Genomic insights unveil the plasmid transfer mechanism and epidemiology of hypervirulent Klebsiella pneumoniae in Vietnam.

Hypervirulent Klebsiella pneumoniae (hvKp) is a significant cause of severe invasive infections in Vietnam, yet data on its epidemiology, population structure and dynamics are scarce. We screened hvKp isolates from patients with bloodstream infections (BSIs) at a tertiary infectious diseases hospital in Vietnam and healthy individuals, followed by whole genome sequencing and plasmid analysis. Among 700 BSI-causing Kp strains, 100 (14.3%) were hvKp. Thirteen hvKp isolates were identified from 350 rectal swabs of healthy adults; none from 500 rectal swabs of healthy children. The hvKp isolates were genetically diverse, encompassing 17 sequence types (STs), predominantly ST23, ST86 and ST65. Among the 113 hvKp isolates, 14 (12.6%) carried at least one antimicrobial resistance (AMR) gene, largely mediated by IncFII, IncR, and IncA/C plasmids. Notably, the acquisition of AMR conjugative plasmids facilitated horizontal transfer of the non-conjugative virulence plasmid between K. pneumoniae strains. Phylogenetic analysis demonstrated hvKp isolates from BSIs and human carriage clustered together, suggesting a significant role of intestinal carriage in hvKp transmission. Enhanced surveillance is crucial to understand the factors driving intestinal carriage and hvKp transmission dynamics for informing preventive measures. Furthermore, we advocate the clinical use of our molecular assay for diagnosing hvKp infections to guide effective management.

Variation in Ventral Coloration Pattern and Aposematism in Tropical Warty Newts.

Aposematic coloration plays a crucial role in animal defense, and it is shaped by a complex interplay of factors such as physiological limitations and sexual and natural selection. Warty newts within the genus Paramesotriton exhibit significant variation in ventral coloration. In this study, we quantified the percentage of red ventral area to investigate aposematic ventral coloration in Paramesotriton deloustali and P. guangxiensis across eight populations in northern Vietnam. To assess the interaction between predators and the aposematic signals, we conducted experiments employing three types of clay replicas of newts: dorsal, red ventral, and black ventral models. Our findings revealed a significant variation in the red ventral area among different populations. Additionally, a significant correlation was detected between the red ventral area of the newt and the annual temperature range. In clay model experiments, a significant difference in predator attack rates was observed between dorsal and ventral clay models. Interestingly, there was no significant difference in attack rates between red and black ventral types. Our study suggested that the variation in the red ventral area of warty newts is probably influenced by multiple factors, including genetic constraints, sex, ambient environment, and diet. Furthermore, our results supported the effectiveness of displaying aposematic coloration as an antipredator defense mechanism in warty newts. However, variations in body size and the pressure of mammal predation might not play a significant role in determining aposematic coloration.

Dual anticancer and antibacterial activity of fluorescent naphthoimidazolium salts.

Cancer has emerged as a significant global health challenge, ranking as the second leading cause of death worldwide. Moreover, cancer patients frequently experience compromised immune systems, rendering them susceptible to bacterial infections. Combining anticancer and antibacterial properties in a single drug could lead to improved overall treatment outcomes and patient well-being. In this context, the present study focused on a series of hydrophilic naphthoimidazolium salts with donor groups (NI-R), aiming to create dual-functional agents with antibacterial and anticancer activities. Among these compounds, NI-TPA demonstrated notable antibacterial activity, particularly against drug-resistant bacteria, with MIC value of 7.8 µg mL-1. Furthermore, NI-TPA exhibited the most potent cytotoxicity against four different cancer cell lines, with an IC50 range of 0.67-2.01 µg mL-1. The observed high cytotoxicity of NI-TPA agreed with molecular docking and dynamic simulation studies targeting c-Met kinase protein. Additionally, NI-TPA stood out as the most promising candidate for two-photo excitation, fluorescence bioimaging, and localization in lysosomes. The study findings open new avenues for the design and development of imidazolium salts that could be employed in phototheranostic applications for cancer treatment and bacterial infections.

Imidazolium-Based Heavy-Atom-Free Photosensitizer for Nucleus-Targeted Fluorescence Bioimaging and Photodynamic Therapy.

The development of heavy-atom-free photosensitizers (PSs) for photodynamic therapy (PDT) has encountered significant challenges in achieving simultaneous high fluorescence emission and reactive oxygen species (ROS) generation. Moreover, the limited water solubility of these PSs imposes further limitations on their biomedical applications. To overcome these obstacles, this study presents a molecular design strategy employing hydrophilic heavy-atom-free PSs based on imidazolium salts. The photophysical properties of these PSs were comprehensively investigated through a combination of experimental and theoretical analyses. Notably, among the synthesized PSs, the ethylcarbazole-naphthoimidazolium (NI-Cz) conjugate exhibited efficient fluorescence emission (ΦF = 0.22) and generation of singlet oxygen (ΦΔ = 0.49), even in highly aqueous environments. The performance of NI-Cz was validated through its application in fluorescence bioimaging and PDT treatment in HeLa cells. Furthermore, NI-Cz holds promise for two-photon excitation and type I ROS generation, nucleus localization, and selective activity against Gram-positive bacteria, thereby expanding its scope for the design of heavy-atom-free PSs and phototheranostic applications.

Uncovering the lack of awareness of sand mining impacts on riverbank erosion among Mekong Delta residents: insights from a comprehensive survey.

Global sand demand due to infrastructure construction has intensified sand mining activities in many rivers, with current rates of sand extraction exceeding natural replenishment. This has created many environmental problems, particularly concerning riverbank stability, which adversely affects the livelihoods of people in the Vietnamese Mekong Delta (VMD). However, sand mining's social impacts in the region remain inadequately understood. Here we assess locals' perception of sand mining activities in the VMD and its impacts on riverbank erosion. Residents living along the Bassac River, a hotspot of sand mining, were interviewed. Our results showed that while sand mining is perceived as destructive to the environment, few were aware of its role in worsening riverbank erosion. Only residents directly affected by riverbank collapse were aware of the implications of sand mining and its negative effect on bank stability, as they seem to have actively sought clarification. Our findings highlight the need for greater awareness and understanding among the locals regarding sand mining's impact on riverbank stability.

Demographic and ecological niche dynamics of the Vietnam warty newt, Paramesotriton deloustali: Historical climate influences.

Quaternary climatic cycles strongly affected the genetic diversification and ranges of organisms, shaping current genetic structures and distribution patterns. Urodeles provide ideal examples for exploring these dynamics over time and across space. In this study, we integrated a phylogeographic approach and ensemble species distribution modeling (eSDM) to infer the historical demography and distribution patterns of the Vietnam warty newt, Paramesotriton deloustali. Mitochondrial data revealed two groups, West and East, which diverged approximately 1.92 million years ago (Mya). Diversification was likely driven by change in the climate during early stages of the Pleistocene, with increasing monsoon and drought intensities. Biogeographic analysis indicated that the newt's current distribution formed as a result of vicariance events. In addition, the two groups occupy distinct ecological niches. Demographic reconstruction showed signs of expansion in the effective population sizes of the two major groups beginning around 0.11 and 0.15 Mya, respectively. However, eSDM showed fluctuating predicted distributions during the last interglacial, last glacial maximum, mid-Holocene, and present. Mountain systems in northern Vietnam are likely to have served as climatic refuges and to have played a crucial role in safeguarding species from the effects of climate change.

Passive acoustic monitoring using smartphones reveals an alarming gibbon decline in a protected area in the central Annamite Mountains, Vietnam.

Monitoring populations is critical for understanding how they respond to anthropogenic disturbance and for management of protected areas. The use of passive acoustic monitoring can improve monitoring efforts as it allows for collection of data on vocal animals at spatial and temporal scales that are difficult using only human observers. In this study, we used a multiseason occupancy model to monitor occurrence, apparent extinction, and colonization probabilities of a northern yellow-cheeked gibbon, Nomascus annamensis population with acoustic data collected from mobile smartphones in Dakrong Nature Reserve, Vietnam. Forty-five sites were randomly selected for repeated surveys in 2019 and 2022. At each site, a mobile smartphone was attached to a tree and recorded sounds for 4.2 days and 3.89 days on average, in 2019 and 2022, respectively. We manually annotated spectrograms for the presence of gibbon calls, and we detected gibbons at 24 and 12 recording posts in 2019 and 2022, respectively. Estimated local apparent extinction from occupancy models was high with 67% of occupied sites in 2019 becoming unoccupied in 2022. Apparent colonization was low with ~25% of unoccupied sites in 2019 becoming occupied in 2022. As a result, the apparent occurrence probability declined from 0.58 in 2019 to 0.30 in 2022. If the absence of calls indicates that cells are unoccupied this would mean an alarming decline of the gibbon population in the nature reserve. We suggest that in the areas with high hunting pressure, monitoring intervals should be shortened to at least yearly. In addition, urgent actions, such as patrolling, or gun confiscation, should be implemented to conserve the gibbon populations in Dakrong Nature Reserve and other protected areas with the same management context.

Readability and beyond - Health literacy and numeracy and COVID-19 communications in early childhood education: Are we communicating effectively?

OBJECTIVE: Analyse the linguistic and numerical complexity of COVID-19-related health information communicated from Australian national and state governments and health agencies to national and local early childhood education (ECE) settings. METHODS: Publicly available health information (n = 630) was collected from Australian national and state governments and health agencies, and ECE agencies and service providers. A purposive sample of documents (n = 33) from 2020 to 2021 was analysed inductively and deductively combining readability, health numeracy and linguistic analyses and focusing on the most frequent actionable health advice topics. RESULTS: COVID-19 health advice most frequently related to hygiene, distancing and exclusion. Readability scores in 79% (n = 23) of documents were above the recommended grade 6 reading level for the public. Advice was delivered using direct linguistic strategies (n = 288), indirect strategies (n = 73), and frequent mitigating hedges (n = 142). Most numerical concepts were relatively simple, but lacked elaborative features (e.g., analogies) and/or required subjective interpretation. CONCLUSION: COVID-19 health advice available to the ECE sector included linguistic and numerical information open to mis/interpretation making it difficult to understand and implement. PRACTICE IMPLICATIONS: Combining readability scores with measures of linguistic and numerical complexity offers a more holistic approach to assessing accessibility of health advice and improving health literacy among its recipients.

Bank liquidity hoarding during the COVID-19 pandemic.

This paper examines the association between bank liquidity hoarding (BLH) and the COVID-19 pandemic. Using a sample of U.S. banks and applying fixed effect estimators, we reveal that banks rack up liquidity assets and liabilities when the pandemic escalates. Our finding holds with alternative BLH and COVID-19 proxies and is further validated by falsification tests. Additional analysis reveals that BLH improves bank stability by reducing earnings volatility, non-performing loans and the propensity to go bankrupt. This study supports the existing literature on BLH and economic adversities and expands our understanding of BLH during the COVID-19 pandemic.

Adaptive capacity of high- and low dyke farmers to hydrological changes in the Vietnamese Mekong delta.

This research assesses the adaptive capacity of farmers in the Vietnamese Mekong Delta's floodplains (VMD) with respect to hydrological changes. Currently, climate change and socio-economic developments induce extreme- and diminishing floods, which in turn increase farmers' vulnerability. This research assesses farmers' adaptive capacity to hydrological changes using two prevalent farming systems: high dykes featuring triple-crop rice farming and low dykes where fields are left fallow during the flood season. We examine (1) farmers' perceptions on a changing flood regime and their current vulnerabilities and (2) farmers' adaptive capacity through five sustainability capitals. Methods include a literature review and qualitative interviews with farmers. Results show that extreme floods are becoming less frequent and damaging, depending on arrival time, depth, residence time, and flow velocity. In extreme floods, farmers' adaptive capacity is generally strong, and only low dyke farmers experience damage. As for diminishing floods, which is an emerging phenomenon, the overall adaptive capacity of farmers is remarkably weaker and varies between high- and low dyke farmers. Financial capital is lower for low dyke farmers due to their double-crop rice system, and natural capital is low for both farmer groups due to a decrease in soil- and water quality, affecting yields and increasing investment costs. Farmers also struggle with an unstable rice market due to strong fluctuating prices for seeds, fertilizers, and other inputs. We conclude that both high- and low dyke farmers have to cope with new challenges, including fluctuating flood patterns and the depletion of natural resources. Increasing farmers resilience should focus on exploring better crop varieties, adjusting crop calendars, and shifting to less water-intensive crops.

A review on the status and modeling of suitable habitats of the southern white-cheeked gibbon.

The southern white-cheeked gibbon Nomascus siki is endemic to Indochina and is classified as critically endangered on the International Union for Conservation of Nature (IUCN) Red List. The most updated information on the status of this species dates back to a decade ago. As hunting has tremendous impacts on wildlife in Southeast Asia, the population of N. siki might have changed a lot in the last decade. Updated information on the status and potential distribution of this species is critically important for conservation and prioritization, especially for N. siki because of its undefined distribution range. The goal of this study was to review the population status of N. siki in Vietnam and Lao People's Democratic Republic (PDR) and to model its potential distribution. In Vietnam, this species has been intensively surveyed in all major areas of occurrence from 2016 to 2021. The total number of N. siki groups recorded and estimated in Vietnam were 324 and 483, respectively. In Lao PDR, the occurrence of N. siki has been confirmed in Nam Kading, Nakai Nam Theun, Hin Nam No, and Phou Hinpoun national protected areas. However, population estimates are generally lacking. The suitable habitat of N. siki was predicted from about 105.00° to 106.80° E longitude and from about 16.60° to 17.90° N latitude located in Quang Binh and Quang Tri provinces (Vietnam), and Khammounan and Savannakhet provinces (Lao PDR). The area of the potential distribution range is about 9894.15 km2, both in Vietnam and Lao PDR. Particularly, the high, medium, and low suitable habitats were estimated at around 1229.58 km2, 3019.68 km2, and 5644.89 km2, respectively. The area of suitable habitat of N. siki in Vietnam was predicted to be 4151.25 km2, of which only 1257.93 km2 (30.30%) is in the protected area network. Dong Chau-Khe Nuoc Trong and Bac Huong Hoa Nature Reserves, and Phong Nha-Ke Bang National Park should receive priority for conservation of N. siki in Vietnam. Improving conservation beyond the protected areas' boundaries or transforming the forest enterprises and watershed protection forests into protected areas should also be considered as an alternative for the conservation of N. siki. In Lao PDR, surveys of the species in its entire distribution range should be the first priority.

LMP1-EBV Gene Deletion Mutations and HLA Genotypes of Nasopharyngeal Cancer Patients in Vietnam.

Nasopharyngeal carcinoma (NPC) is the most common cancer among head and neck cancers in Vietnam. We aimed to identify the rate of a 30 bp deletion mutation of the LMP1-EBV gene in nasopharyngeal biopsy tissue samples, the HLA genotypes of NPC patients, and the relationship between these two targets. Patients with NPC at Can Tho Oncology Hospital from September 2014 to December 2018 were selected. A length of 30 bp of the del-LMP1-EBV gene was analyzed using a PCR technique, and the HLA genotypes in patients' blood samples were analyzed with PCR-SSO technology. HLA-B*15 gene carriers had the highest risk of 30 bp LMP1-EBV gene deletion mutation, which was found in 51 out of 70 patients (72.9%). Carriers of the HLA-B*15 allele had a 4.6-fold increased risk of a 30 bp del-LMP1-EBV gene compared with non-carriers of this allele. The initial identification of NPC was related to the 30 bp del-LMP1-EBV gene and high frequencies of the -A*02, -B*15, -DRB1*12, -DQB1*03, and -DQA1*01 HLA alleles. Our study results suggest an association of the 30 bp del-LMP1-EBV gene and the HLA-B*15 allele with NPC susceptibility.

Case report: Immune pressure on hematopoietic stem cells can drastically expand glycosylphosphatidylinositol-deficient clones in paroxysmal nocturnal hemoglobinuria.

Introduction: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematological disease characterized by intravascular hemolysis, thrombosis, and bone marrow (BM) failure. Although PNH is caused by excessive proliferation of hematopoietic stem cell (HSC) clones with loss of function mutations in phosphatidylinositol N-acetylglucosaminyltransferase subunit A (PIGA) genes, what drives PNH clones to expand remains elusive. Case description: We present a case of a 26-year-old female who presented with hemolytic anemia, thrombocytopenia, and leukopenia. Flow cytometry analysis of peripheral blood showed that 71.9% and 15.3% of the granulocytes and erythrocytes were glycosylphosphatidylinositol-anchored protein deficient (GPI[-]) cells. The patient was diagnosed with PNH with non-severe aplastic anemia. Deep-targeted sequencing covering 390 different genes of sorted GPI(-) granulocytes revealed three different PIGA mutations (p.I69fs, variant allele frequency (VAF) 24.2%; p.T192P, VAF 5.8%; p.V300fs, VAF 5.1%) and no other mutations. She received six cycles of eculizumab and oral cyclosporine. Although the patient's serum lactate dehydrogenase level decreased, she remained dependent on red blood cell transfusion. Six months after diagnosis, she received a syngeneic bone marrow transplant (BMT) from a genetically identical healthy twin, following an immune ablative conditioning regimen consisting of cyclophosphamide 200 mg/kg and rabbit anti-thymocyte globulin 10 mg/kg. After four years, the patient's blood count remained normal without any signs of hemolysis. However, the peripheral blood still contained 0.2% GPI (-) granulocytes, and the three PIGA mutations that had been detected before BMT persisted at similar proportions to those before transplantation (p.I69fs, VAF 36.1%; p.T192P, VAF 3.7%; p.V300fs, VAF 8.6%) in the small PNH clones that persisted after transplantation. Conclusions: The PNH clones that had increased excessively before BMT decreased, but persisted at low percentages for more than four years after the immunoablative conditioning regimen followed by syngeneic BMT. These findings indicate that as opposed to conventional theory, immune pressure on HSCs, which caused BM failure before BMT, was sufficient for PIGA-mutated HSCs to clonally expand to develop PNH.

Soybean microbiome composition and the impact of host plant resistance.

Microbial communities play an important role in the growth and development of plants, including plant immunity and the decomposition of complex substances into absorbable nutrients. Hence, utilizing beneficial microbes becomes a promising strategy for the optimization of plant growth. The objective of this research was to explore the root bacterial profile across different soybean genotypes and the change in the microbial community under soybean cyst nematode (SCN) infection in greenhouse conditions using 16S rRNA sequencing. Soybean genotypes with soybean cyst nematode (SCN) susceptible and resistant phenotypes were grown under field and greenhouse conditions. Bulked soil, rhizosphere, and root samples were collected from each replicate. Sequencing of the bacterial 16S gene indicated that the bacterial profile of soybean root and soil samples partially overlapped but also contained different communities. The bacterial phyla Proteobacteria, Actinobacteria, and Bacteroidetes dominate the soybean root-enriched microbiota. The structure of bacteria was significantly affected by sample year (field) or time point (greenhouse). In addition, the host genotype had a small but significant effect on the diversity of the root microbiome under SCN pressure in the greenhouse test. These differences may potentially represent beneficial bacteria or secondary effects related to SCN resistance.

Computational Study on the Nature of Bonding between Silver Ions and Nitrogen Ligands.

In this paper, the nature of silver ion-nitrogen atom bonding in the complexation with ammonia, azomethine, pyridine, and hydrogen cyanide from one to four coordinations is studied at the B97-1 level of density functional theory. The results indicate that the two-coordinated complex of the silver ion with different nitrogen ligands representing sp, sp2, and sp3 orbital hybridizations is the most stable form having the shortest Ag+-N bond distance, highest vibrational frequencies, largest bond order, and favorable Gibbs free energy of formation. Natural bond orbital analyses further show that σ-donation from the nitrogen lone pair to the silver empty 5s orbital is dominant in the dative metal-ligand bonding character with N-sp3 having the largest contribution among the different N atomic orbital hybridizations. Natural energy decomposition analyses further show that the two-coordinated complexes have enhanced electrostatic interaction and charge transfer energies over other coordination types leading them to be more stable. For this reason, the two-coordinated complexes would be a better representation for studying bonding and interaction in silver ion complexes.

Synthesis of glycyrrhetinic acid-modified liposomes to deliver Murrayafoline A for treatment of hepatocellular carcinoma.

Hepatocellular carcinoma is a common type of cancer associated with a high mortality rate. Among several bioactive compounds, Murrayafoline A (MuA) has been proved as a bio substance that exhibits great potentials in treating liver cancer. In order to overcome the high cytotoxicity and low solubility of MuA, a delivery system based on nanocarriers is necessary to deliver MuA towards the desired target. In the present study, 18ß-glycyrrhetinic acid (GA), which is known as a ligand for liver targeting, was used to construct the cholesterol-poly (ethylene glycol)-glycyrrhetinic acid (GA-PEG-Chol) conjugate and liposome for MuA administration. The compound was then examined for therapeutic efficacy and safety in HUVEC and HepG2 cells in 2D and 3D cell cultures. Results have shown that MuA-loaded liposomes had IC50 value of 2 µM in HepG2 and had the cytosolic absorption of 8.83 ± 0.97 ng/105 cells, while The IC50 value of MuA-loaded liposomes in HUVEC cell lines was 15 µM and the the cytosolic absorption was recorded as 3.62 ± 0.61 cells. The drug test on the 3D cancer sphere platform of the HepG2 cancer sphere showed that MuA-loaded GA liposomes had the highest efficacy at a concentration of 100 µg/mL. In short, these results suggest that MuA-loaded GA liposomes have the potential for maintenance drug delivery and liver targeting.

Dynamic multivariate analysis for pollution assessment and river habitat conservation in the Vietnamese La Buong watershed.

Analysis of temporal patterns of high-dimensional time-series water quality data is essential for pollution management worldwide. This study has applied dynamic factor analysis (DFA) and cluster analysis (CA) to analyze time-series water quality data monitored at the five stations installed along the La Buong river in Southern Vietnam. Application of the DFA identified two types of temporal patterns, one of the run-off driven parameters (total suspended solid (TSS), turbidity, and iron) and the other of diffuse source pollution. The association of the variables like BOD5 and COD at most stations to the run-off-driven parameters revealed their sharing of drivers. On the contrary, separating variables like phosphate (PO43) at the three upstream stations from the run-off patterns suggested their local point-source origin. The DFA-derived factors were later used in the time-point CA to explore the seasonality of water quality parameters and their pollution intensities compared to regulatory levels. The result suggested intensification in wet season of Fe, TSS, BOD5, and COD concentrations at most sites, which are unobservable in run-off detached parameters like reactive nitrogen, phosphate (PO43-), and E. coli. These findings generated robust insights to support water quality management for river habitat conservation.