The P2 nucleic acid binding protein of Sugarcane bacilliform virus is a viral pathogenic factor.

Background: Saccharum spp. is the primary source of sugar and plays a significant role in global renewable bioenergy. Sugarcane bacilliform virus (SCBV) is one of the most important viruses infecting sugarcane, causing severe yield losses and quality degradation. It is of great significance to reveal the pathogenesis of SCBV and resistance breeding. However, little is known about the viral virulence factors or RNA silencing suppressors and the molecular mechanism of pathogenesis. Methods: To systematically investigate the functions of the unknown protein P2 encoded by SCBV ORF2. Phylogenetic analysis was implemented to infer the evolutionary relationship between the P2 of SCBV and other badnaviruses. The precise subcellular localization of P2 was verified in the transient infiltrated Nicotiana benthamiana epidermal mesophyll cells and protoplasts using the Laser scanning confocal microscope (LSCM). The post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS) RNA silencing suppressor activity of P2 was analyzed, respectively. Furthermore, restriction digestion and RT-qPCR assays were conducted to verify the probable mechanism of P2 on repressing DNA methylation. To explore the pathogenicity of P2, a potato virus X-based viral vector was used to heterologously express SCBV P2 and the consequent H2O2 accumulation was detected by the 3,3'-diaminobenzidine (DAB) staining method. Results: Phylogenetic analysis shows that SCBV has no obvious sequence similarity and low genetic relatedness to Badnavirus and Tungrovirus representatives. LSCM studies show that P2 is localized in both the cytoplasm and nucleus. Moreover, P2 is shown to be a suppressor of PTGS and TGS, which can not only repress ssRNA-induced gene silencing but also disrupt the host RNA-directed DNA methylation (RdDM) pathway. In addition, P2 can trigger an oxidative burst and cause typical hypersensitive-like response (HLR) necrosis in systemic leaves of N. benthamiana when expressed by PVX. Overall, our results laid a foundation for deciphering the molecular mechanism of SCBV pathogenesis and made progress for resistance breeding.

Therapeutic effect of iturin A on Candida albicans oral infection and its pathogenic factors.

Candida albicans is responsible for conditions ranging from superficial infections such as oral or vaginal candidiasis to potentially fatal systemic infections. It produces pathogenic factors contributing to its virulence. Iturin A, a lipopeptide derived from Bacillus sp., exhibits a significant inhibitory effect against C. albicans. However, its exact mechanism in mitigating the pathogenic factors of C. albicans remains to be elucidated. This study aimed to explore the influence of iturin A on several pathogenic attributes of C. albicans, including hypha formation, cell membrane permeability, cell adhesion, biofilm formation, and therapeutic efficacy in an oral C. albicans infection model in mice. The minimal inhibitory concentration of iturin A against C. albicans was determined to be 25 µg/mL in both YEPD and RPMI-1640 media. Iturin A effectively inhibited C. albicans hyphal formation, decreased cell viability within biofilms, enhanced cell membrane permeability, and disrupted cell adhesion in vitro. Nonetheless, iturin A did not significantly affect the phospholipase activity or hydrophobicity of C. albicans. A comparative study with nystatin demonstrated the superior therapeutic efficacy of iturin A in a mouse model of oral C. albicans infection, significantly decreasing C. albicans count and inhibiting both fungal hypha formation and tongue surface adhesion. High-dose iturin A treatment (25 µg/mL) in mice had no significant effects on blood indices, tongue condition, or body weight, indicating the potential for iturin A in managing oral infections. This study confirmed the therapeutic potential of iturin A and provided valuable insights for developing effective antifungal therapies targeting C. albicans pathogenic factors.

Functional identification of a novel C7 protein of tomato yellow leaf curl virus.

Tomato yellow leaf curl virus (TYLCV) is a monopartite geminivirus, and one of the most devastating plant viruses in the world. TYLCV is traditionally known to encode six viral proteins in bidirectional and partially overlapping open reading frames (ORFs). However, recent studies have shown that TYLCV encodes additional small proteins with specific subcellular localizations and potential virulence functions. Here, a novel protein named C7, encoded by a newly-described ORF in the complementary strand, was identified as part of the TYLCV proteome using mass spectrometry. The C7 protein localized to the nucleus and cytoplasm, both in the absence and presence of the virus. C7 was found to interact with two other TYLCV-encoded proteins: with C2 in the nucleus, and with V2 in the cytoplasm, forming conspicuous granules. Mutation of C7 start codon ATG to ACG to block the translation of C7 delayed the onset of viral infection, and the mutant virus caused milder virus symptoms and less accumulations of viral DNAs and proteins. Using the potato virus X (PVX)-based recombinant vector, we found that ectopic overexpression of C7 resulted in more severe mosaic symptoms and promoted a higher accumulation of PVX-encoded coat protein in the late virus infection stage. In addition, C7 was also found to inhibit GFP-induced RNA silencing moderately. This study demonstrates that the novel C7 protein encoded by TYLCV is a pathogenicity factor and a weak RNA silencing suppressor, and that it plays a critical role during TYLCV infection.

The S100B Protein: A Multifaceted Pathogenic Factor More Than a Biomarker.

S100B is a calcium-binding protein mainly concentrated in astrocytes in the nervous system. Its levels in biological fluids are recognized as a reliable biomarker of active neural distress, and more recently, mounting evidence points to S100B as a Damage-Associated Molecular Pattern molecule, which, at high concentration, triggers tissue reactions to damage. S100B levels and/or distribution in the nervous tissue of patients and/or experimental models of different neural disorders, for which the protein is used as a biomarker, are directly related to the progress of the disease. In addition, in experimental models of diseases such as Alzheimer's and Parkinson's diseases, amyotrophic lateral sclerosis, multiple sclerosis, traumatic and vascular acute neural injury, epilepsy, and inflammatory bowel disease, alteration of S100B levels correlates with the occurrence of clinical and/or toxic parameters. In general, overexpression/administration of S100B worsens the clinical presentation, whereas deletion/inactivation of the protein contributes to the amelioration of the symptoms. Thus, the S100B protein may be proposed as a common pathogenic factor in different disorders, sharing different symptoms and etiologies but appearing to share some common pathogenic processes reasonably attributable to neuroinflammation.

Characterization of gut dominant microbiota in obese patients with nonalcoholic fatty liver disease.

In obese patients, non-alcoholic fatty liver (NAFLD) is common. However, whether there is a connection between the gut microbiota and the onset of NAFLD in obese people is yet unknown. Using quantitative real-time PCR, the microbiota of feces of the eligible 181 obese individuals was identified to compare the differences in gut microbiota between obesity with NAFLD and simple obesity. According to the findings, the gut dominant microbiota was similar between obesity with NAFLD and simple obesity. Nonetheless, compared to the simple obesity group, the quantity of Faecalibacterium prausnitzii colonies was much lower in the obesity with the NAFLD group. Bacteroides were present in greater than 65% of both groups. Bacteroides, Clostridium leptum, and Clostridium butyricum accounted for more than 80% of the cases in the obesity with NAFLD group, whereas Bacteroides, Clostridium butyricum, and F. prausnitzii accounted for more than 80% of the cases in the simple obesity group. We look for potential contributing variables to obesity-related NAFLD and potential prevention measures for obese people. Based on a multi-factor logistic regression analysis, lymphocytes may be a risk factor for obesity with NAFLD while F. prausnitzii may be a protective factor. Additionally, F. prausnitzii is positively impacted by Bacteroides, Clostridium leptum, Clostridium butyricum, and Eubacterium rectale, yet adversely impacted by Enterobacteriaceae. Notably, lymphocytes and F. prausnitzii may help determine whether obese patients would develop NAFLD.

Epidemiological characteristics of foodborne disease outbreaks in Shaoxing City from 2012 to 2022 / 预防医学

Objective@#To investigate the epidemiological characteristics of foodborne disease outbreaks in Shaoxing City, Zhejiang Province, from 2012 to 2022, so as to provide the evidence for improving the foodborne disease control strategy. @*Methods@#Foodborne disease outbreaks in Shaoxing City from 2012 to 2022 were collected from National Foodborne Disease Outbreak Monitoring System in China, including populations, places of outbreak, pathogenic factors and suspected foods. The temporal distribution, regional distribution, distribution of outbreak places and pathogenic factors of foodborne disease outbreaks were descriptively analyzed.@*Results@#A total of 89 foodborne disease outbreaks were reported in Shaoxing City from 2012 to 2022, covering totally 699 patients, with an average annual attack rate of 6.35%. The outbreak peaked during the period between June and October (73 outbreaks, 82.02%), and family was the predominant place of outbreak (41 outbreaks, 46.07%). There were 83 outbreaks with known pathogenic factors, including 51 outbreaks caused by microbial factors, with Vibrio parahaemolyticus, Salmonella and norovirus as predominant pathogens, and 29 outbreaks caused by fungi and their toxins, which were all poisonous mushrooms poisoning, resulting in 2 deaths. In addition, there were 3 outbreaks caused by chemical factors. @*Conclusions@#The outbreak of foodborne diseases predominantly occurred in summer and autumn in Shaoxing City from 2012 to 2022. Family was the predominant place of outbreak, and toxic mushroom poisoning was the most lethal pathogenic factor.

Inactivation of a wheat protein kinase gene confers broad-spectrum resistance to rust fungi.

Wheat crops are frequently devastated by pandemic stripe rust caused by Puccinia striiformis f. sp. tritici (Pst). Here, we identify and characterize a wheat receptor-like cytoplasmic kinase gene, TaPsIPK1, that confers susceptibility to this pathogen. PsSpg1, a secreted fungal effector vital for Pst virulence, can bind TaPsIPK1, enhance its kinase activity, and promote its nuclear localization, where it phosphorylates the transcription factor TaCBF1d for gene regulation. The phosphorylation of TaCBF1d switches its transcriptional activity on the downstream genes. CRISPR-Cas9 inactivation of TaPsIPK1 in wheat confers broad-spectrum resistance against Pst without impacting important agronomic traits in two years of field tests. The disruption of TaPsIPK1 leads to immune priming without constitutive activation of defense responses. Taken together, TaPsIPK1 is a susceptibility gene known to be targeted by rust effectors, and it has great potential for developing durable resistance against rust by genetic modifications.

Increased Vascular Permeability Due to Spread and Invasion of Vibrio vulnificus in the Wound Infection Exacerbates Potentially Fatal Necrotizing Disease.

Vibrio vulnificus is known to cause necrotizing soft tissue infections (NSTIs). However, the pathogenic mechanism causing cellulitis, necrotizing fasciitis, muscle necrosis, and rapidly developing septicemia in humans have not been fully elucidated. Here, we report a multilayer analysis of tissue damage after subcutaneous bacterial inoculation as a murine model of V. vulnificus NSTIs. Our histopathological examination showed the progression of cellulitis, necrotizing fasciitis, and muscle necrosis worsening as the infection penetrated deeper into the muscle tissue layers. The increase in vascular permeability was the primary cause of the swelling and congestion, which are acute signs of inflammation in soft tissue and characteristic of human NSTIs. Most importantly, our sequential analysis revealed for the first time that V. vulnificus not only spreads along the skin and subcutaneous tissues or fascia but also invades deeper muscle tissues beyond the fascia as the crucial process of its lethality. Also, increased vascular permeability enabled V. vulnificus to proliferate in muscle tissue and enter the systemic circulation, escalating the bacterium's lethality. Our finding may yield important clinical benefits to patients by helping physicians understand the impact of surgical debridement on the patient's quality of life. Furthermore, this study provides a promising system to accelerate studies of virulence factors and eventually help establish new therapies.

Development and study of nutrient media for determining the biological properties of Listeria.

The commercial nutrient media for investigation of the biologic properties of L. monocytogenes is developed. The efficiency of the use of developed media for determination of motility and lecithinase activity of Listeria in the establishment of the isolated culture to the pathogenic species is shown. These nutrient media are developed for visually accurate registration of the motility and lecithinase activity of Listeria when identifying the isolated cultures improving the diagnostics of listeriosis.

Analysis of epidemiological characteristics and pathogenic factors of sepsis-related acute liver injury / 中华急诊医学杂志

Objective:To analyze the epidemiological characteristics, high risk factors and pathogenic factors of sepsis-related liver injury patients by collecting epidemiological data and the sequencing results.Methods:A total of 288 sepsis patients been admited to the Emergency Department of the First Affiliated Hospital of Air Force Military Medical University from January 1, 2018 to December 31,2019 were selected and divided into sepsis liver injury group ( n = 44) and sepsis without liver injury group ( n = 244) according to whether acute liver injury occurred or not. The differences ofthe general data, hematological parameters, severity of illness and other indicators at admission between the two groups were compared and analyzed. Logistic regression was used to analyze the risk factors of sepsis-related liver injury. Total of 8 septic patients with liver injury and 4 septic patients without liver injury were selected for RNA-sequencing. Ribonucleic acid (RNA) was extracted from peripheral blood mononuclear cell of patients, detected using RNA-seq, and differential genes were screened and analyzed. Results:Compared with the sepsis without liver injury group, patients in the liver injury group suffered less hypertension (11.4% vs. 30.3%) and relatively more chronic renal insufficiency (40.9% vs. 12.1%); more patients were admitted to the emergency department due to renal disease (43.2% vs. 24.6%), higher sequential organ failure score (SOFA) and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score (SOFA (points) 9.86 ± 3.59 vs. 5.41 ± 3.13, APACHE Ⅱ (points) (16.07 ± 4.41) vs. (14.46 ± 3.77), with prolonged hospital days (d): 8 (4.75, 13.75) vs. 6 (2, 9)]; in the liver injury group, the incidence of infection in respiratory and digestive systems (70.5% vs. 18.0%) andthe chance of infection with Staphylococcus aureus were higher (9.1% vs. 2.0%), and laboratory parameters (procalcitonin (PCT), lactate dehydrogenase (LDH), partial thromboplastin time (APTT), direct bilirubin (DBIL), aspartate aminotransferase (ALT), alanine aminotransferase (AST)) were significantly increased [PCT (μg/L) (23.90 ± 33.22) vs. (10.95 ± 20.18), LDH (U/L) 540.00 (370.50, 1177.00) vs. 168.00 (98.65, 875.18), APTT (s) (41.50 ± 3.13) vs. (36.23 ± 5.27), DBIL (μmol/L) 18.50 (10.10, 58.85) vs. 10.30 (7.60, 16.85), ALT (U/L) 67.00 (41.25, 164.00) vs. 29.00 (18.00, 51.25), AST (U/L), 101.00 (51.25, 174.75) vs. 35.00 (25.00, 65.50)], while platelet (PLT) and albumin (Alb) were significantly lower than those in the sepsis without liver injury group [PLT (× 10 9/L) 62.50 (38.50, 164.25) vs. 90.5 (66.25, 165.5), Alb (g/L) (30.17 ± 7.16) vs. (34.20 ± 6.50)] (all P < 0.05).Logistic regression analysis revealed that Staphylococcus aureus infection, thrombocytopenia, elevated procalcitonin, elevated lactate dehydrogenase, elevated total bilirubin, and elevated glutamyltransferase were associated with sepsis with acute liver injury (odds ratio, OR) with 95% confidence interval (95% CI) of 0.1167 (0.0380~0.7300), 0.9836 (1.0060~1.0290), 0.9986 (1.0000~1.0001), 0.9745 (1.0040~1.0170), 1.0020 (0.9940~1.0000), and 0.9931 (1.0000~1.0001), respectively. A total of 311 significantly differential expressed genes (DEGs) were selected, with 151 up-regulated genes and 160 down-regulated genes compared with the septic non-liver injury group. Further bioinformatics analysis reveled that the top 10 GO sequences are:①platelet α granules,② platelet α granule cavity,③wound healing,④cell migration,⑤multicellular organism process,⑥anatomical structure development,⑦cartilage ossification,⑧tissue development,⑨ keratinization,⑨Multicellular biological development. And KEGG pathway enrichment analysis revealed that human disease-related pathways were dominant, mainly including purine metabolism, AGE-RAGE signaling pathway, p53 signaling pathway, porphyrin and chlorophyll metabolism, nitrogen metabolism, mineral nutrient absorption, protein processing in the endoplasmic reticulum, and FoXo signaling pathway. Conclusions:Staphylococcus aureus infection, thrombocytopenia, elevated procalcitonin, elevated lactate dehydrogenase, elevated total bilirubin, and elevated glutamyltransferase were independent risk factors for sepsis liver injury. Coagulation dysfunction, apoptosis, and metabolic level changes may be important mechanisms of sepsis-associated liver injury, which are related to purine metabolism, porphyrin and chlorophyll metabolism and the expression of genes related to FoXo signaling pathway, Hippo signaling pathway, and p53 signaling pathway.

Research progress of ocular surface pathophysiological changes in dry eye / 国际眼科杂志(Guoji Yanke Zazhi)

@#The incidence of dry eye is increasing year by year, and it has become one of the most common ophthalmic diseases. The main symptoms of dry eye disease are dry, foreign body sensation, burning in eyes, itchy and viscous secretion. These discomforts affect the daily life, efficiency of work and study, mental health and physical function of patients with dry eye. Dry eye is a multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities play etiological roles. Meanwhile, there are changes in the tissue structure and ocular surface microenvironment of the eyes of patients with dry eye. In view of the fact that dry eye is an important public health problem, which seriously affects people's visual quality and life quality, studying the pathophysiology of dry eye is of great significance for efficient diagnosis, more targeted treatment and reduction of adverse events. This paper reviewed the research progress in the pathophysiology of dry eye in recent years.

Epidemiological features of foodborne disease outbreaks in Shanghai 2010 to 2020 / 上海预防医学

ObjectiveTo analyze the epidemiological features of foodborne disease outbreaks in Shanghai and to find the risk factors. MethodsWe collected the data of foodborne disease outbreaks occurred in Shanghai between 2010 and 2020， analyzed the characteristics of outbreaks， including time and geographic distribution， pathogenic factors and possible reasons caused outbreaks. ResultsBetween 2010 and 2020， there were 108 foodborne disease outbreaks with 1 736 cases， 45 inpatient cases and 1 death. May to September was the epidemic period， with about 64.81% of the outbreak occurrence. 39.81% outbreaks occurred in Pudong， Songjiang and Chongming Districts. Most outbreaks occurred in small restaurants （25%） and most foodborne cases were in staff canteen outbreaks （27.53%）. The main possible reasons caused outbreaks were improper food storage （19.44%）， cross-contamination （14.81%） and improper cooking （12.04%）. The major pathogenic factor was biological， caused 75.92% outbreaks and 77.59% cases. Methanol poisoning caused 1 death. The main contaminated food caused outbreaks was meat （17.59%）， multiple food （12.04%） and aquatic products （11.11%）. ConclusionThe foodborne disease outbreaks in Shanghai caused inpatient cases and death. We should pay more attention to foodborne disease outbreaks and we can control the risk factors by strengthening supervision and carrying out health education to reduce foodborne disease outbreaks.

Key Amino Acids for Pepper Vein Yellows Virus P0 Protein Pathogenicity, Gene Silencing, and Subcellular Localization.

Pepper vein yellows virus (PeVYV) is a newly recognized Polerovirus extracted from Chinese pepper. The symptoms of PeVYV-infested pepper plants comprise intervein yellow staining, leaf curl formation and other malformations, and leaf internodal shrinkage, but the roles of the viral proteins remain undetermined. The P0 protein of the genus Polerovirus has established post-transcriptional gene silencing (PTGS) activity. This investigation focused on the PeVYV-encoded P0 protein and assessed its potential virulence capacity, PTGS activity, and tendencies to localize in the nucleus. This study revealed that P0 influenced the pathogenic properties of a specific heterologous potato virus X. In addition, P0 proteins impaired local gene silencing, although they did not regulate generalized gene silencing within Nicotiana benthamiana 16c plants. Furthermore, P0 proteins localized mainly in the nucleus, particularly in the nucleolus. P0 deletion mutagenesis demonstrated that the F-box motif (56-72 amino acids, AAs) of P0 was essential for symptom determination, inhibition of PTGS, and subcellular localization. Mutation analysis of the F-box motif of P0 protein indicated that AA 57 of the P0 protein was a pivotal site in symptom development and that AA 56 of the P0 protein was indispensable for inhibiting PTGS and subcellular localization. The outcomes obtained here suggest that further studies should be conducted on the molecular mechanisms of amino acids of the F-box domain of P0 protein in the interaction of PeVYV with plants.

Pathogenic Factors Identification of Brain Imaging and Gene in Late Mild Cognitive Impairment.

Mild cognitive impairment (MCI) is a dangerous signal of severe cognitive decline. It can be separated into two steps: early MCI (EMCI) and late MCI (LMCI). As the post-state of MCI and pre-state of Alzheimer's disease (AD), LMCI receives insufficient attention in the field of brain science, causing the internal mechanism of LMCI has not been well understood. To better explore the focus and pathological mechanism of LMCI, a method called genetic evolved random forest (GERF) is applied. Resting functional magnetic resonance imaging (rfMRI) and gene data are obtained from 62 subjects (36 LMCI and 26 normal controls), and Pearson correlation analysis is adopted to perform the multimodal fusion of two types of data to construct fusion features. We identified pathogenic brain regions and genes that are highly related to LMCI using GERF and achieves a good effect. Compared with the normal control (NC) group, the abnormal brain regions of LMCI are PUT.L, PreCG.L, IFGtriang.R, REC.R, DCG.R, PoCG.L, and HES.L, and the pathogenic genes are FHIT, RF00019, FRMD4A, PTPRD, and RBFOX1. More importantly, most of these risk genes and abnormal brain regions have been confirmed to be related to AD and MCI in previous studies. In this study, we mapped them to LMCI with higher accuracies, so as to provide a more robust understanding of the physiological mechanism of MCI.

Study on different pathogenic factors in different disease stages of patients with Wilson disease.

OBJECTIVE: To investigate in different stages of patients with Wilson disease (WD), there are different pathogenic factors such as metal deposition, oxidative stress, and inflammatory response in the brain. METHODS: A total of 32 untreated WD patients and 10 normal controls were enrolled in the study. The neurological symptoms were evaluated using the modified Young scale. Liver function, metal metabolism, susceptibility-weighted imaging (SWI), diffusion tensor imaging (DTI), and magnetic resonance spectroscopy (MRS) examination were done. The clinical disease stages were divided into metal deposition period, fiber damage period, and neuronal necrosis period according to the imaging results. The content of 24-h urine copper, serum copper, and serum iron; and the levels of catalase (CAT), glutathione peroxidase (GSH-PX), malondialdehyde (MDA), nitric oxide (NO), nitric oxide synthase (NOS), superoxide dismutase (SOD), interleukin (IL-1), and tumor necrosis factor alpha (TNF-α) were detected. RESULTS: The contents of urinary copper in WD patients at neuronal necrosis stage were lower than those in patients at the metal deposition stage (P = 0.011) and fiber injury stage (P = 0.023). The contents of NOS (P = 0.039) and NO (P = 0.047) in WD patients at the stage of fiber injury were higher than those of the normal control, while GSH-PX (P = 0.025) and CAT (P = 0.041) were lower in the neuronal necrosis stage. In the stage of neuronal necrosis, the levels of IL-1 (P = 0.030) and TNF-α were higher than those of the normal control (P = 0.042). The neurological symptom scores in patients with fiber injury (P = 0.013) and neuron injury were higher than those with metal deposition (P = 0.026). CONCLUSION: There are different pathogenic factors in different stages of WD. At the neuronal necrosis stage, copper deposition was decreased in WD patients. In the stage of fiber injury and neuronal necrosis, there is oxidative stress injury in WD patients. In the neuronal necrosis phase, WD patients have an inflammatory response.

Proteome size reduction in Apicomplexans is linked with loss of DNA repair and host redundant pathways.

Apicomplexans are alveolate parasites which include Plasmodium falciparum, the main cause of malaria, one of the world's biggest killers from infectious disease. Apicomplexans are characterized by a reduction in proteome size, which appears to result from metabolic and functional simplification, commensurate with their parasitic lifestyle. However, other factors may also help to explain gene loss such as population bottlenecks experienced during transmission, and the effect of reducing the overall genomic information content. The latter constitutes an 'informational constraint', which is proposed to exert a selective pressure to evolve and maintain genes involved in informational fidelity and error correction, proportional to the quantity of information in the genome (which approximates to proteome size). The dynamics of gene loss was examined in 41 Apicomplexan genomes using orthogroup analysis. We show that loss of genes involved in amino acid metabolism and steroid biosynthesis can be explained by metabolic redundancy with the host. We also show that there is a marked tendency to lose DNA repair genes as proteome size is reduced. This may be explained by a reduction in size of the informational constraint and can help to explain elevated mutation rates in pathogens with reduced genome size. Multiple Sequentially Markovian Coalescent (MSMC) analysis indicates a recent bottleneck, consistent with predictions generated using allele-based population genetics approaches, implying that relaxed selection pressure due to reduced population size might have contributed to gene loss. However, the non-randomness of pathways that are lost challenges this scenario. Lastly, we identify unique orthogroups in malaria-causing Plasmodium species that infect humans, with a high proportion of membrane associated proteins. Thus, orthogroup analysis appears useful for identifying novel candidate pathogenic factors in parasites, when there is a wide sample of genomes available.

SARS-CoV-2 nsp1: Bioinformatics, Potential Structural and Functional Features, and Implications for Drug/Vaccine Designs.

The emerging coronavirus disease (COVID-19) caused by SARS-CoV-2 has led to social and economic disruption globally. It is urgently needed to understand the structure and function of the viral proteins for understanding of the viral infection and pathogenesis and development of prophylaxis and treatment strategies. Coronavirus non-structural protein 1 (nsp1) is a notable virulence factor with versatile roles in virus-host interactions and exhibits unique characteristics on sequence, structure, and function mode. However, the roles and characteristics of SARS-CoV-2 nsp1 are currently unclear. Here, we analyze the nsp1 of SARS-CoV-2 from the following perspectives: (1) bioinformatics analysis reveals that the novel nsp1 is conserved among SARS-CoV-2 strains and shares significant sequence identity with SARS-CoV nsp1; (2) structure modeling shows a 3D α/ß-fold of SARS-CoV-2 nsp1 highly similar to that of the SARS-CoV homolog; (3) by detailed, functional review of nsp1 proteins from other coronaviruses (especially SARS-CoV) and comparison of the protein sequence and structure, we further analyzed the potential roles of SARS-CoV-2 nsp1 in manipulating host mRNA translation, antiviral innate immunity and inflammation response and thus likely promoting viral infection and pathogenesis, which are merited to be tested in the future. Finally, we discussed how understanding of the novel nsp1 may provide valuable insights into the designs of drugs and vaccines against the unprecedented coronavirus pandemic.

RPP30, a transcriptional regulator, is a potential pathogenic factor in glioblastoma.

BACKGROUND: Old age has been demonstrated to be a risk factor for GBM, but the underlying biological mechanism is still unclear. We designed this study intending to determine a mechanistic explanation for the link between age and pathogenesis in GBM. RESULTS: The expression of RPP30, an independent prognostic factor in GBM, was negatively correlated with age in both tumor and non-tumor brain samples. However, the post-transcriptional modifications carried out by RPP30 were different in primary GBM and non-tumor brain samples. RPP30 affected protein expression of cancer pathways by performing RNA modifications. Further, we found that RPP30 was related to drug metabolism pathways important in GBM. The decreased expression of RPP30 in older patients might be a pathogenic factor for GBM. CONCLUSION: This study revealed the role of RPP30 in gliomagenesis and provided the theoretical foundation for targeted therapy. METHODS: In total, 616 primary GBM samples and 41 non-tumor brain samples were enrolled in this study. Transcriptome data and clinical information were obtained from the CGGA, TCGA, and GSE53890 databases. Gene Set Variation Analysis and Gene Ontology analyses were the primary analytical methods used in this study. All statistical analyses were performed using R.

Chemotactic invasion in deep soft tissue by Vibrio vulnificus is essential for the progression of necrotic lesions.

Necrotizing soft tissue infections (NSTI) progress to severe necrosis and result in fatal sepsis within a short time. Vibrio vulnificus is a causative agent and can spread from the initial infection site through soft tissue finally to the systemic circulation of the host. The motility and chemotaxis of this bacterium are essential for proliferation and lethality in a murine model of the infection, but their role in pathogenicity has not been characterized. In this study, we revealed the roles of motility and chemotaxis during the process of V. vulnificus infection. We compared a nonmotile mutant and two nonchemotactic mutants with their parent strain (WT) with regard to bacterial spread using an in vivo imaging system (IVIS) and invasion by detection of bacteria from the muscle and spleen of a murine infection model. WT rapidly spread throughout the infected thigh and invaded deep muscle causing severe tissue damage. The detection rate in the systemic circulation and the lethality were high. On the other hand, the nonmotile mutant stayed at the inoculation site, and the nonchemotactic mutants spread only slowly through the soft tissue of the infected thigh. Detection in the systemic circulation, the degree of tissue damage, and the lethality of nonchemotactic mutants were significantly reduced in mice compared with WT. This study demonstrated that chemotaxis is essential for invasion from the infection site to the deep and distant tissues and the main pathogenic factor for the rapid progression leading to sepsis in V. vulnificus NSTI.

GlgA plays an important role in the induction of hydrosalpinx by Chlamydia muridarum.

While glycogen synthase A deficiency can reduce the growth and proliferation of Chlamydia muridarum, the effect of glycogen synthase A on the pathogenic process of C. muridarum remains unclear. To characterize the effect of glycogen synthase A deficiency on the pathogenicity of C. muridarum in the genital tract, BALB/c mice were intravaginally inoculated with wild-type, plasmid-free and glycogen synthase A-deficient C. muridarum, and the genital tract tissue was isolated to assess the severity of hydrosalpinx and the levels of oviduct dilatation at day 60 after infection. The glycogen storage capacity and in vitro infection ability of different C. muridarum strains were analyzed by periodic acid-Schiff staining and quantification of progeny elementary body(EB) formation. The tissue homogenate was used to determine the recovery of different C. muridarum strains. The results show that glycogen synthase A-deficient C. muridarum induced reduction of hydrosalpinx and attenuated the extent of oviduct dilatation in mice, and exhibited reduced growth and proliferation in the mouse lower genital tract. In addition, glycogen synthase A point mutations at different sites reduced the glycogen storage capacity and in vitro infectivity of C. muridarum to different degrees. Glycogen synthase A deficiency also reduced the host inflammatory reaction and ascending infection of C. muridarum.