BMC Microbiology最新文献

{"title":"Comparison of microbial diversity and carbohydrate-active enzymes in the hindgut of two wood-feeding termites, Globitermes sulphureus (Blattaria: Termitidae) and Coptotermes formosanus (Blattaria: Rhinotermitidae).","authors":"Zhidong Zhang, Kai Wang, Chuanshan Zou, Ting Zhao, Wenbin Wu, Cai Wang, Yan Hua","doi":"10.1186/s12866-024-03623-8","DOIUrl":"10.1186/s12866-024-03623-8","url":null,"abstract":"<p><strong>Background: </strong>Wood-feeding termites have been employed as sources of novel and highly efficient lignocellulolytic enzymes due to their ability to degrade lignocellulose efficiently. As a higher wood-feeding termite, Globitermes sulphureus (Blattaria: Termitidae) plays a crucial role as a decomposer in regions such as Vietnam, Singapore, Myanmar, and Yunnan, China. However, the diversity of its gut microbiome and carbohydrate-active enzymes (CAZymes) remains unexplored. Here, we analyzed the diversity of hindgut microbial communities and CAZymes in a higher wood-feeding termite, G. sulphureus, and a lower wood-feeding termite, Coptotermes formosanus (Blattaria: Rhinotermitidae).</p><p><strong>Results: </strong>16S rRNA sequencing revealed that Spirochaetota, Firmicutes, and Fibrobacterota were the dominant microbiota in the hindgut of the two termite species. At the phylum level, the relative abundances of Proteobacteria and Bacteroidota were significantly greater in the hindgut of C. formosanus than in G. sulphureus. At the genus level, the relative abundances of Candidatus_Azobacteroides and Escherichia-Shigella were significantly lower in the hindgut of G. sulphureus than in C. formosanus. Metagenomic analysis revealed that glycoside hydrolases (GHs) with cellulases and hemicellulases functions were not significantly different between G. sulphureus and C. formosanus. Interestingly, the cellulases in G. sulphureus were mainly GH5_2, GH5_4, GH6, GH9, and GH45, while the hemicellulases were mainly GH11, GH8, GH10, GH11, GH26, and GH53. In C. formosanus, the cellulases were mainly GH6 and GH9, and the hemicellulases were mainly GH5_7, GH5_21, GH10, GH12, and GH53. In addition, β-glucosidase, exo-β-1,4-glucanase, and endo-β-1,4-glucanase activities did not differ significantly between the two termite species, while xylanase activity was higher in G. sulphureus than in C. formosanus. The bacteria encoding GHs in G. sulphureus were mainly Firmicutes, Fibrobacterota, and Proteobacteria, whereas Bacteroidota and Spirochaetota were the main bacteria encoding GHs in C. formosanus.</p><p><strong>Conclusions: </strong>Our findings characterized the microbial composition and differences in the hindgut microbiota of G. sulphureus and C. formosanus. Compared to C. formosanus, G. sulphureus is enriched in genes encoding for hemicellulase and debranching enzymes. It also highlights the rich diversity of GHs in the hindgut microbiota of G. sulphureus, including the GH5 subfamily, GH6, and GH48, with the GH6 and GH48 not previously reported in other higher termites. These results strengthen the understanding of the diversity of termite gut microbiota and CAZymes.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"470"},"PeriodicalIF":4.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11556000/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615065","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":"Hydrogen-rich water 400ppb as a potential strategy for improving ruminant nutrition and mitigating methane emissions.","authors":"Kang Mao, Guwei Lu, Yitian Zang, Qinghua Qiu, Xianghui Zhao, Kehui Ouyang, Mingren Qu, Yanjiao Li","doi":"10.1186/s12866-024-03638-1","DOIUrl":"10.1186/s12866-024-03638-1","url":null,"abstract":"<p><p>The objective of this study was to evaluate the effects of different concentrations of hydrogen-rich water (HRW) on in vitro rumen fermentation characteristics and the dynamics of bacterial communities. The experiment included four treatment groups: a control (CON) and hydrogen-rich water (HRW) at 200, 400, and 800 ppb. Each group was analyzed at 12-hour (h) and 48-hour (h) time points with five replicates, totaling 40 samples. The experimental results highlighted the HRW_800ppb group as the top production in terms of gas production and CH₄ content. In contrast, the HRW_200ppb group exhibited significantly lower methane levels at both 12 h and 48 h (P < 0.05). Regarding rumen fermentation, the HRW_400ppb group significantly increased the levels of ammonia nitrogen (NH₃-N) and microbial crude protein (MCP) at 12 h fermentation, but reduced the dry matter degradation rate (P < 0.05). After 48 h, the HRW_400ppb group had highest MCP content (P < 0.05), but no significant differences in NH₃-N and dry matter degradation rate compared with the CON group (P > 0.05). Although HRW did not significantly benefit the synthesis of total volatile fatty acids (TVFA) and individual VFA, the HRW_800ppb group significantly increased the ratio of acetate to propionate (P < 0.05). Based on CH₄ emissions and MCP synthesis, we selected the HRW_400ppb group for subsequent bacterial community analysis. Bacterial community analysis showed that at 12 h, compared with the CON group, the Bacterial community analysis revealed that the HRW_400ppb group had significant increases in the Simpson index, Firmicutes, Streptococcus, Schwartzia, Prevotellaceae_YAB2003_group, and Oribacterium, and decreases in Prevotella, Ruminobacter, Succinivibrio, unclassified_Succinivibrionaceae, and Prevotellaceae_UCG-003 (P < 0.05). At 48 h, the Prevotellaceae_YAB2003_group and Oribacterium abundances continued to rise significantly, while Rikenellaceae_RC9_gut_group and Succiniclasticum abundances fell in the HRW_400ppb group (P < 0.05). Correlation analysis indicated a negative link between CH₄ and Streptococcus, and a positive correlation between the abundance of Rikenellaceae_RC9_gut_group and CH₄. Collectively, these results indicate that HRW can modulate rumen fermentation and microbial community structure to reduce methane emissions without significantly affecting VFA synthesis, highlighting its potential as drinking water for enhancing ruminant nutrition and mitigating the environmental impact of livestock farming.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"469"},"PeriodicalIF":4.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11555914/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615104","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":"Emergence of hypervirulent and carbapenem-resistant Klebsiella pneumoniae from 2014 - 2021 in Central and Eastern China: a molecular, biological, and epidemiological study.","authors":"Chunyang Wu, Yu Huang, Peiyao Zhou, Haojin Gao, Bingjie Wang, Huilin Zhao, Jiao Zhang, Liangxing Wang, Ying Zhou, Fangyou Yu","doi":"10.1186/s12866-024-03614-9","DOIUrl":"10.1186/s12866-024-03614-9","url":null,"abstract":"<p><strong>Background: </strong>In recent years, the hypervirulent and carbapenem-resistant Klebsiella pneumoniae has been increasingly reported worldwide. The objective of this study was to compare the antibiotic resistance and virulence profiles of carbapenem-resistant hypervirulent K.pneumoniae (CR-hvKP) and hypervirulent carbapenem-resistant K.pneumoniae (hv-CRKP) and identify the prevailing strain in clinical settings.</p><p><strong>Methods: </strong>In this study, hv-CRKP or CR-hvKP were identified based on the results of whole-genome analysis (WGS), multilocus sequence typing (MLST) and the antimicrobial susceptibility testing. We then compared antibiotic resistance and virulence profiles between CR-hvKP and hv-CRKP through the antimicrobial susceptibility testing and a series of virulence experiments including biofilm formation ability detection method, the resistance test against human serum, siderophore production test, neutrophil phagocytosis assay and Galleria mellonella infection model. Additionally, pathway enrichment analysis was conducted to assess the effect of SNPs on the phenotype.</p><p><strong>Results: </strong>In this study, we categorized 17.4% of hypervirulent and carbapenem-resistant K. pneumoniae strains as CR-hvKP and 82.6% as hv-CRKP. Among them, 84.2% (16/19) of CR-hvKP strains harboring carbapenemase genes exhibited lower imipenem and meropenem MIC values compared to hv-CRKP strains. The virulence potential of hv-CRKP and CR-hvKP was confirmed by using virulence experiments in vitro and in vivo, showing that virulence of the CR-hvKP strains was comparable to that of hv-CRKP strains. Notably, the 90 hv-CRKP strains were classified into 3 different ST types and 8 capsule types, each showing varying degrees of resistance and virulence. We observed that subclonal replacement was within the predominant hv-CRKP clone, with the ST11-KL64 strain, characterized by high-level resistance and virulence emerging as the currently prevailing subclone, replacing ST11-KL47. KEGG enrichment analysis showed that pathways associated with the citrate cycle (TCA cycle), glycolysis/gluconeogenesis, glutathione metabolism, two-component regulatory system, and folate metabolism were significantly enriched among the group expressing different levels of capsular polysaccharides.</p><p><strong>Conclusions: </strong>The hv-CRKP strains exhibited a greater survival advantage in the hospital environment than CR-hvKP strains. Notably, the ST11-KL64 hv-CRKP strain which displayed a high level of resistance and hypervirulence, warrants the most clinical vigilance.</p><p><strong>Clinical trial number: </strong>Not applicable.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"465"},"PeriodicalIF":4.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11552131/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615100","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":"Impact of TiO₂, ZnO, and Ag nanoparticles on anammox activity in enriched river Nile sediment cultures: unveiling differential effects and environmental implications.","authors":"Mohamed A Abd El-Aziz, Ali M Saeed, Mohamed K Ibrahim, Wael S El-Sayed","doi":"10.1186/s12866-024-03603-y","DOIUrl":"10.1186/s12866-024-03603-y","url":null,"abstract":"<p><strong>Background: </strong>The increasing use of nanoparticles (NPs) necessitates investigation of their impact on wastewater treatment processes, particularly anammox, a critical biological nitrogen removal pathway. This study explored the effects of short-term exposure to TiO₂, ZnO, and Ag-NPs on anammox activity in enriched cultures derived from River Nile sediments.</p><p><strong>Materials and methods: </strong>Anammox bacteria were identified and enriched, with activity confirmed through 16S rRNA and hydrazine oxidoreductase (hzo) gene amplification and sequencing. Activity assays demonstrated efficient ammonium removal by the enriched culture. Subsequently, the impact of different sized and concentrated NPs on anammox activity was assessed.</p><p><strong>Results: </strong>XRD analysis confirmed NP behavior within the microcosms: TiO₂ transformed, ZnO partially dissolved, and Ag remained ionic. hzo gene expression served as a biomarker for anammox bacterial activity. Interestingly, 100 nm TiO₂-NPs up-regulated hzo expression, potentially indicating a non-inhibitory transformed phase. Conversely, ZnO and Ag-NPs across all sizes and concentrations significantly down-regulated hzo expression, suggesting detrimental effects. Ag-NPs amended microcosms showed a significant reduction (79%) in hzo gene expression and a detrimental effect on bacterial populations. Overall, anammox activity mirrored hzo expression patterns, with TiO₂ (21 and 25 nm, respectively) exhibiting the least inhibition, followed by ZnO and Ag-NPs.</p><p><strong>Conclusion: </strong>This study highlights the differential effects of NPs on anammox, with the order of impact being Ag > ZnO > TiO₂. These findings provide valuable insights into the potential environmental risks of NPs on anammox-mediated nitrogen cycling in freshwater ecosystems.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"468"},"PeriodicalIF":4.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11552349/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615117","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":"Co-existence of antibiotic resistance and virulence factors in carbapenem resistant Klebsiella pneumoniae clinical isolates from Alexandria, Egypt.","authors":"Aya T El-Kholy, Mohammed A El-Kholy, Hoda Omar, Elsayed Aboulmagd","doi":"10.1186/s12866-024-03600-1","DOIUrl":"10.1186/s12866-024-03600-1","url":null,"abstract":"<p><strong>Background: </strong>The emergence and spread of carbapenem resistance among Enterobacteriaceae, particularly Klebsiella pneumoniae, constitute a serious threat to public health, since carbapenems are the last line of defense in the treatment of life-threatening infections caused by drug-resistant Enterobacteriaceae. The current study investigated the co-existence of different virulence factors and carbapenemases in carbapenem-resistant Klebsiella pneumoniae clinical isolates from Alexandria, Egypt.</p><p><strong>Results: </strong>Phenotypic characterization of virulence factors indicated that 41.5% of the isolates were strong biofilm producers, while hypermucoviscosity was detected in 14.9% of the isolates. All isolates harbored five or more virulence factor encoding genes. entB, ycfM, mrkD and fimH were detected in all isolates, while only one isolate was negative for ybtS. uge, iutA, rmpA and kpn were detected in 61 (64.8%), 55 (58.5%), 41 (43.6%) and 27 (28.7%) isolates, respectively, while all isolates lacked magA and k2A. Phenotypic detection of carbapenemases was explored by performing CarbaNP and mCIM/eCIM. CarbaNP test showed positive results in 98.9% of the isolates and positive mCIM tests were observed in all isolates, while 68 (72.3%) isolates showed positive eCIM tests. bla_NDM was the most prevalent carbapenemase encoding gene (92.5%) followed by the bla_OXA-48 (51.1%), while bla_KPC was detected in only one (1.06%) isolate. bla_VIM, bla_IMP and bla_GES were not detected in any of the tested isolates.</p><p><strong>Conclusions: </strong>The widespread of carbapenem-resistant Klebsiella pneumoniae represents a major problem in health care settings. A significant association between certain virulence factors and carbapenemase-encoding genes was observed. Antibiotic stewardship programs and infection control policies should be effectively implemented especially in hospitals to limit the spread of such highly virulent pathogens.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"466"},"PeriodicalIF":4.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11552214/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615061","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":"More powerful dysregulation of Helicobacter pylori East Asian-type CagA on intracellular signalings.","authors":"Xiaofei Ji, Zekun Sun, Hao Wu, Jianhui Zhang, Shuzhen Liu, Xinying Cao, Bin Wang, Feifan Wang, Ying Zhang, Boqing Li, Jiankai Feng, Huilin Zhao","doi":"10.1186/s12866-024-03619-4","DOIUrl":"10.1186/s12866-024-03619-4","url":null,"abstract":"<p><strong>Background: </strong>Chronic infection by Helicobacter pylori strains expressing cytotoxin-associated gene A (CagA) are the strongest risk factor for gastric cancer. CagA can be classified into East Asian-type and Western-type (CagA^E and CagA^W), with CagA^E being more closely associated with gastric cancer. This study aimed to investigate the impact of CagA^E on intracellular signaling pathways to explain its high oncogenicity.</p><p><strong>Results: </strong>Mutant H. pylori strains expressing either CagA^E or CagA^W were generated by transforming CagA^E/W-expression plasmid into CagA-deleted G27 strain (G27^ΔCagA). In human gastric epithelial cells (GES-1) infection, CagA^E induced more severe cytopathic changes, including higher interleukin-8 (IL-8) secretion, reduced cell viability, more pronounced \"hummingbird phenotype\" alterations, and increased cell migration and invasion compared to CagA^W. Transcriptome analysis revealed that CagA^E had a stronger effect on the up-regulation of key intracellular processes, including tumor necrosis factor-ɑ (TNF-ɑ) signal pathway via nuclear factor kappa-B (NF-κB), inflammatory response, interferon-γ (IFN-γ) response, hypoxia, ultraviolet (UV) response, and Kirsten Rat Sarcoma Viral Oncogene Homolog (KRAS) signaling. A significant upregulation of hypoxia-related genes was a notable feature of CagA^E. GES-1 cells infected with CagA^E exhibited more severe intracellular hypoxia and higher levels of reactive oxygen species (ROS) than those infected with CagA^W. Inhibition of hypoxia-inducible factor-1α (HIF-1α), which blocks hypoxia signaling, mitigated CagA^E-induced cell migration, emphasizing the role of hypoxia in mediating CagA^E effects.</p><p><strong>Conclusions: </strong>The study provides transcriptome evidence of CagA-associated intracellular regulation during H. pylori infection, demonstrating that CagA^E exerts stronger effects on intracellular signaling than CagA^W. These findings offer insights into the heightened carcinogenic potential of CagA^E in H. pylori-induced gastric cancer.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"467"},"PeriodicalIF":4.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11552142/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615123","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":"Correction: Synergistic potential of Leu₁₀-teixobactin and cefepime against multidrug-resistant Staphylococcus aureus.","authors":"Augustine Jing Jie Koh, Maytham Hussein, Varsha Thombare, Simon Crawford, Jian Li, Tony Velkov","doi":"10.1186/s12866-024-03630-9","DOIUrl":"10.1186/s12866-024-03630-9","url":null,"abstract":"","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"464"},"PeriodicalIF":4.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11552117/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615083","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":"Surface-functionalized UIO-66-NH₂ for dual-drug delivery of vancomycin and amikacin against vancomycin-resistant Staphylococcus aureus.","authors":"Nazanin Rahmanian, Pooria Moulavi, Fatemeh Ashrafi, Aram Sharifi, Sepideh Asadi","doi":"10.1186/s12866-024-03615-8","DOIUrl":"10.1186/s12866-024-03615-8","url":null,"abstract":"<p><strong>Background: </strong>Conventional antibacterial compounds can inhibit the growth of microorganisms, but their adverse effects and the development of drug limit their widespread use. The current study aimed to synthesize PEG-coated UIO-66-NH₂ nanoparticles loaded with vancomycin and amikacin (VAN/AMK-UIO-66-NH₂@PEG) and evaluate their antibacterial and anti-biofilm activities against vancomycin-resistant Staphylococcus aureus (VRSA) clinical isolates.</p><p><strong>Methods: </strong>The VAN/AMK-UIO-66-NH₂@PEG were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS) to determine their size, polydispersity index (PDI), encapsulation efficiency (EE%), zeta-potential, drug release profile, and physical stability. Antibacterial activity was evaluated using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill assays. Biofilm formation by VRSA was assessed using the crystal violet (CV) and minimum biofilm eradication concentration (MBEC) assays. The effect of sub-MIC concentrations of the formulations on the expression of biofilm-related genes (icaA, icaD) and resistance-related genes (mecA, vanA) was investigated using quantitative real-time polymerase chain reaction (RT-qPCR).</p><p><strong>Results: </strong>As demonstrated by MIC, MBC and time-kill assay, the VAN/AMK-UIO-66-NH₂@PEG nanoparticles exhibited enhanced antibacterial activity against VRSA isolates compared to free drugs and prepared formulations. Furthermore, CV and MBEC tests indicated that the VAN/AMK-UIO-66@NH₂/PEG can reduce biofilm formation dramatically compared to VAN/AMK and VAN/AMK-UIO-66@NH₂, due to its great drug release properties. This study also found that the expression level of the mecA, vanA, icaA, and icaD genes in VAN/AMK-UIO-66@NH₂/PEG treated VRSA isolates was substantially decreased compared to other groups.</p><p><strong>Conclusions: </strong>These findings highlighted the efficiency of VAN/AMK-UIO-66@NH₂/PEG in combating antimicrobial resistance and biofilm formation in VRSA isolates. Future studies, particularly in vivo models, are necessary to evaluate the safety, efficacy, and clinical applicability of these nanoparticles for the treatment of bacterial infections.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"462"},"PeriodicalIF":4.0,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11546402/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615069","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":"Screening of biomarkers in acute radiation enteritis based on microbiome and clustering methods.","authors":"Chenying Ma, Xiaoting Xu, Songbing Qin, Juying Zhou","doi":"10.1186/s12866-024-03620-x","DOIUrl":"10.1186/s12866-024-03620-x","url":null,"abstract":"<p><strong>Background: </strong>Radiation enteritis (RE) is a common complication of radiotherapy for abdominal and pelvic tumors, adversely affecting treatment outcomes and patients' quality of life. Gut microbiome alterations may contribute to RE development, but the underlying pathogenic factors are not fully understood. This study aimed to characterize the intestinal microbial changes associated with RE and severe acute radiation enteritis (SARE) and to identify predictive biomarkers.</p><p><strong>Methods: </strong>We enrolled 50 cervical cancer patients undergoing radiotherapy and 15 healthy women (controls). Stool samples were collected at the baseline and during weeks 2, 4, and 6 of radiotherapy, and then analyzed using 16 S rDNA sequencing and bioinformatics.</p><p><strong>Results: </strong>Although the Bacteroidetes/Firmicutes (B/F) ratio was higher in patients with RE or SARE, it alone could not predict these conditions. Three enterotypes were identified based on dominant genera: Blautia (enterotype 1), Escherichia-Shigella (enterotype 2), and Faecalibacterium (enterotype 3). A decrease in Blautia and an increase in Escherichia-Shigella and Faecalibacterium were correlated with RE and SARE. Univariate logistic regression revealed that the Faecalibacterium enterotype at the baseline was associated with a 4.4-fold higher risk of developing SARE (odds ratio 5.400; P = 0.017). The Escherichia-Shigella enterotype was also linked to increased SARE incidence.</p><p><strong>Conclusion: </strong>These findings suggest that while single bacterial genera or the B/F ratio are insufficient predictors, enterotype classification may serve as a potential biomarker for predicting SARE in patients undergoing radiotherapy.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"463"},"PeriodicalIF":4.0,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11545530/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615068","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":"MotY modulates proton-driven flagellar motor output in Pseudomonas aeruginosa.","authors":"Sanyuan Fu, Maojin Tian, Min Chen, Zhengyu Wu, Rongjing Zhang, Junhua Yuan","doi":"10.1186/s12866-024-03602-z","DOIUrl":"10.1186/s12866-024-03602-z","url":null,"abstract":"<p><p>MotY homologs are present in a variety of monotrichous bacterial strains and are thought to form an additional structural T ring in flagellar motors. While MotY potentially plays an important role in motor torque generation, its impact on motor output dynamics remains poorly understood. In this study, we investigate the role of MotY in P. aeruginosa, elucidating its interactions with the two sets of stator units (MotAB and MotCD) using Förster resonance energy transfer (FRET) assays. Employing a newly developed bead assay, we characterize the dynamic behavior of flagellar motors in motY mutants, identifying MotY as the key functional protein to affect the clockwise bias of naturally unbiased motors in P. aeruginosa. Our findings reveal that MotY enhances stator assembly efficiency without affecting the overall assembly of the flagellar structure. Additionally, we demonstrate that MotY is essential for maintaining motor torque and regulating switching rates. Our study highlights the physiological significance of MotY in fine-tuning flagellar motor function in complex environments.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":"24 1","pages":"461"},"PeriodicalIF":4.0,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11546298/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142615125","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}