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Lumpy skin disease (LSD) is a transboundary, systemic, viral disease of cattle. The first outbreaks of LSD were reported in Lang Son Province of Vietnam (bordered to China), and an official document has been submitted to OIE on 1 November 2020. Here, we described first the genetic profiles of this pathogen based on four well-known marker regions. The LSD virus isolated in these first outbreaks was 100% identical to viruses isolated in China (2019) based on the p32 and RP030 genes. Additionally, it is very close to the virus isolated in Russia (2017) based on the p32, RP030, thymidine kinase and ORF103 genes (100%, 99.01%, 99.08% and 99.47% identities). This finding is new, and a success in LSD virus isolation using MDBK cells from first outbreaks is important for vaccine development to control and eradicate LSD in Vietnam.

Objective: The rapid and reliable detection of the African swine fever virus (ASFV) plays an important role in emergency control and preventive measures of ASF. Some methods have been recommended by FAO/OIE to detect ASFV in clinical samples, including realtime polymerase chain reaction (PCR). However, mismatches in primer and probe binding regions may cause a false-negative result. Here, a slight modification in probe sequence has been conducted to improve the qualification of real-time PCR based on World Organization for Animal Health (OIE) protocol for accurate detection of ASFV in field samples in Vietnam.Methods: Seven positive confirmed samples (four samples have no mismatch, and three samples contained one mutation in probe binding sites) were used to establish novel real-time PCR with slightly modified probe (Y = C or T) in comparison with original probe recommended by OIE.Results: Both real-time PCRs using the OIE-recommended probe and novel modified probe can detect ASFV in clinical samples without mismatch in probe binding site. A high correlation of cycle quantification (Cq) values was observed in which Cq values obtained from both probes arranged from 22 to 25, suggesting that modified probe sequence does not impede the qualification of real-time PCR to detect ASFV in clinical samples. However, the samples with one mutation in probe binding sites were ASFV negative with OIE recommended probe but positive with our modified probe (Cq value ranked between 33.12-35.78).Conclusion: We demonstrated for the first time that a mismatch in probe binding regions caused a false negative result by OIE recommended real-time PCR, and a slightly modified probe is required to enhance the sensitivity and obtain an ASF accurate diagnosis in field samples in Vietnam.

Since African swine fever virus (ASFV) introduction into Vietnam in 2019, most ASFV strains detected in this country belong to the p72 genotype II and intergenic region (IGR) II variant. Further investigation of the intergenic region of ASFVs isolated in the Capital Hanoi region showed two different variants, IGR I and IGR II, which were located between the I73R and I329L genes of the p72 genotype II ASFV strains. This finding suggests co-circulation of two ASFV variants in the domestic pig population in Vietnam.

Since the first outbreak of African swine fever virus (ASFV) in China in 2018, the disease has spread to Mongolia, Vietnam, Cambodia, Korea, Laos, Myanmar, Philippines, Timor-Leste, Indonesia and Papua New Guinea. ASFV was officially reported in Vietnam on 19 February 2019. The continued spread of ASFV has occurred in the whole country within 7 months. The phylogenetic analysis showed that ASFVs isolated in the North Central region of Vietnam belong to genotype II and serotype 8. Additionally, tandem repeat sequence (TRS) studies indicated that these ASFVs are very close to ASFV strains detected in China and Belgium, 2018, and differ from ASFV isolated in Georgia in 2007.

B cell lymphoma (BCL) families play an important role in apoptosis as a growth factor, cell death programming, cytokine expression and immune-related genes expression. In this study, to investigate the roles of BCLs, we performed genome-wide identification, expression and functional analyses of the BCL family in chicken. Chicken BCLs genes were identified and analyzed by using bioinformatics approach. Expression profiles and Hierarchical cluster analysis of the BCLs genes in different chicken tissues were obtained from the genome-wide RNA-seq in the GEO, and Cluster and Java Treeview, respectively. A total of 16 BCLs genes were identified from the chicken genome, which could be further classified into five distinct groups in the phylogenetic tree. On the other hand, the interaction among BCLs proteins and between BCLs proteins with NF-κB subunits are limited, indicating that the remaining the functions of BCLs protein could be investigated in chicken. Moreover, KEGG pathway analysis indicated that BCL gene family was involved in regulation of apoptotic and immune response. Finally, BCL gene family was differentially expressed in chicken tissues, pathogen infection and growth stages of early chicken early embryo. This study provides significant insights into the potential functions of BCLs in chicken, including the regulation of apoptosis, cell death and expression of immune-related genes.

Background: The first confirmed case of African swine fever (ASF) in Vietnam was reported officially in February 2019. To date, ASF virus (ASFV) have been detected in 63/63 provinces in Vietnam. Currently, real-time polymerase chain reaction (PCR) is considered to be a powerful tool for viral detection in field samples, including ASFV. However, some recent reports have suggested that mismatches in primer and probe binding regions may directly affect real-time PCR qualification, leading a false-negative result.Aim: This study aims to further examine a conflicting result obtained from two OIE recommended methods, conventional PCR and real-time PCR, for ASFV detection.Methods: Two ASF suspected pigs from different provinces in the north of Vietnam were selected for this study based on clinical signs and postmortem lesions. The different results obtained by OIE-recommended conventional PCR and real-time PCR were further analyzed by the Sanger sequencing method and virus isolation in combination with hemadsorption (HAD) test using porcine alveolar macrophages cells.Results: The results showed that when the primer sequence matched perfectly with the sequences of field isolates, a mutation in probe binding region was found, indicating that a single mismatch in the probe binding site may cause a false-negative result by real-time PCR in detecting ASFV in clinical samples in Vietnam. An agreement between conventional PCR, using PPA1/PPA2 primers and two golden standard methods, virus isolation in combination with HAD assay, and sequencing method was observed in this study.Conclusion: A single mismatch in the probe binding site caused a failse-negative result by realtime PCR method in field diagnosis of ASFV. The needs consideration when selecting the appropriate molecular diagnostic methods is based on the current databases of ASFV sequences, particularly for epidemiological surveillance of ASF. Keywords: African swine fever, PCR, Pigs, Real-time PCR, Vietnam

Introduction African swine fever (ASF) was officially reported in Vietnam in February 2019 and spread across the whole country, affecting all 63 provinces and cities. Material and Methods In this study, ASF virus (ASFV) VN/Pig/HaNam/2019 (VN/Pig/HN/19) strain was isolated in primary porcine alveolar macrophage (PAM) cells from a sample originating from an outbreak farm in Vietnam’s Red River Delta region. The isolate was characterised using the haemadsorption (HAD) test, real-time PCR, and sequencing. The activity of antimicrobial feed products was evaluated via a contaminated ASFV feed assay. Results Phylogenetic analysis of the viral p72 and EP402R genes placed VN/Pig/HN/19 in genotype II and serogroup 8 and related it closely to Eastern European and Chinese strains. Infectious titres of the virus propagated in primary PAMs were 106 HAD50/ml. Our study reports the activity against ASFV VN/Pig/HN/19 strain of antimicrobial Sal CURB RM E Liquid, F2 Dry and K2 Liquid. Our feed assay findings suggest that the antimicrobial RM E Liquid has a strong effect against ASFV replication. These results suggest that among the Sal CURB products, the antimicrobial RM E Liquid may have the most potential as a mitigant feed additive for ASFV infection. Therefore, further studies on the use of antimicrobial Sal CURB RM E Liquid in vivo are required. Conclusions Our study demonstrates the threat of ASFV and emphasises the need to control and eradicate it in Vietnam by multiple measures.