of a 12-mo-old backyard chicken. The isolate has a fusion (F) protein cleavage site motif consistent with a low virulent AOAV-1, but it has a unique motif with phenylalanine at position 117 (112G-R-Q-G-R↓F117), which is typical for virulent AOAV-1 strains. The one nucleotide difference at the cleavage site compared to other low-virulence viruses made the isolate detectable by F-gene–specific real-time reverse transcription-PCR (rRT-PCR) developed as a diagnostic test to specifically detect virulent strains. The mean death time determined in eggs and intracerebral pathogenicity index determined in chickens classified the isolate as lentogenic. This is the first report of a lentogenic VG/GA-like virus with a phenylalanine residue at position 117 of the F protein cleavage site in the United States. In addition to concern for potential pathogenic shift of the virus through additional changes at the cleavage site, our finding warrants increased awareness of diagnosticians of potential false positive F-gene rRT-PCR tests. Secuenciación y caracterización del genoma de un aislado similar a VG/GA del ortoavulavirus aviar 1 con un motivo único en el sitio de disociación del gene de fusión. Se identificó una secuencia genómica completa de una cepa similar a la cepa Villegas-Glisson/Universidad de Georgia (VG/GA) del ortoavulavirus aviar 1 (AOAV-1) mediante secuenciación no dirigida de nueva generación de una muestra de hisopo orofaríngeo recolectada de una gallina muerta de traspatio de 12 meses. El aislado tiene un motivo en el sitio de disociación de la proteína de fusión (F) consistente con un ortoavulavirus aviar de baja virulencia, pero tiene un motivo único con fenilalanina en la posición 117 (112G-R-Q-G-R↓F117), que es típico para cepas virulentas del AOAV-1. La diferencia de un nucleótido en el sitio de escisión en comparación con otros virus de baja virulencia hizo que el aislado fuera detectable mediante transcripción reversa y PCR en tiempo real en tiempo real específica del gene F (rtRT-PCR) desarrollada como una prueba de diagnóstico para detectar específicamente a las cepas virulentas. El tiempo medio de muerte determinado en huevos y el índice de patogenicidad intracerebral determinado en pollos clasificaron al aislado como lentogénico. Este es el primer informe en los Estados Unidos de un virus lentogénico similar a VG/GA con un residuo de fenilalanina en la posición 117 del sitio de disociación de la proteína F. Además de la preocupación por el posible cambio patogénico del virus a través de cambios adicionales en el sitio de disociación, nuestro contribuye con un mayor conocimiento por parte del personal de diagnóstico acerca de posibles falsos positivos en las pruebas rtRT-PCR del gene F. [ABSTRACT FROM AUTHOR]

PCR-based assays have become the benchmark for detecting pathogens of poultry and other livestock; however, these techniques are limited in their ability to detect multiple infecting agents, provide limited genetic information on the pathogen, and, for RNA viruses, must be reviewed frequently to assure high sensitivity and specificity. In contrast, untargeted, high-throughput sequencing can rapidly detect all infecting agents in a sample while providing genomic sequence information to allow more in-depth characterization of viruses. Although next-generation sequencing (NGS) offers many advantages, one of its primary limitations is low sensitivity to pathogens given the abundance of host and other non-target sequences in sequencing libraries. We explored methods for improving the sensitivity of NGS to detect respiratory and enteric viruses in poultry from RNA extracts of swab samples. We employed commercial and custom-designed negative enrichment strategies to selectively deplete the most abundant rRNA reads from the host and non-target bacteria; host RNA was diminished from up to 40% of total reads to as low as 3%, and the total number of reads assigned to abundant bacterial classes were reduced greatly. Our treatment resulted in up to a 700-fold increase in the number of viral reads, detection of a greater number of viral agents, and higher average genome coverage for pathogens. Depletion assays added only 2 h to the NGS library preparation workflow. Custom depletion probe design offered significant cost savings (US$7–12 per sample) compared to commercial kits (US$30–50 per sample). [ABSTRACT FROM AUTHOR]

Copyright of Avian Diseases is the property of American Association of Avian Pathologists, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Avian Diseases is the property of American Association of Avian Pathologists, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the 2014–2015 Eurasian lineage clade 2.3.4.4A H5 highly pathogenic avian influenza (HPAI) outbreak in the U.S., backyard flocks with minor gallinaceous poultry and large commercial poultry (chickens and turkeys) operations were affected. The pathogenesis of the first H5N8 and reassortant H5N2 clade 2.3.4.4A HPAI U.S. isolates was investigated in six gallinaceous species: chickens, Japanese quail, Bobwhite quail, Pearl guinea fowl, Chukar partridges, and Ring-necked pheasants. Both viruses caused 80–100% mortality in all species, except for H5N2 virus that caused 60% mortality in chickens. The surviving challenged birds remained uninfected based on lack of clinical disease and lack of seroconversion. Among the infected birds, chickens and Japanese quail in early clinical stages (asymptomatic and listless) lacked histopathologic findings. In contrast, birds of all species in later clinical stages (moribund and dead) had histopathologic lesions and systemic virus replication consistent with HPAI virus infection in gallinaceous poultry. These birds had widespread multifocal areas of necrosis, sometimes with heterophilic or lymphoplasmacytic inflammatory infiltrate, and viral antigen in parenchymal cells of most tissues. In general, lesions and antigen distribution were similar regardless of virus and species. However, endotheliotropism was the most striking difference among species, with only Pearl guinea fowl showing widespread replication of both viruses in endothelial cells of most tissues. The expression of IFN-γ and IL-10 in Japanese quail, and IL-6 in chickens, were up-regulated in later clinical stages compared to asymptomatic birds. [ABSTRACT FROM AUTHOR]

Guineafowl of different ages were inoculated intravenously with a H6N2 wild waterfowl-origin low pathogenicity avian influenza virus (LPAIV). No clinical disease was observed. The infected birds had atrophy of the spleen, thymus, and cloacal bursa when compared with the noninfected control groups. The central and peripheral lymphoid tissues presented either lymphoproliferative or degenerative lesions that increased in intensity from 14 to 21 days postinoculation (DPI). Lymphoid depletion was present in the bursa, thymic lobes, and spleen T-dependent zone. In contrast, lymphoid proliferation was observed in liver, pancreas, and spleen B-dependent zone. Bronchus associated lymphoid tissue hyperplasia was observed in the lungs of the birds at 14 and 21 DPI. The virus was detected by virus isolation and reverse transcription PCR from both oropharyngeal and cloacal swabs with higher isolation rates from the latter. Most birds from the LPAIV inoculated groups shed virus up to 7 DPI. The virus was infrequently isolated from lung, kidney, liver, bursa, or spleen of infected birds until 14 DPI and from two samples (kidney and spleen, 1-yr-old birds) at 21 DPI. These data indicate that the wild bird-origin LPAIV used in this study caused pantropic infection in guineafowl when inoculated intravenously. Caracterización histopatológica y dinámica de eliminación de un virus de influenza aviar H6N2 de baja patogenicidad en gallinas de Guinea ( Numida meleagris) infectadas por vía intravenosa. Gallinas de Guinea de diferentes edades se inocularon por vía intravenosa con un virus de influenza aviar de baja patogenicidad H6N2 originado de aves acuáticas silvestres. No se observó ninguna enfermedad clínica. Las aves infectadas mostraron atrofia del bazo, el timo, y la bolsa cloacal en comparación con las aves no inoculadas del grupo de control. Los tejidos linfoides centrales y periféricos presentaron tanto lesiones linfoproliferativas o degenerativas que aumentaron en intensidad de 14 a 21 días después de la inoculación (DPI). Se observó despoblación linfoide en la bolsa de Fabricio, lóbulos tímicos, y en la zona T-dependiente del bazo. En contraste, se observó proliferación linfoide en el hígado, el páncreas y en la zona B-dependiente del bazo. Se observó hiperplasia del tejido linfoide asociado a los bronquios en los pulmones de las aves a los 14 y 21 días después de la inoculación. El virus fue detectado por el aislamiento viral y transcripción reversa y PCR de hisopos orofaríngeos y cloacales con altas tasas de aislamiento en los últimos. La mayoría de las aves inoculadas con el virus de influenza de baja patogenicidad eliminaron al virus hasta siete días postinoculación. El virus fue aislado con poca frecuencia de pulmón, riñón, hígado, bolsa, y del bazo de las aves infectadas hasta los 14 días después de la inoculación y de dos muestras (riñón y el bazo de aves de un año de edad) hasta los 21 días postinoculación. Estos datos indican que el virus de influenza aviar de baja patogenicidad de origen silvestre utilizado en este estudio causó la infección pantrópica en las gallinas de Guinea inoculadas por vía intravenosa. [ABSTRACT FROM AUTHOR]

Summary Background Ventilator-associated tracheobronchitis has been suggested as an intermediate process between tracheobronchial colonisation and ventilator-associated pneumonia in patients receiving mechanical ventilation. We aimed to establish the incidence and effect of ventilator-associated tracheobronchitis in a large, international patient cohort. Methods We did a multicentre, prospective, observational study in 114 intensive care units (ICU) in Spain, France, Portugal, Brazil, Argentina, Ecuador, Bolivia, and Colombia over a preplanned time of 10 months. All patients older than 18 years admitted to an ICU who received invasive mechanical ventilation for more than 48 h were eligible. We prospectively obtained data for incidence of ventilator-associated lower respiratory tract infections, defined as ventilator-associated tracheobronchitis or ventilator-associated pneumonia. We grouped patients according to the presence or absence of such infections, and obtained data for the effect of appropriate antibiotics on progression of tracheobronchitis to pneumonia. Patients were followed up until death or discharge from hospital. To account for centre effects with a binary outcome, we fitted a generalised estimating equation model with a logit link, exchangeable correlation structure, and non-robust standard errors. This trial is registered with ClinicalTrials.gov , number NCT01791530 . Findings Between Sept 1, 2013, and July 31, 2014, we obtained data for 2960 eligible patients, of whom 689 (23%) developed ventilator-associated lower respiratory tract infections. The incidence of ventilator-associated tracheobronchitis and that of ventilator-associated pneumonia at baseline were similar (320 [11%; 10·2 of 1000 mechanically ventilated days] vs 369 [12%; 8·8 of 1000 mechanically ventilated days], p=0·48). Of the 320 patients with tracheobronchitis, 250 received appropriate antibiotic treatment and 70 received inappropriate antibiotics. 39 patients with tracheobronchitis progressed to pneumonia; however, the use of appropriate antibiotic therapy for tracheobronchitis was associated with significantly lower progression to pneumonia than was inappropriate treatment (19 [8%] of 250 vs 20 [29%] of 70, p<0·0001; crude odds ratio 0·21 [95% CI 0·11–0·41]). Significantly more patients with ventilator-associated pneumonia died (146 [40%] of 369) than those with tracheobronchitis (93 [29%] of 320) or absence of ventilator-associated lower respiratory tract infections (673 [30%] of 2271, p<0·0001). Median time to discharge from the ICU for survivors was significantly longer in the tracheobronchitis (21 days [IQR 15–34]) and pneumonia (22 [13–36]) groups than in the group with no ventilator-associated lower respiratory tract infections (12 [8–20]; hazard ratio 1·65 [95% CI 1·38–1·97], p<0·0001). Interpretation This large database study emphasises that ventilator-associated tracheobronchitis is a major health problem worldwide, associated with high resources consumption in all countries. Our findings also show improved outcomes with use of appropriate antibiotic treatment for both ventilator-associated tracheobronchitis and ventilator-associated pneumonia, underlining the importance of treating both infections, since inappropriate treatment of tracheobronchitis was associated with a higher risk of progression to pneumonia. Funding None. [ABSTRACT FROM AUTHOR]

Highly pathogenic avian influenza virus (HPAIV) and Newcastle disease virus (NDV) are two of the most important viruses affecting poultry worldwide and produce co-infections especially in areas of the world where both viruses are endemic; but little is known about the interactions between these two viruses. The objective of this study was to determine if co-infection with NDV affects HPAIV replication in chickens. Only infections with virulent NDV strains (mesogenic Pigeon/1984 or velogenic CA/2002), and not a lentogenic NDV strain (LaSota), interfered with the replication of HPAIV A/chicken/Queretaro/14588-19/95 (H5N2) when the H5N2 was given at a high dose (106.9 EID50) two days after the NDV inoculation, but despite this interference, mortality was still observed. However, chickens infected with the less virulent mesogenic NDV Pigeon/1984 strain three days prior to being infected with a lower dose (105.3-5.5 EID50) of the same or a different HPAIV, A/chicken/Jalisco/CPA-12283-12/2012 (H7N3), had reduced HPAIV replication and increased survival rates. In conclusion, previous infection of chickens with virulent NDV strains can reduce HPAIV replication, and consequently disease and mortality. This interference depends on the titer of the viruses used, the virulence of the NDV, and the timing of the infections. The information obtained from these studies helps to understand the possible interactions and outcomes of infection (disease and virus shedding) when HPAIV and NDV co-infect chickens in the field. [ABSTRACT FROM AUTHOR]

The article discusses a study that examines the potency, efficacy, and antigenic mapping of H7 avian influenza virus vaccines against the 2012 H7N3 highly pathogenic avian influenza virus from Mexico. It also examines the efficacy of 11 other H7 AIV vaccines and an antigenic map of hemagglutination inhibition assay data with all the vaccines and challenge viruses. It aims to identify other potential vaccine strains and to characterize the relationship between genetic and antigenic distance.

Summary: Objective: During the first pandemic, some patients with pandemic (H1N1) 2009 influenza were treated with corticosteroids. The objective of this study was to assess the effect on survival of corticosteroid therapy in patients with pandemic (H1N1) 2009 influenza. Methods: Prospective, observational, multicenter study performed in 148 ICU. Data were recorded in the GTEI/SEMICYUC registry. Adult patients with pandemic (H1N1) 2009 influenza confirmed by rt-PCR were included in the analysis. Database records specified corticosteroid type and reason for corticosteroid treatment. Results: 372 patients with the diagnosis of primary viral pneumonia and completed outcomes treated in an ICU were included in the database. Mechanical ventilation was used in 70.2% of the patients. 136 (36.6%) patients received corticosteroids after a diagnosis of primary viral pneumonia. Obesity (35.6% vs 47.8% p = 0.021) and asthma (7.6% vs 15.4% p = 0.018), were more frequent in the group treated with corticosteroids. A Cox regression analysis adjusted for severity and potential confounding factors found that the use of corticosteroid therapy was not significantly associated with mortality (HR = 1.06, 95% CI 0.626–1.801; p = 0.825). Conclusions: Corticosteroid therapy in a selected group of patients with primary viral pneumonia due to pandemic (H1N1) 2009 influenza does not improve survival. [ABSTRACT FROM AUTHOR]

The article offers information on a study which described the development of a real-time reverse transcription polymerase chain reaction (RRT-PCR) test targeting a highly conserved HA2 H7 region for the identification of all H7 subtype avian influenza viruses (PanH7). A brief review of the related literature is presented. Materials and methods used included RNA purification, defining the oligonucleotide design and validation on clinical samples, among others. It discusses the findings of the study.

The article focuses on a study which described two approaches to attenuate the target avian influenza virus (AIV). The approaches include the mutation of highly pathogenic hemagglutinin (HA) cleavage site to make it low pathogenic, and the replication of full-length nonstructured (NS) gene segment with a naturally truncated 124-amino acid NS1 coding gene from A/turkey/Oregon173 (H7N3) virus (tkOR71trNS 1). Study authors constructed A/duck/Vietnam/Baclieu/09107 (rH5NI/PR8/trNS1) virus with five PR8 internal genes, tkOR71 trNS1 gene, and A/chicken/lndonesia/7/03 N1 neuraminidase gene. They found that rH5NI/PR8/trNS1 virus caused no disease in a separate intranasal inoculation test in four-week-old specific-pathogen-free chickens.

The article details a study which investigated the onset of antibody response to the nonstructural protein (NS1) in chickens infected with low pathogenic avian influenza (LPAI) virus. The study also evaluated the diagnostic potential of a baculovirus-expressed purified NS1 protein in an indirect ELISA-based discriminated between naturally infected and vaccinated-only animals (DIVA) strategy. Study authors found that vaccinated birds that were challenged with highly pathogenic avian influenza (AI) showed a higher NS1 antibody response. They discovered that the detectable immune response to NS1 in chickens develop later than the response to hemagglutinin (HA).

The article discusses a study which investigated the use of a quantitative neuraminidase (NA) inhibition (NI) test using MUN (2'-[4-methylumbelliferyl]-α-D-Nacetylneuraminic acid sodium salt hydrate) as an alternative to fetiun-based NI test in a heterologous neuraminidase differentiation of infected from vaccinated animals (DIVA). Study authors examined the serum NI activity in chickens that received vaccines containing different H5 and NA subtypes and challenged with a highly pathogenic avian influenza (HPAI) H5N2 virus. Study authors concluded that their findings showed the variation in the duration of the initial detection of NI activity against NA protein.

The article discusses the efficacy of commercial avian influenza oil emulsion vaccines of different genetic origins in protecting two-week-old white leghorn chickens and one-week-old Pekin ducks from highly pathogenic (HP) H5N1 avian influenza (AI) viruses in Vietnam. The study found that 75 to 100 percent of vaccinated chickens and all but one duck are protected from mortality. It observed differences in the levels of hemagglutination inhibition (HI) antibody titers induced by the vaccines. Study authors concluded that although the vaccines effectively protect against disease and mortality, updated and more efficient vaccines are needed for optimal protection.

The article focuses on a study which biologically characterized low pathogenic avian influenza H6N2 viruses in chickens and ducks in an effort to compare the adaptation of such viruses. The study examined the clinical signs, virus shedding and immune response to infection in four-week-old white leghorn chickens and two-week-old Pekin ducks. Virus shedding for all of the viruses was found in the oral-pharyngeal swabs from chickens at two and four days postinoculation (PI). Study authors concluded that H6N2 viruses can infect chickens and ducks, and the adaptation of such viruses is better in chickens based on the number of birds shedding virus and histopathology.

The type of endurance training in tennis will be more or less specific depending on the different biomechanical and motor actions and tactical situations, both, at the time of execution of the stroke and during the different on-court movements. However, the dynamics of the change of direction and rhythm are also fundamental. More often than not, the presence of accelerations and decelerations in sprints and stops will be a differential factor for speed and endurance in tennis. We can, thus, easily infer that a load could be very specific in a certain context and not in another one. [ABSTRACT FROM AUTHOR]

The article examines the pathogenesis, virus shedding, and serologic response in specific-pathogen-free (SPF) chickens and commercial turkeys against H4, H6, and H9 type low pathogenic avian influenza viruses from wild birds. The serum of four-week-old chickens and three-week-old turkeys were collected and examined for antibodies against avian influenza virus. Sequenced were the hemagglutinin genes of the viruses. More virus from both the oropharynx and cloaca were shed by the SPF chickens based on virus detection results. The predominance of lesions in the respiratory and gastrointestinal tract were shown by the microscopic lesion results in both species. The reasons for the difficulty of virus detection are discussed.

The article discusses a study on the removal of real-time reverse transcription polymerase chain reaction (RT-PCR) inhibitors from cloacal swab samples and tissues for improved diagnosis of Avian influenza virus by RT-PCR. It notes that the sensitivity and accuracy of the real-time RT-PCR diagnostics can be compromised by various factors, such as ribonucleic acid (RNA) extraction, primer and probe design, RT-PCR enzymes, thermocycling conditions and PCR inhibitors. The 3 different chemistries for RNA extraction which were tested in the study are cited.

This article discusses a study which examined real-time reverse transcription-polymerase chain reaction (rRT-PCR) and two commercial immunoassays for virus detection in ducks. For experimental infection purposes, a low pathogenecity avian influenza virus (LPAIV) was chosen in this study. Particular focus is given to the virus isolation process. Results of the study showed that immunoassay A was able to detect virus at days two and three postinoculation (PI) with cloacal swabs, while immunoassay B was able to detect the virus from two to four days PI. It also found that rRT-PCR was able to detect the virus from days one through seven PI with oropharyngeal swabs.

The article presents a study which compared viral shedding after vaccination with inactivated and live Newcastle Disease (ND) vaccines formulated with wild-type and recombinant viruses. It found that the reduction of viral shed from vaccinated birds infected with ND virus could potentially reduce the impact of an outbreak and help to prevent spread of disease. It revealed that virus shed can be controlled by choosing vaccines that are more genetically similar to the challenge virus and recommended that minimizing virus shed may be a useful strategy to limit the spread of the disease.