Tumor-derived exosomal PD-L1: a new perspective in PD-1/PD-L1 therapy for lung cancer.

Exosomes play a crucial role in facilitating intercellular communication within organisms. Emerging evidence indicates that a distinct variant of programmed cell death ligand-1 (PD-L1), found on the surface of exosomes, may be responsible for orchestrating systemic immunosuppression that counteracts the efficacy of anti-programmed death-1 (PD-1) checkpoint therapy. Specifically, the presence of PD-L1 on exosomes enables them to selectively target PD-1 on the surface of CD8+ T cells, leading to T cell apoptosis and impeding T cell activation or proliferation. This mechanism allows tumor cells to evade immune pressure during the effector stage. Furthermore, the quantification of exosomal PD-L1 has the potential to serve as an indicator of the dynamic interplay between tumors and immune cells, thereby suggesting the promising utility of exosomes as biomarkers for both cancer diagnosis and PD-1/PD-L1 inhibitor therapy. The emergence of exosomal PD-L1 inhibitors as a viable approach for anti-tumor treatment has garnered significant attention. Depleting exosomal PD-L1 may serve as an effective adjunct therapy to mitigate systemic immunosuppression. This review aims to elucidate recent insights into the role of exosomal PD-L1 in the field of immune oncology, emphasizing its potential as a diagnostic, prognostic, and therapeutic tool in lung cancer.

Role in post-translational modification of M2-type pyruvate kinase in tumorigenesis and development. / M2åž‹ä¸™é ®é ¸æ¿€é ¶ç¿»è¯‘åŽä¿®é¥°åœ¨è‚¿ç˜¤å‘ç”Ÿå’Œå‘å±•ä¸­çš„ä½œç”¨.

PKM2, also known as M2-type pyruvate kinase, has attracted significant attention due to its crucial role in glycolysis and its abnormal expression in various tumors. With the discovery of PKM2's non-metabolic functions, the transition between its pyruvate kinase activity (in the tetrameric form in the cytoplasm) and protein kinase activity (in the dimeric form in the nucleus) has once again made PKM2 a target of interest in cancer research. Studies have shown that PKM2 is a protein susceptible to various post-translational modifications, and different post-translational modifications play important regulatory roles in processes such as PKM2 cellular localization, structure, and enzyme activity conversion. In this review, we focused on the recent progress of multiple post-translational modifications of PKM2 and their important roles in tumor initiation and development. For example, phosphorylation and acetylation promote nuclear translocation by altering PKM2 cell localization; glycosylation and ubiquitination can promote the formation of dimer structure by affecting the structural transformation of PKM2; succinylation and redox modification promoted the enhancement of PKM2 kinase activity by affecting the transformation of kinase activity. Both changes affect the structure and cell localization of PKM2 and they play a role in promoting or inhibiting tumor development via altering its kinase activity.

An MRI-Based Radiomics Nomogram to Assess Recurrence Risk in Sinonasal Malignant Tumors.

BACKGROUND: Sinonasal malignant tumors (SNMTs) have a high recurrence risk, which is responsible for the poor prognosis of patients. Assessing recurrence risk in SNMT patients is a current problem. PURPOSE: To establish an MRI-based radiomics nomogram for assessing relapse risk in patients with SNMT. STUDY TYPE: Retrospective. POPULATION: A total of 143 patients with 68.5% females (development/validation set, 98/45 patients). FIELD STRENGTH/SEQUENCE: A 1.5-T and 3-T, fat-suppressed fast spin echo (FSE) T2-weighted imaging (FS-T2WI), FSE T1-weighted imaging (T1WI), and FSE contrast-enhanced T1WI (T1WI + C). ASSESSMENT: Three MRI sequences were used to manually delineate the region of interest. Three radiomics signatures (T1WI and FS-T2WI sequences, T1WI + C sequence, and three sequences combined) were built through dimensional reduction of high-dimensional features. The clinical model was built based on clinical and MRI features. The Ki-67-based and tumor-node-metastasis (TNM) model were established for comparison. The radiomics nomogram was built by combining the clinical model and best radiomics signature. The relapse-free survival analysis was used among 143 patients. STATISTICAL TESTS: The intraclass/interclass correlation coefficients, univariate/multivariate Cox regression analysis, least absolute shrinkage and selection operator Cox regression algorithm, concordance index (C index), area under the curve (AUC), integrated Brier score (IBS), DeLong test, Kaplan-Meier curve, log-rank test, optimal cutoff values. A P value < 0.05 was considered statistically significant. RESULTS: The T1 + C-based radiomics signature had best prognostic ability than the other two signatures (T1WI and FS-T2WI sequences, and three sequences combined). The radiomics nomogram had better prognostic ability and less error than the clinical model, Ki-67-based model, and TNM model (C index, 0.732; AUC, 0.765; IBS, 0.185 in the validation set). The cutoff values were 0.2 and 0.7 and then the cumulative risk rates were calculated. DATA CONCLUSION: A radiomics nomogram for assessing relapse risk in patients with SNMT may provide better prognostic ability than the clinical model, Ki-67-based model, and TNM model. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 5.

Rule extraction from biased random forest and fuzzy support vector machine for early diagnosis of diabetes.

Due to concealed initial symptoms, many diabetic patients are not diagnosed in time, which delays treatment. Machine learning methods have been applied to increase the diagnosis rate, but most of them are black boxes lacking interpretability. Rule extraction is usually used to turn on the black box. As the number of diabetic patients is far less than that of healthy people, the rules obtained by the existing rule extraction methods tend to identify healthy people rather than diabetic patients. To address the problem, a method for extracting reduced rules based on biased random forest and fuzzy support vector machine is proposed. Biased random forest uses the k-nearest neighbor (k-NN) algorithm to identify critical samples and generates more trees that tend to diagnose diabetes based on critical samples to improve the tendency of the generated rules for diabetic patients. In addition, the conditions and rules are reduced based on the error rate and coverage rate to enhance interpretability. Experiments on the Diabetes Medical Examination Data collected by Beijing Hospital (DMED-BH) dataset demonstrate that the proposed approach has outstanding results (MCC = 0.8802) when the rules are similar in number. Moreover, experiments on the Pima Indian Diabetes (PID) and China Health and Nutrition Survey (CHNS) datasets prove the generalization of the proposed method.

Struvite crystallization by using active serpentine: An innovative application for the economical and efficient recovery of phosphorus from black water.

Recovery of phosphorus from wastewater through struvite crystallization is one of the most attractive methods. However, the cost of chemical consumption makes this technology is unattractive to some extent. In this work, highly active serpentine was prepared by one-step mechanical activation and then used to recover phosphate as struvite from the black water containing 132.8 mg/L phosphorus and 3144 mg/L ammonia nitrogen. The results indicated that the prepared active serpentine can release magnesium ions and hydroxide ions simultaneously into an aqueous solution and is an ideal raw material for struvite crystallization. The factors for phosphorus recovery in this process mainly include mechanical activation intensity, serpentine dosage, and contact time. For the actual black water, a high recovery rate of phosphorus (>98%) is achieved by using active serpentine as the magnesium and alkali source for struvite precipitation. The recovery product was identified as struvite with a median particle size of 32.96 µm. It was confirmed that the mechanical activation damaged the crystal structure of the raw serpentine, improving the activity of Mg2+ and OH-. The undissolved Si-containing particles act as crystal seeds, accelerating the struvite crystallization process. Furthermore, a pilot-scale test was conducted with a rural public toilet in Xiong'an New District, Hebei Province. The results showed that an acceptable phosphorus recovery (98%) could be achieved using active serpentine. Additionally, it was demonstrated that the serpentine process to recover phosphate as struvite reduced the cost by 54.4% in compared with an ordinary chemical process. The active serpentine is a promising dual source of magnesium and alkali for the phosphorus recovery by the struvite method. It has a potential prospect for the large-scale application in phosphorus recovery and struvite fertilizer production.

Nitrogen and phosphorous recycling from human urine by household electrochemical fixed bed in sparsely populated regions.

Decentralized treatment of human urine in sparsely populated regions could avoid the problem of sewage collection in traditionally centralized treatment schemes and simultaneously utilize the recovered N/P fertilizer in-situ to nurture gardens. Herein, an integrated electrochemical fixed bed packed with divided magnesite and carbon zones was constructed for the pretreatment of human urine, followed by the recovery of 95.0% NH4+ and 85.8% PO43- via struvite precipitation and NH3 volatilization as well as the on-site employment of the produced struvite as fertilizer. In the process, the acid/base zones created by electrochemical water splitting dissolved the magnesite filler as the Mg2+ source of struvite, further creating an ideal pH environment for struvite precipitation and NH3 volatilization in the effluent. Without the need to control solution pH by chemical addition, the system can resist impacts from changes in water quality by adjustment of the current density and flow rate, indicating its great potential for automatic operation. Life cycle assessment indicated that the on-site employment of produced struvite avoids the long-distance fertilizer transportation required for fertilization, thus reducing carbon emission by a hundred million tons per year if the household facility is driven by clean electricity.

Nickel phosphide on Ni foam as anode and peroxymonosulfate as the chemical oxidizer for effective direct urea fuel cell.

The direct urea fuel cell (DUFC) is a low cost and competitive approach for contemporaneous urine or urea-contaminated wastewater treatment and electricity generation. However, the lack of efficient urea oxidation reaction (UOR) electrocatalysts and suitable electron acceptors remains a challenge for practical applications. Here, we developed a DUFC system using Ni2P@Ni foam as the anode and peroxymonosulfate (PMS) as the chemical oxidizers. The Ni2P@Ni foam anode showed a high oxidation activity for UOR with an onset potential of 0.30 V vs. Ag/AgCl and Tafel slope of 34.4 mV/dec. PMS with high theoretical potential improved the cell voltage to 1.43 V. A power density of DUFC up to 4.91 mW/cm2 was achieved using PMS at room temperature, which was approximately twice as high as using H2O2 (2.38 mW/cm2). NiII/NiIII was the redox active species on the Ni2P anode in the DUFC process, and NiII was electrochemically oxidized to NiIII, which reverted to NiII by urea reduction. When real human urine was used as the fuel, a power density of 4.46 mW/cm2 can be achieved at room temperature. This DUFC with high cell performance showed potential application in urea wastewater treatment.

Effects of season and food on the scatter-hoarding behavior of rodents in temperate forests of Northeast China.

To explore the differences in hoarding strategies of rodents for different seeds in various seasons, we labeled and released the seeds of Pinus koraiensis, Corylus mandshurica, Quercus mongolica and Prunus sibirica in temperate forests of Northeast China and investigated the fate of the seeds in spring and autumn. The analysis showed that the hoarding strategies of the rodents varied substantially between seasons. The seeds were consumed faster in the spring than in the autumn. More than 50% of the seeds in the two seasons were consumed by the 16th day. It took 36 days to consume 75% of the seeds in the spring and 44 days in the autumn. The rate of consumption of the seeds in the spring was greater than in the autumn, and the rate of spread of the seeds was greater in the autumn. The distances of removal for the consumption and dispersal of seeds in the spring (3.26 ± 3.21 m and 4.15 ± 3.52 m, respectively) were both shorter than those in the autumn (3.74 ± 3.41 m and 4.87 ± 3.94 m, respectively). In addition, the fate of different seeds varied significantly owing to differences in hoarding strategies. The seeds of the three preferred species, P. koraiensis, C. mandshurica, and Q. mongolica, were quickly consumed. More than 90% of the seeds of these species were consumed. Only 21% of Pr. sibirica seeds were slowly consumed, and the two seasons had the same seed consumption rate patterns: the consumption rate of P. koraiensis seeds was the highest, followed by C. mandshurica, then Q. mongolica, and finally Pr. sibirica. The median removal times of the two seasons were different, but the rules were the same: P. koraiensis was the shortest, followed by C. mandshurica, and the third was Q. mongolica. In both seasons, the most predated in situ seeds were those of P. koraiensis; the most hoarded seeds were those of C. mandshurica, and the most unconsumed seeds were those of Pr. sibirica.

First Report on Natural Infection of Nodavirus in an Echinodermata, Sea Cucumber (Apostichopus japonicas).

Cross-species transmission of emerging viruses happens occasionally due to epidemiological, biological, and ecological factors, and it has caused more concern recently. Covert mortality nodavirus (CMNV) was revealed to be a unique shrimp virus that could cross species barrier to infect vertebrate fish. In the present study, CMNV reverse transcription-nested PCR (RT-nPCR)-positive samples were identified from farmed sea cucumber (Apostichopus japonicas) in the CMNV host range investigation. The amplicons of RT-nPCR from sea cucumber were sequenced, and its sequences showed 100% identity with the RNA-dependent RNA polymerase gene of the original CMNV isolate. Histopathological analysis revealed pathologic changes, including karyopyknosis and vacuolation of the epithelial cells, in the sea cucumber intestinal tissue. The extensive positive hybridization signals with CMNV probe were shown in the damaged epithelial cells in the in situ hybridization assay. Meanwhile, transmission electron microscopy analysis revealed CMNV-like virus particles in the intestine epithelium. All the results indicated that the sea cucumber, an Echinodermata, is a new host of CMNV. This study supplied further evidence of the wide host range of CMNV and also reminded us to pay close attention to its potential risk to threaten different aquaculture animal species.

Dynamics and Microevolution of Vibrio parahaemolyticus Populations in Shellfish Farms.

Vibrio parahaemolyticus is becoming the leading cause of acute bacterial gastroenteritis, but its population dynamics in aquafarms have received limited attention. To address this research gap, we selected three shellfish farms to examine the impacts of ocean currents and the transport of live aquatic animals on the transmission and microevolution of V. parahaemolyticus by using multilocus sequence typing (MLST) and whole-genome sequencing. MLST and genomic analysis revealed that the community structure of V. parahaemolyticus in Dalian and Donggang was relatively stable in the presence of ocean currents; however, horizontal gene transfer of mobile genetic elements (MGEs) between Dalian and Donggang was very common. Further analysis indicated that the transport of live aquatic animals from Dalian to Xiamen not only introduced new V. parahaemolyticus populations but also allowed the exchange of genetic material between the two sites. More interestingly, Dalian-originated strain ST722 was introduced to Xiamen farms, resulting in one MLST allele change and the acquisition of two genomic islands from indigenous isolates in Xiamen within 8 months; such alterations are thought to promote the adaptation of V. parahaemolyticus These results provide direct observations of how ocean currents and the transport of live aquatic animals contribute to the dissemination and genetic mixture of V. parahaemolyticus, which provides insights into the dynamics and microevolution of V. parahaemolyticus in aquacultural environments.IMPORTANCE Globally, V. parahaemolyticus-related gastroenteritis outbreaks caused by seafood consumption represent an increasing threat to human health. Despite advances in our understanding of the global epidemiology of pandemic V. parahaemolyticus, fundamental questions about the key driving forces for the spread of V. parahaemolyticus at regional and national scales remain unanswered. This study revealed that the transregional transport of aquatic animals and the movement of ocean currents both contributed to the mixing of V. parahaemolyticus populations. More importantly, this study demonstrated how genetic mixture occurred between introduced and endemic V. parahaemolyticus populations via the transport of aquatic animals, which accelerated bacterial adaptation by transferring ecologically important functions. These results suggest that human activities entail a risk of the emergence of new virulent populations for both aquatic animals and humans by horizontal gene transfer and provide important insights into the microevolution and population mixing of V. parahaemolyticus.

Solid-State Fermentation of Aspergillus niger to Optimize Extraction Process of Isoliquiritigenin from Glycyrrhiza uralensis.

We successfully extracted isoliquiritigenin from Glycyrrhiza uralensis via fermentation with Aspergillus niger and ultrasonic-assisted extraction. In brief, we used A. niger fermentation to culture G. uralensis powder, and we optimized some key parameters such as reaction conditions of pH, inoculation concentration of A. niger, fermentation time, and solid-liquid ratio. Based on a single-factor experiment, we utilized the response surface methodology (RSM) approach to optimize this extraction procedure. Using the RSM approach, optimized conditions of pH = 3.694, the solid-liquid ratio = 1 : 2.155, and the inoculation concentration of A. niger = 1466745 were selected. Optimized conditions resulted in an extraction efficiency of 1.525 mg/g. These results showed that the extraction of isoliquiritigenin was most affected by pH and then the time of fermentation and the solid-liquid ratio. Overall, the developed extraction technique yielded 5 times the amount of isoliquiritigenin when compared to traditional methods.

Observations of the foraging behavior and activity patterns of the Korean wood mouse, Apodemus peninsulae, in China, using infra-red cameras.

Apodemus peninsulae, a dominant rodent species in temperature forests of northeastern China, is a model animal to explore the ecological functions of reciprocal coevolution of animals and plants. From August to October 2016, 24 infra-red cameras were installed to study the feeding behavior and activity patterns of A. peninsulae in its natural environment. By analyzing 5618 video records, we found that feeding behavior, followed by motor and sentinel behaviors, was their main activity. In the behavior spectra, motor behavior (creep, walk, and skip), feeding behavior (forage, feeding, transport, hoarding, and clean), and sentinel behavior (alert, flee, banishment, and coexistence) accounted for 57.96%, 40.36%, and 1.68% of their behavior, respectively. The peak of feeding behavior occurred between 18:00 and 23:00, and feeding behavior frequency, duration, and activity rhythms differ among August to October. Furthermore, activity was the greatest after sunset and before sunrise, indicating a nocturnal lifestyle; however, from August to October, the start time of the activity was earlier, and the end time was later than usual. On average, mice spent 21.6 ± 11.6 times/night feeding, with a duration of 63.58 ± 98.36 s; while they spent less time in foraging, 39.05 ± 51.63 s. We found a significant difference in feeding and foraging frequency, with mice spending on average 10.84 ± 9.85 times/night and 9.23 ± 11.17 times/night, respectively. Our results show that feeding and foraging behavior is also influenced by light intensity, suggesting a preference for crepuscular periods of the day. Infra-red cameras are very useful in detecting activity patterns of animals that are not easily observable; these cameras are able to capture a large amount of valuable information for research into ecological functions.

A Study of the Ionic Liquid-Based Ultrasonic-Assisted Extraction of Isoliquiritigenin from Glycyrrhiza uralensis.

We successfully extracted isoliquiritigenin from Glycyrrhiza uralensis through the utilization of an ionic liquid-based ultrasonic-assisted extraction (ILUAE) approach. Briefly, we utilized the solution of 1-butyl-3-methylimidazolium bromide ([BMIM]Br) as solvent and optimized key ILUAE parameters such as solid-liquid ratios, concentrations of ionic liquids, and the times of ultrasonication. Based on a single-factor experiment, we utilized the response surface method (RSM) approach to optimize the extraction procedure. The approach revealed that the optimal energy consumption time was 120 min, with the ultrasonic extraction temperature of 60°C. Using these optimized parameters together with the solid-liquid ratio (dried G. uralensis powder: [BMIM]Br of 0.3 mol/L) of 1 : 16.163 and the [BMIM]Br of 0.3 mol/L, we achieved a 0.665 mg/g extraction yield. Overall, these findings thus indicate that we were able to effectively use ILUAE as an efficient approach to reliably extract isoliquiritigenin in a reproducible and environmentally friendly manner.

The Impact of Water Intrusion on Pathogenic Vibrio Species to Inland Brackish Waters of China.

The estuary is the ecological niche of pathogenic Vibrio spp. as it provides abundant organic and inorganic nutrients from seawater and rivers. However, little is known about the ecology of these Vibrio species in the inland brackish water area. In this study, their co-occurrence and relationships to key environmental constraints (salinity and temperature) in the Hun-Tai River of China were examined using the most probable number polymerase chain reaction (MPN-PCR) approach. We hereby report 2-year continuous surveillance based on six water indices of the Hun-Tai River. The results showed that seawater intrusion maximally reached inland as far as 26.5 km for the Hun-Tai River. Pathogenic Vibrio spp. were detected in 21.9% of the water samples. In particular, V. cholerae, V. parahaemolyticus, and V. vulnificus were isolated in 10 (10.4%), 20 (20.8.5%), and 2 (2.08%) samples, respectively. All V. parahaemolyticus strains were tdh gene negative, 10% were positive for the trh gene. Multi-locus sequence typing (MLST) divided V. parahaemolyticus strains into 12 sequence types (STs) for the Hun-Tai River. Five STs were respectively present in various locations along the Hun-Tai River. The PCR assay for detecting six virulence genes and Vibrio seventh pandemic island I and II revealed three genotypes in 12 V. cholerae isolates. The results of our study showed that seawater intrusion and salinity have profound effects on the distribution of pathogenic Vibrio spp. in the inland river, suggesting a potential health risk associated with the waters of the Hun-Tai River used for irrigation and drinking.

National Safety Survey of Animal-use Commercial Probiotics and Their Spillover Effects From Farm to Humans: An Emerging Threat to Public Health.

BACKGROUND: Human-use probiotics have recently been associated with clinical infections and antibiotic resistance transfer, raising public concern over their safety. However, despite their extensive application in aquaculture and animal husbandry, the safety of animal-use probiotics remains poorly described. METHODS: We evaluated the safety of 92 animal-use probiotics from China. The pattern of spread of pathogens from probiotics and the consequent public health implications were also examined by conducting in-field genomic surveillance at 2 farms. RESULTS: A total of 123 probiotic Bacillus species isolates were obtained from 92 brands of probiotics, of which 45 isolates were resistant to antibiotics. Notably, 33.7% of probiotic products were contaminated with life-threatening pathogens such as Klebsiella pneumoniae. Genomic surveillance at a chicken farm identified an anthrax toxin-positive Bacillus cereus strain in a probiotic product used as a feed supplement, which was transferred into the groundwater and to a nearby fish farm. Following up retrospective analysis of the surveillance data during 2015-2018 in 3 provinces retrieved 2 B. cereus strains from human with intestinal anthrax symptoms and confirmed the transmission of B. cereus from farm to human. Surveillance of anthrax toxin revealed that cya was detected in 8 of 31 farms. CONCLUSIONS: This study provides the first national safety survey of animal-use probiotics in China and confirms the spillover effects of probiotics from the farms to human. These results suggest that the large-scale application of pathogen-containing probiotics leads to the transfer of pathogens, with worrisome implications for public health. Good Manufacturing Practice should be implemented during the production of all probiotics.Animal-use probiotic products are frequently contaminated with viable pathogenic bacteria. This study revealed that virulent probiotic organisms and contaminating pathogens were colonized with farm animals and shed into the environment, which facilitated the transfer of pathogens to humans.

Long-distance transmission of pathogenic Vibrio species by migratory waterbirds: a potential threat to the public health.

A potential mechanism for the global distribution of waterborne pathogens is through carriage by the migratory waterbirds. However, this mode of transmission has yet been confirmed epidemiologically. Here, we conducted whole genome sequencing of Vibrio spp. collected from waterbirds, sediments, and mollusks in the estuary of the Liaohe River in China to investigate this transmission mode. We found that a V. parahaemolyticus strain isolated from a waterbird was clonally related to the other V. parahaemolyticus strains obtained from the sediments and mollusks, and three V. mimicus strains isolated from bird feces were genomically related to those found in the mollusks and upstream groundwater, suggesting that the bird-carried Vibrio strains were acquired through the direct predation of the local mollusks. Surprisingly, two bird-carried V. parahaemolyticus strains belonging to the same clone were identified in Panjin and Shanghai, which are over 1,150 km apart, and another two were found at two locations 50 km apart, further supporting that waterbirds are capable of carrying and disseminating these pathogens over long distances. Our results provide the first evidence of direct transmission from mollusks to waterbirds and confirm that waterbirds act as disseminating vehicles of waterborne pathogens. Effective surveillance of migratory waterbirds along their routes will be valuable for predicting future epidemics of infectious diseases.

A Human Intestinal Infection Caused by a Novel Non-O1/O139 Vibrio cholerae Genotype and Its Dissemination Along the River.

Non-O1/O139 Vibrio cholerae is increasingly reported in the clinical settings. However, intestinal infections via the consumption of non-O1/O139 V. cholerae-carrying seafood are rarely documented in China. In this study, we reported a case of mild watery diarrhea in a young male, caused by non-O1/O139 V. cholerae in the downstream of Liaohe River. Epidemiological investigation showed that this intestinal infection potentially associated with the raw consumption of mollusc. Prior to this finding, we conducted a 6-month pathogen surveillance of three locations along the Liaohe River and identified three environmental non-O1/O139 V. cholerae strains. To confirm the epidemiological links between clinical and environmental strains, high-resolution genomic typing was employed and revealed that V. cholerae isolated from human stool sample was genomically related to the one found in local mollusc and shared a common ancestor with other environmental strains obtained in the upstream sites of the Liaohe River. This fact suggests that the river is a natural reservoir for non-O1/O139 V. cholerae which poses a potential threat to the public health. In summary, our results deepened the insights on the transmission of non-pandemic V. cholerae strains and underscored the significance of genomic surveillance for drinking water along the river sites.

Infection of covert mortality nodavirus in Japanese flounder reveals host jump of the emerging alphanodavirus.

Interspecies transmission of viruses, where a pathogen crosses species barriers and jumps from its original host into a novel species, has been receiving increasing attention. Viral covert mortality disease, caused by covert mortality nodavirus (CMNV), is an emerging disease that has recently had a substantial impact on shrimp aquaculture in Southeast Asia and Latin America. While investigating the host range of CMNV, we found that this virus is also capable of infecting populations of the farmed Japanese flounder Paralichthys olivaceus, a vertebrate host. The infected fish were being raised in aquaculture facilities that were also producing marine shrimp. Through RT-nPCR, targeting the RNA-dependent RNA polymerase (RdRp) gene of CMNV, we found that 29 % of the fish sampled were positive. The amplicons were sequenced and aligned to the RdRp gene of shrimp CMNV and were found to have 98 % identity. Histopathological examination indicated that CMNV-positive fish showed vacuolation of nervous tissue in the eye and brain, as well as extensive necrosis of cardiac muscle. In situ hybridization showed positive reactions in tissues of the eye, brain, heart, liver, spleen and kidney of infected fish. Transmission electron microscopy showed the presence of CMNV-like particles in all of the above-mentioned tissues, except for brain. The novel finding of a shrimp alphanodavirus that can also infect farmed P. olivaceus indicates that this virus is capable of naturally crossing the species barrier and infecting another vertebrate. This finding will contribute to the development of efficient strategies for disease management in aquaculture.