Relationship Between the Serotypes and Hemagglutinin Gene Sequences of Avibacterium paragallinarum.

Avibacterium paragallinarum has been subtyped into three serogroups (A, B, and C) and nine serovars (A-1, A-2, A-3, A-4, B-1, C-1, C-2, C-3, and C-4) according to the Page and Kume schemes. Both schemes use the hemagglutination inhibition test for serotyping. However, the relationship between the hemagglutinin gene (HMTp210) sequences and serotypes of A. paragallinarum is still unclear. This problem is partly due to the lack of information on the complete HMTp210 sequence from the formal reference strain of Page serogroup B (strain 0222 or Spross). In this study, we determined the complete HMTp210 sequence of strain Spross. The sequence of Spross and those of other HMTp210 sequences retrieved from GenBank were used to conduct phylogenetic analyses to investigate the relationship between the serotypes and HMTp210 sequences of A. paragallinarum. Four phylogenetic clusters, designated clusters A-1, A-2, B, and C, were identified. Clustering based on complete HMTp210 sequences correlates with serotyping based on hemagglutination inhibition tests. Serovar A-2 was found to contain a chimeric HMTp210 gene that might have resulted from recombination between serovar A-1 and serovar C-1. In addition, phylogenetic analysis based on partial sequences (approximately nucleotides 1-1200) of HMTp210 was sufficient to discriminate between serogroups A, B, and C. These findings could be valuable for developing a molecular method for serotyping of A. paragallinarum.

Relación entre los serotipos y las secuencias génicas de hemaglutinina de Avibacterium paragallinarum. Avibacterium paragallinarum se ha subtipificado en tres serogrupos (A, B y C) y nueve serovares (A-1, A-2, A-3, A-4, B-1, C-1, C-2, C- 3 y C-4) de acuerdo con los esquemas Page y Kume. Ambos esquemas utilizan la prueba de inhibición de la hemaglutinación para la serotipificación. Sin embargo, la relación entre las secuencias del gene de la hemaglutinina (HMTp210) y los serotipos de A. paragallinarum aún no está clara. Este problema se debe en parte a la falta de información sobre la secuencia completa del gene HMTp210 de la cepa de referencia formal del serogrupo B de Page (cepa 0222 o Spross). En este estudio, se determinó la secuencia completa de HMTp210 de la cepa Spross. La secuencia de Spross y las de otras secuencias del gene HMTp210 obtenidas de GenBank se utilizaron para realizar análisis filogenéticos para investigar la relación entre los serotipos y las secuencias de HMTp210 de A. paragallinarum. Se identificaron cuatro agrupaciones filogenéticas, denominadas grupos A-1, A-2, B y C. La agrupación basada en las secuencias completas del gene HMTp210 se correlaciona con la serotipificación basada en pruebas de inhibición de la hemaglutinación. Se encontró que el serovar A-2 contenía un gene HMTp210 quimérico que podría haber resultado de la recombinación entre el serovar A-1 y el serovar C-1. Además, el análisis filogenético basado en secuencias parciales (aproximadamente nucleótidos 1-1200) del gene HMTp210 fue suficiente para discriminar entre los serogrupos A, B y C. Estos hallazgos podrían ser valiosos para desarrollar un método molecular para la serotipificación de A. paragallinarum.

Serotypes and Hemagglutinin Gene Sequences of Avibacterium paragallinarum Isolated in Taiwan.

Despite routine vaccine use, sporadic outbreaks of infectious coryza in poultry continue to occur in Taiwan. This study was designed to determine the serotypes and the complete nucleotide sequences of a hemagglutinin gene (HMTp210) of Avibacterium paragallinarum isolated in Taiwan between 1994 and 2017. Hemagglutination inhibition tests showed that these isolates belong to serogroups B and C. Sequence analyses of the HMTp210 gene showed that Taiwanese serogroup B isolates are most similar (94.7%-98.2% identity) to strain FARPER-174 isolated in Peru in 2015. In contrast, Taiwanese serogroup C isolates are most similar (96.3%-99.8% identity) to strain H-18 isolated in Japan in 1976. This is the first report showing the presence of A. paragallinarum of serogroup B in Taiwan. In addition, one Taiwanese isolate showed cross-reactivity with serogroup B and C antisera. This isolate contains a chimeric HMTp210 gene that might result from recombination between serogroups B and C. These findings could be valuable for the epidemiologic study and molecular serotyping of A. paragallinarum.

Serotipos y secuencias de genes de hemaglutinina de Avibacterium paragallinarum aislados en Taiwán. A pesar del uso rutinario de vacunas, en Taiwán continúan ocurriendo brotes esporádicos de coriza infecciosa en avicultura. Este estudio fue diseñado para determinar los serotipos y las secuencias de nucleótidos completas de un gene de hemaglutinina (HMTp210) de Avibacterium paragallinarum aislado en Taiwán entre 1994 y 2017. Las pruebas de inhibición de la hemaglutinación mostraron que estos aislamientos pertenecen a los serogrupos B y C. El análisis de secuencias del gene HMTp210 mostró que los aislamientos del serogrupo B taiwaneses son más similares (94.7% ­98.2% de identidad) a la cepa FARPER-174 aislada en Perú en el año 2015. En contraste, los aislamientos del serogrupo C taiwaneses son más similares (96.3% ­99.8% de identidad) a la cepa H -18 aislada en Japón en 1976. Este es el primer reporte que muestra la presencia de A. paragallinarum del serogrupo B en Taiwán. Además, un aislado taiwanés mostró reactividad cruzada con los antisueros del serogrupo B y C. Este aislado contiene un gene HMTp210 quimérico que podría resultar de la recombinación entre los serogrupos B y C. Estos hallazgos podrían ser valiosos para el estudio epidemiológico y la serotipificación molecular de A. paragallinarum.

Epidemiology and molecular characterization of chicken anaemia virus from commercial and native chickens in Taiwan.

Chicken infectious anaemia (CIA) is a disease with a highly economic impact in the poultry industry. The infected chickens are characterized by aplastic anaemia and extreme immunosuppression, followed by the increased susceptibility to secondary infectious pathogens and suboptimal immune responses for vaccination. Commercially available CIA vaccines are routinely used in the breeders in Taiwan to protect their progeny with maternal-derived antibodies. However, CIA cases still occur in the field and little is known about the genetic characteristics of Taiwanese chicken anaemia viruses (CAVs). In this study, CAV DNA was detected in 72 of 137 flocks collected during 2010-2015. Among the PCR-positive samples, the coding regions of 51 CAVs were sequenced. Phylogenetic analysis of the VP1 gene revealed that, although most of Taiwanese CAVs belonged to genotypes II and III, some isolates were clustered into a novel genotype (genotype IV). Moreover, a Taiwanese isolate in this novel genotype IV appeared to be derived from a recombination event between genotypes II and III viruses. Five Taiwanese CAV isolates were highly similar to the vaccine strains, 26P4 or Del-Ros. Taken together, these results indicate that the sequences of CAVs in Taiwan are variable, and inter-genotypic recombination had occurred between viruses of different genotypes. Moreover, vaccine-like strains might induce clinical signs of CIA in chickens. Our findings could be useful for understanding the evolution of CAVs and development of a better control strategy for CIA.

Plasma pharmacokinetics and tissue depletion of cyromazine and its metabolite melamine following oral administration in laying chickens.

The study was designed to characterize the plasma pharmacokinetics and tissue depletion profiles (including eggs) of cyromazine (CYR) in chickens following oral administration alone or in combination with melamine (MEL). In order to assess the pharmacokinetic profile of CYR, chickens were administered 1 or 10 mg/kg (single oral doses), whereas residue studies were conducted in chickens fed CYR alone (5 or 10 mg/kg) or CYR (5 mg/kg) and MEL (5 mg/kg) for a period of 14 days. Estimates for the apparent volume of distribution (1.66 L/kg), clearance (7.17 mL/kg/min), and elimination half-life (2.82 h) were derived by noncompartmental analyses. The highest concentration of CYR occurred in liver but fell below detectable limits within 3 days following drug withdrawal from feed. Combined feeding of MEL with CYR did not significantly alter CYR tissue levels. CYR residues were detected only in egg white and were undetectable at the 2nd day postadministration. No MEL was found in eggs unless it had been added to the feed, and when present, it almost exclusively restricted to the egg white. Based upon the results of this initial study of CYR pharmacokinetics and residue depletion, it appears that use of CYR as a feed additive either alone (5 or 10 mg/kg) or in combination with MEL (both agents at 5 mg/kg) does not produce unsafe residue levels in edible products as long as appropriate withdrawal periods are followed for tissues (3 days) and eggs (2 days). However, our results indicate that adoption of a zero-day withdrawal period should be reconsidered in light of these results.

The Fimbrial Protein is a Virulence Factor and Potential Vaccine Antigen of Avibacterium paragallinarum.

Fimbriae are recognized as virulence factors and potential vaccine antigens of several pathogenic bacteria, but the function of the fimbriae from Avibacterium paragallinarum is not well known. In this study, a gene encoding the fimbrial protein FlfA was identified in A. paragallinarum . Sequencing analysis of the putative promoter region of flfA suggests that flfA expression in A. paragallinarum might be controlled by phase variation. The flfA gene from A. paragallinarum was expressed as a recombinant protein (r-FlfA) in Escherichia coli . Immunization with r-FlfA conferred chickens protection against challenge infection with A. paragallinarum . Virulence assays showed that the flfA-deficient mutants of A. paragallinarum were less virulent than their parental wild-type strains. These results indicated that the fimbrial protein FlfA is a virulence factor and potential vaccine antigen from A. paragallinarum .

Construction of an infectious plasmid clone of Muscovy duck parvovirus by TA cloning and creation of a partially attenuated strain.

Muscovy duck parvovirus (MDPV) infection is a highly contagious and fatal disease of Muscovy ducklings. The infectious clone methodology is a valuable tool to study the pathogenic mechanisms of viruses, but no infectious clone of MDPV is yet available. In this study, a plasmid clone containing the full-length genome of MDPV was constructed using the TA cloning methodology. This MDPV clone was found to be infectious after transfection of primary Muscovy duck embryo fibroblast cells and passage in embryonated Muscovy duck eggs. Site-directed mutagenesis showed that the K75N mutation in the VP1 protein of MDPV resulted in the partial attenuation of the virus. The availability of an MDPV infectious clone can facilitate investigation of the pathogenic mechanisms of MDPV and development of vaccines against diseases caused by MDPV.

Analysis of a bio-dynamic model via Lyapunov principle and small-world network for tuberculosis.

The study will apply Lyapunov principle to construct a dynamic model for tuberculosis (TB). The Lyapunov principle is commonly used to examine and determine the stability of a dynamic system. To simulate the transmissions of vector-borne diseases and discuss the related health policies effects on vector-borne diseases, the authors combine the multi-agent-based system, social network and compartmental model to develop an epidemic simulation model. In the identity level, the authors use the multi-agent-based system and the mirror identity concept to describe identities with social network features such as daily visits, long-distance movement, high degree of clustering, low degree of separation and local clustering. The research will analyse the complex dynamic mathematic model of TB epidemic and determine its stability property by using the popular Matlab/Simulink software and relative software packages. Facing the current TB epidemic situation, the development of TB and its developing trend through constructing a dynamic bio-mathematical system model of TB is investigated. After simulating the development of epidemic situation with the solution of the SMIR epidemic model, the authors will come up with a good scheme to control epidemic situation to analyse the parameter values of a model that influence epidemic situation evolved. The authors will try to find the quarantining parameters that are the most important factors to control epidemic situation. The SMIR epidemic model and the results via numerical analysis may offer effective prevention with reference to controlling epidemic situation of TB.

Cirrus cloud top temperatures retrieved from radiances in the National Polar-Orbiting Operational Environmental Satellite System--Visible Infrared Imager Radiometer Suite 8.55 and 12.0 microm bandpasses.

We describe what is believed to be a new approach developed for the National Polar-Orbiting Operational Environmental Satellite System (NPOESS) to retrieve pixel-level, cirrus cloud top temperatures (CTTs) from radiances observed in the 8.55 and 12.0 microm bandpasses. The methodology solves numerically a set of nonlinear algebraic equations derived from the theory of radiative transfer based upon the correlation between emissivities in these two bandpasses. This new approach has been demonstrated using NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) as a proxy to Visible Infrared Imager Radiometer Suite (VIIRS) data. Many scenes have been analyzed covering a wide range of geophysical conditions, including single-layered and multilayered cirrus cloud situations along with diverse backgrounds and seasons. For single-layer clouds, the new approach compares very favorably with the MODIS 5 km resolution cloud products; the mean CTT for both methods are very close, while the standard deviation for the new approach is smaller. However, in multilayered cloud situations, the mean CTTs for the new approach appear to be colder than the CTTs from MODIS cloud products, which are acknowledged to be too warm. Finally, partly because the new approach is applied at the pixel level, CTTs do not increase toward cloud edges as is seen in the MODIS products. Based upon these initial results, the new approach to retrieve improved VIIRS cloud top properties has been incorporated into the ground-based data processing segment of the NPOESS system where prelaunch testing of all VIIRS algorithms continues.

Comparison of the University of California at Los Angeles Line-by-Line Equivalent Radiative Transfer Model and the Moderate-Resolution Transmission Model for accuracy assessment of the National Polar-Orbiting Operational Environmental Satellite System's Visible-Infrared Imager-Radiometer Suite cloud algorithms.

To support the verification and implementation of the National Polar-Orbiting Operational Environmental Satellite System's Visible-Infrared Imaging-Radiometric Suite (VIIRS) algorithms used for inferring cloud environmental data records, an intercomparison effort has been carried out to assess the consistency between the simulated cloudy radiances-reflectances from the University of California at Los Angeles Line-by-Line Equivalent Radiative Transfer Model and those from the Moderate-Resolution Transmission Model (MODTRAN) with the 16 stream Discrete Ordinate Radiative Transfer Model (DISORT) incorporated. For typical ice and water cloud optical depths and particle sizes, we found discrepancies in the visible and near-infrared reflectances from the two models, which presumably are due to the difference in phase function (nonspherical versus Henyey-Greenstein), different numbers of phase function expansion terms (16 versus 200 terms), and different treatment of forward peak truncation in each model. Using the MODTRAN4, we also found substantial differences in the infrared radiances for optically thick clouds. These differences led to the discovery by MODTRAN4 developers of an inconsistency in the MODTRAN4-DISORT interface. MODTRAN4 developers corrected the inconsistency, which provided dramatic reductions in the differences between the two radiative transfer models. The comparison not only affects the prospective test plan for the VIIRS cloud algorithms but also should lead to improvements in future MODTRAN releases.

Induction of cytokine genes and IL-1alpha by chemical hypoxia in PC12 cells.

The role of cytokine in neuronal injury was examined in rat pheochromocytoma (PC12) cells under chemical hypoxia (i.e. KCN) and glucose deprivation. The mRNA levels of interleukin-1alpha (IL-1alpha), IL-6, and tumor necrosis factor-alpha (TNF-alpha) were measured by reverse transcription-polymerase chain reaction (RT-PCR) in PC12 cells exposed to 0.5 mM KCN for various time intervals. Cytokine mRNA levels expressed to peak levels 30 minutes after KCN treatment and declined gradually until 240 min. The IL-1alpha activity reached the highest levels 2 hr after the same KCN treatment. Under parallel conditions, KCN increased cytosolic free calcium concentration ([Ca2+]i) in the absence of glucose. However, IL-1alpha mRNA induction by KCN was not altered under calcium-free conditions in PC12 cells, indicating its induction was Ca2+-independent. However, the phosphatidylcholine (PC)-specific phospholipase C (PLC) inhibitor D609 decreased the KCN-induced IL-1alpha mRNA and protein in PC12 cells suggests that PC-PLC might play a role in cytokine induction during hypoxia.

Laser transmission through thin cirrus clouds.

A near-infrared airborne-laser transmission model for thin cirrus clouds has been developed on the basis of the successive-order-of-scattering approach to account for multiple scattering by randomly and horizontally oriented ice crystals associated with an aircraft-target system. Direct transmission and transmission due to multiple scattering are formulated specifically for this geometric system, in which scattering and absorption associated with aerosols, water vapor, and air are accounted for. A number of sensitivity experiments have been performed for investigation of the effect of aircraft-target position, cirrus cloud optical depth, and ice crystal size on laser transmission for tactical applications. We show that transmission contributions produced by orders of scattering higher than 1 are small and can be neglected. The possibility of horizontal orientation of ice crystals can enhance transmission of laser beams in the aircraft-target geometry. Transmitted energy is strongly dependent on the horizontal distance between the aircraft and the target and on the cloud optical depth as well as on whether the cloud is above or below the aircraft.

Selective subcellular redistributions of protein kinase C isoforms by chemical hypoxia.

The mechanisms of neuronal degeneration following hypoxia/ischemia remain undefined, but the processes include increases in neurotransmitter release, elevation of cytosolic-free calcium concentration, and changes in signal transduction pathways. Activation of the multigene family of protein kinase C (PKC) has been associated with the release of neurotransmitter and the survival of neurons. Therefore, to understand which PKC isozymes are involved in hypoxia/ischemia-induced neuronal degeneration, we examined PKC isozymes after chemical hypoxia (i.e., KCN exposure) in PC12 cells. Cell toxicity, as measured by lactate dehydrogenase (LDH) release, was increased significantly by KCN in glucose-free DMEM and was exaggerated by acute 12-O-tetradecanoyl phorbol-13-acetate (TPA) pretreatment. Under parallel conditions, KCN elevated cytosolic-free calcium ([Ca2+]i) in glucose-free but not in glucose containing DMEM, and TPA pretreatment did not exaggerate KCN's effect on [Ca2+]i. Thus, increases in [Ca2+]i are not sufficient for the synergistic toxic effect of KCN and TPA. In the glucose-free DMEM, selective PKC isozyme inhibitor Go 6976 at 10 nM completely inhibited KCN-induced LDH release and at higher concentrations (1 microM) inhibited the basal levels of LDH release. The protein levels of PKCs in the nuclear, membrane, and cytosolic fractions were measured by Western blot analysis using antibodies against specific isoforms. Two Ca2+-dependent (-alpha, -gamma) and four Ca2+-independent (-delta, -epsilon, -zeta, and -lambda) isozymes were identified and two isozymes (-beta and -theta) were not detected in the subcellular fractions of PC12 cells. Treatment of the cells with TPA significantly activated translocation of conventional PKC-gamma from the cytosol to the membrane and nuclear fractions and other PKC isozymes (-alpha, -delta, and -epsilon) from the cytosol to the membrane, but not atypical PKC-zeta and -lambda. Although only the levels in the nuclear PKC-gamma but not other PKC isozymes were increased significantly following KCN, the levels of cPKC-alpha and -gamma in the membrane mainly- and those and PKC-epsilon in the nucleus-were increased when KCN was combined with TPA. In addition, this condition (TPA + KCN) did not affect the TPA insensitive atypical isozymes, PKC-zeta or -lambda. Taking the results together, differential activation/translocation of PKC isozymes by KCN and TPA is important in the regulation of chemical hypoxia-induced cell injury in PC12 cells.

Remote sensing of cirrus cloud parameters using advanced very-high-resolution radiometer 3.7- and 1 O.9-microm channels.

We develop a retrieval scheme by using advanced very-high-resolution radiometer (AVHRR) 3.7- and 10.9-microm data to compute simultaneously the temperature, optical depth, and mean effective ice-crystal size for cirrus clouds. The methodology involves the numerical solution of a set of nonlinear algebraic equations derived from the theory of radiative transfer. The solution requires the correlation of emissivities of two channels in terms of the effective extinction ratio. The dependence of this ratio on ice-crystal size distribution is examined by using an adding-doubling radiative transfer program. Investigation of the effects of cirrus parameters on upwelling radiances reveals that the brightnesstemperature difference between the two channels becomes larger for colder cirrus and smaller ice-crystal sizes. We apply the current retrieval scheme to satellite data collected at 0930 UTC, 28 October 1986, over the region of the First International Satellite Cloud Climatology Project Regional Experiment CirrusIntesive Field Observation. We select the data over an area (~ 44 degrees N, 92 degrees W) near Fort McCoy, Wisconsin, for analysis. The retrieved cirrus heights compare reasonably well with lidar measurements taken at Fort McCoy 2 h after a satellite overpass at the target region. The retrieved mean effective crystal size is close to that derived from in situ aircraft measurements over Madison, Wisconsin, six hours after a satellite overpass.

Infrared transmission through cirrus clouds: a radiative model for target detection.

An IR transmission model for thin and subvisual cirrus clouds composed of hexagonal ice crystals with a specific use for target detection has been developed. The present model includes parameterizations of the ice crystal size distribution and the position of cirrus clouds in terms of ambient temperature. To facilitate the scattering and absorption calculations for hexagonal column and plate crystals in connection with transmission calculations, we have developed parameterized equations for their single scattering properties by using the results computed from a geometric ray-tracing program. The successive order-of-scattering approach has been used to account for multiple scattering of ice crystals associated with a target-detector system. The direct radiance, path radiance, and radiances produced by multiple scattering and background radiation involving cirrus clouds have been computed for 3.7- and 10-,microm wavelengths. We show that the background radiance at the 3.7-,microm wavelength is relatively small so that a high contrast may be obtained using this wavelength for the detection of airborne and ground-based objects in the presence of thin cirrus clouds. Finally, using the present model, including a simple prediction scheme for the ice crystal size distribution and cloud position, the transmission of infrared radiation through cirrus clouds can be efficiently evaluated if the target-detector geometry is defined.