BMC Microbiology最新文献

{"title":"The healthy human gut as a covert reservoir for mobile antimicrobial resistance: nationwide genomic surveillance of Enterobacter cloacae complex in China.","authors":"Heyuan Lun, Zelin Yan, Jing Wang, Haojin Dong, Yonglu Huang, Yongning Wu, Aixin Yan, Rong Zhang","doi":"10.1186/s12866-026-05535-1","DOIUrl":"10.1186/s12866-026-05535-1","url":null,"abstract":"<p><strong>Background: </strong>Enterobacter cloacae complex (ECC) is a formidable opportunistic pathogen, yet its ecological niche and role as a silent reservoir for antimicrobial resistance (AMR) in the healthy human gut remain underappreciated. Herein, we aim to characterize the prevalence, genomic epidemiology, and mobile resistome of ECC in a widespread healthy demographic.</p><p><strong>Methods: </strong>In a nationwide, cross-sectional genomic surveillance study conducted across China (2024-2025), we analyzed 10,300 fecal samples from healthy individuals across 31 provinces. High-resolution whole-genome sequencing (WGS), comparative genomics, and conjugation assays were employed to resolve species identity, delineate phylogenetic relationships, and trace the mobility of high-priority resistance determinants.</p><p><strong>Results: </strong>We recovered 148 non-duplicate ECC isolates, establishing a community carriage prevalence of 1.44%. Among them, Enterobacter hormaechei emerged as the predominant species (49.3%). WGS revealed a highly diverse population structure harboring critical resistance determinants, including mcr genes (4.1%), tet(X4) (3.4%), and carbapenemases (9.5%, predominantly bla_NDM). Notably, this study provides, to our knowledge, the first evidence of tet(X4)-positive ECC in the gut carriage of healthy individuals in China. While mcr and tet(X4) were dispersed across diverse sequence types (STs), bla_NDM carriage was strongly concentrated in specific lineages, notably ST143 and ST171. Genomic and conjugation analyses showed that tet(X4), bla_NDM, and mcr were associated with conserved mobile genetic contexts (e.g., an IS1 family transposase-hydrolase-tet(X4)-IS91-like element ISVsa3 structure for tigecycline resistance), and successful transfer was confirmed for selected representative bla_NDM-positive isolates.</p><p><strong>Conclusions: </strong>The healthy human gastrointestinal tract can harbor ECC isolates carrying clinically important AMR determinants, including resistance genes located within mobile genetic contexts. These findings support the integration of community-based genomic surveillance into AMR monitoring strategies to better understand asymptomatic carriage of resistant ECC.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13647819/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149126701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of a phage-inclusive multimodal strategy for recurrent urinary tract infections.","authors":"Simone C Lieberknecht-Jouy, Thomas Fließwasser, Dajana Pavlovic, Lucas J Fein, Verena Wiemann, Trang Do, Denia Frank, Tobias Weirauch, Annika Y Classen, Silvia Würstle, Thomas A Wichelhaus, Maria J G T Vehreschild","doi":"10.1186/s12866-026-05524-4","DOIUrl":"10.1186/s12866-026-05524-4","url":null,"abstract":"<p><p>Urinary tract infections (UTIs) are among the most common bacterial infections worldwide and are associated with high recurrence rates and substantial morbidity. New therapeutic approaches are urgently needed, especially for recurrent UTIs (rUTIs), among which phage therapy represents a promising option. Here, we systematically evaluated the performance of six E. coli phages under urinary tract-relevant conditions and established a quantitative area-under-the-curve (AUC)-based framework for the rational selection of therapeutic phages. Phage lysis behavior was tested under oxic and anoxic conditions, revealing modulation by oxygen availability. Phages were also screened for biofilm-degrading activity, and in silico depolymerase predictions were compared with in vitro results, showing strong correlation. Phage-antibiotic interactions and refined treatment strategies were further investigated. Phages G9062, G10400, and MM02 emerged as the most promising candidates, remaining stable and active in urine under physiological pH fluctuations and exhibiting synergistic effects with gentamicin and fosfomycin, but not with the bacteriostatic nitrofurantoin. Importantly, we demonstrate that treatment sequence is a critical determinant of efficacy, with phage administration prior to antibiotic exposure consistently producing the strongest synergistic effects. These findings highlight the potential of phages as an integral component of a holistic therapeutic strategy for rUTIs.Importance Recurrent urinary tract infections (rUTIs) are a major clinical challenge characterized by repeated episodes, increasing antimicrobial resistance, and a substantial socioeconomic burden. Although bacteriophages represent a promising alternative or adjunct to antibiotics, their clinical translation has been hindered by the lack of standardized criteria for phage selection, dosing, and combination with antibiotics. This study addresses these gaps by defining key determinants of phage efficacy under conditions relevant to the urinary tract. Our findings highlight that phage performance is strongly shaped by the treatment environment and by interactions with antibiotics, and that inappropriate combinations or treatment sequences may compromise efficacy. By providing quantitative and transferable frameworks for evaluating phage effectivity, this work advances the rational development of phage-based therapies and helps bridge the gap between experimental phage research and clinically actionable treatment strategies for rUTI.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13474533/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148757904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-frequency magnetic fields induce oxidative and genotoxic stress and growth stimulation in lactic acid bacteria.","authors":"Ufuk Ülker, Ali Aydın, Tünay Karan, Hatice Kanbur Çavuş, Recep Şahingöz","doi":"10.1186/s12866-026-05508-4","DOIUrl":"10.1186/s12866-026-05508-4","url":null,"abstract":"<p><strong>Background: </strong>Low-frequency magnetic fields are increasingly encountered in environmental and industrial settings, yet their biological effects on probiotic lactic acid bacteria (LAB) remain incompletely characterized. This study evaluated the impact of direct current (DC) and alternating current (AC) magnetic fields on growth, redox homeostasis, and genomic integrity in representative LAB strains.</p><p><strong>Methods: </strong>Lactobacillus acidophilus, Lactobacillus bulgaricus, Lactobacillus rhamnosus, Lactobacillus pentosus, Lactobacillus casei, and Lacticaseibacillus paracasei were exposed to DC and AC magnetic fields. Bacterial growth was assessed by optical density. Oxidative stress parameters-including total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), intracellular glutathione (GSH), and malondialdehyde (MDA)-were quantified, and genotoxicity was evaluated using DNA fragmentation assays and DNA absorbance at 260 nm.</p><p><strong>Results: </strong>Type III two-way ANOVA identified magnetic field intensity as the dominant determinant of bacterial responses, with significant effects in 41 of 48 models, whereas magnetic field type was significant in 28 models and field type × intensity interactions in 18 models. Increasing field intensity significantly altered culture turbidity (OD600), TOS, OSI, GSH, MDA, DNA fragmentation, and DNA absorbance at 260 nm across most bacterial species (p < 0.05). Oxidative stress biomarkers exhibited the largest effect sizes (partial η² frequently > 0.90), while significant interaction effects were observed predominantly for TOS and OSI, indicating species-dependent differences between AC and DC exposure. Overall, oxidative stress was strongly associated with DNA damage and alterations in bacterial growth.</p><p><strong>Conclusions: </strong>Low-intensity AC and DC magnetic fields induced significant oxidative and genotoxic responses that were governed primarily by magnetic field intensity rather than field type. The predominance of oxidative stress-related effects, together with their strong association with DNA damage, suggests that redox imbalance represents the principal mechanism underlying bacterial responses to magnetic field exposure. These findings indicate that probiotic lactic acid bacteria retain short-term physiological tolerance while exhibiting increased DNA fragmentation and evidence of altered genomic integrity at higher magnetic field intensities.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13673761/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149206472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of monensin residues on microbial community and the attenuation of antibiotic resistance genes during chicken manure composting","authors":"Ting Liang, Liting Cao, Anchun Cheng, Zhentao Cheng, Deyuan Ou, Xichen Gu, Xuqin Song, Jian Yang","doi":"10.1186/s12866-026-05509-3","DOIUrl":"https://doi.org/10.1186/s12866-026-05509-3","url":null,"abstract":"Monensin is a polyether ionophore antibiotic widely used to prevent coccidiosis and inhibit Gram-positive bacteria. Composting is widely regarded as an effective strategy for reducing the abundance of antibiotic resistance genes (ARGs) in manure. However, the long half-life of monensin may impose selective pressure on ARG attenuation, while its potential ecological risk remains unclear. In this study, metagenomics was used to analyze the effect of monensin residues on microbial communities during chicken manure composting (1, 15, and 45 days). Results showed that monensin significantly changed the structure of microbial communities during composting. It suppressed functional groups within Firmicutes and Actinobacteria, particularly the genera Bacillus and Streptomyces . Simultaneously, it promoted tolerant taxa, including Proteobacteria and the genus Halomonas . The results of qPCR for six representative ARGs ( aadD , ant2-I , sul1 , sul2 , tetZ , and tetL ) revealed that monensin could reduce the attenuation of some ARGs. Furthermore, monensin increased the abundance of several mobile genetic elements (MGEs) during the middle composting phase, especially the integron intI1 and transposase tnpA . Co-occurrence network analysis suggested stronger associations among specific ARGs, MGEs, and tolerant bacteria under monensin exposure, indicating a potential increase risk of ARG dissemination. Monensin may suppress ARGs attenuation during manure composting by changing microbial communities and increasing the potential risk of ARG dissemination via MGEs. This study will provide a theoretical basis for the treatment of livestock waste and ecological risk assessment of monensin.","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148861229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing biodegradation of polycyclic aromatic hydrocarbons using bacterial consortia and biofilm.","authors":"Mohamed Ashraf, Aly E Abo-Amer, Mohamed Ghazy, Ahmed Labena, Ahmed Abdel-Mawgood","doi":"10.1186/s12866-026-05144-y","DOIUrl":"10.1186/s12866-026-05144-y","url":null,"abstract":"<p><p>The release of petroleum and its constituents, such as polycyclic aromatic hydrocarbons (PAHs), into the environment poses a significant global threat due to their toxic, genotoxic, mutagenic, and/or carcinogenic properties. Using indigenous PAH-degrading bacteria to decontaminate the PAHs is an eco-friendly, convenient, and non-expensive way in comparison to other traditional physical and chemical methods. In the present study, several bacteria were isolated from petroleum-contaminated soils using a culture-enrichment technique. Phenanthrene and naphthalene were used as representative examples of the PAHs and as sole carbon and energy sources for the isolated bacteria. Three isolates (A1, A3, and B8-1) were selected as the most potent phenanthrene and naphthalene degraders. These three most potent isolates were used to build up four different consortiums, and both the individual isolates and developed consortiums were induced to set up biofilms. The results showed that the highest growth and degradation rate of phenanthrene and naphthalene were achieved at 37 °C and pH 7. Individual strains had higher phenanthrene degrading capacities compared to microbial consortiums in both planktonic and biofilm forms. Additionally, the developed-biofilm displays an increase in the degradation rate of individual isolates A1, A3, and consortiums. Finally, the selected biofilm degraders were used to investigate the PAHs degradation ability in an artificially contaminated soil. The finding of this experiment demonstrate that the biofilm mode of growth could be more effective in PAHs degradation compared to planktonic cultures, thus it can be applied effectively to remediate PAHs-contaminated soils. The most potent PAHs degraders were identified using 16 S rRNA, and the phylogenetic sequence analysis of the three isolates was affiliated as B8-1(Bacillus paramycoides), A1(Bacillus paranthracis), and A3(Bacillus licheniformis).</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13471667/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148721162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative genomics of fatal ST308/O11 Pseudomonas aeruginosa from Egypt characterizes conserved resistance architecture, integron-associated multidrug resistance modules, and blaNDM-1 resistance islands.","authors":"Ahmed A Sanad, Ghada A El-Sherbeny, Adel A El-Morsi, Ahmed F Gad, Hossam I Gebeer, Mohamed G Seadawy","doi":"10.1186/s12866-026-05465-y","DOIUrl":"10.1186/s12866-026-05465-y","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Pseudomonas aeruginosa is a major cause of ventilator-associated pneumonia (VAP) and is increasingly associated with extensive antimicrobial resistance, limiting therapeutic options and contributing to poor clinical outcomes. The emergence of high-risk clones that combine multidrug resistance and virulence-associated traits represents a growing public health concern.In this study, 100 clinical P. aeruginosa isolates recovered from VAP patients were screened using culture-based identification and antimicrobial susceptibility testing. Two isolates exhibiting the most extensive resistance profiles, consistent with pandrug-resistant (PDR) phenotypes, and associated with fatal clinical outcomes were selected for whole-genome sequencing using Oxford Nanopore technology.Comprehensive genomic analyses were performed to characterize antimicrobial resistance determinants, chromosomal resistance mutations, virulence-associated genes, mobile genetic elements, genomic islands, and phylogenomic relationships. Both isolates were assigned to sequence type ST308 and serogroup O11, a globally disseminated high-risk lineage. Core-genome phylogenomic analysis of 52 genomes identified 144,617 informative SNPs across 5,085 shared core genes and showed that the two Egyptian isolates differed by only 74 core-genome SNPs while clustering within the international ST308 lineage.The isolates harbored an extensive resistome including blaNDM-1, blaOXA-10, blaOXA-488, qnrVC1, rmtF, sul1, sul2, floR, and msrE. High-confidence chromosomal resistance mutations were detected in gyrA (T83I), parC (S87L), oprD (Q402HfsTer99), nalC, nalD, and pmrB, supporting resistance to fluoroquinolones, carbapenems, and polymyxins. Two complete class 1 integrons and one In0 structure, all carrying the class 1 integrase IntI1, were identified, comprising integron-associated multidrug resistance modules containing qnrVC1, aadA11, aac(6')-II, dfrB5, sul1, qacEΔ1, rmtF, blaOXA-10, and blaPAC-1. In contrast, blaNDM-1 was located within a distinct ISVsa3-associated resistance island together with ble and msrE. Genomic island analysis further demonstrated the co-localization of key resistance determinants and the exoU virulence factor within predicted genomic islands.Both isolates carried a highly conserved virulome, including exoU, exoT, type VI secretion system components, iron-acquisition systems, and biofilm-associated genes. Collectively, these findings indicate the convergence of resistance islands, integron-associated multidrug resistance modules, chromosomal resistance mechanisms, and virulence-associated determinants within a globally disseminated ST308/O11 high-risk clone associated with fatal VAP cases in Egypt.To our knowledge, this study provides the first comprehensive genomic characterization of ST308/O11 P. aeruginosa exhibiting a pandrug-resistant phenotype based on the antimicrobial panel tested and associated with fatal ventilator-associated pneumonia in Egypt. Furthermore, by i","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13452102/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148688607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing the degradation of cellulose and hemicellulose in chili pepper straw waste using Cellulomonas iranensis 7-12, which was isolated from naturally decayed chili pepper straw.","authors":"Mengting Chen, Zhiye Tian, Jiaya Chen, Xiaoping Li, Yongjun Wu, Xilong Shen, Shuoqiu Tong, Jin Jin, Cen Li, Meng Zhao, Liangcai Xiong, Sana Gul, Lintao Ren, Lincheng Zhang","doi":"10.1186/s12866-026-05520-8","DOIUrl":"https://doi.org/10.1186/s12866-026-05520-8","url":null,"abstract":"<p><p>The sustainable valorization of agricultural waste, such as chili pepper straw, is often challenged by the absence of effective microbes that can degrade cell wall components. In this study, metagenomic analysis found that Pseudomonadota was the dominant phylum in the carboxymethyl cellulose (CMC)-enriched microbial communities. In addition, a cellulolytic bacterial strain, designated as Cellulomonas iranensis 7-12, was isolated from naturally decayed chili pepper straw and identified by colony morphology, Gram staining, 16 S rRNA gene sequencing, and genome-based average nucleotide identity (ANI) analysis. Within 30 h, C. iranensis 7-12 displayed robust cellulolytic activity, causing nearly complete disintegration of filter paper, a cellulose model substrate. In contrast, chili pepper straw, a structurally more complex lignocellulosic substrate, was only partially degraded, with dry-weight loss increasing from 11.98% in the uninoculated control to 32.63% after 4 d of fermentation with C. iranensis 7-12. C. iranensis 7-12 exhibited a predominantly extracellular cellulase-xylanase activity profile, with extracellular xylanase activity reaching 3.41 U/mL and exceeding the measured cellulase activities. Whole-genome sequencing of C. iranensis 7-12 identified a complete 3.79-Mb circular chromosome and a diverse CAZyme repertoire, including glycoside hydrolase families related to cellulose and hemicellulose degradation, carbohydrate-binding modules, carbohydrate esterases, and secretion-associated proteins. Moreover, scanning electron microscopy (SEM) examination revealed that the surface and internal microstructure of chili pepper straw were disrupted. Similarly, Fourier-transform infrared (FTIR) spectroscopy analysis showed marked changes in the characteristic absorption bands associated with cellulose, hemicellulose, and lignin-containing structures, indicating partial degradation of polysaccharide components and lignin-associated structural alteration. Collectively, C. iranensis 7-12 shows great potential for the bioconversion of chili pepper straw and the high-performance microbes will be further developed for the effective use of biomass resources.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491628/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148788272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urban green roofs host intrinsic resistomes shaped by management but not dominated by pathogenic resistance.","authors":"Rubén Martínez-Cuesta, Alexandra Craighero, Susanne Walch, Brigitte Helmreich, Michael Schloter, Stefanie Schulz","doi":"10.1186/s12866-026-05495-6","DOIUrl":"10.1186/s12866-026-05495-6","url":null,"abstract":"<p><strong>Background: </strong>Urban green roofs are increasingly introduced to enhance urban biodiversity and ecosystem services, yet their role in shaping antimicrobial resistance in cities remains unclear. Using long-read metagenomic sequencing, we characterized antimicrobial resistance genes (ARGs) across an experimental extensive green roof system with plots under four different management regimes specifically designed to test the influence of vegetation and organic amendments, as green waste, which although widely used to improve substrate quality, has been flagged as a potential ARG source.</p><p><strong>Results: </strong>We detected 62 ARGs across the four management regimes, which were dominated by target-modification and mixed mechanisms conferring resistance to naturally occurring antibiotics such as bacitracin (bacA) and rifamycin (arr, rox, rph), rather than efflux-based multidrug resistance, which is typically co-selected by anthropogenic pollutants. The ARGs were mainly chromosomally encoded, with only two ARGs located on plasmids, and associated with non-pathogenic environmental taxa. The management regime had a significant effect on ARG richness, ARG composition and plasmid abundance, but not on average genome size-normalized ARG abundance. We also detected aph3-II and tlmA as enriched in the unamended samples, which were carried by oligotrophic bacteria, pointing towards microbial competition in a nutrient-limited environment.</p><p><strong>Conclusions: </strong>Overall, our findings indicate that green roof management supports a substrate resistome driven by ecological constraints rather than clinical threats. However, further research is required to evaluate potential risks and support the safe integration of green roofs within a One Health framework.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13445745/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148677232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil flooding suppresses Fusarium wilt in watermelon by modulating soil chemical properties and microbial community richness.","authors":"HuiFang Lv, Ying Zhang, LingLing Wang, Zulan Ou, CongSheng Yan, HuanXin Zhang","doi":"10.1186/s12866-026-05469-8","DOIUrl":"https://doi.org/10.1186/s12866-026-05469-8","url":null,"abstract":"<p><p>Soil flooding is a well-documented agricultural practice for disease control, but the underlying mechanisms are still poorly understood. The objective of this study was to investigate the effect of soil flooding on watermelon growth, soil chemical properties, enzyme activities, and the diversity and richness of microbial community structure, and to examine the relationships between these factors and wilt incidence. The results showed that soil flooding reduced the population of FON and Fusarium wilt incidence, promoted plant growth, increased soil AP and AK contents, increased UA and ALPA activities, but decreased soil SOM and AN contents (P < 0.05). Bacterial diversity and richness were significantly higher, whereas fungal diversity and richness were significantly lower under soil flooding (P < 0.05). The microbial community structure was significantly altered by soil flooding. The relative abundance of bacterial phyla such as Actinobacteriota, Chloroflexi, and Bacteroidota increased, whereas that of the dominant fungal phylum Ascomycota decreased. Compared with continuous cropping, soil flooding increased the relative abundance of potentially beneficial microbes like Geobacillus, Bacillus, Nocardioides, and Penicillium (P < 0.05). In addition, the relative abundance of potentially pathogenic fungi such as Fusarium was reduced on day 30 after soil flooding (P < 0.05). Soil AK and AN influenced both bacterial and fungal microbial communities. The SEM analysis revealed that the indirect pathways from bacterial and fungal community richness, AK, and AN to watermelon Fusarium wilt were the primary drivers of disease incidence. In conclusion, soil flooding improves soil chemical properties and rebuilds a healthy soil microbiota, thus effectively suppressing watermelon Fusarium wilt.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13491702/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148788246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metagenomic and cultivation-based description of a syntrophic butyrate-oxidizing bacterium from a thermophilic and high-ammonia biogas process.","authors":"Malin Tiefensee, Nils Weng, Jonas A Ohlsson, Maria Westerholm","doi":"10.1186/s12866-026-05457-y","DOIUrl":"10.1186/s12866-026-05457-y","url":null,"abstract":"<p><strong>Background: </strong>Ammonia inhibition in anaerobic digestion can lead to butyrate accumulation and reduced methane yield. Despite the importance of syntrophic butyrate oxidation in mitigating this effect, the microorganisms and interactions involved under high-ammonia conditions remain poorly understood. Here, we combine metagenomics and cultivation studies to describe a novel ammonia-tolerant syntrophic butyrate-oxidizing bacterium and its interactions with acetate-oxidizing bacteria and hydrogenotrophic methanogens enriched from a high-ammonia, thermophilic biogas process.</p><p><strong>Results: </strong>The enrichment culture degraded butyrate at rates of 0.12-0.47 mmol/day. Amplicon sequencing and phylogenetic analyses of a retrieved metagenome-assembled genome (MAG) assigned the putative syntrophic butyrate-oxidizing bacterium (SBOB) to the genus Syntrophothermus, for which we propose the provisional species name 'Candidatus Syntrophothermus ammoniitolerans'. Metagenomic analyses revealed the genomic potential for β-oxidation and essential electron transfer pathways associated with syntrophic energy conservation. Furthermore, one additional MAG (MAG9) possessed a complete β-oxidation pathway but lacked key genes associated with reverse electron transfer, making its role as a SBOB uncertain. Acetate produced during butyrate oxidation was further oxidized by syntrophic acetate-oxidizing bacteria and ultimately converted to methane by hydrogenotrophic methanogens, illustrating a tightly coupled metabolic network that supports butyrate degradation under high-ammonia conditions. Three methanogenic MAGs, affiliated with the genera Methanoculleus and Methanothermobacter, were identified as potential hydrogen- or formate-consuming partners.</p><p><strong>Conclusions: </strong>Together, these results identify a novel syntrophic butyrate-oxidizing candidate that enables butyrate degradation under high-ammonia conditions via tightly coupled interactions with acetate-oxidizing bacteria and hydrogenotrophic methanogens, sustaining methane production under ammonia stress.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"26 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2026-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13422317/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148618655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}