Immunolocalization and functional analysis of Opisthorchis viverrini-M60-like-1 metallopeptidase in animal models.

Host mucins have crucial physical roles in preventing the parasitic establishment and maturation, and also in expelling the invading parasites. However, some parasites utilize mucinase enzymes to facilitate the infection. Recently, we have identified a mucinase enzyme of the liver fluke Opisthorchis viverrini, Ov-M60-like-1, which exhibits metallopeptidase activity against bovine submaxillary mucin substrate. Here, we aimed to study the localization of this enzyme in O. viverrini and the bile duct of hamsters using immunohistochemistry and functional analysis by mucin digestion in hamsters and mice tissues. The results showed that Ov-M60-like-1 was detected strongly in the tegument, tegumental cells, vitelline glands and mature eggs with miracidium. Expression in the gut, ovary and testis of the parasite was moderate while parenchyma showed slight colour intensity. In addition, the mucinase was also detected in the host biliary epithelial cells and goblet cells surrounding the worm. The mucinase assay revealed that the Ov-M60-like-1 could digest neutral mucin in the parenchyma, testis and seminal receptacle, but not the mucin in the tegument, tegumental cells and vitelline glands of the worm. The enzyme can also digest mucin in the cholangiocytes and modified the mixture type in the bile duct goblet cells of the infected hamsters, a susceptible host. In contrast, the enzyme was unable to digest neutral, acid and mixture mucin in the bile duct of the mice, a non-susceptible host. These findings indicate that Ov-M60-like-1 may have functions in both housekeeping tasks and host­parasite interactions, especially in modification of host susceptibility.

Deep learning-enabled imaging flow cytometry for high-speed Cryptosporidium and Giardia detection.

Imaging flow cytometry has become a popular technology for bioparticle image analysis because of its capability of capturing thousands of images per second. Nevertheless, the vast number of images generated by imaging flow cytometry imposes great challenges for data analysis especially when the species have similar morphologies. In this work, we report a deep learning-enabled high-throughput system for predicting Cryptosporidium and Giardia in drinking water. This system combines imaging flow cytometry and an efficient artificial neural network called MCellNet, which achieves a classification accuracy >99.6%. The system can detect Cryptosporidium and Giardia with a sensitivity of 97.37% and a specificity of 99.95%. The high-speed analysis reaches 346 frames per second, outperforming the state-of-the-art deep learning algorithm MobileNetV2 in speed (251 frames per second) with a comparable classification accuracy. The reported system empowers rapid, accurate, and high throughput bioparticle detection in clinical diagnostics, environmental monitoring and other potential biosensing applications.

Arbuscular mycorrhizal fungal inoculation and soil zinc fertilisation affect the productivity and the bioavailability of zinc and iron in durum wheat.

There is a growing recognition of the role of arbuscular mycorrhizal fungi (AMF) in food security, specifically the potential for AMF to enhance the yield and mineral nutrition-including phosphorus, zinc (Zn), and iron (Fe)-of food crops. However, the bioavailability of Zn and Fe for humans in the grain of cereal crops can be overestimated by failing to consider the abundance of phytic acid (PA). This is because PA can chelate the micronutrients, making them difficult to absorb. In order to understand the effect of an AM fungus and soil Zn concentration on the productivity and nutritional quality of food parts, this study examined the growth and nutritional responses of durum wheat, with and without inoculation with Rhizophagus irregularis, at five soil Zn concentrations. Growth and nutrient responses of the plants to soil Zn amendment was stronger than responses to AMF. However, the protective effect of AMF under soil Zn toxicity conditions was observed as reduced Zn concentration in the mycorrhizal durum wheat grain at Zn50. Here, AMF inoculation increased the concentration of PA in durum wheat grain but had no effect on the concentration of Zn and Fe; this consequently reduced the predicted bioavailability of grain Zn and Fe, which could lead to a decrease in nutritional quality of the grain. This research suggests that in soil with low (available) phosphorus and Zn concentrations, AMF may reduce the food quality of durum wheat because of an increase in PA concentration, and thus, a decrease in the bioavailability of Zn and Fe.

Metagenomics Reveals the Impact of Wastewater Treatment Plants on the Dispersal of Microorganisms and Genes in Aquatic Sediments.

Wastewater treatment plants (WWTPs) release treated effluent containing mobile genetic elements (MGEs), antibiotic resistance genes (ARGs), and microorganisms into the environment, yet little is known about their influence on nearby microbial communities and the retention of these factors in receiving water bodies. Our research aimed to characterize the genes and organisms from two different WWTPs that discharge into Lake Michigan, as well as from surrounding lake sediments to determine the dispersal and fate of these factors with respect to distance from the effluent outfall. Shotgun metagenomics coupled to distance-decay analyses showed a higher abundance of genes identical to those in WWTP effluent genes in sediments closer to outfall sites than in sediments farther away, indicating their possible WWTP origin. We also found genes attributed to organisms, such as those belonging to Helicobacteraceae, Legionellaceae, Moraxellaceae, and Neisseriaceae, in effluent from both WWTPs and decreasing in abundance in lake sediments with increased distance from WWTPs. Moreover, our results showed that the WWTPs likely influence the ARG composition in lake sediments close to the effluent discharge. Many of these ARGs were located on MGEs in both the effluent and sediment samples, indicating a relatively broad propensity for horizontal gene transfer (HGT). Our approach allowed us to specifically link genes to organisms and their genetic context, providing insight into WWTP impacts on natural microbial communities. Overall, our results suggest a substantial influence of wastewater effluent on gene content and microbial community structure in the sediments of receiving water bodies.IMPORTANCE Wastewater treatment plants (WWTPs) release their effluent into aquatic environments. Although treated, effluent retains many genes and microorganisms that have the potential to influence the receiving water in ways that are poorly understood. Here, we tracked the genetic footprint, including genes specific to antibiotic resistance and mobile genetic elements and their associated organisms, from WWTPs to lake sediments. Our work is novel in that we used metagenomic data sets to comprehensively evaluate total gene content and the genetic and taxonomic context of specific genes in environmental samples putatively impacted by WWTP inputs. Based on two different WWTPs with different treatment processes, our findings point to an influence of WWTPs on the presence, abundance, and composition of these factors in the environment.

Aqueous Polymeric Hollow Particles as an Opacifier by Emulsion Polymerization Using Macro-RAFT Amphiphiles.

A robust polymerization technique that enables the surfactant-free aqueous synthesis of a high solid content latex containing polymeric hollow particles is presented. Uniquely designed amphiphilic macro-reversible addition fragmentation chain transfer (RAFT) copolymers were used as sole stabilizers for monomer emulsification as well as for free-radical emulsion polymerization. The polymerization was found to be under RAFT control, generating various morphologies from spherical particles, wormlike structures to polymer vesicles. The final particles were dominantly polymeric vesicles which had a substantially uniform and continuous polymer layer around a single aqueous filled void. They produced hollow particles once dried and were successfully used as opacifiers to impart opacity into polymer paint films. This method is simple, can be performed in a controllable and reproducible manner, and may be performed using diverse procedures.

Biodistribution and Clearance of Stable Superparamagnetic Maghemite Iron Oxide Nanoparticles in Mice Following Intraperitoneal Administration.

Nanomedicine is an emerging field with great potential in disease theranostics. We generated sterically stabilized superparamagnetic iron oxide nanoparticles (s-SPIONs) with average core diameters of 10 and 25 nm and determined the in vivo biodistribution and clearance profiles. Healthy nude mice underwent an intraperitoneal injection of these s-SPIONs at a dose of 90 mg Fe/kg body weight. Tissue iron biodistribution was monitored by atomic absorption spectroscopy and Prussian blue staining. Histopathological examination was performed to assess tissue toxicity. The 10 nm s-SPIONs resulted in higher tissue-iron levels, whereas the 25 nm s-SPIONs peaked earlier and cleared faster. Increased iron levels were detected in all organs and body fluids tested except for the brain, with notable increases in the liver, spleen, and the omentum. The tissue-iron returned to control or near control levels within 7 days post-injection, except in the omentum, which had the largest and most variable accumulation of s-SPIONs. No obvious tissue changes were noted although an influx of macrophages was observed in several tissues suggesting their involvement in s-SPION sequestration and clearance. These results demonstrate that the s-SPIONs do not degrade or aggregate in vivo and intraperitoneal administration is well tolerated, with a broad and transient biodistribution. In an ovarian tumor model, s-SPIONs were shown to accumulate in the tumors, highlighting their potential use as a chemotherapy delivery agent.

Preparation of Inert Polystyrene Latex Particles as MicroRNA Delivery Vectors by Surfactant-Free RAFT Emulsion Polymerization.

We present the preparation of 11 nm polyacrylamide-stabilized polystyrene latex particles for conjugation to a microRNA model by surfactant-free RAFT emulsion polymerization. Our synthetic strategy involved the preparation of amphiphilic polyacrylamide-block-polystyrene copolymers, which were able to self-assemble into polymeric micelles and "grow" into polystyrene latex particles. The surface of these sterically stabilized particles was postmodified with a disulfide-bearing linker for the attachment of the microRNA model, which can be released from the latex particles under reducing conditions. These nanoparticles offer the advantage of ease of preparation via a scaleable process, and the versatility of their synthesis makes them adaptable to a range of applications.

RAD51 G135C genetic polymorphism and their potential role in gastric cancer induced by Helicobacter pylori infection in Bhutan.

In order to evaluate the role of the RAD51 G135C genetic polymorphism on the risk of gastric cancer induced by Helicobacter pylori infection, we determined allele frequency and genotype distribution of this polymorphism in Bhutan--a population documented with high prevalence of gastric cancer and extremely high prevalence of H. pylori infection. The status of RAD51 G135C was examined by restriction fragment length polymorphism analysis of PCR amplified fragments and sequencing. Histological scores were evaluated according to the updated Sydney system. G135C carriers showed significantly higher scores for intestinal metaplasia in the antrum than G135G carriers [mean (median) 0·33 (0) vs. 0·08 (0), P = 0·008]. Higher scores for intestinal metaplasia of G135C carriers compared to those of G135G carriers were also observed in H. pylori-positive patients [0·3 (0) vs. 0·1 (0), P = 0·002] and H. pylori-positive patients with gastritis [0·4 (0) vs. 0·1 (0), P = 0·002] but were not found in H. pylori-negative patients. Our findings revealed that a combination of H. pylori infection and RAD51 G135C genotype of the host showed an increasing score for intestinal metaplasia. Therefore, RAD51 G135C might be the important predictor for gastric cancer of H. pylori-infected patients.

Identification of important and potentially avoidable risk factors in a prospective audit study of neonatal deaths in a paediatric hospital in Vietnam.

AIM: Neonatal deaths (≤28 days) account for more than half of child mortality in Vietnam. Presumably most die in hospital, but data are scarce. This study aimed to identify risk factors of death among hospitalised neonates. METHODS: We prospectively studied all neonatal deaths and expected deaths (discharged alive after withdrawal of life-sustaining treatment) in a Vietnamese tertiary paediatric hospital during a 12-month period in 2009-2010. The medical files were audited classifying admission prognosis, discharge outcome, cause of death/expected death according to two classifications, and important and potentially avoidable risk factors during the hospital stay. RESULTS: Among 5763 neonates admitted, 235 deaths and 67 expected deaths were included. According to both classifications, major causes were congenital malformations, prematurity and severe infections. Six risk factors were identified in 85% (60/71) of the neonates with a relatively good prognosis: recognition or response to danger signs, internal transfers, nosocomial infections, sepsis management, access to usual equipment/staff, and family perception. CONCLUSION: Among 302 neonatal deaths/expected deaths, the major causes were congenital malformations, prematurity and severe infections. Six important and potentially avoidable risk factors could be addressed in the subgroup with relatively good admission prognosis, without implementing new technology or major organisational changes.

An annotated checklist of centipedes (Chilopoda) of Vietnam.

The centipede fauna of Vietnam is reviewed from the literature. A total of 71 species in 26 genera, 13 families in four orders, Scolopendromorpha, Geophilomorpha, Lithobiomorpha and Scutigeromorpha, has been recorded from Vietnam. Four genera, Tonkinodentus, Alluropus, Anopsobiella and Megalacrus, are monotypic; and twenty-two species and subspecies are known only from Vietnam. Distribution data for each species is provided here to promote further studies on the centipede fauna of Vietnam.

Promoting Respectful Maternity Care by Reducing Unnecessary Episiotomies: Experiences from Centers of Excellence for Breastfeeding in Vietnam.

(1) Background: Routine episiotomy is not recommended by international guidelines; however, it occurs at a high rate in Vietnam. (2) Methods: A process to reduce unnecessary episiotomies was developed and implemented as part of the Centers of Excellence for Breastfeeding initiative, which aims to deliver high-quality breastfeeding and early essential newborn care services within a supportive policy environment. The aim of this project report is to outline the steps undertaken to reduce episiotomies, the experience in pilot hospitals, and the process towards changing policy. (3) Results: During the 14 months following the change in episiotomy policy, pilot hospital records showed no infant death or injury. Monthly monitoring data from four pilot hospitals showed that the prevalence of episiotomy was substantially lower than the average in national hospitals in Vietnam. Facilitators to reducing the episiotomy rate include the incentive of Centers of Excellence for Breastfeeding designation and supportive hospital leadership. Challenges include the ambiguity of Vietnam's national guideline on episiotomy and lack of routine monitoring on the episiotomy rate and indications. (4) Discussion: Our experience suggests that through training and routine monitoring hospitals can apply a policy of selective episiotomy and reduce the practice, particularly among multiparous women, and improve breastfeeding rates.(5) Conclusions: Sharing our experience of implementing this process and offering four areas for action will hopefully contribute to expanded use of mother-friendly, evidence-based care as policy and routine practice in Vietnam and similar settings.

Prematurity, asphyxia and congenital malformations underrepresented among neonates in a tertiary pediatric hospital in Vietnam.

BACKGROUND: Estimated 17,000 neonates (≤ 28 days of age) die in Vietnam annually, corresponding to more than half of the child mortality burden. However, current knowledge about these neonates is limited. Prematurity, asphyxia and congenital malformations are major causes of death in neonates worldwide. To improve survival and long term development, these vulnerable neonates need access to the specialized neonatal care existing, although limited, in lower middle-income countries like Vietnam. The aim of this study was to describe these conditions in a specialized Vietnamese hospital, compared to a Danish hospital. METHODS: We performed a comparative observational study of all neonates admitted to a tertiary pediatric hospital in South Vietnam in 2009-2010. The data were prospectively extracted from the central hospital registry and included basic patient characteristics and diagnoses (International Classification of Diseases, 10th revision). Prematurity, asphyxia and designated congenital malformations (oesophageal atresia, gastroschisis, omphalocoele, diaphragmatic hernia and heart disease) were investigated. In a subgroup, the prematurity diagnosis was validated using a questionnaire. The hospitalization ratio of each diagnosis was compared to those obtained from a Danish tertiary hospital. The Danish data were retrieved from the neonatal department database for a ten-year period. RESULTS: The study included 5763 neonates (missing<1%). The catchment population was 726,578 live births. The diagnosis was prematurity in 7%, asphyxia in 2% and one of the designated congenital malformations in 6%. The diagnosis of prematurity was correctly assigned to 85% of the neonates, who were very premature or had very low birth weight according to the questionnaire, completed by 2196 neonates. Compared to the Danish Hospital, the hospitalization ratios of neonates diagnosed with prematurity (p<0.01), asphyxia (p<0.01) and designated congenital malformations (p<0.01- 0.04) were significantly lower. CONCLUSION: Our findings suggest the investigated diagnoses were underrepresented in the Vietnamese study hospital. In contrast, relatively mild diagnoses were frequent. These results indicate the use of specialized care may not be optimal. Pre-hospital selection mechanisms were not investigated and additional studies are needed to optimise utilisation of specialized care and improve neonatal survival.

Two new Drawida (Oligochaeta, Moniligastridae) earthworms from Vietnam.

Two new earthworm species are described, namely Drawidaangiang sp. nov. and Drawidacochinchina sp. nov. The former can be recognized by having male pores on spiniform penises in intersegment 10/11, an erect and sac-shaped spermathecal atrium, glandular prostate, the capsule coiled one round, the vas deferens strongly coiled but small, two large, round, genital markings on segments ix-x, and three gizzards in xiii-xv. The latter species is distinguished in having the male pores placed on highly elevated, backwardly directed, conical penises in 10/11, a slender spermathecal atrium, a glandular prostate, a somewhat folded capsule, the vas deferens strongly coiled as a bunch and equal size to the testis sacs, a pair of genital markings located closely anterior to the penises with 1-3 additional ones in xi-xii, and three or four gizzards in xiii-xvi. The DNA barcode fragment of the COI gene was extracted for each species, and the COI genetic distances and phylogenetic analysis also supported two new species..

Performance evaluation of a PET insert for preclinical MRI in stand-alone PET and simultaneous PET-MRI modes.

BACKGROUND: This study aimed to evaluate the performance of a preclinical PET insert in three configurations: as a stand-alone unit outside the MRI bore, inside the bore of a cryogen-free 3T MRI and, finally, while performing simultaneous PET/MRI studies. METHODS: The PET insert consists of two rings of six detectors, each detector comprising 8 × 12 SiPMs reading out dual offset layers of pixelated LYSO crystals with a 1.4-mm pitch. The inner diameter is 60 mm, transaxial field of view (FoV) 40 mm and axial FoV 98 mm. Evaluation was based on NEMA NU 4-2008 guidelines with appropriate modifications. Spatial resolution and sensitivity were measured inside and outside the MR bore. Image quality, count rate and quantitative performance were measured in all three configurations. The effect of temperature stability on PET sensitivity during fast spin echo sequences was also evaluated. B0 field homogeneity and T1 and T2 relaxation times were measured using a water-filled phantom, with and without simultaneous PET operation. Finally, PET and MRI scans of a mouse injected with 10 MBq [18F]NaF and a mouse injected with 16 MBq [18F]FDG were performed in sequential and simultaneous modes. RESULTS: Peak absolute sensitivity was 10.15% with an energy window of 250-750 keV. Absolute sensitivity values outside and inside the MR bore with MR idle agreed to within 0.1%. Outside the MR bore, spatial resolution was 1.21/1.59 mm FWHM (radial/tangential) 5 mm from the centre of the FoV which compared well with 1.19/1.26 mm FWHM inside the MR bore. There were no substantial differences between all three scan configurations in terms of peak NEC rate (175 kcps at 17 MBq), scatter or random fractions. Uniformity and recovery coefficients were also consistent between scanning modes. B0 field homogeneity and T1 and T2 relaxation times were unaltered by the presence of the PET insert. No significant differences were observed between sequential and simultaneous scans of the animals. CONCLUSIONS: We conclude that the performance of the PET insert and MRI system is not significantly affected by the scanning mode.

The Association between a Novel Baby-Friendly Hospital Program and Equitable Support for Breastfeeding in Vietnam.

Background: Rates of early initiation of breastfeeding are low in Southeast Asia, despite evidence that increased initiation of early breastfeeding would lead to better long-term infant and child health and decrease inequities in long-term health and well-being. In response, a novel performance-based, baby-friendly hospital program designates hospitals that adhere to evidence-based early essential newborn care (EENC) and breastfeeding interventions as Centers of Excellence for Breastfeeding (COE). This study examined whether hospital participation in the program was associated with better breastfeeding outcomes. Methods: Hospitals (n = 28) were invited into the program in December 2018. Hospitals developed an improvement plan for promoting a breastfeeding-friendly environment and meeting the standards of the COE accreditation process and were enrolled on a rolling basis over the course of a year. Post-partum surveys were conducted with parents (n = 9585) from January 2019 through April 2020 to assess their breastfeeding and post-partum experience. Segmented regression models were used to assess how breastfeeding outcomes evolved before and after hospital enrollment in the COE program. Results: Enrollment was associated with a 6 percentage-point (95% CI: 3, 9) increase in the level of early initiation of breastfeeding, which continued to increase in the post-enrollment period, and a 5 percentage-point (95% CI: 2, 9) increase in the level of exclusive breastfeeding during hospital stay. We did not observe evidence that enrollment was immediately associated with receipt of lactation counseling or exclusive breastfeeding at survey time. Conclusion: The prevalence of early and exclusive breastfeeding increased after enrollment in the COE program, suggesting that the program has the potential to improve breastfeeding initiation rates and longer-term child health and well-being. Further research should be conducted to examine whether the program has an impact on the overall duration of breastfeeding.

Rare bioparticle detection via deep metric learning.

Recent deep neural networks have shown superb performance in analyzing bioimages for disease diagnosis and bioparticle classification. Conventional deep neural networks use simple classifiers such as SoftMax to obtain highly accurate results. However, they have limitations in many practical applications that require both low false alarm rate and high recovery rate, e.g., rare bioparticle detection, in which the representative image data is hard to collect, the training data is imbalanced, and the input images in inference time could be different from the training images. Deep metric learning offers a better generatability by using distance information to model the similarity of the images and learning function maps from image pixels to a latent space, playing a vital role in rare object detection. In this paper, we propose a robust model based on a deep metric neural network for rare bioparticle (Cryptosporidium or Giardia) detection in drinking water. Experimental results showed that the deep metric neural network achieved a high accuracy of 99.86% in classification, 98.89% in precision rate, 99.16% in recall rate and zero false alarm rate. The reported model empowers imaging flow cytometry with capabilities of biomedical diagnosis, environmental monitoring, and other biosensing applications.

A microfluidic chip enables fast analysis of water microplastics by optical spectroscopy.

Microplastics contaminating drinking water is a growing issue that has been the focus of a few recent studies, where a major bottleneck is the time-consuming analysis. In this work, a micro-optofluidic platform is proposed for fast quantification of microplastic particles, the identification of their chemical nature and size, especially in the 1-100 µm size range. Micro-reservoirs ahead of micro-filters are designed to accumulate all trapped solid particles in an ultra-compact area, which enables fast imaging and optical spectroscopy to determine the plastic nature and type. Furthermore, passive size sorting is implemented for splitting the particles according to their size range in different reservoirs. Besides, flow cytometry is used as a reference method for retrieving the size distribution of samples, where chemical nature information is lost. The proof of concept of the micro-optofluidic platform is validated using model samples where standard plastic particles of different size and chemical nature are mixed.

Biodistribution of onasemnogene abeparvovec DNA, mRNA and SMN protein in human tissue.

Spinal muscular atrophy type 1 (SMA1) is a debilitating neurodegenerative disease resulting from survival motor neuron 1 gene (SMN1) deletion/mutation. Onasemnogene abeparvovec (formerly AVXS-101) is a gene therapy that restores SMN production via one-time systemic administration. The present study demonstrates widespread biodistribution of vector genomes and transgenes throughout the central nervous system (CNS) and peripheral organs, after intravenous administration of an AAV9-mediated gene therapy. Two symptomatic infants with SMA1 enrolled in phase III studies received onasemnogene abeparvovec. Both patients died of respiratory complications unrelated to onasemnogene abeparvovec. One patient had improved motor function and the other died shortly after administration before appreciable clinical benefit could be observed. In both patients, onasemnogene abeparvovec DNA and messenger RNA distribution were widespread among peripheral organs and in the CNS. The greatest concentration of vector genomes was detected in the liver, with an increase over that detected in CNS tissues of 300-1,000-fold. SMN protein, which was low in an untreated SMA1 control, was clearly detectable in motor neurons, brain, skeletal muscle and multiple peripheral organs in treated patients. These data support the fact that onasemnogene abeparvovec has effective distribution, transduction and expression throughout the CNS after intravenous administration and restores SMN expression in humans.

Four new species of Amynthas earthworms in southeastern Vietnam (Annelida, Oligochaeta, Megascolecidae).

Four new earthworm species of the genus Amynthas Kinberg, 1867 are described from southeastern Vietnam, named A. longiprostaticus sp. nov., A. dorsomorrioides sp. nov., A. minhdam sp. nov., and A. ocularius sp. nov. A. longiprostaticus sp. nov. belongs to the A. minimus group of species, characterized by spermathecal pores in 5/6. It is distinguished by small body size with length 5-7 cm, and by elongate prostate glands, which extend over more than 10 segments. A. dorsomorrioides sp. nov. belongs to the A. morrisi group, characterized by holandry and spermathecal pores in 5/6/7. It is distinguished by a dorsal location of these pores, by one pair of large genital markings presetal in xvii, and by the absence of genital markings in the spermathecal region. A. minhdam sp. nov. also belongs to the A. morrisi group, and is distinguished by a pair of genital markings located medially in xviii and by the spermathecal diverticula, which have a small seminal chamber sub-divided by constrictions into 4 or 5 parts, in chain-form. A. ocularius sp. nov. belongs to the A. gracilis group by virtue of holandry and spermathecal pores in 5/6/7/8. It is distinguished by numerous small genital markings in the male region, postsetal in xviii and presetal in xix, and arranged in a peculiar fashion reminiscent of eyeglasses connected by a bridge. With these descriptions, there are now 119 species of Amynthas known in Vietnam.

A review and notes on the phylogenetic relationship of the centipede genus Otostigmus Porat, 1876 (Chilopoda: Scolopendromorpha: Scolopendridae) from Vietnam.

The genus Otostigmus Porat, 1876 is reviewed based on recent material collected from parts of Vietnam. A total of nine species are documented and imaged. The phylogeny of the genus Otostigmus is analyzed based on a 603-bp dataset of the cytochrome c oxidase subunit I (COI) gene. The average K2P genetic distance between Otostigmus species is 19%, and eight of nine species are considered to be monophyletic, except O. amballae. The phylogenetic relationship between Otostigmus species necessitates a deeper study with more samples and genetic data. In addition, an identification key to all Otostigmus species is provided for the fauna of Vietnam.