Genomic and phenotypic analyses reveal Paenibacillus polymyxa PJH16 is a potential biocontrol agent against cucumber fusarium wilt.

In recent years, bacterial-based biocontrol agents (BCA) have become a new trend for the control of fungal diseases such as fusarium wilt that seriously threaten the yield and quality of cucumber, which are transmitted through infested soil and water. This study was set out with the aim of figuring the mechanism of the isolated rhizobacterial strain Paenibacillus polymyxa PJH16 in preventing Fusarium oxysporum f. sp. cucumerinum (Foc). Biocontrol and growth-promoting experiments revealed that bacterial strain causes effective inhibition of the fungal disease through a significant growth-promoting ability of plants, and had activities of ß-1,3-glucanase, cellulase, amylase and protease. It could produce siderophore and indole-3-acetic acid, too. Using the high-throughput sequencing tool PacBio Sequel II system and the database annotation, the bacterial strain was identified as P. polymyxa PJH16 and contained genes encoding for presence of biofilm formation, antimicrobial peptides, siderophores and hydrolyases. From comparing data between the whole genome of P. polymyxa PJH16 with four closely related P. polymyxa strains, findings revealed markedly the subtle differences in their genome sequences and proposed new antifungal substances present in P. polymyxa PJH16. Therefore, P. polymyxa PJH16 could be utilized in bioengineering a microbial formulation for application as biocontrol agent and bio-stimulant, in the future.

Reliable biological and multi-omics research through biometrology.

Metrology is the science of measurement and its applications, whereas biometrology is the science of biological measurement and its applications. Biometrology aims to achieve accuracy and consistency of biological measurements by focusing on the development of metrological traceability, biological reference measurement procedures, and reference materials. Irreproducibility of biological and multi-omics research results from different laboratories, platforms, and analysis methods is hampering the translation of research into clinical uses and can often be attributed to the lack of biologists' attention to the general principles of metrology. In this paper, the progresses of biometrology including metrology on nucleic acid, protein, and cell measurements and its impacts on the improvement of reliability and comparability in biological research are reviewed. Challenges in obtaining more reliable biological and multi-omics measurements due to the lack of primary reference measurement procedures and new standards for biological reference materials faced by biometrology are discussed. In the future, in addition to establishing reliable reference measurement procedures, developing reference materials from single or multiple parameters to multi-omics scale should be emphasized. Thinking in way of biometrology is warranted for facilitating the translation of high-throughput omics research into clinical practices.

Chromosome-scale genomes of five Hongmu species in Leguminosae.

The Legume family (Leguminosae or Fabaceae), is one of the largest and economically important flowering plants. Heartwood, the core of a tree trunk or branch, is a valuable and renewable resource employed for centuries in constructing sturdy and sustainable structures. Hongmu refers to a category of precious timber trees in China, encompassing 29 woody species, primarily from the legume genus. Due to the lack of genome data, detailed studies on their economic and ecological importance are limited. Therefore, this study generates chromosome-scale assemblies of five Hongmu species in Leguminosae: Pterocarpus santalinus, Pterocarpus macrocarpus, Dalbergia cochinchinensis, Dalbergia cultrata, and Senna siamea, using a combination of short-reads, long-read nanopore, and Hi-C data. We obtained 623.86 Mb, 634.58 Mb, 700.60 Mb, 645.98 Mb, and 437.29 Mb of pseudochromosome level assemblies with the scaffold N50 lengths of 63.1 Mb, 63.7 Mb, 70.4 Mb, 61.1 Mb and 32.2 Mb for P. santalinus, P. macrocarpus, D. cochinchinensis, D. cultrata and S. siamea, respectively. These genome data will serve as a valuable resource for studying crucial traits, like wood quality, disease resistance, and environmental adaptation in Hongmu.

Genome sequencing and analysis of Bacillus velezensis VJH504 reveal biocontrol mechanism against cucumber Fusarium wilt.

One major issue in reducing cucumber yield is the destructive disease Cucumber (Cucumis sativus L.) wilt disease caused by Fusarium oxysporum f. sp. cucumerinum (Foc). When using the isolate VJH504 isolated from cucumber rhizosphere soil and identified as Bacillus velezensis, the growth of Foc in the double culture experiment was effectively inhibited. Phenotypic, phylogenetic, and genomic analyses were conducted to enhance understanding of its biocontrol mechanism. According to the result of the phenotype analysis, B. velezensis VJH504 could inhibit cucumber fusarium wilt disease both in vitro and in vivo, and significantly promote cucumber seed germination and seedling growth. Additionally, the tests of growth-promoting and biocontrol characteristics revealed the secretion of proteases, amylases, ß-1,3-glucanases, cellulases, as well as siderophores and indole-3-acetic acid by B. velezensis VJH504. Using the PacBio Sequel II system, we applied the complete genome sequencing for B. velezensis VJH504 and obtained a single circular chromosome with a size of 3.79 Mb. A phylogenetic tree was constructed based on the 16S rRNA gene sequences of B. velezensis VJH504 and 13 other Bacillus species, and Average Nucleotide Identity (ANI) analysis was performed using their whole-genome sequences, confirming isolateVJH504 as B. velezensis. Following this, based on the complete genome sequence od B. velezensis VJH504, specific functional analysis, Carbohydrate-Active Enzymes (CAZymes) analysis, and secondary metabolite analysis were carried out, predicting organism's abilities for biofilm formation, production of antifungal CAZymes, and synthesis of antagonistic secondary metabolites against pathogens. Afterwards, a comparative genomic analysis was performed between B. velezensis VJH504 and three other B. velezensis strains, revealing subtle differences in their genomic sequences and suggesting the potential for the discovery of novel antimicrobial substances in B. velezensis VJH504. In conclusion, the mechanism of B. velezensis VJH504 in controlling cucumber fusarium wilt was predicted to appear that B. velezensis VJH504is a promising biocontrol agent, showcasing excellent application potential in agricultural production.

Effects of Rhizosphere Microbial Communities on Cucumber Fusarium wilt Disease Suppression.

Cucumber Fusarium wilt is a worldwide soil-borne disease that seriously restricts the yield and quality of cucumber. The rhizosphere soil microbiome, as the first line of defense against pathogens invading plant roots, plays a key role in rhizosphere immune formation and function. The purpose of this study was to reveal the key microecological factors and dominant microbial flora affecting cucumber resistance and susceptibility to Fusarium wilt by analyzing the physical and chemical properties and microbial flora of rhizosphere soil with different degrees of susceptibility and resistance to cucumber Fusarium wilt, thereby laying a foundation to establish cucumber resistance to the Fusarium wilt rhizosphere core microbiome. Firstly, Illumina Miseq sequencing technology was used to evaluate the physical and chemical properties and microbial groups of cucumber rhizosphere soil at different health levels, and the key environmental factors and microbial factors related to cucumber Fusarium wilt were screened out. Subsequently, PICRUSt2 and FUNGuild were used to predict the functions of rhizosphere bacteria and fungi. Combined with functional analysis, the possible interactions among soil physical and chemical properties, cucumber rhizosphere microorganisms, and Fusarium wilt were summarized. The results showed that the available potassium content in the rhizosphere soil of healthy cucumber decreased by 10.37% and 0.56%, respectively, compared with the rhizosphere soil of severely susceptible cucumber and mildly susceptible cucumber. Exchangeable calcium content increased by 25.55% and 5.39%; the α diversity Chao1 index of bacteria and fungi in the rhizosphere soil of healthy cucumber was significantly lower than that in the rhizosphere soil of seriously infected cucumber, and the MBC content of its physical and chemical properties was also significantly lower than that in the rhizosphere soil of seriously infected cucumber. There was no significant difference in the Shannon and Simpson diversity indexes between healthy cucumber rhizosphere soil and seriously infected cucumber rhizosphere soil. The results of the ß diversity analysis showed that the bacterial and fungal community structure of healthy cucumber rhizosphere soil was significantly different from that of severely and mildly infected cucumber rhizosphere soil. At the genus level, through statistical analysis, LEfSe analysis, and RDA analysis, the key bacterial and fungal genera with potential biomarker values were screened out as SHA_26, Subgroup_22, MND1, Aeromicrobium, TM7a, Pseudorhodoplanes, Kocuria, Chaetomium, Fusarium, Olpidium, and Scopulariopsis, respectively. The bacteria SHA_26, Subgroup_22, and MND1 related to cucumber Fusarium wilt inhibition belong to Chloroflexi, Acidobacteriota, and Proteobacteria, respectively. Chaetomiacea belongs to Sordariomycates. The results of functional prediction showed that changes to the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway in the bacterial microbiota were concentrated in tetracycline biosynthesis, selenocompound metabolism, lipopolysaccharide biosynthesis, etc., which were mainly involved in the metabolism of terpenoids and polyketides, energy metabolism, metabolism of other amino acids, glycan biosynthesis and metabolism, lipid metabolism, cell growth and death, transcription, metabolism of cofactors and vitamins, and biosynthesis of other secondary metabolites. The difference in fungi was mainly dung saprotroph-ectomycorrhizal-soil saprotroph-wood saprotroph. Through the correlation analysis and functional predictions of the key environmental factors, microbial flora, and cucumber health index in cucumber rhizosphere soil, we determined that the inhibition of cucumber Fusarium wilt was a synergistic effect of environmental factors and microbial flora, and a model diagram was drawn to briefly explain its mechanism. This work will provide a basis for the biological control of cucumber Fusarium wilt in the future.

Potential of fecal microbiota for detection and postoperative surveillance of colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is one of the most common cancers. In recent studies, the gut microbiota has been reported to be potentially involved in aggravating or favoring CRC development. However, little is known about the microbiota composition in CRC patients after treatment. In this study, we explored the fecal microbiota composition to obtain a periscopic view of gut microbial communities. We analyzed microbial 16S rRNA genes from 107 fecal samples of Chinese individuals from three groups, including 33 normal controls (NC), 38 CRC patients (Fa), and 36 CRC post-surgery patients (Fb). RESULTS: Species richness and diversity were decreased in the Fa and Fb groups compared with that of the NC group. Partial least squares discrimination analysis showed clustering of samples according to disease with an obvious separation between the Fa and NC, and Fb and NC groups, as well as a partial separation between the Fa and Fb groups. Based on linear discriminant analysis effect size analysis and a receiver operating characteristic model, Fusobacterium was suggested as a potential biomarker for CRC screening. Additionally, we found that surgery greatly reduced the bacterial diversity of microbiota in CRC patients. Some commensal beneficial bacteria of the intestinal canal, such as Faecalibacterium and Prevotella, were decreased, whereas the drug-resistant Enterococcus was visibly increased in CRC post-surgery group. Meanwhile, we observed a declining tendency of Fusobacterium in the majority of follow-up CRC patients who were still alive approximately 3 y after surgery. We also observed that beneficial bacteria dramatically decreased in CRC patients that recidivated or died after surgery. This revealed that important bacteria might be associated with prognosis. CONCLUSIONS: The fecal bacterial diversity was diminished in CRC patients compared with that in NC. Enrichment and depletion of several bacterial strains associated with carcinomas and inflammation were detected in CRC samples. Fusobacterium might be a potential biomarker for early screening of CRC in Chinese or Asian populations. In summary, this study indicated that fecal microbiome-based approaches could be a feasible method for detecting CRC and monitoring prognosis post-surgery.

Comprehensive characterization of plasma cell-free Echinococcus spp. DNA in echinococcosis patients using ultra-high-throughput sequencing.

BACKGROUND: Echinococcosis is a life-threatening parasitic disease caused by Echinococcus spp. tapeworms with over one million people affected globally at any time. The Echinococcus spp. tapeworms in the human body release DNA to the circulatory system, which can be a biomarker for echinococcosis. Cell-free DNA (cfDNA) is widely used in medical research and has been applied in various clinical settings. As for echinococcosis, several PCR-based tests had been trialed to detect cell-free Echinococcus spp. DNA in plasma or serum, but the sensitivity was about 20% to 25%. Low sensitivity of PCR-based methods might be related to our limited understanding of the features of cell-free Echinococcus spp. DNA in plasma, including its concentration, fragment pattern and release source. In this study, we applied ultra-high-throughput sequencing to comprehensively investigate the characteristics of cell-free Echinococcus spp. DNA in plasma of echinococcosis patients. METHODOLOGY/PRINCIPAL FINDINGS: We collected plasma samples from 23 echinococcosis patients. Total plasma cfDNA was extracted and sequenced with a high-throughput sequencing platform. An average of 282 million read pairs were obtained for each plasma sample. Sequencing data were analyzed with bioinformatics workflow combined with Echinococcus spp. sequence database. After identification of cell-free Echinococcus spp. reads, we found that the cell-free Echinococcus spp. reads accounted for 1.8e-5 to 4.0e-9 of the total clean reads. Comparing fragment length distribution of cfDNA between Echinococcus spp. and humans showed that cell-free Echinococcus spp. DNA of cystic echinococcosis (CE) had a broad length range, while that of alveolar echinococcosis (AE) had an obvious peak at about 135 bp. We found that most of the cell-free Echinococcus spp. DNA reads were from the nuclear genome with an even distribution, which might indicate a random release pattern of cell-free Echinococcus spp. DNA. CONCLUSIONS/SIGNIFICANCE: With ultra-high-throughput sequencing technology, we analyzed the concentration, fragment length, release source, and other characteristics of cell-free Echinococcus spp. DNA in the plasma of echinococcosis patients. A better understanding of the characteristics of cell-free Echinococcus spp. DNA in plasma may facilitate their future application as a biomarker for diagnosis.

Long-Term Survival Analysis of Stereotactic Ablative Radiotherapy Versus Liver Resection for Small Hepatocellular Carcinoma.

PURPOSE: To compare the efficacy of stereotactic ablative radiation therapy (SABR) versus liver resection for small hepatocellular carcinoma (HCC) ≤5 cm with Child-Pugh A cirrhosis. METHODS AND MATERIALS: This retrospective study included 117 patients with small HCCs with 1 or 2 nodules. Eighty-two patients received SABR (SABR group), and 35 patients underwent liver resection (resection group). Overall survival (OS) and progression-free survival (PFS) were analyzed. One-to-one matched pairs between the 2 groups were created using propensity score matching to reduce the potential confounding effect of treatment and selection bias. RESULTS: There was no between-group difference in OS and PFS. Before propensity score matching, the 1-, 3-, and 5-year OS was 96.3%, 81.8%, and 70.0% in the SABR group and 93.9%, 83.1%, and 64.4% in the resection group, respectively (P=.558). The 1-, 3- and 5-year PFS was 81.4%, 50.2%, and 40.7% in the SABR group and 68.0%, 58.3%, and 40.3% in the resection group, respectively (P=.932). After propensity score matching, 33 paired patients were selected from the SABR and resection groups. The 1-, 3-, and 5-year OS was 100%, 91.8%, and 74.3% in the SABR group and 96.7%, 89.3%, and 69.2% in the resection group, respectively (P=.405). The 1-, 3-, and 5-year PFS was 84.4%, 59.2%, and 43.9% in the SABR group and 69.0%, 62.4%, and 35.9% in the resection group, respectively (P=.945). There was a similarity of hepatotoxicity between the 2 groups. The SABR group showed fewer complications, such as hepatic hemorrhage, hepatic pain, and weight loss. Acute nausea was significantly more frequent in the SABR group than in the resection group. CONCLUSION: For patients with small primary HCC with 1 or 2 nodules and Child-Pugh A cirrhosis, SABR has local effects that are similar to those with liver resection. Stereotactic ablative radiation therapy has an advantage over resection in being less invasive.

Long-term survival analysis in combined transarterial embolization and stereotactic body radiation therapy versus stereotactic body radiation monotherapy for unresectable hepatocellular carcinoma >5 cm.

BACKGROUND: The survival following transarterial chemoembolization (TACE) alone is still low in unresectable hepatocellular carcinoma (HCC) with almost patients developing disease progression after treatment. There is need to investigate additional therapeutic options that would intensify the initial response to TACE. The present study was to retrospectively compare the outcome and evaluate the prognostic factors of stereotactic body radiation therapy (SBRT) alone or as an adjunct to transarterial embolization (TAE) or TACE in the treatment of HCC >5 cm. METHODS: From January 2011 to April 2015, 77 patients received SBRT followed by TAE or TACE (TAE/TACE + SBRT group) and 50 patients received SBRT alone (SBRT group). The dose of SBRT was 30-50 Gy which was prescribed in 3-5 fractions. Eligibility criteria were: a longest tumor diameter >5.0 cm and Child-Turcotte-Pugh (CTP) Class A or B. Exclusion criteria included tumor thrombus, lymph node involvement and extrahepatic metastasis. RESULTS: The median follow-up period was 20.5 months. Median tumor size was 8.5 cm (range, 5.1-21.0 cm). Median overall survival (OS) in the TAE/TACE + SBRT group was 42.0 months versus 21.0 months in the SBRT group. The 1-, 3- and 5-year OS was 75.5, 50.8, and 46.9 % in the TAE/TACE + SBRT group and was 62.4, 32.9, and 32.9 % in the SBRT group, respectively (P = 0.047). The 1-, 3- and 5-year distant metastasis-free survival (DMFS) was 66.3, 44.3, and 40.6 % in the TAE/TACE + SBRT group and was 56.8, 26.1, and 17.4 % in the SBRT group, respectively (P = 0.049). The progression-free survival (PFS) and local relapse-free survival (LRFS) were not significantly different between the two groups. In the entire patient population, a biologically effective dose (BED10) ≥100 Gy and an equivalent dose in 2 Gy fractions (EQD2) ≥74 Gy were significant prognostic factors for OS, PFS, LRFS and DMFS. CONCLUSIONS: SBRT combined with TAE/TACE may be an effective complementary treatment approach for HCC >5 cm in diameter. BED10 ≥100 Gy and EQD2 ≥74 Gy should receive more attention when the SBRT plan is designed.