Interactions between climate change, urban infrastructure and mobility are driving dengue emergence in Vietnam.

Dengue is expanding globally, but how dengue emergence is shaped locally by interactions between climatic and socio-environmental factors is not well understood. Here, we investigate the drivers of dengue incidence and emergence in Vietnam, through analysing 23 years of district-level case data spanning a period of significant socioeconomic change (1998-2020). We show that urban infrastructure factors (sanitation, water supply, long-term urban growth) predict local spatial patterns of dengue incidence, while human mobility is a more influential driver in subtropical northern regions than the endemic south. Temperature is the dominant factor shaping dengue's distribution and dynamics, and using long-term reanalysis temperature data we show that warming since 1950 has expanded transmission risk throughout Vietnam, and most strongly in current dengue emergence hotspots (e.g., southern central regions, Ha Noi). In contrast, effects of hydrometeorology are complex, multi-scalar and dependent on local context: risk increases under either short-term precipitation excess or long-term drought, but improvements in water supply mitigate drought-associated risks except under extreme conditions. Our findings challenge the assumption that dengue is an urban disease, instead suggesting that incidence peaks in transitional landscapes with intermediate infrastructure provision, and provide evidence that interactions between recent climate change and mobility are contributing to dengue's expansion throughout Vietnam.

Effect of Fish Oil and Linseed Oil on Intake, Milk Yield and Milk Fatty Acid Profile in Goats.

This study aimed to evaluate the effect of incorporating linseed oil and fish oil in the diet on intake, ruminal fermentation, milk yield, and milk fatty acid profiles in dairy goats. Four crossbred Saanen lactating goats in mid-lactation and milking 1.30 ± 0.28 g/day were used in a 4 × 4 Latin square design. The basal diet contained concentrate and Para grass (C:F 40:60). Treatments included a basal diet without oil supplementation (Ctrl) or with 2.5% linseed oil (LO2.5), 2.5% linseed oil and fish oil (3:2, w/w, LFO2.5), and 4.16% linseed oil and fish oil (3:2, w/w, LFO4.16). Diets had no effect on intake, milk yield, milk composition, or ruminal fermentation (p > 0.05). Compared with Ctrl, lower (p < 0.05) proportions of C10:0-C14:0 in milk fat were observed with LFO4.16. Compared with the Ctrl and linseed oil added alone, feeding LFO4.16 led to a greater (p < 0.01) concentration of C18:1 t11. Compared with both the Ctrl and LO2.5 diets, milk c9,t11 CLA was 4.53 and 2.94 times greater with the LFO4.16 diet. Compared with Ctrl and LO2.5 diets (0.06% and 0.08%), goats fed LFO2.5, and LFO4.16 had greater (p < 0.001) concentrations of C22:6n-3 (0.63% and 0.87%). Overall, the combined data suggested that including 4.16% linseed oil and fish oil in the diet of dairy goats was effective in improving the concentrations of health-promoting fatty acids in milk without affecting milk production.

Grape seed tannin extract and polyunsaturated fatty acids affect in vitro ruminal fermentation and methane production.

Condensed tannins (CT), one of the most ubiquitous compounds in the plant kingdom, can modulate ruminal nutrient metabolism. Objectives were to study potential interactions of CT and polyunsaturated fatty acids (PUFA) on ruminal fermentation, biohydrogenation (BH), and methane production. Ruminal fluid obtained from lactating Holstein Friesian cows was used. All experiments were carried out as a completely randomized design with the same mixed diet: control (60:40 forage:concentrate) without supplement (CON), 2.5% soybean oil (SBO), and SBO + grape seed tannin extract (GSTE) at 0.2%, 0.4%, 0.6%, or 0.8% dietary DM (ST0.2, ST0.4, ST0.6, and ST0.8, respectively). Compared with CON (84.7 mM), total VFA concentration was not affected by SBO, but decreased (P < 0.001) with ST0.8 vs. ST0.6 (75.3 vs. 78.3 mM). Relative to CON, methane production was depressed (P < 0.001) by 17.7% and 28.0% in ST0.4 and ST0.8. The highest (P < 0.001) mean concentrations of c9,t11 CLA and C18:1 t11 were observed with ST0.4 compared with CON, but there was no difference between SBO and CT-containing diets. Disappearance of C18:2 c9,c12 was 49.1% vs. 50.3% in CON vs. SBO, whereas it ranged from 39.9% to 46.3% in CT-containing diets after 2 h incubation (P < 0.001). Concentrations of c9,t11 CLA with supplemental SBO and ST0.8 nearly peaked (P < 0.001) at 2 h incubation, but this fatty acid peaked (P > 0.05) at 6 h incubation and remained higher (P < 0.001; 15.9-17.0 µg/mL) at 24 h incubation with ST0.2, ST0.4, and ST0.6 compared with other diets (13.5-14.5 µg/mL). Compared with CON (50.6 µg/mL), concentration of C18:1 t11 with SBO and CT-containing diets reached a peak (P < 0.001; 241-265 µg/mL) at 12 h incubation. Concentration of C18:0 was 171%-231% higher (P < 0.001) with SBO and CT relative to CON at 24 h incubation. Overall, these results demonstrated that PUFA in SBO are more effective in modulating ruminal BH and CH4 production when combined with CT. However, high doses of added CT can reduce ruminal VFA concentration. Thus, a level of 0.4% GSTE added to diets containing 2.5% PUFA from plant origin might be suitable for optimizing ruminal fermentation and BH of C18:2 c9,c12 to fatty acid intermediates that could have beneficial effects to human health.

Condensed tannins can modulate methane emissions and ruminal biohydrogenation, but effects depend on type and dose. We used an in vitro fermentation system to investigate the effect of increasing doses (0%, 0.2%, 0.4%, 0.6%, and 0.8% dry matter) of grape tannin seed extract (GSTE) in a diet supplemented at 2.5% dry matter with soybean oil on methane production and biohydrogenation. Feeding soybean oil and GSTE at 0.6% and 0.8% reduced content of ruminal volatile fatty acids. Methane production (mL/g dry matter) was lower in the diet containing GSTE at 0.4%. Inclusion of GSTE at 0.2% and 0.4% increased concentration of C18:2 c9,c112, C18:3n3, c9,t11 conjugated linoleic acid and total polyunsaturated fatty acids after 24 h of incubation. The present findings contribute to a better understanding of the effect of condensed tannins from grape seed extract on ruminal fermentation and biohydrogenation.

Partial substitution of fish oil for linseed oil enhances beneficial fatty acids from rumen biohydrogenation but reduces ruminal fermentation and digestibility in growing goats.

This study was performed to investigate effects of partial replacement of fish oil (FO) for linseed oil (LO) on digestibility, ruminal fermentation and biohydrogenation in growing goats. Experiment 1 was carried out in four growing male goats aged 6 months in a 4 × 4 Latin square design. Goats were fed a basal diet supplemented with 25 g/kg dry matter either LO alone or in combination with tuna FO. Treatments were developed by replacing FO for LO at ratios of 0, 5, 10 and 15 g/kg DM corresponding to FO-0, FO-5, FO-10 and FO-15, respectively. Experiment 2 was carried out in an in vitro incubation system including 12 fermenters with the same four treatments. Each fermenter consisted of 40 mL goat ruminal fluid, 160 mL warm buffer, 2 g mixed substrates, and 50 mg FO-0, FO-5, FO-10 or FO-15. Fish oil inclusion reduced (P < 0.05) digestibility and nitrogen retention in Experiment 1. Increasing doses of FO in the diet induced a strong drop (P < 0.001) in ruminal total volatile fatty acid (VFA) concentration and protozoa population at 3 h post incubation, but did not affect individual VFA proportions. Substitution of FO for LO decreased mean concentrations of C18:0 (P = 0.057), c-9,c-12 C18:2 and C18:3n-3 (P < 0.001), but increased (P < 0.001) C20:5n-3 and C22:6n-3. Feeding FO-10 enhanced formation of ruminal c-9,t-11 conjugated linoleic acid (CLA) concentration compared with FO-0. Overall, combined data suggest that to improve ruminal concentrations of C20:5n-3, C22:6n-3, and c-9,t-11 CLA for deposition in tissues or milk with minimal risk of affecting digestibility and ruminal fermentation, a dietary supplementation of 15 g/kg LO and 10 g/kg FO would be suitable.

Multicenter Study of Device-Associated Infection Rates, Bacterial Resistance, Length of Stay, and Mortality in Intensive Care Units of 2 Cities of Vietnam: International Nosocomial Infection Control Consortium Findings.

OBJECTIVE: The aim of the study was to report the results of the International Nosocomial Infection Control Consortium (INICC) study conducted from May 2008 to March 2015. METHODS: A device-associated healthcare-acquired infection surveillance study in three adult intensive care units (ICUs) and 1 neonatal ICU from 4 hospitals in Vietnam using U.S. the Centers for Disease Control and Prevention's National Healthcare Safety Network (CDC/NHSN) definitions and criteria as well as INICC methods. RESULTS: We followed 1592 adult ICU patients for 12,580 bed-days and 845 neonatal ICU patients for 4907 bed-days. Central line-associated bloodstream infection (CLABSI) per 1000 central line-days rate was 9.8 in medical/surgical UCIs and 1.5 in the medical ICU. Ventilator-associated pneumonia (VAP) rate per 1000 mechanical ventilator-days was 13.4 in medical/surgical ICUs and 23.7 in the medical ICU. Catheter-associated urinary tract infection (CAUTI) rate per 1000 urinary catheter-days was 0.0 in medical/surgical ICUs and 5.3 in the medical ICU. While most device-associated healthcare-acquired infection rates were similar to INICC international rates (4.9 [CLABSI]; 16.5 [VAP]; 5.3 [CAUTI]), they were higher than CDC/NHSN rates (0.8 [CLABSI], 1.1 [VAP], and 1.3 [CAUTI]) for medical/surgical ICUs, with the exception of CAUTI rate for medical/surgical ICU and CLABSI rate for the medical ICU. Because of limited resources of our Vietnamese ICUs, cultures could not be taken as required by the CDC/NHSN criteria, and therefore, there was underreporting of CLABSI and CAUTI, influencing their rates. Most device utilization ratios and bacterial resistance percentages were higher than INICC and CDC/NHSN rates. CONCLUSIONS: Device-associated healthcare-acquired infection rates found in the ICUs of our study were higher than CDC/NHSN US rates, but similar to INICC international rates. It is necessary to build more capacity to conduct surveillance and prevention strategies.

Metabolome-Based Discrimination Analysis of Shallot Landraces and Bulb Onion Cultivars Associated with Differences in the Amino Acid and Flavonoid Profiles.

Shallot landraces and varieties are considered an important genetic resource for Allium breeding due to their high contents of several functional metabolites. Aiming to provide new genetic materials for the development of a novel bulb onion cultivar derived from intraspecific hybrids with useful agronomic traits from shallots, the metabolic profiles in the bulbs of 8 Indonesian shallot landraces and 7 short-day and 3 long-day bulb onion cultivars were established using LC-Q-TOF-MS/MS. Principal component analysis, partial least squares discriminant analysis, and dendrogram clustering analysis showed two major groups; group I contained all shallot landraces and group II contained all bulb onion cultivars, indicating that shallots exhibited a distinct metabolic profile in comparison with bulb onions. Variable importance in the projection and Spearman's rank correlation indicated that free and conjugated amino acids, flavonoids (especially metabolites having flavonol aglycone), and anthocyanins, as well as organic acids, were among the top metabolite variables that were highly associated with shallot landraces. The absolute quantification of 21 amino acids using conventional HPLC analysis showed high contents in shallots rather than in bulb onions. The present study indicated that shallots reprogrammed their metabolism toward a high accumulation of amino acids and flavonoids as an adaptive mechanism in extremely hot tropical environments.

Pilot Monitoring of Antimicrobial Residues in Chicken and Pork in Vietnam.

ABSTRACT: Antibiotic residues in consumer foods pose a threat to human health and contribute to increasing antimicrobial resistance. The study was conducted from January to July 2019 in six provinces in Vietnam. In total, 360 pork samples and 360 chicken samples were collected for analysis. The samples were first screened with an enzyme-linked immunosorbent assay test kit for residues in the beta-lactam, tetracycline, and sulfonamide groups. All positive and suspected positive samples were confirmed by liquid chromatography-tandem mass spectrometry to determine the concentration of ampicillin, amoxicillin, sulfamethazine, sulfaquinoxaline, oxytetracycline, and doxycycline residues. The final confirmed result showed that 13 (3.6%), 99 (27.5%), and 16 (4.4%) chicken samples and 13 (3.6%), 29 (8.1%), and 29 (8.1%) pork samples were positive or suspected positive with beta-lactam, tetracycline, and sulfonamide residues, respectively. The liquid chromatography-tandem mass spectrometry method detected amoxicillin (8.1 to 151.6 ng/g), ampicillin (1.9 to 7.5 ng/g), doxycycline (1.1 to 491.1 ng/g), oxytetracycline (1.1 to 12.9 ng/g), sulfaquinoxaline (1.1 to 7.3 ng/g), and sulfamethazine (1.0 to 1,556.5 ng/g) in positive or suspected positive pork and chicken samples. Tetracycline (18%) was the most frequently found residue, followed by sulfonamide (6%). The proportion of chicken samples with a residue level higher than the maximum residue limit (3%) and the level of tetracycline residue were significantly higher than pork (1%). A significantly higher proportion of samples with residue levels higher than MRL (4%) and the highest levels of tetracycline residue were observed in north Vietnam. This data can help motivate decision-making toward lowering the use of antimicrobials in livestock and antibiotic residue in livestock products.

Antimicrobial residues and resistance against critically important antimicrobials in non-typhoidal Salmonella from meat sold at wet markets and supermarkets in Vietnam.

Excessive antimicrobial usage and deficiencies in hygiene in meat production systems may result in undesirable human health hazards, such as the presence of antimicrobial drug residues and non-typhoidal Salmonella (NTS), including antimicrobial resistant (AMR) NTS. Recently, Vietnam has witnessed the emergence of integrated intensive animal production systems, coexisting with more traditional, locally-sourced wet markets. To date no systematic studies have been carried out to compare health hazards in beef, pork and chicken in different production systems. We aimed to: (1) estimate the prevalence of antimicrobial residues in beef, pork and chicken meat; (2) investigate the prevalence and levels of NTS contamination; and (3) investigate serovar distribution and AMR against critically important antimicrobials by animal species and type of retail (wet market vs. supermarket) in Vietnam. Fresh pork, beef and chicken meat samples (N=357) sourced from wet markets and supermarkets in Ho Chi Minh City (HCMC), Hanoi and Dong Thap were screened for antimicrobial residues by PremiTest, and were further investigated by Charm II. Samples from HCMC (N=113) were cultured using ISO 6579:2002/Amd 1:2007. NTS bacteria were quantified using a minimum probable number (MPN) technique. NTS isolates were assigned to serovar by Multilocus Sequence Typing (MLST), and were investigated for their phenotypic susceptibility against 32 antimicrobials. A total of 26 (7.3%) samples tested positive by PremiTest (9.5% beef, 4.1% pork and 8.4% chicken meat). Sulfonamides, tetracyclines and macrolides were detected by Charm in 3.1%, 2.8% and 2.0% samples, respectively. Overall, meat samples from wet markets had a higher prevalence of residues than those from supermarkets (9.6% vs. 2.6%) (p=0.016). NTS were isolated from 68.4% samples from HCMC. Chicken samples from wet markets had by far the highest NTS counts (median 3.2 logMPN/g). NTS isolates displayed high levels of resistance against quinolones (52.2%) and ß-lactams (49.6%), but low levels against 3rd generation cephalosporins (4.4%) and aminoglycosides (0.8%). The highest adjusted prevalence of multidrug resistance (MDR) corresponded to isolates from chicken meat and pork (OR 8.3 and 1.8, respectively) (baseline=beef). S. Kentucky was the most common serovar identified (11 from chicken, 1 from beef) and 91.7% isolates was MDR. 11/12 isolates corresponded to ST198, a worldwide-disseminated multi-resistant NTS clone. We recommend stepping up policy measures to promote responsible antimicrobial use in animal production, as well as awareness about withdrawal periods to limit the hazard of residues in animal products, and improving slaughtering/hygiene procedures to limit cross-contamination with NTS, particularly in poultry wet markets.

Molecular and biochemical identification of alien chromosome additions in shallot (Allium cepa L. Aggregatum group) carrying extra chromosome(s) of bunching onion (A. fistulosum L.).

To develop the bunching onion (Allium fistulosum L.; genomes, FF) chromosome-specific genetic markers for identifying extra chromosomes, eight shallot (A. cepa L. Aggregatum group; genomes, AA)--A. fistulosum monosomic addition plants (AA+nF) and 62 shallot--A. fistulosum single-alien deletion plants (AAF-nF) were analyzed by 23 different chromosome-specific genetic markers of shallot. The eight monosomic addition plants consisted of one AA+2F, two AA+6F, and five AA+8F. Of the 62 single-alien deletion plants, 60 could be identified as six different single-alien deletion lines (AAF-1F, -3F, -4F, -6F, -7F, and -8F) out of the eight possible types. Several single-alien deletion lines were classified on the basis of leaf and bulb characteristics. AAF-8F had the largest number of expanded leaves of five deletion plants. AAF-7F grew most vigorously, as expressed by its long leaf blade and biggest bulb size. AAF-4F had very small bulbs. AAF-7F and AAF-8F had different bulbs from those of shallot as well as other types of single-alien deletion lines in skin and outer scale color. Regarding the sugar content of the bulb tissues, the single-alien deletion lines showed higher fructan content than shallot. Moreover, shallot could not produce fructan with degree of polymerization (DP) 12 or higher, although the single-alien deletion lines showed DP 20 or higher. The content of S-alk(en)yl-L-cysteine sulfoxide (ACSO) in the single-alien deletion lines was significantly lower than that in shallot. These results indicated that chromosomes from A. fistulosum might carry anonymous factors to increase the highly polymerized fructan production and inhibit the synthesis of ACSO in shallot bulbs. Accordingly, alien chromosomes from A. fistulosum in shallot would contribute to modify the quality of shallot bulbs.

Construction of SSR-based chromosome map in bunching onion (Allium fistulosum).

We have constructed a linkage map of bunching onion (Allium fistulosum L., 2n = 16) using an F(2) population of 225 plants. The map consists of 17 linkage groups with 212 bunching onion SSR markers and 42 bulb onion (A. cepa L.) SSR, InDel, CAPS or dCAPS markers, covering 2,069 cM. This is the first report of a linkage map mainly based on SSR markers in the genus Allium. With the 103 anchor markers [81 bunching onion SSRs, 11 bulb onion SSRs and 11 bulb onion non-SSRs (1 InDel, 9 CAPSs and 1 dCAPS)] whose chromosome assignments were identified in A. cepa and/or A. fistulosum, via the use of several kinds of Allium alien addition lines, 16 of the 17 linkage groups were connected to the 8 basic chromosomes of A. cepa.

Production and characterization of alien chromosome additions in shallot (Allium cepa L. Aggregatum group) carrying extra chromosome(s) of Japanese bunching onion (A. fistulosum L.).

First and second backcrosses of amphidiploid hybrids (2n = 4x = 32, genomes AAFF) between shallot (Allium cepa Aggregatum group) and A. fistulosum were conducted to produce A. cepa - A. fistulosum alien addition lines. When shallot (A. cepa Aggregatum group) was used as a pollinator, the amphidiploids and allotriploids set germinable BC(1) and BC(2) seeds, respectively. The 237 BC(1) plants mainly consisted of 170 allotriploids (2n = 3x = 24, AAF) and 42 hypo-allotriploids possessing 23 chromosomes, i.e., single-alien deletions (2n = 3x-1 = 23, AAF-nF). The single-alien deletions in the BC(1) progeny showed dwarfing characteristics and were discriminated from the allotriploids (2n = 24) and hyper-allotriploids (2n = 25) by means of flow cytometric analysis. The chromosome numbers of 46 BC(2) seedlings varied from 16 to 24. Eight monosomic additions (2n = 2x+1 = 17, AA+nF) and 20 single-alien deletions were found in these BC(2) seedlings. Consequently, six kinds of A. cepa - A. fistulosum alien chromosome additions possessing different chromosome numbers (2n = 17, 18, 20, 21, 22, 23) were recognized in the BC(1) and BC(2) populations. A total of 79 aneuploids, including 62 single-alien deletions, were analyzed by a chromosome 6F-specific isozyme marker (Got-2) in order to recognize its existence in their chromosome complements. This analysis revealed that two out of 62 single-alien deletions did not possess 6F. One (AAF-6F) out of the possible eight single-alien deletions could be identified at first. The present study is a first step toward the development of a useful tool, such as a complete set of eight different single-alien deletions, for the rapid chromosomal assignment of genes and genetic markers in A. fistulosum.

Effect of single alien chromosome from shallot (Allium cepa L. Aggregatum group) on carbohydrate production in leaf blade of bunching onion (A. fistulosum L.).

We used a complete set of Allium fistulosum - shallot (A. cepa Aggregatum group) monosomic addition lines (FF+1A - FF+8A) to identify shallot chromosomes affecting the production of sugars. In the alien addition lines grown over two years in an experimental field at Yamaguchi University (34 degrees N, 131 degrees E), shallot chromosomes 2A and 8A altered sugar contents in leaf-bunching onion (A. fistulosum). Except for FF+2A, every monosomic addition accumulated non-reducing sugars in winter leaf blades. FF+8A caused an increase in the amounts of non-reducing sugars in the winter. FF+2A hardly produced non-reducing sugar throughout the two-year study. These results indicated that genes related to non-reducing sugar metabolism are located on the 2A and 8A chromosomes. The results of regression analyses using 2002 data on A. fistulosum and the monosomic addition set revealed a correlation (r = 0.63 +/- 0.07; mean +/- SE., n = 9) between reducing sugar and monosaccharide (Glc+Fru) contents but no correlation between non-reducing sugar and sucrose contents. This result indicates the existence of other polysaccharides (e.g., scorodose) as non-reducing sugars in the leaf blade.