Mining biosynthetic gene clusters in Paenibacillus genomes to discover novel antibiotics.

BACKGROUND: Bacterial antimicrobial resistance poses a severe threat to humanity, necessitating the urgent development of new antibiotics. Recent advances in genome sequencing offer new avenues for antibiotic discovery. Paenibacillus genomes encompass a considerable array of antibiotic biosynthetic gene clusters (BGCs), rendering these species as good candidates for genome-driven novel antibiotic exploration. Nevertheless, BGCs within Paenibacillus genomes have not been extensively studied. RESULTS: We conducted an analysis of 554 Paenibacillus genome sequences, sourced from the National Center for Biotechnology Information database, with a focused investigation involving 89 of these genomes via antiSMASH. Our analysis unearthed a total of 848 BGCs, of which 716 (84.4%) were classified as unknown. From the initial pool of 554 Paenibacillus strains, we selected 26 available in culture collections for an in-depth evaluation. Genomic scrutiny of these selected strains unveiled 255 BGCs, encoding non-ribosomal peptide synthetases, polyketide synthases, and bacteriocins, with 221 (86.7%) classified as unknown. Among these strains, 20 exhibited antimicrobial activity against the gram-positive bacterium Micrococcus luteus, yet only six strains displayed activity against the gram-negative bacterium Escherichia coli. We proceeded to focus on Paenibacillus brasilensis, which featured five new BGCs for further investigation. To facilitate detailed characterization, we constructed a mutant in which a single BGC encoding a novel antibiotic was activated while simultaneously inactivating multiple BGCs using a cytosine base editor (CBE). The novel antibiotic was found to be localized to the cell wall and demonstrated activity against both gram-positive bacteria and fungi. The chemical structure of the new antibiotic was elucidated on the basis of ESIMS, 1D and 2D NMR spectroscopic data. The novel compound, with a molecular weight of 926, was named bracidin. CONCLUSIONS: This study outcome highlights the potential of Paenibacillus species as valuable sources for novel antibiotics. In addition, CBE-mediated dereplication of antibiotics proved to be a rapid and efficient method for characterizing novel antibiotics from Paenibacillus species, suggesting that it will greatly accelerate the genome-based development of new antibiotics.

Cytotoxicity of amine-modified polystyrene MPs and NPs on neural stem cells cultured from mouse subventricular zone.

Microplastics (MPs) and nanoplastics (NPs) are found in various environments such as aquatic, terrestrial, and aerial areas. Once ingested and inhaled, these tiny plastic debris damaged the digestive and respiratory organ systems in animals. In humans, the possible connection between MPs and various diseases such as lung diseases has been raised. Yet, the impact of MPs on the human nervous system has been unclear. Previous research using animals and cultured cells showed possible neurotoxicity of MPs and NPs. In this study, we used neural stem cells cultured from mouse subventricular zone to examine the effects of polystyrene (PS) NPs and MPs with sizes of 0.1 µm, 1 µm, and 2 µm on the cell proliferation and differentiation. We observed that only positively charged NPs and MPs, but not negatively charged ones, decreased cell viability and proliferation. These amine-modified NPs and MPs decreased both neurogenesis and oligodendrogenesis. Finally, fully differentiated neurons and oligodendrocytes were damaged and removed by the application of NPs and MPs. All these effects varied among different sizes of NPs and MPs, with the greatest effects from 1 µm and the least effects from 2 µm. These results clearly demonstrate the cytotoxicity and neurotoxicity of PS-NPs and MPs.

Mesoporous Silica Nanoparticles as a Potential Nanoplatform: Therapeutic Applications and Considerations.

With advances in nanotechnology, nanoparticles have come to be regarded as carriers of therapeutic agents and have been widely studied to overcome various diseases in the biomedical field. Among these particles, mesoporous silica nanoparticles (MSNs) have been investigated as potential nanocarriers to deliver drug molecules to various target sites in the body. This review introduces the physicochemical properties of MSNs and synthesis procedures of MSN-based nanoplatforms. Moreover, we focus on updating biomedical applications of MSNs as a carrier of therapeutic or diagnostic cargo and review clinical trials using silica-nanoparticle-based systems. Herein, on the one hand, we pay attention to the pharmaceutical advantages of MSNs, including nanometer particle size, high surface area, and porous structures, thus enabling efficient delivery of high drug-loading content. On the other hand, we look through biosafety and toxicity issues associated with MSN-based platforms. Based on many reports so far, MSNs have been widely applied to construct tissue engineering platforms as well as treat various diseases, including cancer, by surface functionalization or incorporation of stimuli-responsive components. However, even with the advantageous aspects that MSNs possess, there are still considerations, such as optimizing physicochemical properties or dosage regimens, regarding use of MSNs in clinics. Progress in synthesis procedures and scale-up production as well as a thorough investigation into the biosafety of MSNs would enable design of innovative and safe MSN-based platforms in biomedical fields.

Infrared thermographic changes after decompression surgery in patients with carpal tunnel syndrome.

BACKGROUND: Digital infrared thermal imaging (DITI), which detects infrared rays emitted from body surface to create a body heat map, has been utilized at various musculocutaneous conditions. Notably, DITI can demonstrate autonomic vasomotor activity in the nerve-innervated area, and thus may be of use in carpal tunnel syndrome (CTS). In this study, we compared DITI findings before and after carpal tunnel release (CTR) surgery in patients with unilateral CTS to investigate the corresponding neurophysiological changes. METHODS: In this retrospective cohort study, DITI parameters such as the temperature differences between the median and ulnar nerve territories and median nerve-innervated digital anisometry were measured. Subjective symptom duration, pain scale, and ultrasonographic findings were also compared before and after CTR. Patients were evaluated before and 6 weeks after CTR, respectively. RESULTS: A total of 27 patients aged 59.0 ± 11.2 years were finally included. After CTR, median nerve-innervated thermal anisometry was improved (2.55 ± 0.96 °C to 1.64 ± 1.34 °C; p = 0.003). The temperature differences between the median and ulnar nerve territories were not significantly changed. Subjective pain, the Simovic Weinberg Clinical Scale, and palmar bowing of the flexor retinaculum were also significantly improved (p <  0.001 for all comparisons). CONCLUSIONS: Our results demonstrated that DITI findings could reflect an improvement in autonomic function after CTR. Therefore, DITI can be an objective method to assess pre- and post-operative neurophysiologic changes in CTS.

Bacillus integrative plasmid system combining a synthetic gene circuit for efficient genetic modifications of undomesticated Bacillus strains.

BACKGROUND: Owing to CRISPR-Cas9 and derivative technologies, genetic studies on microorganisms have dramatically increased. However, the CRISPR-Cas9 system is still difficult to utilize in many wild-type Bacillus strains owing to Cas9 toxicity. Moreover, less toxic systems, such as cytosine base editors, generate unwanted off-target mutations that can interfere with the genetic studies of wild-type strains. Therefore, a convenient alternative system is required for genetic studies and genome engineering of wild-type Bacillus strains. Because wild-type Bacillus strains have poor transformation efficiencies, the new system should be based on broad-host-range plasmid-delivery systems. RESULTS: Here, we developed a Bacillus integrative plasmid system in which plasmids without the replication initiator protein gene (rep) of Bacillus are replicated in a donor Bacillus strain by Rep proteins provided in trans but not in Bacillus recipients. The plasmids were transferred to recipients through a modified integrative and conjugative element, which is a wide host range plasmid-delivery system. Genetic mutations were generated in recipients through homologous recombination between the transferred plasmid and the genome. The system was improved by adding a synthetic gene circuit for efficient screening of the desired mutations by double crossover recombination in recipient strains. The improved system exhibited a mutation efficiency of the target gene of approximately 100% in the tested wild-type Bacillus strains. CONCLUSION: The Bacillus integrative plasmid system developed in this study can generate target mutations with high efficiency when combined with a synthetic gene circuit in wild-type Bacillus strains. The system is free of toxicity and unwanted off-target mutations as it generates the desired mutations by traditional double crossover recombination. Therefore, our system could be a powerful tool for genetic studies and genome editing of Cas9-sensitive wild-type Bacillus strains.

Elicitation of Innate Immunity by a Bacterial Volatile 2-Nonanone at Levels below Detection Limit in Tomato Rhizosphere.

Bacterial volatile compounds (BVCs) exert beneficial effects on plant protection both directly and indirectly. Although BVCs have been detected in vitro, their detection in situ remains challenging. The purpose of this study was to investigate the possibility of BVCs detection under in situ condition and estimate the potentials of in situ BVC to plants at below detection limit. We developed a method for detecting BVCs released by the soil bacteria Bacillus velezensis strain GB03 and Streptomyces griseus strain S4-7 in situ using solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Additionally, we evaluated the BVC detection limit in the rhizosphere and induction of systemic immune response in tomato plants grown in the greenhouse. Two signature BVCs, 2-nonanone and caryolan-1-ol, of GB03 and S4-7 respectively were successfully detected using the soil-vial system. However, these BVCs could not be detected in the rhizosphere pretreated with strains GB03 and S4-7. The detection limit of 2-nonanone in the tomato rhizosphere was 1 µM. Unexpectedly, drench application of 2-nonanone at 10 nM concentration, which is below its detection limit, protected tomato seedlings against Pseudomonas syringae pv. tomato. Our finding highlights that BVCs, including 2-nonanone, released by a soil bacterium are functional even when present at a concentration below the detection limit of SPME-GC-MS.

Cell Factory Engineering of Undomesticated Bacillus Strains Using a Modified Integrative and Conjugative Element for Efficient Plasmid Delivery.

A large number of Bacillus strains have been isolated from various environments and many of them have great potential as cell factories. However, they have been rarely developed as cell factories due to their poor transformation efficiency. In this study, we developed a highly efficient plasmid delivery system for undomesticated Bacillus strains using a modified integrative and conjugative element (MICE), which was designed to be activated by an inducer, prevent self-transfer, and deliver desired plasmids to the recipient cells. The MICE system was demonstrated to successfully introduce a gfp-containing plasmid into all 41 undomesticated Bacillus subtilis strains tested and eight other Bacillus species. The MICE was used to deliver a cytosine base editor (CBE)-based multiplex genome-editing tool for the cell factory engineering of the Bacillus species. The introduced CBE enabled one-step inactivation of the major extracellular protease genes of the tested strains. The engineered strains were used as hosts for heterologous expression of nattokinase, which resulted in various enzyme expression levels. The results suggested that the MICE and CBE systems can be powerful tools for genetic engineering of undomesticated Bacillus strains, and greatly contribute to the expansion of the Bacillus cell factory.

Cytosine Base Editor-Mediated Multiplex Genome Editing to Accelerate Discovery of Novel Antibiotics in Bacillus subtilis and Paenibacillus polymyxa.

Genome-based identification of new antibiotics is emerging as an alternative to traditional methods. However, uncovering hidden antibiotics under the background of known antibiotics remains a challenge. To over this problem using a quick and effective genetic approach, we developed a multiplex genome editing system using a cytosine base editor (CBE). The CBE system achieved simultaneous double, triple, quadruple, and quintuple gene editing with efficiencies of 100, 100, 83, and 75%, respectively, as well as the 100% editing efficiency of single targets in Bacillus subtilis. Whole-genome sequencing of the edited strains showed that they had an average of 8.5 off-target single-nucleotide variants at gRNA-independent positions. The CBE system was used to simultaneously knockout five known antibiotic biosynthetic gene clusters to leave only an uncharacterized polyketide biosynthetic gene cluster in Paenibacillus polymyxa E681. The polyketide showed antimicrobial activities against gram-positive bacteria, but not gram-negative bacteria and fungi. Therefore, our findings suggested that the CBE system might serve as a powerful tool for multiplex genome editing and greatly accelerating the unraveling of hidden antibiotics in Bacillus and Paenibacillus species.

Effects of taxol on neuronal differentiation of postnatal neural stem cells cultured from mouse subventricular zone.

Taxol (paclitaxel), a chemotherapeutic agent for several cancers, can adversely affect the peripheral nervous system. Recently, its negative impact on cognitive function in cancer patients has become evident. In rodents, taxol impaired learning and memory, with other possible negative effects on the brain. In this study, we investigated the effects of taxol on cultured neural stem cells (NSCs) from the mouse neurogenic region, the subventricular zone (SVZ). Taxol significantly decreased both proliferation and neuronal differentiation of NSCs. Transient treatment with taxol for one day during a 4-day differentiation greatly decreased neurogenesis along with an abnormal cell cycle progression. Yet, taxol did not kill differentiated Tuj1+ neurons and those neurons had longer neurites than neurons under control conditions. For glial differentiation, taxol significantly reduced oligodendrogenesis as observed by immunostaining for Olig2 and O4. However, differentiation of astrocytes was not affected by taxol. In contrast, differentiated oligodendrocytes were extremely sensitive to taxol. Almost no Olig2-positive cells were observed after three days of treatment with taxol. Taxol has distinct effects on neurons and glial cells during their production through differentiation from NSCs as well as post-differentiation. Thus, we suggest that taxol might interfere with neurogenesis of NSCs possibly through a disturbance in the cell cycle and may eliminate differentiated oligodendrocytes.

A therapeutic neutralizing antibody targeting receptor binding domain of SARS-CoV-2 spike protein.

Vaccines and therapeutics are urgently needed for the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we screen human monoclonal antibodies (mAb) targeting the receptor binding domain (RBD) of the viral spike protein via antibody library constructed from peripheral blood mononuclear cells of a convalescent patient. The CT-P59 mAb potently neutralizes SARS-CoV-2 isolates including the D614G variant without antibody-dependent enhancement effect. Complex crystal structure of CT-P59 Fab/RBD shows that CT-P59 blocks interaction regions of RBD for angiotensin converting enzyme 2 (ACE2) receptor with an orientation that is notably different from previously reported RBD-targeting mAbs. Furthermore, therapeutic effects of CT-P59 are evaluated in three animal models (ferret, hamster, and rhesus monkey), demonstrating a substantial reduction in viral titer along with alleviation of clinical symptoms. Therefore, CT-P59 may be a promising therapeutic candidate for COVID-19.

Diagnostic Role of Flexion-extension Central Motor Conduction Time in Cervical Spondylotic Myelopathy.

STUDY DESIGN: Retrospective study. OBJECTIVE: The purpose of this study was to assess the diagnostic usefulness of flexion-extension central motor conduction time(CMCT) for patients with cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: Previous reports have suggested that cervical cord compression can be aggravated by neck motions. Thus, the importance of dynamic magnetic resonance imaging (MRI) has been emphasized. However, authors of this study found no reports conducted at the time of this research on whether flexion-extension CMCT was useful for detecting myelopathy. METHODS: We enrolled 227 patients with CSM for this study. We acquired CMCT recorded from the abductor pollicis brevis muscle. All patients underwent a dynamic CMCT study during neck flexion and extension as well as a static study during neutral neck. Static and dynamic MRIs were also scanned. We read all MR images using Muhle classification (MC). RESULTS: CMCT was significantly delayed with flexion (P < 0.01) and extension (P < 0.01) compared to neutral neck position. Patients with MC grade 1 and 2 showed significant lag in CMCT during flexion and extension. No significant lag by neck motion was observed for those in the MC grade 3. We also evaluated the amount of CMCT variation according to MC grade change (G0, G1, G2) by neck motion. Delta-CMCT of both G1 and G2 were significantly larger than those of G0 in both flexion and extension. In neutral neck, the CMCT showed significant difference between MC grades 1 and 3. They also displayed significant delay with delay with high signal intensity on T2 MRI. More than one-third of the patients whose CMCT was within normal range in neutral neck presented abnormal CMCT in neck flexion (35.3%) and extension (37.8%). CONCLUSION: CMCT is significantly slower in both neck flexion and neck extension than in the neutral neck position. These findings reflect the dynamic cervical cord impingement.Level of Evidence: 4.

N-Acetylcysteine extends lifespan of Drosophila via modulating ROS scavenger gene expression.

N-Acetylcysteine (NAc) has been shown to play a diversity of favorable health-related roles (e.g., antioxidant, paracetamol antidote, mucolytics, neuroprotective agent). Having said that, here in this study, we evaluate the health-promoting properties of NAc, particularly its ability to modulate organismal longevity. We note that 1 mg/ml NAc prolonged the lifespan of Drosophila. Furthermore, it was observed that NAc increased the capability of these flies to resist environmental stresses measured by starvation and paraquat stress assays. In an effort to reveal cellular mechanisms behind this interesting phenomenon, qPCR was performed, uncovering that transcript levels of catalase and phospholipid hydroperoxide glutathione peroxidase-key enzymes to fend off reactive oxygen species (ROS) assaults, were up-regulated. Correspondingly, enzyme activities of catalase and glutathione peroxidase were increased as well. Combined, we hope our research helps broaden the spectrum of clinical application for NAc so that one may eventually determine if NAc is a potentially useful anti-aging agent by encouraging others to scrutinize the hidden health benefits of NAc.

Evaluation of epithelial transport and oxidative stress protection of nanoengineered curcumin derivative-cyclodextrin formulation for ocular delivery.

Ocular drug delivery has been a well-known route for the drug administration for the treatment of ocular diseases. However, numerous anatomical and physiological barriers prevailing in the eye itself create considerable challenges for achieving the necessitated therapeutic efficacy along with ocular bioavailability. However, recent advances in nanoengineered strategies hold definite promises in terms of devising improved ophthalmic medicines for the effective drug delivery to target the sites with enhanced ocular bioavailability. Curcumin, a hydrophobic polyphenol yellow colored compound, and its metabolic reduced product, tetrahydrocurcumin (THC), have been known for their beneficial pharmacological functions, such as anti-inflammatory or anti-oxidant activities at various tissue sites. However, the low aqueous solubility of these compounds results in their poor bioavailability, thereby limiting their widespread application. Therefore, in the present study, we investigated the changes in drug solubility by forming inclusion complexes with different derivatives of hydroxypropyl (HP)-cyclodextrins (CD). To this end, the spray drying technique was used for nanoengineering curcumin or THC-loaded formulations to improve the stability of formulations during the storage. The formulations were characterized in terms of physicochemical properties and cellular permeability. The results demonstrated that the encapsulation of curcumin (or THC) into the HP-CDs significantly increased the drug solubility and enhanced the corneal and retinal epithelial permeability. Curcumin or THC complexes in HP-CDs with improved bioavailability also induced anti-oxidant activity (SOD1, CAT1, and HMOX1) in higher levels in the ocular epithelial cells and showed oxidative protection effects in rabbit cornea tissues that will boost up their application in ocular medicine.

Expansion of antibacterial spectrum of xanthorrhizol against Gram-negatives in combination with PMBN and food-grade antimicrobials.

Xanthorrhizol (XTZ), isolated from Curcuma xanthorrhiza, has potent antifungal and antibacterial activity. It shows very strong activity against Gram-positive bacteria, such as Streptococcus mutans and Staphylococcus aureus, but is generally not active against Gram-negative bacteria. In this study, we explored the possibility of using a combination strategy for expanding the antimicrobial spectrum of XTZ against Gram-negative bacteria. To take advantage of XTZ being a food-grade material, 10 food-grade or generally recognized as safe (GRAS) antimicrobial compounds with low toxicities were selected for combination therapy. In addition, polymyxin B nonapeptide (PMBN), which is less toxic than polymyxin B, was also selected as an outer membrane permeabilizer. The antibacterial activity of various double or triple combinations with or without XTZ were assayed in vitro against four Gram-negative bacterial species (Escherichia coli, Salmonella enterica serovar Typhi, Salmonella enterica serovar Typhimurium, and Vibrio cholerae), with synergistic combinations exhibiting clear activity subjected to further screening. The combinations with the greatest synergism were XTZ + PMBN + nisin, XTZ + PMBN + carvacrol, and XTZ + PMBN + thymol. These combinations also showed potent antimicrobial activity against Shigella spp., Yersinia enterocolitica, and Acinetobacter baumannii. In time-kill assays, the three combinations achieved complete killing of E. coli within 2 h, and S. Typhi and V. cholera within 15 min. This is the first report on expanding the activity spectrum of XTZ against Gram-negative bacteria through combination with PMBN and food-grade or GRAS substances, with the resulting findings being particularly useful for increasing the industrial and medical applications of XTZ.

Use of coliphages to investigate norovirus contamination in a shellfish growing area in Republic of Korea.

A number of severe norovirus outbreaks due to the consumption of contaminated shellfish have been reported recently. In this study, we evaluated the distribution of coliphage densities to determine their efficacy as fecal indicators of enteric viruses, including noroviruses, in water samples collected from a shellfish growing area in Republic of Korea over a period of approximately 1 year. Male-specific and somatic coliphages in water samples were analyzed using the single agar layer method, and norovirus genogroups I and II, which infect mainly humans, were analyzed using duplex reverse transcription quantitative PCR. Male-specific and somatic coliphages were detected widely throughout the study area. Several environmental parameters, including salinity, precipitation, temperature, and wind speed were significantly correlated with coliphage concentrations (P < 0.05). Moreover, the concentrations of male-specific coliphages were positively correlated with the presence of human noroviruses (r = 0.443; P < 0.01). The geospatial analysis with coliphage concentrations using a geographic information system revealed that densely populated residential areas were the major source of fecal contamination. Our results indicate that coliphage monitoring in water could be a useful approach to prevent norovirus contamination in shellfish.

Ilex paraguariensis Extends Lifespan and Increases an Ability to Resist Environmental Stresses in Drosophila.

Aging is a complex process resulting in (1) a decline in body functions and capacity to withstand environmental stress and (2) an increased susceptibility to diseases including, but not limited to, cardiovascular disorders, diabetes, cancer, and dementia. Among a number of herbal products used to alleviate symptoms associated with aging is Ilex paraguariensis (IP). This product has been reported to have anticancer, anti-inflammatory, and antioxidant activities. However, its effect on an organisms' longevity has not been thoroughly studied to date. Here, we report that 10 mg/mL IP supplementation significantly extended the lifespan of Drosophila. Additionally, IP enhanced flies' ability to resist environmental stress as estimated using starvation, paraquat, and desiccation assays. Additional experiments revealed insignificant changes in weight gain, physical activity, and metabolic profiles such as levels of water, lipid, and protein in flies receiving IP supplementation. Rather, levels of messenger RNA for enzymes that scavenge reactive oxygen species (i.e., superoxide dismutases, catalase, and glutathione peroxidase) were found to be significantly altered despite subtle changes in their catalytic activities. We hope that our research demonstrating IP-induced lifespan extension and related biological mechanisms of this interesting phenomenon will encourage further studies, which may eventually determine whether IP has utility as a novel antiaging agent.

Development and characterization of novel chimeric monoclonal antibodies for broad spectrum neutralization of rabies virus.

Current post-exposure prophylaxis for rabies virus infection has several limitations in terms of supply, cost, safety, and efficacy. Attempts to replace human or equine rabies immune globulins (HRIG or ERIG) have been made by several companies and institutes. We developed potent monoclonal antibodies to neutralize a broad spectrum of rabies viruses by screening hybridomas received from the U.S. Centers for Disease Control and Prevention (CDC). Two kinds of chimeric human antibodies (chimeric #7 and #17) were constructed by cloning the variable regions from selected hybridomas and the constant region of a human antibody. Two antibodies were bound to antigenic site III and I/IV, respectively, and were able to neutralize 51 field isolates of rabies virus that were isolated at different times and places such as Asia, Africa, North America, South America, and Australia. These two antibodies neutralize rabies viruses with high efficacy in an in vivo test using Syrian hamster and mouse models and show low risk for adverse immunogenicity.

Jujube (Ziziphus Jujuba Mill.) fruit feeding extends lifespan and increases tolerance to environmental stresses by regulating aging-associated gene expression in Drosophila.

Jujube (Ziziphus Jujuba Mill.) fruit has been utilized as an adjunct to alleviate medical symptoms including, but not limited to, anorexia, fatigue, anxiety and mild diarrhea for centuries. Despite a growing body of literature revealing jujube fruit's health promoting properties such as anti-cancer, anti-inflammation and anti-oxidant effects (shown with cell-based in vitro platforms), there is a paucity of studies systemically examining its impact on whole organisms or throughout the entire course of life utilizing in vivo model systems. Thus, here in this study, we conducted a series of experiments to investigate if jujube fruit can modify an organism's longevity using a live Drosophila model. We found that jujube fruit feeding extended not only lifespan but also healthspan examined by stress assays such as starvation and paraquat treatment. In an effort to shed light on the mechanisms of these jujube-related benefits at the molecular level, we report that messenger RNA (mRNA) levels of 14-3-3ε, a negative FoxO (Forkhead box O transcription factor) regulator, was dramatically diminished while the abundance of d4E-BP mRNA transcript (drosophila eukaryotic translation initiation factor 4E binding protein), a FoxO target gene, was increased, suggesting enhanced FoxO activity with jujube fruit feeding. In conclusion, we hope our results will lead to multidisciplinary research to investigate the potential benefit of jujube fruit as a novel anti-aging agent.

Occurrence of novel GII.17 and GII.21 norovirus variants in the coastal environment of South Korea in 2015.

Human norovirus (HNoV), a positive-sense RNA virus, is the main causative agent of acute viral gastroenteritis. Multiple pandemic variants of the genogroup II genotype 4 (GII.4) of NoV have attracted great attention from researchers worldwide. However, novel variants of GII.17 have been overtaking those pandemic variants in some areas of East Asia. To investigate the environmental occurrence of GII in South Korea, we collected water samples from coastal streams and a neighboring waste water treatment plant in North Jeolla province (in March, July, and December of 2015). Based on capsid gene region C analysis, four different genotypes (GII.4, GII.13, GII.17, and GII.21) were detected, with much higher prevalence of GII.17 than of GII.4. Additional sequence analyses of the ORF1-ORF2 junction and ORF2 from the water samples revealed that the GII.17 sequences in this study were closely related to the novel strains of GII.P17-GII.17, the main causative variants of the 2014-2015 HNoV outbreak in China and Japan. In addition, the GII.P21-GII.21 variants were identified in this study and they had new amino acid sequence variations in the blockade epitopes of the P2 domain. From these results, we present two important findings: 1) the novel GII.P17-GII.17 variants appeared to be predominant in the study area, and 2) new GII.21 variants have emerged in South Korea.

Re-emergence of a GII.4 Norovirus Sydney 2012 Variant Equipped with GII.P16 RdRp and Its Predominance over Novel Variants of GII.17 in South Korea in 2016.

Noroviruses are major causative pathogen of nonbacterial acute gastroenteritis worldwide. Of the seven genogroups of noroviruses suggested recently, genogroup II genotype 4 (GII.4) had been the most common genotype identified in hospitalized patients in the last few decades. However, since the latter half of 2014, new variants of GII.17 have been reported as the main causes of outbreaks over GII.4 in East Asia and have also occurred in America and Europe. In this study, we monitored norovirus GII in coastal streams at South Gyeongsang province and South Jeolla province of South Korea from March 2015 to May 2016. Norovirus GII.17 capsid sequences were predominantly detected until September 2015 in water samples. However, we found that the number of positive cases of the norovirus GII.4 Sydney 2012 capsid sequence has been increasing since December 2015, overtaking that of GII.17 in 2016. The RdRp genotype of this predominant GII.4 variant in 2016 was identified as GII.P16. The emergence and predominance of the GII.4 pandemic capsid sequence harboring a different RdRp genotype suggested the potential for a future pandemic.