Clinical studies suggest aberrant neurotransmitter concentrations in the brains of patients with schizophrenia (SCZ). Numerous studies have indicated deviant glutamate concentrations in SCZ, although the findings are inconsistent. Moreover, alterations in glutamate concentrations could be linked to personality traits in SCZ. Here, we examined the relationships between personality dimensions and glutamate concentrations in a voxel encompassing the occipital cortex (OCC) and another voxel encompassing the left superior temporal sulcus (STS). We used proton magnetic resonance spectroscopy to examine glutamate concentrations in the OCC and the STS in 19 SCZ and 21 non-psychiatric healthy control (HC) participants. Personality dimensions neuroticism, extraversion, openness, agreeableness and conscientiousness were assessed using the NEO-FFI questionnaire. SCZ compared to HC showed higher glutamate concentrations in the STS, reduced extraversion scores, and enhanced neuroticism scores. No group differences were observed for the other personality traits and for glutamate concentrations in the OCC. For the SCZ group, glutamate concentrations in STS were negatively correlated with the neuroticism scores [r = -0.537, p = 0.018] but this was not found in HC [r(19) = 0.011, p = 0.962]. No other significant correlations were found. Our study showed an inverse relationship between glutamate concentrations in the STS and neuroticism scores in SCZ. Elevated glutamate in the STS might serve as a compensatory mechanism that enables patients with enhanced concentrations to control and prevent the expression of neuroticism.

Background: Fatigue is a severe problem in the rail industry, which may jeopardize train crew's health and safety. Nonetheless, a preliminary review of all empirical evidence for train crew fatigue is still lacking. The aim of the present paper is, therefore, to provide a preliminary description of occupational fatigue in the rail industry. This paper reviews the literature with the research question examining the risk factors associated with train crew fatigue, covering both papers published in refereed journals and reports from trade organizations and regulators. It assesses the progress of research on railway fatigue, including research on the main risk factors for railway fatigue, the association between fatigue and railway incidents, and how to better manage fatigue in the railway industry. Methods: Systematic searches were performed in both science and industry databases. The searches considered studies published before August 2017. The main exclusion criterion was fatigue not being directly measured through subjective or objective methods. Results: A total of 31 studies were included in the main review. The causes of fatigue included long working hours, heavy workload, early morning or night shifts, and insufficient sleep. Poor working environment, particular job roles, and individual differences also contributed to fatigue. Conclusion: Fatigue in the rail industry includes most of the features of occupational fatigue, and it is also subject to industry-specific factors. The effect of fatigue on well-being and the fatigued population in the railway industry are still not clear. Future studies can consider associations between occupational risk factors and perceived fatigue by examining the prevalence of fatigue and identifying the potential risk factors in staff within the railway industry.

Music and speech both communicate emotional meanings in addition to their domain-specific contents. But it is not clear whether and how the two kinds of emotional meanings are linked. The present study is focused on exploring the emotional connotations of musical timbre of isolated instrument sounds through the perspective of emotional speech prosody. The stimuli were isolated instrument sounds and emotional speech prosody categorized by listeners into anger, happiness and sadness, respectively. We first analyzed the timbral features of the stimuli, which showed that relations between the three emotions were relatively consistent in those features for speech and music. The results further echo the size-code hypothesis in which different sound timbre indicates different body size projections. Then we conducted an ERP experiment using a priming paradigm with isolated instrument sounds as primes and emotional speech prosody as targets. The results showed that emotionally incongruent instrument-speech pairs triggered a larger N400 response than emotionally congruent pairs. Taken together, this is the first study to provide evidence that the timbre of simple and isolated musical instrument sounds can convey emotion in a way similar to emotional speech prosody.

Toll-like receptors (TLRs) play key roles in cerebral ischemia and reperfusion injury by inducing the production of inflammatory mediators, such as interleukins (ILs) and tumor necrosis factor-alpha (TNF-α). According to recent studies, ursolic acid (UA) regulates TLR signaling and exhibits notable anti-inflammatory properties. In the present study, we explored the mechanism by which UA regulates inflammation in the rat middle cerebral artery occlusion and reperfusion (MCAO/R) model. The MCAO/R model was induced in male Sprague-Dawley rats (MCAO for 2 h, followed by reperfusion for 48 h). UA was administered intragastrically at 0.5, 24, and 47 h after reperfusion. The direct high mobility group box 1 (HMGB1) inhibitor glycyrrhizin (GL) was injected intravenously after 0.5 h of ischemia as a positive control. The degree of brain damage was estimated using the neurological deficit score, infarct volume, histopathological changes, and neuronal apoptosis. We assessed IL-1β, TNF-α, and IL-6 levels to evaluate post-ischemic inflammation. HMGB1 and TLR4 expression and phosphorylation of nuclear factor kappa-light-chain-enhancer of activated B cell (NFκB) were also examined to explore the underlying mechanism. UA (10 and 20 mg/kg) treatment significantly decreased the neurological deficit scores, infarct volume, apoptotic cells, and IL-1β, TNF-α, and IL-6 concentrations. The infarct area ratio was reduced by (33.07 ± 1.74), (27.05 ± 1.13), (27.49 ± 1.87), and (39.74 ± 2.14)% in the 10 and 20 mg/kg UA, GL, and control groups, respectively. Furthermore, UA (10 and 20 mg/kg) treatment significantly decreased HMGB1 release and the TLR4 level and inactivated NFκB signaling. Thus, the effects of intragastric administration of 20 mg/kg of UA and 10 mg/kg of GL were similar. We provide novel evidence that UA reduces inflammatory cytokine production to protect the brain from cerebral ischemia and reperfusion injury possibly through the HMGB1/TLR4/NFκB signaling pathway.

Repetitive transcranial magnetic stimulation (rTMS) can be used in various neurological disorders. However, neurobiological mechanism of rTMS is not well known. Therefore, in this study, we examined the global gene expression patterns depending on different frequencies of repetitive magnetic stimulation (rMS) in both undifferentiated and differentiated Neuro-2a cells to generate a comprehensive view of the biological mechanisms. The Neuro-2a cells were randomly divided into three groups-the sham (no active stimulation) group, the low-frequency (0.5 Hz stimulation) group, and high-frequency (10 Hz stimulation) group-and were stimulated 10 min for 3 days. The low- and high-frequency groups of rMS on Neuro-2a cells were characterized by transcriptome array. Differentially expressed genes were analyzed using the Database of Annotation Visualization and Integrated Discovery program, which yielded a Kyoto Encyclopedia of Genes and Genomes pathway. Amphetamine addiction pathway, circadian entrainment pathway, long-term potentiation (LTP) pathway, neurotrophin signaling pathway, prolactin signaling pathway, and cholinergic synapse pathway were significantly enriched in high-frequency group compared with low-frequency group. Among these pathways, LTP pathway is relevant to rMS, thus the genes that were involved in LTP pathway were validated by quantitative real-time polymerase chain reaction and western blotting. The expression of glutamate ionotropic receptor N-methyl d-aspartate 1, calmodulin-dependent protein kinase II (CaMKII) δ, and CaMKIIα was increased, and the expression of CaMKIIγ was decreased in high-frequency group. These genes can activate the calcium (Ca2+)-CaMKII-cAMP-response element-binding protein (CREB) pathway. Furthermore, high-frequency rMS induced phosphorylation of CREB, brain-derived neurotrophic factor (BDNF) transcription via activation of Ca2+-CaMKII-CREB pathway. In conclusion, high-frequency rMS enhances the expression of BDNF by activating Ca2+-CaMKII-CREB pathway in the Neuro-2a cells. These findings may help clarify further therapeutic mechanisms of rTMS.

Perinatal hypoxic-ischemic encephalopathy (HIE) can lead to neurodevelopmental disorders, including cerebral palsy. Standard care for neonatal HIE includes therapeutic hypothermia, which provides partial neuroprotection; magnetic resonance imaging (MRI) is often used to assess injury and predict outcome after HIE. Immature rodent models of HIE are used to evaluate mechanisms of injury and to examine the efficacy and mechanisms of neuroprotective interventions such as hypothermia. In this study, we first confirmed that, in the CD1 mouse model of perinatal HIE used for our research, MRI obtained 3 h after hypoxic ischemia (HI) could reliably assess initial brain injury and predict histopathological outcome. Mice were subjected to HI (unilateral carotid ligation followed by exposure to hypoxia) on postnatal day 7 and were imaged with T2-weighted MRI and diffusion-weighted MRI (DWI), 3 h after HI. Clearly defined regions of increased signal were comparable in T2 MRI and DWI, and we found a strong correlation between T2 MRI injury scores 3 h after HI and histopathological brain injury 7 days after HI, validating this method for evaluating initial injury in this model of HIE. The more efficient, higher resolution T2 MRI was used to score initial brain injury in subsequent studies. In mice treated with hypothermia, we found a significant reduction in T2 MRI injury scores 3 h after HI, compared to normothermic littermates. Early hypothermic neuroprotection was maintained 7 days after HI, in both T2 MRI injury scores and histopathology. In the normothermic group, T2 MRI injury scores 3 h after HI were comparable to those obtained 7 days after HI. However, in the hypothermic group, brain injury was significantly less 7 days after HI than at 3 h. Thus, early neuroprotective effects of hypothermia were enhanced by 7 days, which may reflect the additional 3 h of hypothermia after imaging or effects on later mechanisms of injury, such as delayed cell death and inflammation. Our results demonstrate that hypothermia has early neuroprotective effects in this model. These findings suggest that hypothermia has an impact on early mechanisms of excitotoxic injury and support initiation of hypothermic intervention as soon as possible after diagnosis of HIE.

A systematic search revealed 68 empirical studies of neurophysiological [EEG, event-related brain potential (ERP), fMRI, PET] variables as potential outcome predictors in patients with Disorders of Consciousness (diagnoses Unresponsive Wakefulness Syndrome [UWS] and Minimally Conscious State [MCS]). Data of 47 publications could be presented in a quantitative manner and systematically reviewed. Insufficient power and the lack of an appropriate description of patient selection each characterized about a half of all publications. In more than 80% studies, neurologists who evaluated the patients' outcomes were familiar with the results of neurophysiological tests conducted before, and may, therefore, have been influenced by this knowledge. In most subsamples of datasets, effect size significantly correlated with its standard error, indicating publication bias toward positive results. Neurophysiological data predicted the transition from UWS to MCS substantially better than they predicted the recovery of consciousness (i.e., the transition from UWS or MCS to exit-MCS). A meta-analysis was carried out for predictor groups including at least three independent studies with N > 10 per predictor per improvement criterion (i.e., transition to MCS versus recovery). Oscillatory EEG responses were the only predictor group whose effect attained significance for both improvement criteria. Other perspective variables, whose true prognostic value should be explored in future studies, are sleep spindles in the EEG and the somatosensory cortical response N20. Contrary to what could be expected on the basis of neuroscience theory, the poorest prognostic effects were shown for fMRI responses to stimulation and for the ERP component P300. The meta-analytic results should be regarded as preliminary given the presence of numerous biases in the data.

Previous evidence suggests that hallucinations and delusions may be detected in patients with the most severe forms of motor disability including locked-in syndrome (LIS). However, such phenomena are rarely described in LIS and their presence may be underestimated as a result of the severe communication impairment experienced by the patients. In this study, we retrospectively reviewed the clinical history and the neuroimaging data of a cohort of patients with LIS in order to recognize the presence of hallucinations and delusions and to correlate it with the pontine damage and the presence of any cortical volumetric changes. Ten patients with LIS were included (5 men and 5 women, mean age 50.1 ± 14.6). According to the presence of indicators of symptoms, these patients were categorized as hallucinators (n = 5) or non-hallucinators (n = 5). MRI images of patients were analyzed using Freesurfer 6.0 software to evaluate volume differences between the two groups. Hallucinators showed a selective cortical volume loss involving the fusiform (p = 0.001) and the parahippocampal (p = 0.0008) gyrus and the orbital part of the inferior frontal gyrus (p = 0.001) in the right hemisphere together with the lingual (p = 0.01) and the fusiform gyrus (p = 0.01) in the left hemisphere. Moreover, a volumetric decrease of bilateral anterior portions of the precuneus was recognized in the hallucinators (right p = 0.01; left p = 0.001) as compared to non-hallucinators. We suggested that the presence of hallucinations and delusions in some LIS patients could be accounted for by the combination of a damage of the corticopontocerebellar pathways with cortical changes following the primary brainstem injury. The above areas are embedded within cortico-cortical and cortico-subcortical loops involved in self-monitoring and have been related to the presence of hallucinations in other diseases. The two main limitations of our study are the small sample of included patients and the lack of a control group of healthy individuals. Further studies would be of help to expand this field of research in order to integrate existing theories about the mechanisms underlying the generation of hallucinations and delusions in neurological patients.

Oxidative stress plays a pivotal role in the initiation and progression of cardiac diseases. Estrogens have been demonstrated to exert pleiotropic cardioprotective effects, among which antioxidative stress is one of the key effects linking estrogens to cardioprotection. By using a microRNAs (miRs) microarray screening approach, we discovered an increase in miR-494, which is known to exert cardioprotective effects, in estrogen-treated cardiomyocytes. We hypothesized that the upregulation of miR-494 might contribute to estrogen-mediated cardioprotection against oxidative stress. We found that E2 stimulates miR-494 expression via ERα in both cardiomyocytes and the myocardium of female mice. The miR-494 inhibitor attenuated the protective effect of 17β-estradiol (E2) against oxidative stress-induced injury in cardiomyocytes. By contrast, the miR-494 mimic protected cardiomyocytes against oxidative stress-induced cardiomyocyte injury. Using real-time PCR, western blot and dual-luciferase reporter gene analyses, we identified nuclear factor kappa B (NF-κB) repressing factor (NKRF) as the miR-494 target in cardiomyocytes. E2 was found to inhibit NKRF, thus activating NF-κB through a miR-494-dependent mechanism. In addition, the protective effects of E2 and miR-494 against oxidative stress in cardiomyocytes were eliminated by the NF-κB inhibitor. In summary, this study demonstrates for the first time that estrogen inhibits NKRF expression through ERα-mediated upregulation of miR-494 in cardiomyocytes, leading to the activation of NF-κB, which in turn results in an increase in antioxidative defense. ERα-mediated upregulation of miR-494 may contribute to estrogen protection of cardiomyocytes against oxidative stress.

17β-Estradiol (E2) regulates the expression of female sexual behavior by acting through estrogen receptor (ER) α and β. Previously, we have shown that ERβ knockout female mice maintain high level of lordosis expression on the day after behavioral estrus when wild-type mice show a clear decline of the behavior, suggesting ERβ may be involved in inhibitory regulation of lordosis. However, it is not identified yet in which brain region(s) ERβ may mediate an inhibitory action of E2. In this study, we have focused on the dorsal raphe nucleus (DRN) that expresses ERβ in higher density than ERα. We site specifically knocked down ERβ in the DRN in ovariectomized mice with virally mediated RNA interference method. All mice were tested weekly for a total of 3 weeks for their lordosis expression against a stud male in two consecutive days: day 1 with the hormonal condition mimicking the day of behavioral estrus, and day 2 under the hormonal condition mimicking the day after behavioral estrus. We found that the level of lordosis expression in ERβ knockdown (βERKD) mice was not different from that of control mice on day 1. However, βERKD mice continuously showed elevated levels of lordosis behavior on day 2 tests, whereas control mice showed a clear decline of the behavior on day 2. These results suggest that the expression of ERβ in the DRN may be involved in the inhibitory regulation of sexual behavior on the day after behavioral estrus in cycling female mice.

The human enteric pathogen Salmonella enterica leads a cross-kingdom lifestyle, actively colonizing and persisting on plants in between animal hosts. One of the questions that arises from this dual lifestyle is how S. enterica is able to adapt to such divergent hosts. Metabolic pathways required for S. enterica animal colonization and virulence have been previously identified, but the metabolism of this bacterium on plants is poorly understood. To determine the requirements for plant colonization by S. enterica, we first screened a library of metabolic mutants, previously examined in a systemic mouse typhoidal model, for competitive plant colonization fitness on alfalfa seedlings. By comparing our results to those reported in S. enterica-infected murine spleens, we found that the presence of individual nutrients differed between the two host niches. Yet, similar metabolic pathways contributed to S. enterica colonization of both plants and animals, such as the biosynthesis of amino acids, purines, and vitamins and the catabolism of glycerol and glucose. However, utilization of at least three metabolic networks differed during the bacterium's plant- and animal-associated lifestyles. Whereas both fatty acid biosynthesis and degradation contributed to S. enterica animal colonization, only fatty acid biosynthesis was required during plant colonization. Though serine biosynthesis was required in both hosts, S. enterica used different pathways within the serine metabolic network to achieve this outcome. Lastly, the metabolic network surrounding manA played different roles during colonization of each host. In animal models of infection, O-antigen production downstream of manA facilitates immune evasion. We discovered that manA contributed to S. enterica attachment, to seeds and germinated seedlings, and was essential for growth in early seedling exudates, when mannose is limited. However, only seedling attachment was linked to O-antigen production, indicating that manA played additional roles critical for plant colonization that were independent of surface polysaccharide production. The integrated view of S. enterica metabolism throughout its life cycle presented here provides insight on how metabolic versatility and adaption of known physiological pathways for alternate functions enable a zoonotic pathogen to thrive in niches spanning across multiple kingdoms of life.

Nitrification is the two-step aerobic oxidation of ammonia to nitrate via nitrite in the nitrogen-cycle on earth. However, very limited information is available on how fertilizer regimes affect the distribution of nitrite oxidizers, which are involved in the second step of nitrification, across aggregate size classes in soil. In this study, the community compositions of nitrite oxidizers (Nitrobacter and Nitrospira) were characterized from a red soil amended with four types of fertilizer regimes over a 26-year fertilization experiment, including control without fertilizer (CK), swine manure (M), chemical fertilization (NPK), and chemical/organic combined fertilization (MNPK). Our results showed that the addition of M and NPK significantly decreased Nitrobacter Shannon and Chao1 index, while M and MNPK remarkably increased Nitrospira Shannon and Chao1 index, and NPK considerably decreased Nitrospira Shannon and Chao1 index, with the greatest diversity achieved in soils amended with MNPK. However, the soil aggregate fractions had no impact on that alpha-diversity of Nitrobacter and Nitrospira under the fertilizer treatment. Soil carbon, nitrogen and phosphorus in the soil had a significant correlation with Nitrospira Shannon and Chao1 diversity index, while total potassium only had a significant correlation with Nitrospira Shannon diversity index. However, all of them had no significant correlation with Nitrobacter Shannon and Chao1 diversity index. The resistance indices for alpha-diversity indexes (Shannon and Chao1) of Nitrobacter were higher than those of Nitrospira in response to the fertilization regimes. Manure fertilizer is important in enhancing the Nitrospira Shannon and Chao1 index resistance. Principal co-ordinate analysis revealed that Nitrobacter- and Nitrospira-like NOB communities under four fertilizer regimes were differentiated from each other, but soil aggregate fractions had less effect on the nitrite oxidizers community. Redundancy analysis and Mantel test indicated that soil nitrogen, carbon, phosphorus, and available potassium content were important environmental attributes that control the Nitrobacter- and Nitrospira-like NOB community structure across different fertilization treatments under aggregate levels in the red soil. In general, nitrite-oxidizing bacteria community composition and alpha-diversity are depending on fertilizer regimes, but independent of the soil aggregate.

This paper proposes bio-preservation as a tool to assure quality and safety of Spanish-style table olives cv. Bella di Cerignola. Lactobacillus plantarum 5BG was inoculated in ready to sell olives packaged in an industrial plant by using a half-volume brine (4% NaCl; 2% sucrose). The samples were stored at 4°C. The survival of the inoculated strain, the microbiological quality, the sensory scores and the survival of a strain of Listeria monocytogenes inoculated in brines were evaluated. The persistence of the Lb. plantarum bio-preserving culture was confirmed on olives (≥6.5 Log CFU/g) and in brine (≥7 Log CFU/ml). Bio-preserved olives (SET1) showed a better sensory profile than chemically acidified control olives (SET2) and the texture was the real discriminative parameter among samples. Bio-preserved olives recorded better scores during storage because of their ability to retain good hardness, crunchiness, and fibrousness without cracks. The inoculation of Lb. plantarum positively acted on the safety of olives, as the D-value of L. monocytogenes was reduced from 40 (SET2) to 5 days (SET1). In conclusion, Lb. plantarum 5BG and the physico-chemical conditions achieved in the settled procedure are suitable for the industrial packaging of Bella di Cerignola table olives, improving the process by halving brining volumes and avoiding chemical stabilizers, and significantly reducing the salt concentration. The final product is also safely preserved for almost 5 months as suggested by the reduction of the survival rate of L. monocytogenes.

The effects of probiotics on host gastrointestinal health have become an area of particular interest in the field of probiotic research. However, the impact of the host intestinal environment on genomic changes in probiotic organisms remains largely unknown. To investigate, Lactobacillus plantarum P-8, a well-studied probiotic bacterium, was consumed by healthy human volunteers and rats. Then, the persistence and genomic stability of P-8 in the host gut were surveyed. qPCR results revealed that after the consumption of one dose, P-8 could be detected in the host gastrointestinal tract for 4-5 weeks. By contrast, after 4 successive weeks of consumption, P-8 could be detected for up to 17 weeks after consumption ceased. In total, 92 P-8 derived strains were isolated from fecal samples and their genomes were sequenced and analyzed. Comparative genomic analysis detected 19 SNPs, which showed the characteristics of neutral evolution in the core genome. In nearly half of samples (n = 39, 42%), the loss of one to three plasmids was observed. The frequent loss of plasmids indicated reductive evolution in the accessory genome under selection pressure within the gastrointestinal tract. We also observed a 609-bp 23S rRNA homologous fragment that may have been acquired from other species after intake. Our findings offer insight into the complex reactions of probiotics to the gut environment during survival in the host. The in vivo genomic dynamics of L. plantarum P-8 observed in this study will aid the commercial development of probiotics with more stable characteristics.

Increased intestinal epithelial barrier function damages caused by early weaning stress have adverse effects on swine health and feed utilization efficiency. Probiotics have emerged as the promising antibiotic alternatives used for intestinal barrier function damage prevention. Our previous data showed that Lactobacillus frumenti was identified as a predominant Lactobacillus in the intestinal microbiota of weaned piglets. However, whether the intestinal epithelial barrier function in piglets was regulated by L. frumenti is still unclear. Here, piglets received a PBS vehicle or PBS suspension (2 ml, 108 CFU/ml) containing the L. frumenti by oral gavage once a day during the period of 6-20 days of age prior to early weaning. Our data demonstrated that oral administration of L. frumenti significantly improved the intestinal mucosal integrity and decreased the serum endotoxin and D-lactic acid levels in early-weaned piglets (26 days of age). The intestinal tight junction proteins (including ZO-1, Occludin, and Claudin-1) were significantly up-regulated by L. frumenti administration. The serum immunoglobulin G (IgG) levels, intestinal secretory immunoglobulin A (sIgA) levels, and interferon-γ (IFN-γ) levels were significantly increased by L. frumenti administration. Furthermore, our data revealed that oral administration of L. frumenti significantly increased the relative abundances of health-promoting microbes (including L. frumenti, Lactobacillus gasseri LA39, Parabacteroides distasonis, and Kazachstania telluris) and decreased the relative abundances of opportunistic pathogens (including Desulfovibrio desulfuricans and Candida humilis). Functional alteration of the intestinal bacterial community by L. frumenti administration was characterized by the significantly increased fatty acids and protein metabolism and decreased diseases-associated metabolic pathways. These findings suggest that L. frumenti facilitates intestinal epithelial barrier function maintenance in early-weaned piglets and may be a promising antibiotic alternative used for intestinal epithelial barrier function damage prevention in mammals.

Active volcanoes in Antarctica contrast with their predominantly cold surroundings, resulting in environmental conditions capable of selecting for versatile and extremely diverse microbial communities. This is especially true on Deception Island, where geothermal, marine, and polar environments combine to create an extraordinary range of environmental conditions. Our main goal in this study was to understand how microbial community structure is shaped by gradients of temperature, salinity, and geochemistry in polar marine volcanoes. Thereby, we collected surface sediment samples associated with fumaroles and glaciers at two sites on Deception, with temperatures ranging from 0 to 98°C. Sequencing of the 16S rRNA gene was performed to assess the composition and diversity of Bacteria and Archaea. Our results revealed that Deception harbors a combination of taxonomic groups commonly found both in cold and geothermal environments of continental Antarctica, and also groups normally identified at deep and shallow-sea hydrothermal vents, such as hyperthermophilic archaea. We observed a clear separation in microbial community structure across environmental gradients, suggesting that microbial community structure is strongly niche driven on Deception. Bacterial community structure was significantly associated with temperature, pH, salinity, and chemical composition; in contrast, archaeal community structure was strongly associated only with temperature. Our work suggests that Deception represents a peculiar "open-air" laboratory to elucidate central questions regarding molecular adaptability, microbial evolution, and biogeography of extremophiles in polar regions.

Humanized mouse model generated by grafting primary human hepatocytes (PHHs) to immunodeficient mouse has contributed invaluably to understanding the pathogenesis of hepatitis B virus (HBV). However, the source of PHHs is limited, which necessitates the search for alternatives. Recently, hepatocyte-like cells (HLCs) generated from human induced pluripotent stem cells (hiPSCs) have been used for in vitro HBV infection. Herein, we developed a robust human liver chimeric animal model to study in vivo HBV infection by engrafting the hiPSC-HLCs to Fah-/-Rag2-/-IL-2Rγc-/-SCID (FRGS) mice. After being optimized by a small molecule, XMU-MP-1, the hiPSC-HLCs engrafted FRGS (hHLC-FRGS) mice displayed approximately 40% liver chimerism at week 6 after engraftment and maintained at this level for at least 14 weeks. Viremia and HBV infection markers include antigens, RNA, DNA, and covalently closed circular DNA were detectable in HBV infected hHLC-FRGS mice. Furthermore, hiPSC-HLCs and hHLC-FRGS mice were successfully used to evaluate different antivirals. Therefore, we established a humanized mouse model for not only investigating HBV pathogenesis but also testing the effects of the anti-HBV drugs. Highlights:    (1) The implanted hiPSC-HLCs established a long-term chimerism in FRGS mice liver.    (2) hHLC-FRGS mice are adequate to support chronic HBV infection with a full viral life cycle.    (3) hiPSC-HLCs and hHLC-FRGS mice are useful tools for evaluation of antivirals against HBV infection in vitro and in vivo. Research in Context  To overcome the disadvantages of using primary human hepatocytes, we induced human pluripotent stem cells to hepatocyte-like cells (hiPSC-HLCs) that developed the capability to express important liver functional markers and critical host factors for HBV infection. The hiPSC-HLCs were permissive for the HBV infection and supported a full HBV replication. The hiPSC-HLCs were then engrafted to immunodeficient mouse to establish a chimeric liver mouse model, which was capable of supporting HBV infection in vivo and evaluating the effects of antiviral drugs. Our results shed light into improving the cellular and animal models for studying HBV and other hepatotropic viruses.

The rate of invasive group B Streptococcus (GBS) infections is steadily increasing, particularly in older persons and in adults with diabetes and other comorbidities. This population includes persons with a foreign body (e.g., who have undergone arthroplasty). In a rat tissue cage model, we evaluated the efficacy of adjunctive gentamicin (GEN) administered systemically (5 mg/kg body weight) every 24 h, or locally (12.5 mg/L tissue cage concentration) every 24 or 72 h, in combination with penicillin (PEN) administered systemically (250,000 IU/kg body weight three times per day). The efficacy was evaluated on two different sessile forms of GBS: transition (i.e., in between planktonic and biofilm) and biofilm. After 3 days of treatment, the mean bacterial load reduction of transition-form GBS was greater in all PEN-GEN combination groups than in the PEN monotherapy group (P ≤ 0.03). The 6-day regimen decreased the bacterial load significantly in comparison to the 3-day regimen, irrespective of growth form and adjunctive GEN (P < 0.01). After 6 days of treatment, the mean reduction in transition-form GBS was greater with PEN plus GEN administered locally every 24 h than with PEN monotherapy (P = 0.03). These results were not confirmed with biofilm GBS. The difference in mean bacterial load reduction between all PEN-GEN and PEN monotherapy groups was <100 CFU/mL. Hence, synergy criteria were not fulfilled. Adjunctive systemic GEN consists of potential side effects and showed poor efficacy in this study. Combining systemic PEN and local GEN has a potential application in the treatment of streptococcal implant-associated infections.

The degradation of allochthonous terrestrial organic matter, such as recalcitrant lignin and hemicellulose from plants, occurs in the ocean. We hypothesize that bacteria instead of white-rot fungi, the model organisms of aerobic lignin degradation within terrestrial environments, are responsible for lignin degradation in the ocean due to the ocean's oligotrophy and hypersalinity. Warm oxic seawater from the Eastern Mediterranean Sea was enriched on lignin in laboratory microcosms. Lignin mineralization rates by the lignin-adapted consortia improved after two sequential incubations. Shotgun metagenomic sequencing detected a higher abundance of aromatic compound degradation genes in response to lignin, particularly phenylacetyl-CoA, which may be an effective strategy for marine microbes in fluctuating oxygen concentrations. 16S rRNA gene amplicon sequencing detected a higher abundance of Gammaproteobacteria and Alphaproteobacteria bacteria such as taxonomic families Idiomarinaceae, Alcanivoraceae, and Alteromonadaceae in response to lignin. Meanwhile, fungal Ascomycetes and Basidiomycetes remained at very low abundance. Our findings demonstrate the significant potential of bacteria and microbes utilizing the phenylacetyl-CoA pathway to contribute to lignin degradation in the Eastern Mediterranean where environmental conditions are unfavorable for fungi. Exploring the diversity of bacterial lignin degraders may provide important enzymes for lignin conversion in industry. Enzymes may be key in breaking down high molecular weight lignin and enabling industry to use it as a low-cost and sustainable feedstock for biofuels or other higher-value products.

Endophytic bacteria associated with medicinal plants possess unique strategies that enhance growth and suvival of host plants, many of which are mediated by distinctive secondary metabolites. These bacteria and their secondary metabolites are important subjects for both basic and applied research aimed at sustainable agriculture. In the present study, 114 endophytic strains isolated from the wild ethnomedicinal plant Glycyrrhiza uralensis (licorice) were screened for their in vitro antimicrobial activities against common fungal pathogens of tomato (Fusarium oxysporum f. sp., Fulvia fulva, Alternaria solani), cotton (Fusarium oxysporum f. sp. Vesinfectum, Verticillium dahliae), pomegranite (Ceratocystis fimbriata), Cymbidinium (Colletotrichum gloeosporioides), and Tsao-ko (Pestalotiopsis microspora and Fusarium graminearum) and the common bacteria Staphylococcus aureus, Bacillus cereus, Salmonella enteritidis, and Escherichia coli. Several Bacillus strains, particularly Bacillus atrophaeus and Bacillus mojavensis, had a broad spectrum of antifungal and antibacterial activity. A total of 16 strains, selected based on broad antimicrobial activity, were shown to contain at least one putative secondary metabolite-encoding gene (i.e., polyketide synthase or non-ribosomal peptide synthetase) and/or one lytic enzyme (i.e., protease, cellulase, lipase, chitinase), which may be important mediators of antagonistic activity against pathogens. Five strains, representing Bacillus atrophaeus and Bacillus mojavensis, were selected for plant growth chamber experiments based on strong in vitro antifungal activities. All five strains significantly reduced disease severity in Arabidopsis thaliana plants challenged with V. dahlia infection. Gas-chromatography/mass-spectrometry analysis of cell-free extracts of Bacillus atrophaeus strain XEGI50 showed that at least 13 compounds were produced only during co-cultivation with V. dahlia, including putative compounds known to have antimicrobial activity, such as 1,2-benzenedicarboxylic acid, bis (2-methylpropyl) ester; 9,12-octadecadienoic acid (Z,Z)-, methyl ester; 9-octadecenoic acid, methyl ester, (E)-; and decanedioic acid, bis(2-ethylhexyl) ester. To our knowledge, this study is the first to report that bacteria isolated from G. uralensis have biocontrol abilities. Our findings provide new insights into the antimicrobial activities of natural endophytes, particularly B. atrophaeus, and suggest this species may a promising candidate as a biocontrol agent to confer resistance to Verticillium wilt disease and other phytopathogens in cotton and other crops.