Search

The novel duck reovirus (NDRV) is an emerging, contagious infection. To better realize the pathogenic mechanism of NDRV in ducks, an infection experiment was conducted. The resulting data demonstrated that typical gross lesions were observed in the infected ducks. NDRV was able to replicate in various tissues, leading to these pathological lesions, especially on the liver and spleen. Real-time quantitative PCR showed that the expression of most innate immune-related genes was up-regulated and the antiviral innate immune response could be established in both the liver and spleen. This study indicates that NDRV is a pantropic virus. To resist viral infection, several pathogen recognition receptors can cooperatively recognize NDRV and initiate innate immunity, but the responses are different between different tissues. As far as we know, this is the first systematic investigation of the pathogenicity of NDRV in Cherry Valley ducks based on the host's innate immunity, and these data will provide new insights into the further study of the disease.

Duck plague caused by duck plague virus (DPV) is an acute and contagious disease. To better understand the pathogenic mechanism of duck plague virus in ducklings, an infection experiment was performed. Our results showed that typical symptoms were observed in the infected ducklings. DPV could replicate quickly in many tissues, leading to pathological lesions, especially on the spleen. Real-time quantitative PCR demonstrated that expression of many innate immune-related genes was mostly up-regulated in the brain and the antiviral innate immune response was established, but not sufficient to restrict viral replication. In contrast, although the expression of many major pattern recognition receptors (PRRs) increased in the spleen, the expression of most cytokines was declined. Our study indicates that DPV is a pantropic virus that can replicate rapidly in tissues, causing serious pathological lesions but the immune responses are different in the spleen and brain. To our knowledge, this is the first report to systematically explore the expression profiles of the immune genes in the DPV-infected ducks. Our data provide a foundation for further study of the pathogenicity of duck plague.

There is a rather limited understanding concerning the antibiotic-resistance of the airborne S. aureus and the transmission of the antibiotic-resistant genes it carries Therefore, we isolated 149 S. aureus strains from the samples collected from the feces, the indoor air and the outdoor air of 6 chicken farms, and performed the research on them with 15 types of antibiotics and the REP-PCR trace identification. The 100% homologous strains were selected to conduct the research on the carrying and transmission status of the antibiotic-resistant genes. The results revealed that 5.37% strains (8/149) were resistant to methicillins (MRSA), and 94% strains (140/149) were resistant to compound sulfamethoxazole, etc. In addition, these strains displayed a resistance to multiple antibiotics (4, 5 or 6 types) and there were also 3 strains resistant to 9 antibiotics. It should be noted that the antibiotic-resistance of some strains isolated from the feces, the indoor and outdoor air was basically the same, and the strains with the same REP-PCR trace identification result carried the same type of antibiotic-resistant genes. The results showed that airborne transmission not only causes the spread of epidemic diseases but also exerts threats to the public health of a community.

Cases of H9N2 avian influenza virus (AIV) in poultry are increasing throughout many Eurasian countries, and co-infections with other pathogens have resulted in high morbidity and mortality in poultry. Few studies have investigated the genetic factors of virus airborne transmission which determine the scope of this epidemic. In this study, we used specific-pathogen-free chickens housed in isolators to investigate the airborne transmissibility of five recombinant H9N2 AIV rescued by reverse genetic technology. The results show that airborne transmission of A/Chicken/Shandong/01/2008 (SD01) virus was related to the neuraminidase (NA) gene, and four amino acid mutations (D368E, S370L, E313K and G381D) within the head region of the SD01 NA, reduced virus replication in the respiratory tract of chickens, reduced virus NA activity, and resulted in a loss of airborne transmission ability in chickens. Similarly, reverse mutations of these four amino acids in the NA protein of r01/NASS virus, conferred an airborne transmission ability to the recombinant virus. We conclude that these four NA residues may be significant genetic markers for evaluating potential disease outbreak of H9N2 AIV, and propose that immediate attention should be paid to the airborne transmission of this virus. Electronic supplementary material The online version of this article (doi:10.1186/s13567-014-0142-3) contains supplementary material, which is available to authorized users.

To accurately quantify airborne Aspergillus fumigatus (A. fumigatus) spores in rabbit houses, the real-time polymerase chain reaction (real-time PCR) and culture-based counting method (CCM) were employed to determine the airborne A. fumigatus spore concentrations. The results showed that, of the three rabbit houses (A, B, and C), the average concentrations of airborne A. fumigatus spores determined by real-time PCR were 3.0 × 103, 3.3 × 103, and 1.5 × 103 spores/m3 air, respectively, while those determined by CCM were 2.5 × 102, 2.8 × 102, and 1.1 × 102 colony-forming unit/m3 air (CFU/m3 air), respectively, i.e., the former concentration was 12–14 times higher than the latter one. Therefore, the conventional CCM underestimated the concentrations of airborne fungal spores, and it is insufficient to determine the microbial aerosol concentration and evaluate the health risk only using CCM.

Supplemental Digital Content is available in the text, To study the effect of knocking down wingless-related MMTV integration site 2 (Wnt2) expression by RNAi on the growth and signaling pathways of ex vitro-cultured keloid fibroblasts (KFB). Human KFB were isolated from 10 keloid patient specimens. The KFB cells were then transfected with 4 pairs of small interfering RNA (siRNA) targeting human Wnt2, respectively. Reverse transcriptase-polymerase chain reaction and Western blot analysis were conducted to verify the knock down of Wnt2, and the expression of β-catenin glycogen synthase kinase-3β (GSK-3β) and cyclin D1 were examined. siRNA Wnt2 transfection (siWnt2) resulted in the significant inhibition of Wnt2 expression at both the mRNA and protein levels. The expression of β-catenin, GSK-3β, p-GSK-3β, and cyclin D1 at the protein level also decreased in siWnt2 cells. siWnt2 resulted in a substantially slower growth and significant delay in cell doubling time of the KFB cells compared with control groups. Further, the siRNA knock down of GSK-3β and β-catenin resulted in slower proliferation rates, respectively. Wnt2 siRNA has an inhibitive effect on keloid fibroblast proliferation, which may be a potential therapeutic approach for keloid and other human fibrotic diseases.

A dynamic equilibrated heuristic algorithm based on the D* principle and mixed-strategy game theory is proposed to resolve the restoration problem at the wavelength level in an automatically switched optical network (ASON). The cost of each edge and the wavelength occupancy was taken into account comprehensively. Nash equilibration between wavelength occupancy and path cost is solved and the evaluation function of the D* algorithm is constructed dynamically using game theory with a mixed strategy. Then, the system restores broken connections rapidly through dynamic route and wavelength assignment (RWA) and ensures a more balanced distribution of network resources in the process of dynamic channel restoration. Simulation results show that the blocking probability is reduced and the restoration probability is promoted effectively by this algorithm. In addition, the rapid and intelligent performance behavior of this algorithm can meet the requirements of restoration time.

Sampling was conducted from June 2007 to May 2008 in an enclosed rabbit house to investigate composition and variability of airborne fungi. Samples were collected using an Andersen-6 sampler, with Sabouraud culture medium as sampling medium. The results showed that monthly mean concentration was 2.79–5.46 × 103 colony forming unit/m3 air (CFU/m3 air), with the maximum level in October, and the minimum level in January. Within a day, the maximum level occurred at 09:00, followed by 17:00 and then 13:00. A total of 6,523 fungal colonies, belonging to 17 genera and 36 species, were obtained. The predominant genera included Cladosporium, Penicillium, Aspergillus and Altemaria, comprising 71.45% of the colony count. The obtained fungi of the year were mainly centralized in the stage D of the sampler (2.0–3.0 μm), accounting for 37.8% of the colonies. The minimum value occurred at stage F (

Evidence is mounting that microorganisms originating from livestock impact the air quality of the animal houses themselves and the public in the surrounding neighborhoods. The aim of this study was to develop efficient bacterial source tracking capabilities to identify sources of Escherichia coli aerosol pollution caused by pigs. Airborne E. coli were isolated from indoor air, upwind air (10 and 50 m away) and downwind air samples (10, 50, 100, 200 and 400 m away) for five swine houses using six-stage Andersen microbial samplers and Reuter-Centrifugal samplers (RCS). E. coli strains from pig fecal samples were also collected simultaneously. The enterobacterial repetitive intergenic consensus polymerize chain reaction (ERIC-PCR) and the repetitive extragenic palindromic (REP-PCR) approaches were used to study the genetic variability and to determine the strain relationships among E. coli isolated from different sites in each swine house. Results showed that 35.1% (20/57) of the bacterial DNA fingerprints from the fecal isolates matched with the corresponding strains isolated from indoor and downwind air samples (similarity ⩾90%). E. coli strains from the indoor and downwind air samples were closely related to the E. coli strains isolated from feces, while those isolated from upwind air samples (swine house C) had low similarity (61–69%). Our results suggest that some strains isolated from downwind and indoor air originated in the swine feces. Effective hygienic measures should be taken in animal farms to prevent or minimize the downwind spread of microorganism aerosol.

The aim of the study was to evaluate the effects of microbial aerosols on ducks' welfare and provide information on which to establish microbial aerosol concentration standards for poultry. A total of 1800 1-d-old Cherry Valley ducks were randomly divided into 5 groups (A, B, C, D and E) with 360 ducks in each. To obtain objective data, each group had three replications. Different microbial aerosol concentrations in different groups were created by controlling ventilation and bedding cleaning frequency. Group A was the control group and hygienic conditions deteriorated progressively from group B to E. A 6-stage Andersen impactor was used to detect the aerosol concentration of aerobes, fungi, gram-negative bacteria and an AGI-30 microbial air sampler detected endotoxins. Physiological stress was evaluated in the ducks by adrenocorticotropic hormone (ACTH) values in serum. To assess the effects of bioaerosol factors, welfare indicators including fluctuating asymmetry (FA), appearance and gait as well as the Lactobacillus caecal concentration were evaluated. The data showed group D had already reached the highest limit of concentration of airborne aerobic bacteria, airborne fungi, airborne gram-negative bacteria and airborne endotoxin. The ducks in this group had significantly increased serum ACTH values and significantly decreased caecal lactobacilli concentration. Furthermore, appearance and gait scores, wing length and overall FA and caecal Lactobacillus concentration in this group were significantly increased at 6 and 8 weeks of age. In conclusion, high concentrations of microbial aerosol adversely affected the welfare of meat ducks. The microbial aerosol values in group D suggest a preliminary upper limit concentration of bioaerosols in ambient air for healthy meat ducks.

Sialyltransferases are key enzymes involved in the biosynthesis of biologically and pathologically important sialic acid-containing molecules in nature. In this study, the activity of a putative sialyltransferase (Pm0160) harboring an inherent mutation D141Y in the conserved DDG motif, which has been identified in GT52 and GT80 families, was restored by reverse mutation. More interestingly, a hydrogen-bond chain was found to form between three conserved residues (Asp141, Asn109, and Asp33) of GT80 sialyltransferases based on recently determined crystal structures. Our mutagenesis experiments demonstrated that the hydrogen-bond chain connecting the general base Asp141 with Nβ4, Nβ1, and Nα1 plays an essential role in maintaining protein structural stability other than keeping the general base Asp141 in a productive orientation for sialic acid transfer.

Duck Tembusu virus (DTMUV) can cause serious disease in ducks, characterized by reduced egg production. Although the virus has been isolated and detection methods developed, the host immune responses to DTMUV infection are unclear. Therefore, we systematically examined the expression of immune-related genes and the viral distribution in DTMUV-infected ducks, using quantitative real-time PCR. Our results show that DTMUV replicates quickly in many tissues early in infection, with the highest viral titers in the spleen 1 day after infection. Rig-1, Mda5, and Tlr3 are involved in the host immune response to DTMUV, and the expression of proinflammatory cytokines (Il-1β, -2, -6, Cxcl8) and antiviral proteins (Mx, Oas, etc.) are also upregulated early in infection. The expression of Il-6 increased most significantly in the tissues tested. The upregulation of Mhc-I was observed in the brain and spleen, but the expression of Mhc-II was upregulated in the brain and downregulated in the spleen. The expression of the interferons was also upregulated to different degrees in the spleen but that of the brain was various. Our study suggests that DTMUV replicates rapidly in various tissues and that the host immune responses are activated early in infection. However, the overexpression of cytokines may damage the host. These results extend our understanding of the immune responses of ducks to DTMUV infection, and provide insight into the pathogenesis of DTMUV attributable to host factors.

Simultaneously occurring myelocytomas caused by avian leukosis virus subgroup J (ALV-J) and Aspergillosis caused by Aspergillus flavus were diagnosed in a commercial layer flock. The mortality was up to 1% at 180 days old in this one of two, fifteen thousand layer flocks. Clinical signs of the affected chickens started from 80 day old, and included inactivity, depressed and anorexia. No respiratory signs were observed. On necropsy, various sized gray to yellow tumor-like nodular lesions were found on viscera. Microscopically, the tumor-like nodules were composed of two kinds of patterns, central caseous necrotic granulomas and multifoci eosinophilic myeloid cell proliferation. Intestinal adenocarcinoma in the duodenum, atrophy lesion in the ovaries, arteritis in various tissues, and hydrocephalus were observed, respectively. Hemotologically, the percentage of heterophils and eosinophils were significantly increased, while lymphocytes, basinophils and monocytes were significantly decreased. Aetiologically, A. flavus was cultured from the liver granulomas, and four strains of ALV-J were isolated from the serum of sick chickens, while ALV-A, ALV-B, MDV and REV were PCR negative. The antibody of ALV-J was negative (viremia) in seven sick chickens. The isolates have the highest nucleotide sequence homology (98.2~98.4%) with the prototype strain HPRS-103 of ALV-J. The evidence in this study shows that the source of ALV-J was from vertical transmission, while the source of A. flavus was not determined. This is the first report of ALV-J and A. flavus occurring naturally and concurrently in commercial layer hens., Istodobna pojava mijelocitoma prouzročenog virusom ptičje leukoze podskupine J (ALV-J) i aspergiloze prouzročene vrstom Aspergillus flavus opisana je u jednom komercijalnom jatu nesilica. Mortalitet je iznosio do 1% u 180 dana starih pilića na jednoj od dvije farme od 15 tisuća nesilica. Zahvaćeni pilići počeli su pokazivati kliničke znakove bolesti u dobi od 80 dana. Bili su nepokretni, potišteni i nisu uzimali hranu. Dišni znakovi nisu bili primijećeni. Pri razudbi su na visceralnim organima ustanovljene sivkaste do žućkaste čvoraste tumorske promjene različite veličine. Mikroskopski su bila ustanovljena dva tipa tumorskih čvorova: granulomi sa središnjom kazeoznom nekrozom i multifokalna proliferacija eozinofilnih mijeloidnih stanica. Ustanovljen je adenokarcinom dvanaesnika, atrofične lezije jajnika, arteritis u različitim tkivima i hidrocefalus. Hematološkom pretragom ustanovljen je značajno povećan postotak neutrofila i eozinofila, dok je broj limfocita, bazofila i monocita bio značajno smanjen. A. flavus bio je izdvojen iz granuloma jetre, a četiri soja virusa leukoze podskupine J bila su izdvojena iz seruma oboljelih pilića. Lančanom reakcijom polimerazom nisu bili dokazani virus leukoze podskupine A i podskupine B, virus Marekove bolesti i virus retikulendotelioze. Protutijela za virus podskupine J nisu bila dokazana pretragom sedam bolesnih pilića. Po nukleotidnom slijedu izolati su pokazivali najvišu homolognost (98,2-98,4%) s prototipnim sojem HPRS-103 virusa leukoze ptica podskupine J. Pokazalo se da se virus prenosio vertikalno, a izvor plijesni A. flavus nije bio ustanovljen. Ovo je prvo izvješće o prirodnoj istodobnoj infekciji virusom leukoze podskupine J i vrstom A. flavus u komercijalnih nesilica.

This study was conducted to understand the enumeration and composition of airborne aerobes and Gram-negative bacteria and the spread of microbial aerosols in hospital environment. The aerobes and Gram-negative bacteria were identified and counted, and the similarity of Escherichia coli from different sites was analyzed by ERIC-PCR. The results showed that the enumerations of aerobes and inhalable aerobes in the corridor and hall were apparently higher than those in the three rooms (P

We improve the signcryption SCS2 proposed by Zheng Y to satisfy public verifiability and forward security simultaneously. Using this improved scheme, a new method of identifying cheaters in secret sharing schemes is proposed. With the method, a private channel is not necessary between the Dealer and each participant, and anyone can verify the authenticity of the share released by any participant during reconstructing the secret.

In order to study E. coli aerosol spreading from chicken houses to their surrounding air, air samples, including indoor and outdoor air (upwind 10 and 50 m as well as downwind 10, 50, 100, 200 and 400 m away) of 5 chicken houses were collected using six-stage Andersen microbial samplers and Reuter-Centrifugal samplers (RCS). E. coli concentrations (CFU/m(3) air) collected from different sampling sites were calculated. E. coli strains from chicken feces samples were also isolated. Furthermore, the enterobacterial repetitive intergenic consensus (ERIC)-PCR method was applied to amplify the isolated E. coli strain DNA samples. Through the genetic similarity analyses of the E. coli obtained from different sampling sites, the spreading of bioaerosol from animal houses to the ambient air was characterized. The results showed that the isolated E. coli concentrations in indoor air (9-63 CFU/m(3)) in 5 chicken houses were higher than those in upwind and downwind air, but there were no significant differences between the indoor and downwind sites 10 m away from all the 5 houses (P0.05). The phylogenetic tree indicated that a part of the E. coli (34.1%) isolated from indoor air had 100% similarity with those isolated from feces, and that most of E. coli isolated (54.5%) from downwind at 10, 50, 100 or even 200 m had 100% similarity with those isolated from indoor air or feces too. But those isolated from upwind air had a lower similarity (73%-92%) with corresponding strains isolated from indoor air or feces. Our results suggested that some strains isolated from downwind air and indoor air originated in the chicken feces, but most of isolates obtained from upwind air samples did not come from the chicken feces or indoor air. Effective hygienic measures should be taken in animal farms to prevent or minimize downwind spreading of microorganism aerosol.

The architecture and features of autonomous decentralized system (ADS) were introduced, the functions, architecture features of railway automatic blocking and continuous transmission line (RACL) and its protection and supervisory control system (RACLPSS) were analyzed, then autonomous decentralized based RACLPSS was put forward, its architecture and operation mechanism were analyzed. Finally, fault location in transmission line protection and supervisory control system (LPSS) was taken as an example to describe the application of autonomous distributed mechanism in RACLPSS. Autonomous decentralized based RACLPSS can ensure the easy realization of on-line expansion, on-line maintenance and fault tolerance, meet the new demand put forward by continuously changed system, it has a good prospect in protection and supervisory control system

The research and application actuality of wavelet post-analysis methods in electrical transient signal analysis was introduced, and several wavelet post-analysis methods were presented, then wavelet average entropy and wavelet distance entropy were taken as examples to show its feasibility, simulation results showed that wavelet entropy is effective for fault detection, which also opened new train of thoughts on fault classification. Finally, application of several post-analysis methods in power system transient signal was discussed, which showed the importance of wavelet post-analysis

The theory of traveling waves and its wavelet representation were presented. The characteristics and fault location research actuality in railway automatic blocking and continuous power transmission line were introduced. Considering the influence of the bus bar, conductor's architecture and the load along the line, the adaptation of traveling waves was analyzed. A method to locate fault by combining zero modal and aerial modal was brought forth, i.e., to distinguish the reflected wave of the faulty point from that of the bus at the opposite terminal by zero mode components and to locate the faulty position by aerial mode component. As for the mixed line, some characteristics can be obtained from the combination of aerial modal and zero modal of fault current, therefore the fault section can be determined. The modeling and simulation of the proposed method are conducted by software PSCAD/EMTDC. The simulation results show that the proposed method is feasible