BMC Microbiology最新文献

{"title":"Whole-genome analysis of Bacillus paranthracis YC06 isolated from healthy individual feces for biodegrading inosine and guanosine.","authors":"Xiaoyu Cao, Yu Zhang, Qianqian Xu, Hai Yan","doi":"10.1186/s12866-025-04063-8","DOIUrl":"10.1186/s12866-025-04063-8","url":null,"abstract":"<p><p>The overproduction of uric acid, driven by its key precursors (inosine and guanosine), leads to hyperuricemia, a metabolic disorder associated with severe complications such as gout and renal dysfunction. Here, a promising bacterial strain YC06 with excellent biodegradation capability for inosine and guanosine was successfully isolated from healthy individual feces and identified as Bacillus paranthracis through average nucleotide identity (ANI) analysis. B. paranthracis YC06 resting cells (live but suspended in PBS buffer) and its cell-free extracts could effectively biodegrade inosine and guanosine in vitro. Whole-genome sequencing revealed a 5,535,183 bp draft genome (52 contigs, 35.22% GC content) containing 5,672 protein-coding genes. B. paranthracis YC06 demonstrated high survival rates in simulated gastrointestinal fluids, supported by the presence of stress-response genes and bile salt hydrolase genes associated with gastrointestinal tolerance. However, this strain exhibited hemolytic activity and no amino acid decarboxylase activity, while hemolysin genes, antibiotic genes and toxin-producing genes were identified, raising potential biosafety concerns for its further application. The gene functional annotation and polymerase chain reaction (PCR) amplification electrophoresis identified key genes (rihA, rihB, deoD and pnp) encoding purine nucleosidase and purine-nucleoside phosphorylase, and combined with biodegradation product analysis, elucidated the pathways of inosine and guanosine biodegradation into hypoxanthine and guanine. Comprehensive safety evaluations, including cytotoxicity assay and in vivo pathogenicity studies, must be conducted to rigorously assess its risks prior to practical utilization.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"335"},"PeriodicalIF":4.0,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12117696/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144156548","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":"Pulmonary metabolic changes in a rabbit model of Pseudomonas aeruginosa pneumonia: insights from metabolomic analysis.","authors":"Fuzhi Lai, Zhibin Zhou, Xiaojiao Xia, Yuxia Du, Jiaming Huang","doi":"10.1186/s12866-025-04060-x","DOIUrl":"10.1186/s12866-025-04060-x","url":null,"abstract":"<p><strong>Background: </strong>The current problem associated with Pseudomonas aeruginosa (PA) pneumonia, which is frequently encountered in clinical settings, is drug resistance. If Pseudomonas aeruginosa pneumonia can be rapidly diagnosed in early stage, the occurrence of drug resistance can be reduced. Therefore, our study aimed to investigate pulmonary metabolic changes associated with PA pneumonia and to identify relevant metabolic biomarkers and key metabolic pathways, providing a reference for rapid diagnosis.</p><p><strong>Methods: </strong>Eighteen rabbits were randomly assigned to either the PA or normal saline (NS) group. Bronchoalveolar lavage fluid (BALF) was analyzed via untargeted liquid chromatography-mass spectrometry (ULCMS) to identify and analyze differentially abundant metabolites between the groups. Univariate comparisons were performed using Student's t-test, while multivariate patterns were analyzed via principal component analysis (PCA) and orthogonal projections to latent structure-discriminant analysis(OPLS-DA).</p><p><strong>Results: </strong>Successful modeling was achieved in 17 rabbits (8 PAs, 9 NSs). The most abundant metabolite classes detected in BALF were lipids and lipid-like molecules, organoheterocyclic compounds, and benzenoids. A total of 2,451 differentially abundant metabolites were identified, including 1,205 upregulated and 1,210 downregulated metabolites. Key metabolic pathways such as histidine metabolism, arginine and proline metabolism, nucleotide metabolism, and ABC transporters were upregulated in the PA group, whereas choline metabolism in the cancer pathway was downregulated.</p><p><strong>Conclusion: </strong>PA pneumonia induces distinctive metabolic alterations in the lungs, highlighting potential biomarkers and pathways that could provide valuable insights for clinical diagnosis and treatment.</p><p><strong>Clinical trial number: </strong>Not applicable.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"338"},"PeriodicalIF":4.0,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12117701/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144172482","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":"Investigating dose-dependent effects of chemical compounds targeting rumen fermentation pathways using an in-vitro rumen fermentation system.","authors":"Rajan Dhakal, André Luis Alves Neves, Rumakanta Sapkota, Prabhat Khanal, Lea Ellegaard-Jensen, Anne Winding, Hanne Helene Hansen","doi":"10.1186/s12866-025-03969-7","DOIUrl":"10.1186/s12866-025-03969-7","url":null,"abstract":"<p><strong>Background: </strong>Ruminal fermentation leads to the formation of methane (CH₄) as a byproduct, which is one of the major greenhouse gases. Despite extensive research efforts involving the use of various anti-methanogenic and hydrogen sink compounds, the current understanding of the dose-response effects of these compounds on the rumen microbiome and fermentation profile is limited. In this study, potential methanogenesis inhibitors or electron acceptors were evaluated for their effects on methane production, fermentation, and prokaryotic community composition. Dose-response effects of sodium 2-bromoethanesulfonate (BES: 0, 2.5, 5, 10 mmol/L), p-hydrocinnamic acid (HoC: 0, 5, 10 mmol/L), and sodium fumarate dibasic (DFS: 0, 5, 10, 20 mmol/L) on dry matter degradation, total gas production, methane concentration and yield, composition and yield of volatile fatty acids, and prokaryote composition were studied during 48 h rumen fermentations.</p><p><strong>Results: </strong>The BES decreased the yield (ml/ g DM) and concentration (%) of CH₄, acetic, isobutyric, and total VFA (t-VFA) concentrations (mmol/g DM), and increased propionic and butyric acid concentrations (mmol/g DM) without affecting dry matter degradability (dDM) as the dose increased. The HoC decreased dDM, total gas production (TGP), CH₄ yield (ml/ g DM) and increased tVFA concentration (mmol/g DM) as the dose increased. The increasing dose of DFS increased the pH, propionic acid and tVFA concentrations (mmol/g DM) and decreased the yield (ml/ g DM) and concentration (%) of CH₄ without affecting dDM. Sodium 2-bromoethanesulfonate, HoC, and DFS doses did not significantly change the alpha-diversity and beta-diversity indices of the prokaryotic communities at the amplicon sequence variant level, although the relative abundances of specific phyla were affected by the treatments. The major bacterial phyla across all samples were Bacteroidetes, Proteobacteria, Firmicutes, Spirochaetota, Verrucomicrobiota, and Patescibacteria.</p><p><strong>Conclusions: </strong>This study demonstrated that (i) all the evaluated compounds affected the targeted metabolic pathways without influencing the structure of the rumen microbial community, (ii) BES inhibited methanogenesis without affecting dry matter degradability, and (iii) HoC and DFS shifted hydrogen utilization towards acetate and propionate production. The recommended doses, to reduce methane during in-vitro rumen fermentation for BES, HoC, and DFS were determined to be 2.5 mmol/L, 5 mmol/L, and 10 mmol/L, respectively. Further research is suggested to understand the interactive effects of methane inhibition compounds, such as BES, in conjunction with H₂ sink compounds such as HoC and DFS. However, caution is advised when using halogenated compounds like BES, as some methanogens have developed resistance and BES is not approved for use as a feed additive for live animals.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"330"},"PeriodicalIF":4.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12107880/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144155827","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":"Valorisation of insect infested sweet sorghum reeds towards production of a fermented beverage.","authors":"Tawanda Proceed Makopa, Thandiwe Semumu, Mpho T Gaaipone, Thato Masemola, Santosh Ramchuran, Urska Vrhovsek, Nerve Zhou","doi":"10.1186/s12866-025-03857-0","DOIUrl":"10.1186/s12866-025-03857-0","url":null,"abstract":"<p><p>Sweet sorghum variety (Sorghum bicolour (L)) commonly known as sweet reeds, Ntšhe, in Setswana, is a valuable cash crop mostly for small scale farmers in Botswana and other southern African countries. These reeds are widely consumed as a delicacy and contribute significantly to food security, employment, and rural incomes. However, infestations by the larval stages of Chilo partellus (stem borer moths) lead to substantial economic losses, as consumers reject worm-infested reeds. To mitigate these losses, valorisation of condemned sweet reeds is attractive. Here, we took advantage of our understanding of yeast-insect interactions to isolate yeasts associated with larval stages of the stem borer moths and investigated their potential for use in the production of an alcoholic sweet sorghum beverage. We report the isolation of thirty-two yeast strains from the larvae and assessed their ability to ferment the simplest sugar, glucose, a constituent of the sweet sorghum juice. Out of the selected yeasts, a subset of fourteen strains belonging to Hanseniaspora and Candida genera were further characterised based on their capacity to ferment more sugars found in sweet sorghum juice. We further assessed the isolates for the ability to tolerate brewing/fermentation-associated stresses and production of complex aroma profiles towards the use of sweet sorghum juice as a sole feedstock to produce a commercial beverage. Our findings suggest that yeast-insect interactions offer a promising approach for converting rejected sweet sorghum stalks into a novel alcoholic beverage, adding economic value to an otherwise discarded resource. Clinical trial number Not applicable.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"331"},"PeriodicalIF":4.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12107736/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144156546","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":"Characterization of Setophoma henanensis sp. Nov., causing root rot on peanut.","authors":"Min Li, Di Liu, Mengke Wang, Kaidi Cui, Liting Chen, Leiming He, Lin Zhou","doi":"10.1186/s12866-025-04057-6","DOIUrl":"10.1186/s12866-025-04057-6","url":null,"abstract":"<p><strong>Background: </strong>Peanut root rot is a common disease worldwide, which can cause serious economic losses to the peanut industry. In 2021, symptoms of peanut root rot were observed in five cities of Henan province, China, i.e., Xinxiang, Puyang, Pingdingshan, Zhumadian, and Nanyang.</p><p><strong>Results: </strong>A total of 22 isolates of Setophoma sp. were obtained from 120 diseased peanut root samples. Based on the morphological characteristics and multilocus phylogenetic analyses with the sequences of ITS, LSU, TUB2, TEF-1a, and RPB2, these fungal isolates were identified as a new species of Setophoma spp., and named as Setophoma henanensis. Through Koch's postulates, we demonstrated that S. henanensis could cause root rot disease in peanuts. Pathogenicity test revealed that S. henanensis could cause root rot symptoms in four different hosts, including corn, wheat, pepper, and Welsh onion, indicating that this species may have a wide host range. Furthermore, S. henanensis was sensitive to all tested fungicides, including difenoconazole, tetramycin, pyraclostrobin, and carboxin.</p><p><strong>Conclusions: </strong>This is the first report of S. henanensis as a new pathogen of peanut root rot in the world. Furthermore, our findings will also provide a basis for further epidemiological research and the development of control strategies.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"329"},"PeriodicalIF":4.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12107722/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144157022","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":"Sex-induced alterations in rumen microbial communities and metabolite profiles: implications for lamb body weight.","authors":"Haibo Wang, Jinshun Zhan, Shengguo Zhao, Haoyun Jiang, Haobin Jia, Yue Pan, Xiaojun Zhong, Junhong Huo","doi":"10.1186/s12866-025-04049-6","DOIUrl":"10.1186/s12866-025-04049-6","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Microbiota-metabolome interactions play a crucial role in host physiological regulation and metabolic homeostasis. The aim of this study was to investigate that sex induces alterations in rumen microbial community composition and metabolite profiles in lambs and the influence on body weight. This study aimed to demonstrate that sex- induced alterations in rumen microbial community and metabolite profiles and blood indices and their linkage to growth performance in lambs.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;This study examined (growth indices, serum indices, rumen fermentation parameters, rumen fluid microbiota community and metabolome profiles) in 180 Hu lambs (90 males, and 90 females) with the same age and diet. At six months, male lambs showed significantly greater body weight, serum indices (glutamic pyruvic transaminase, glutamic oxalacetic transaminase, growth hormone, glucagon-like peptide 1, and ghrelin), and molar percentage of propionic acid, isobutyric acid, butyric acid, isovaleric acid and valeric acid compared to female. However, male had lower VFA molar concentrations (acetic acid, propionic acid, butyric acid, and TVFAs), acetic acid/propionic acid, and VFA molar percentage (acetic acid) than female. Significant sex-related differences were observed in rumen microbiota and metabolic enrichment between genders. Moreover, compared with the females lambs, the relative abundance of Succiniclasticum, uncultured_rumen_bacterium, NK4 A214_group, Veillonellaceae_UCG_001 and Butyrivibrio in the male lambs has been significantly increased, while the relative abundance of Prevotella has been significantly decreased (P &lt; 0.05). Notably, there were significant rumen microbiota-metabolite interactions, especially Firmicutes and Bacteroidota as dominant phyla in the sheep rumen with significant differences in correlation with rumen metabolic modules. Additionally, there are pronounced correlations among the microbiota, particularly within the Firmicutes phylum. Furthermore, the up-regulated metabolites in the rumen fluid of male lambs were predominantly enriched in the amino acid metabolite pathway, and these metabolites exhibited a significant positive correlation with body weight. However, the metabolites that were up-regulated in ewe lambs were predominantly enriched in the lipid metabolic pathway, and these metabolites exhibited a significant negative correlation with body weight. Moreover, lamb rumen microbial markers (Lachnospiraceae_UCG_008, Saccharofermentans, unclassified_Clostridia, Christensenellaceae_R_7_group, Anaerovorax, Mogibacterium, and unclassified_Erysipelotrichaceae) and metabolic markers (C75, 4-Coumarate, Flibanserin,3-Amino-5-mercapto-1,2,4-triazole, 1,3-Propane sultone, Fingolimod phosphate ester, S-,) were significantly positively correlated with body weight, but lamb rumen microbial markers (Anaeroplasma, unclassified_Acholeplasmataceae, uncultured_rumen_bacterum_4c28 d_15) and metabolic mar","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"328"},"PeriodicalIF":4.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12107992/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144155931","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":"Strain-specific interspecies interactions between co-isolated pairs of Staphylococcus aureus and Helcococcus kunzii from chronic wounds.","authors":"Riham Daher, Benjamin A R N Durand, Madjid Morsli, Cassandra Pouget, Jean-Philippe Lavigne, Catherine Dunyach-Remy","doi":"10.1186/s12866-025-04004-5","DOIUrl":"10.1186/s12866-025-04004-5","url":null,"abstract":"<p><strong>Background: </strong>Bacterial infection is major contributor in the delay of wound healing and persistence of non-healing wounds. Bacteria, functioning within complex multicellular communities, facilitate the survival of certain microorganisms in diverse environments. Helcococcus kunzii, a Gram-positive anaerobic commensal coccus, and Staphylococcus aureus, the primary pathogen in chronic wounds, have strong interaction potential, in which H. kunzii decreases the virulence of S. aureus in co-culture in vivo and in vitro.</p><p><strong>Results: </strong>This paper describes the interaction between H. kunzii and S. aureus clinical strains from chronic wounds by examining their transcriptomic behavior (S. aureus virulence genes) and phenotypic features (hemolysin production, growth and biofilm formation). We used five new clinical pairs of H. kunzii and S. aureus strains co-isolated from diabetic foot ulcers (DFU) and one previously studied clinical pair, not co-isolated from the same DFU. H. kunzii strains were sequenced and compared with two H. kunzii strains previously sequenced with high (H13) or low (H10) impact on S. aureus regulatory virulence effectors. Sequencing showed that all strains were phylogenetically similar to H13, with the exception of NHKT2, allowing to predict a potential \"high impact\" on S. aureus virulence. After coculture of clinical strain pairs in medium reflective of a chronic wound environment, we observed a downregulation of agrA and hla, two regulatory and virulence genes of S. aureus, supporting previously results obtained with not co-isolated strains. We confirmed a decrease in S. aureus hemolysin production in cocultures. While coculture did not affect the growth of S. aureus, the presence of H. kunzii appeared to influence the dynamics of S. aureus biofilm formation. Specifically, we noted a significant increase in S. aureus biofilm formation in coculture compared to monoculture during the biofilm maturation stage (after 72 h) for 4/5 of the co-isolated pairs.</p><p><strong>Conclusions: </strong>The effect of reducing the virulence of S. aureus by H. kunzii described previously is not reproducible with co-isolated strains from same DFU. The therapeutic strategy of using H. kunzii as a probiotic should be reconsidered in favor of an approach that targets the underlying mechanisms responsible for this virulence reduction.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"327"},"PeriodicalIF":4.0,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12107998/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144149340","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":"The mechanism of ECT1/E6E7 cervical intraepithelial neoplasia cells regulated by Acinetobacter lwoffii through circ-LDHA/HMGB1.","authors":"Jiayuan Du, Tianmeng Tan, Yaojie Yu, He Wang","doi":"10.1186/s12866-025-04043-y","DOIUrl":"10.1186/s12866-025-04043-y","url":null,"abstract":"<p><strong>Background: </strong>To investigate the mechanism by which Acinetobacter lwoffii-induced circ-LDHA/HMGB1 activation regulates the ability of ECT1/E6E7 cells to promote cervical intraepithelial neoplasia (CIN).</p><p><strong>Methods: </strong>After establishing a co-culture model of Acinetobacter lwoffii and ECT1/E6E7 cells, the proliferation, migration and apoptosis of ECT1/E6E7 cells were detected by CCK8, transwell and flow cytometry assays. The relative expression levels of circ-LDHA and HMGB1 were detected by real-time quantitative PCR (qRT-PCR).</p><p><strong>Results: </strong>Circ-LDHA expression was lower in normal cervical tissues and greater in the cervical cancer group and CIN group than in the normal group (P < 0.05). The optimal coculture model with Acinetobacter lwoffii was an MOI of 100 following 18 h-24 h of coculture. The proliferative activity of the ECT1/E6E7 cells and the relative mRNA expression levels of circ-LDHA and HMGB1 were significantly increased within 36h of coculture, and the apoptosis rate of the ECT1/E6E7 cells was significantly increased after 12 h of coculture. The migration rate of the ECT1/E6E7 cells increased from 12 h to 24 h (all P < 0.05).</p><p><strong>Conclusion: </strong>Acinetobacter lwoffii can regulate the development and progression of CIN by regulating the expression of circ-LDHA and HMGB1 in a time-dependent manner.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"326"},"PeriodicalIF":4.0,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12105123/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144141110","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":"Spatiotemporal distribution and potential functions of N₂O-reducing bacteria in the waters of the Pearl River Estuary.","authors":"Hua Xiang, Yiguo Hong, Jiapeng Wu, Aiming Long","doi":"10.1186/s12866-025-04037-w","DOIUrl":"10.1186/s12866-025-04037-w","url":null,"abstract":"<p><strong>Background: </strong>The reduction of N₂O to N₂, catalyzed by two kinds of N₂O-reducing bacteria, is the only known biological pathway of N₂O sink. However, the distribution and function of N₂O-reducing bacteria in estuarine waters remains unknown. This study investigated the distribution and community characteristics of two clades of N₂O-reducing bacteria (clades I and II) and their potential function in the waters of the Pearl River Estuary (PRE).</p><p><strong>Results: </strong>Our results reveal that the gene abundance of the NosZ-II type of N₂O-reducing bacteria was remarkably higher than the NosZ-I type, specifically 2.29 to 16.41 times higher in summer and 1.63 to 16.68 times higher in winter, indicating that the NosZ-II type should play a major role in reducing N₂O content of the waters of the PRE. Furthermore, higher nosZ I/nir and nosZ II/nir ratios were strongly associated with lower ΔN₂O concentration. The potential rate of N₂O reduction exhibited a gradual increase from upstream to downstream. High-throughput sequencing analysis revealed significant differences in the spatial distribution in the N₂O-reducing bacterial community from upstream to downstream, with Alphaproteobacteria and Bacteroidetes identified as the dominant types of NosZ-I and NosZ-II N₂O-reducing bacteria, respectively. The community composition of two types of N₂O-reducing bacteria was both influenced by NO₂^- concentration in summer. Additionally, co-occurrence analysis demonstrated that 76.67 and 95.45% of the connections between the two clades in summer and winter were positive, indicating a synergistic effect of two types of N₂O-reducing bacteria for N₂O reduction.</p><p><strong>Conclusion: </strong>This study provides novel insights into the ecological distribution and functional potential of NosZ-I and NosZ-II clades of N₂O-reducing bacteria in the PRE, revealing their distinct yet complementary roles in mediating N₂O reduction processes within estuarine waters.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"323"},"PeriodicalIF":4.0,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12105353/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144141533","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":"Pathogenic characterization and mechanism of sequence type 4 Cronobacter sakazakii derived from milk-based infant and baby foods.","authors":"Yuanyuan Zhang, Bin Zhang, Yunjiao Han, Baohua Zhao, Shijie Wang","doi":"10.1186/s12866-025-04040-1","DOIUrl":"10.1186/s12866-025-04040-1","url":null,"abstract":"<p><strong>Background: </strong>Cronobacter sakazakii can cause severe infections in premature infants and neonates through the consumption of contaminated milk-based foods. However, the pathogenesis of sequence type 4 (ST4) C. sakazakii remains to be fully elucidated.</p><p><strong>Results: </strong>In this study, four ST4 C. sakazakii strains were investigated via comparative toxicity, genomic, and transcriptomic analyses to elucidate their pathogenic characteristics and mechanisms. Multilocus sequence typing (MLST) indicated that ST4 C. sakazakii was frequently identified among 36 Cronobacter spp. isolates recovered from milk-based infant and baby foods, and 13 novel STs were also detected. Compared with other ST isolates, ST4 C. sakazakii displayed a higher gut weight to carcass weight ratio (GW/CW), stronger abilities to invade and translocate, and increased secretion of TNF-α, IL-1, and lactate dehydrogenase (LDH) in human brain microvascular endothelial cells (HBMECs) and human U251 glioma cells (U251). Moreover, ST4 C. sakazakii strains with a higher GW/CW ratio significantly disrupted routine blood indices, promoted the secretion of inflammatory factors, and induced severe histopathological changes in the liver, brain, spleen, kidney, and intestine of suckling mice. Although differences in genome composition and known virulence factors were observed among these ST4 C. sakazakii strains with varying pathogenic phenotypes, comparative transcriptomic analyses revealed that the expression of numerous virulence factors and pathways, including ompA, ompW, luxS, rpoS, the Sec secretion system, lipopolysaccharide biosynthesis and assembly, and flagellar assembly, greatly contributed to the high pathogenicity of ST4 C. sakazakii.</p><p><strong>Conclusion: </strong>Our findings suggest that foodborne ST4 C. sakazakii isolates represent a significant potential threat to food safety and public health, particularly for premature and immunocompromised infants.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"25 1","pages":"324"},"PeriodicalIF":4.0,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12105349/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144141520","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}