Background: When the first systematic list of mosquitoes in Nepal was reported in 1990, there was no description ofAedes aegypti(L.), whileAedes albopictus(Skuse) has been included in theStegomyiasubgroup since the 1950s. The first record ofAe. aegyptiin Nepal was reported in 2009, suggesting some coincidence between the invasion of this species and the first record of dengue fever in Nepal in 2006.Results: We performed a field survey of the distribution and insecticide susceptibility ofAe. aegyptiandAe. albopictusin Nepal in 2017 and 2018. Mosquito larvae were collected from used tires located along the streets of Kathmandu, Bharatpur and Pokhara, and a simplified bioassay was used to assess the susceptibility of the larvae to pyrethroid insecticides usingd-allethrin. The presence or absence of point mutations in the voltage-gated sodium channel was also detected by direct sequencing. V1016G was detected at a high frequency and a strong correlation was observed between the frequencies of V1016G and susceptibility indices inAe. aegyptipopulations. F1534C was also detected at a relatively low frequency. InAe. albopictuspopulations, susceptibilities tod-allethrin were high and no point mutations were detected. Analysis of the cytochromecoxidase subunit 1 (cox1) gene was performed for assessing genetic diversity and the existence of two strains were identified inAe. aegyptipopulations. One consisted of 9 globally-distributed haplotypes while the other was derived from an African haplotype.Conclusions: The high pyrethroid resistance, high V1016G frequency, and relatively low quantity of insecticides used to control dengue vectors in Nepal may have resulted in only weak selection pressure favoring insecticide resistance and could support the hypothesis that this species has recently been introduced from neighboring Asian countries where pyrethroid resistance is relatively widespread.

In transfusion-related iron overload, macrophage/reticuloendothelial cells are the first site of haem-derived iron accumulation. The prevention of haem-induced cytotoxicity in macrophages may represent a target for iron overload treatment. Deferasirox, an oral iron chelator, has been used to treat transfusion-related iron overload however, low adherence to the therapy is an issue. Statins, which are widely used for the prevention of atherosclerotic cardiovascular diseases, also have anti-oxidative and anti-inflammatory effects independent of their lipid lowering ones. Whether statins can suppress hemin-induced cytotoxicity and enhance the cytoprotective effects of deferasirox are important considerations to improve transfusion-related iron overload treatment. This study also evaluated the effects of eltrombopag, a thrombopoietin receptor agonist. Human monocytic THP-1 cells were pretreated with statins, deferasirox, and/or eltrombopag, followed by treatment with hemin. Cell viability, reactive oxygen species generation, and the intracellular labile iron pool were measured using flow cytometry. Fluvastatin and another four statins suppressed hemin-induced cell death, reactive oxygen species generation, and increases in the labile iron pool. Moreover, fluvastatin enhanced the suppressive effect of deferasirox on hemin-induced cell death. The effects of eltrombopag were similar to those of the statins. The safety of statins is well established. When used in combination with fluvastatin or other statins, the suppressive effects of deferasirox on hemin-induced cytotoxicity in THP-1 cells were amplified. Further research is necessary to see whether statins will act in the same way in vivo or in human primary monocytes/macrophages.

The threat of antimicrobial resistance in aquatic environments, particularly riverine systems, is escalating, in part due to effluents discharged from healthcare facilities. This issue has been recognized not only in Japan but also in other Asian countries such as Indonesia and Nepal. Nevertheless, existing research remains limited, prompting an investigation into the prevalence of antimicrobial-resistant bacteria in the upstream and downstream sites of environmental rivers. In 2024, six samples were collected from three rivers in Hyogo Prefecture, Japan; five samples from five river sites in Indonesia; and three samples from downstream sites of rivers in Kathmandu, Nepal. These samples were subjected to selective culture–based Next Generation Sequencing and resistome analyses, based exclusively on the selective culture of bacteria propagated on CHROMagar ESBL plates. In Japan and Indonesia, Pseudomonas, Stenotrophomonas and Acinetobacter were frequently detected, whereas Klebsiella was overwhelmingly predominant in Nepal. Significant differences in the similarity of bacterial community composition among sampling sites across the three countries were observed (p < 0.001). Notably, Nepal exhibited the highest abundance level of antimicrobial resistance genes among the three countries, largely consisting of β-lactam resistance genes. In conclusion, these analyses elucidated substantial differences in bacterial community composition and degrees of environmental contamination.

The Anopheles gambiae sensu lato species complex consists of a number of cryptic species with different habitats and behaviours. These morphologically indistinct species are identified by chromosome banding and molecular diagnostic techniques which are still under improvement even though the current SINE method for identification between An. coluzzii and An. gambiae works reliably. This study describes a refinement of the SINE method to increase sensitivity and high throughput method for the identification of both species and An. arabiensis using amplicon dissociation characteristics. Field collected samples, laboratory reared colonies and crossed specimens of the two species were used for the design of the protocol. An. gambiae , An. coluzzii , and hybrids of the two species were provided by the insectary of Vestergaard-NMIMR Vector Labs at the Noguchi Memorial Institute for Medical Research (Ghana) and An. arabiensis from Kenya. Samples were first characterised using conventional SINE PCR method, and further assayed using SYBR green, an intercalating fluorescent dye. The three species and hybrids were clearly differentiated using the melting temperature of the dissociation curves, with derivative peaks at 72 Celsius for An. arabiensis , 75°C for An. gambiae and 86°C for An. coluzzii . The hybrids ( An. gambiae / An. coluzzii ) showed both peaks. This work is the first to describe a SYBR green real time PCR method for the characterization of An. arabiensis , An. gambiae and An. coluzzii and was purposely designed for basic melt-curve analysis (rather than high-resolution melt-curve) to allow it to be used on a wide range of real-time PCR machines.