The construction and characterization of the bi-directional promoter between pp38 gene and 1.8-kb mRNA transcripts of Marek's disease viruses

<p>Abstract</p> <p>Background</p> <p>Marek's disease virus (MDV) has a bi-directional promoter between pp38 gene and 1.8-kb mRNA transcripts. By sequencing for the promoters from 8 different strains (CVI988, 814, GA, JM, Md5, G2, RB1B and 648A), it is found, comparing with the other 7 MDV strains, CVI988 has a 5-bp (from -628 to -632) deletion in this region, which caused a Sp1 site destroyed. In order to analysis the activity of the promoter, the complete bi-directional promoters from GA and CVI988 were, respectively, cloned into pCAT-Basic vector in both directions for the recombinants pP_GA(pp38)-CAT, pP_GA(1.8 kb)-CAT, pP_CVI(pp38)-CAT and pP_CVI(1.8 kb)-CAT. The complete promoter of GA was divided into two single-direction promoters from the replication of MDV genomic DNA, and cloned into pCAT-Basic for pdP_GA(pp38)-CAT and pdP_GA(1.8 kb)-CAT as well. The above 6 recombinants were then transfected into chicken embryo fibroblasts (CEFs) infected with MDV, and the activity of chloramphenicol acetyltransferase (CAT) was measured from the lysed CEFs 48 h post transfection.</p> <p>Results</p> <p>The results showed the activity of the divided promoters was decreased on both directions. In 1.8-kb mRNA direction, it is nearly down to 2.4% (19/781) of the whole promoter, while it keeps 65% (34/52) activity in pp38 direction. The deletion of Sp1 site in CVI988 causes the 20% activity decreased, and has little influence in pp38 direction.</p> <p>Conclusion</p> <p>The present study confirmed their result, and the promoter for the 1.8-kb mRNA transcripts is a much stronger promoter than that in the orientation for pp38.</p

Deletion of 1.8-kb mRNA of Marek's disease virus decreases its replication ability but not oncogenicity

<p>Abstract</p> <p>Background</p> <p>The 1.8-kb mRNA was reported as one of the oncogenesis-related genes of Marek's disease virus (MDV). In this study, the bacterial artificial chromosome (BAC) clone of a MDV field strain GX0101 was used as the platform to generate mutant MDV to examine the functional roles of 1.8-kb mRNA.</p> <p>Results</p> <p>Based on the BAC clone of GX0101, the 1.8-kb mRNA deletion mutant GX0101Δ(A+C) was constructed. The present experiments indicated that GX0101Δ(A+C) retained a low level of oncogenicity, and it showed a decreased replication capacity in vitro and in vivo when compared with its parent virus, GX0101. Further studies in vitro demonstrated that deletion of 1.8-kb mRNA significantly decreased the transcriptional activity of the bi-directional promoter between 1.8-kb mRNA and pp38 genes of MDV.</p> <p>Conclusion</p> <p>These results suggested that the 1.8-kb mRNA did not directly influence the oncogenesis but related to the replication ability of MDV.</p

Veterinary Bacterial Zoonoses

Humans, animals and microorganisms all share the same planet, the last playing critical roles in the cycling of nitrogen and sulfur in nature and the degradation of organic materials. Unfortunately, micro-organismal populations also include infectious bacteria and viruses that cause diseases, with a few that have fatal consequences. We chose veterinary bacterial zoonoses as our Research Topic with the aim of delivering up-to-date scientific knowledge on the subject, addressing the topics of detection approaches, vaccine development and host immune response. Our Research Topic alludes to the One Health approach in addressing three important bacterial diseases, Brucella, Mycobacteria and Chlamydia. A short chapter also elaborates on a highly pathogenic field isolate of Mycobacterium avium spp. Avium and an atypical enteropathogenic Escherichia coli O98 as evolving zoonotic risks. The cover illustration is intended to raise our awareness of the fact that pets play a role in our life as passionate and compassionate friends, but that they also pose a health risk due to carrying a bacterial or a viral zoonotic agent. We hope our Research Topic will further the pursuit of these topics and spark research in other important diseases

The advances of the Chinese Brucella suis strain 2 vaccine

Abstract Brucellosis, a worldwide crucial zoonotic disease, poses global socioeconomic risks to the system by threatening human health and animal reproduction. In recent years, with the increase of animal husbandry, animal brucellosis has become a remarkable health issue in China. To prevent and control the spread of brucellosis, Brucella suis live strain S2 vaccine has been licensed as a multivalent vaccine against the three major zoonotic Brucella species, for example, Brucella melitensis (small ruminants), Brucella abortus (bovids), and B. suis (swine). Following this process, the country enforced control measures based upon B. suis S2 vaccination, which reduced the disease burden in 2022 to 0.66% in the livestock population. The aim of this paper is to review and discuss the biological properties of the S2 vaccine and its wide use in vaccination programs of China, highlighting oral vaccination advantages, validation, and standardization of this vaccine as well as the progress of the S2 vaccination program achieved in the national control of the three zoonotic Brucella species

Effect of Slurry Thickness on the Quality of Aluminized Coatings

Diffusion aluminum coating is crucial to protect aero-engine turbine blades from high-temperature oxidation. Slurry aluminizing, as a commonly-used coating preparation technology, has variations in the process parameters that directly affect the quality of the coating. Therefore, this paper investigates the effect of slurry thickness on coating quality. Different forms of aluminized coatings were obtained by coating nine DZ22B nickel-based superalloy plates of the same size with different slurry thicknesses while keeping other parameters constant. These aluminized coatings were characterized using a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), an X-ray diffractometer (XRD), and a surface gauge. The results show that the AlNi phase dominates the matrix of the aluminized coating, and the outer layer of the coating has white dotted precipitates of Cr. As the slurry thickness increases, the coating thickness increases, and the proportion of the outer layer in the overall coating increases. In contrast, the thickness of the interdiffusion layer does not change significantly. The thicker the slurry, the higher the Al content of the coating surface. A medium-thickness slurry can form a smooth aluminizing coating with a roughness Ra &lt; 4.5 &mu;m surface. The combined results show that a medium-thick slurry can produce a high-quality coating