In this study, the extraction of anthocyanin colorant from karanda fruit (Carissa carandas L.) was carried out and optimized with multiple single factor assays. Selected conditions for yield maximization consisted of ripen fruits with black-purple color, material size of thin slices (1.0–1.5 mm), solvent of EtOH 50%, material/ solvent ratio of 1:3, temperature of 50 °C, extraction time of 45 min, and two extraction cycles. The anthocyanin content in the extract was 277.2 mg/L, which is equivalent to 9.33 mg anthocyanin per gram of dry material. Aqueous solutions of the extract and dried extracts from Carissa carandas fruit were evaluated for stability at two temperature conditions, namely room temperature (30 ± 2 °C) and 45 °C. The temperature exerted great impact on color change, anthocyanin content and the degree of polymerization of anthocyanin. Aqueous solutions of extract with citric acid (3.0–5.0 g/L) were generally more color stable and less anthocyanin degradable than those without citric acid. In the DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging assay, The half maximal inhibitory concentration (IC50) of the dried extract was 87.56 μg/mL, which was approximately 29 times higher than that of vitamin C. After 3-month storage at −18 °C, IC50 of the dried extract was 173.67 μg/mL.

Of 1,050 fecal specimens collected from January 2013 to August 2015 from children with acute gastroenteritis, 149 (14.2%) were found to be positive for norovirus. Norovirus GII was the most predominant genogroup (98.65%; 147 of 149). The genotypes detected in this study were GI (2; 1.3%), GII.Pe-GII.4 (109; 73.1%), GII.P17-GII.17 (16; 10.7%), GII.P12-GII.3 (8; 5.4%), GII.P12-GII.12 (8; 5.4%), GII.P4-GII.4 (5; 3.4%), and the recombinant GII.Pe-GII.17 (1; 0.7%). Of these, the novel GII.17 strain was the second most predominant, and the number of affected children appeared to continuously increase over time (2013 [2; 4.4%], 2014 [4; 9.3%], and 2015 [10; 16.4%]). Phylogenetic analysis of the full genome and ORF1, ORF2, and ORF3 nucleotide sequences showed that GII.17 was grouped in cluster III with other strains isolated from 2013 to 2015 and had a different evolutionary history from strains collected in 1978 to 2002 and 2005 to 2009 formed clusters I and II. However, the phylogenetic trees also showed that cluster III was divided into subclusters IIIa (CAU-55 and CAU-85) and IIIb (Kawasaki 2014) (CAU-193, CAU-265, CAU-267, CAU-283, and CAU-289). Comparative analysis of the VP1 capsid protein using 15 complete amino acid sequences from noroviruses isolated from 1978 to 2015 showed 99 amino acid changes. These results could be helpful for epidemiological studies to understand circulating norovirus genotypes in population.

Background Porcine epidemic diarrhea (PED) is a highly contagious swine disease caused by the PED virus (PEDV), which is a member of the family Coronaviridae . Since the first outbreaks in Belgium and the United Kingdom were reported in 1971, PED has spread throughout many countries around the world and causing significant economic loss. This study was conducted to investigate the recent distribution of PEDV strains in Vietnam during the 2015–2016 seasons. Methods A total of 30 PED‐specific PCR‐positive intestinal and faecal samples were collected from unvaccinated piglets in Vietnam during the 2015–2016 seasons. The full length of the spike (S) gene of these PEDV strains were analysed to determine their phylogeny and genetic relationship with other available PEDV strains globally. Results Phylogenetic analysis of the complete S gene sequences revealed that the 28 Vietnamese PEDV strains collected in the northern and central regions clustered in the G2 group (both G2a and G2b sub‐groups), while the other 2 PEDV strains (HUA‐PED176 and HUA‐PED254) collected in the southern region were clustered in the G1/G1b group/sub‐group. The nucleotide (nt) and deduced amino acid (aa) analyses based on the complete S gene sequences showed that the Vietnamese PEDV strains were closely related to each other, sharing nt and aa homology of 93.2%–99.9% and 92.6%–99.9%, respectively. The N‐glycosylation patterns and mutations in the antigenic region were observed in Vietnamese PEDV strains. Conclusions This study provides, for the first time, up‐to‐date information on viral circulation and genetic distribution, as well as evidence to assist in the development of effective PEDV vaccines in Vietnam.

A total of 18 rotavirus G9 strains in South Korea were collected during five rotavirus seasons between 2005 and 2010. The relationship between these strains was examined by analyzing the genetic variation of two major structural genes, VP7 and VP4. All the rotavirus isolates were of the G9P[8] genotype. The VP7 phylogenetic analysis demonstrated that all of the G9 rotaviruses circulating in South Korea belonged to lineage IIId and were within three single clusters. The amino acid comparison of the antigenic regions of the VP7 gene suggests possible common progenitors of these strains. Phylogenetic analysis of P[8] VP4 genotypes indicated three lineages, P[8]-2, P[8]-3, and P[8]-4, with P[8]-3 being the most common. The results of this study provide information on the genetic relatedness of rotavirus G9 strains circulating in South Korea over recent years and can be utilized for the development of effective vaccines and the identification of reference strains for future efficacy studies.

The epidemiology of human group A rotavirus was analyzed by examining genotypic data acquired from 1989 to 2009 in South Korea. This information was derived from all the available published articles on rotavirus studies in South Korea, retrieved from both the PubMed and KoreaMed databases. Four common G types (G1, G2, G3, and G4) and three common P types (P[8], P[4], and P[6]) accounted for approximately 93% and 99% of the rotavirus reports, respectively. The G9 type was frequently detected after 2000, and because of this prevalence, it is considered to be the fifth most important G type rotavirus after the G1.G4 genotypes. Less common G types of the virus such as G12, G11, and G10 were detected in some geographic settings, and it is important to consider the context of these subtypes and their epidemiological significance. The P[9] virus genotype was observed in the study and has been discussed in many other studies; however, the P[3], P[10] and P[25] genotypes were rarely detected in the epidemiological research. In general, the distributions of the G and P genotypes showed temporal and geographical fluctuations, and a nationwide rotavirus vaccine program that targeted these genotypes demonstrated effectiveness in protecting against the circulating rotavirus strains. However, further analysis is needed to determine the true long-term effectiveness of these vaccines; the analysis should also consider the unexpected effects of vaccinations, such as vaccine-induced diseases, herd immunity, and changes in host susceptibilities.

BackgroundFoot-and-mouth disease virus (FMDV) is one of the highest risk factors that affects the animal industry of the country. The virus causes production loss and high ratio mortality in young cloven-hoofed animals in Vietnam. The VP1 coding gene of 80 FMDV samples (66 samples of the serotype O and 14 samples of the serotype A) collected from endemic outbreaks during 2006–2014 were analyzed to investigate their phylogeny and genetic relationship with other available FMDVs globally.ResultsPhylogenetic analysis indicated that the serotype O strains were clustered into two distinct viral topotypes (the SEA and ME-SA), while the serotype A strains were all clustered into the genotype IX. Among the study strains, the amino acid sequence identities were shared at a level of 90.1–100, 92.9–100, and 92.8–100% for the topotypes SEA, ME-SA, and genotype IX, respectively. Substitutions leading to changes in the amino acid sequence, which are critical for the VP1 antigenic sites were also identified. Our results showed that the studied strains are most closely related to the recent FMDV isolates from Southeast Asian countries (Myanmar, Thailand, Cambodia, Malaysia, and Laos), but are distinct from the earlier FMDV isolates within the genotypes.ConclusionsThis study provides important evidence of recent movement of FMDVs serotype O and A into Vietnam within the last decade and their genetic accumulation to be closely related to strains causing FMD in surrounding countries.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0896-0) contains supplementary material, which is available to authorized users.

African Swine Fever (ASF) is a highly infectious viral disease with high mortality. The most recent ASF outbreak in Vietnam occurred in 2019, posing a threat to spread to the neighboring Asian countries. Without a commercial vaccine or efficient chemotherapeutics successfully developed, rapid diagnosis and necessary biosecurity procedures are required to control the disease. While the diagnosis method of ASF recommended by the World Organization of Animal Health is real-time PCR, it is not . CC-BY-NC-ND 4.

A rare rotavirus, RVA/Human-wt/KOR/CAU12-2/2012/G11P[25], was isolated from a 16-year-old female with fever and diarrhea during the 2012 rotavirus surveillance in South Korea using a cell culture system, and its full genome sequence was determined and analyzed. Strain CAU12-2 exhibited a G11-P[25]-I12-R1-C1-M1-A1-N1-T1-E1-H1 genotype constellation. Phylogenetic analysis of this strain revealed that it is a human-porcine reassortant of two distant relatives of the G11 strains circulating in the world. The VP7 and VP4 genes are most closely related to those of human G11P[25] viruses (Dhaka6, KTM368, and N-38 strains) identified in South Asia, whereas the VP1 gene originated from a porcine G11P[7] virus (YM strain) that was identified in South America. The VP6 gene was found to belong to the new genotype I12. This study indicates that the G11-P[25]-I12 genotype was introduced into the South Korean population by interspecies transmissions of human and animal rotaviruses, followed by multiple reassortment events.