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EBioMedicine Apr 2024Chemoresistance is a critical factor contributing to poor prognosis in clinical patients with cancer undergoing postoperative adjuvant chemotherapy. The role of gut...
BACKGROUND
Chemoresistance is a critical factor contributing to poor prognosis in clinical patients with cancer undergoing postoperative adjuvant chemotherapy. The role of gut microbiota in mediating resistance to tumour chemotherapy remains to be investigated.
METHODS
Patients with CRC were categorised into clinical benefit responders (CBR) and no clinical benefit responders (NCB) based on chemotherapy efficacy. Differential bacterial analysis using 16S rRNA sequencing revealed Desulfovibrio as a distinct microbe between the two groups. Employing a syngeneic transplantation model, we assessed the effect of Desulfovibrio on chemotherapy by measuring tumour burden, weight, and Ki-67 expression. We further explored the mechanisms underlying the compromised chemotherapeutic efficacy of Desulfovibrio using metabolomics, western blotting, colony formation, and cell apoptosis assays.
FINDINGS
In comparison, Desulfovibrio was more abundant in the NCB group. In vivo experiments revealed that Desulfovibrio colonisation in the gut weakened the efficacy of FOLFOX. Treatment with Desulfovibrio desulfuricans elevates serum S-adenosylmethionine (SAM) levels. Interestingly, SAM reduced the sensitivity of CRC cells to FOLFOX, thereby promoting the growth of CRC tumours. These experiments suggest that SAM promotes the growth and metastasis of CRC by driving the expression of methyltransferase-like 3 (METTL3).
INTERPRETATION
A high abundance of Desulfovibrio in the intestines indicates poor therapeutic outcomes for postoperative neoadjuvant FOLFOX chemotherapy in CRC. Desulfovibrio drives the manifestation of METTL3 in CRC, promoting resistance to FOLFOX chemotherapy by increasing the concentration of SAM.
FUNDING
This study is supported by Wuxi City Social Development Science and Technology Demonstration Project (N20201005).
Topics: Humans; Apoptosis; Colorectal Neoplasms; Desulfovibrio desulfuricans; Fluorouracil; Methyltransferases; RNA, Ribosomal, 16S; Leucovorin; Organoplatinum Compounds; Antineoplastic Combined Chemotherapy Protocols
PubMed: 38484555
DOI: 10.1016/j.ebiom.2024.105041 -
Genes & Diseases Jan 2023It is increasingly aware that gut microbiota is closely associated with atherosclerosis. However, which and how specific gut bacteria regulate the progression of...
It is increasingly aware that gut microbiota is closely associated with atherosclerosis. However, which and how specific gut bacteria regulate the progression of atherosclerosis is still poorly understood. In this study, modified linear discriminant analysis was performed in comparing the gut microbiota structures of atherosclerotic and non-atherosclerotic mice, and () was found to be associated with atherosclerosis. treated mice showed significantly aggravated atherosclerosis. The proatherogenic effect of was attributed to its ability to increase intestinal permeability and subsequent raise in the transit of lipopolysaccharide (LPS) from the intestine to the bloodstream. Excessive LPS in the blood can elicit local and systemic inflammation and activate Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling of endothelial cells. TAK-242, a specific inhibitor of TLR4, can ameliorate the development of -induced atherosclerosis by blocking the LPS-induced activation of TLR4/NF-κB signaling.
PubMed: 37013030
DOI: 10.1016/j.gendis.2021.09.007 -
New Biotechnology Dec 2022A range of Desulfovibrio spp. can reduce metal ions to form metallic nanoparticles that remain attached to their surfaces. The bioreduction of palladium (Pd) has been...
A range of Desulfovibrio spp. can reduce metal ions to form metallic nanoparticles that remain attached to their surfaces. The bioreduction of palladium (Pd) has been given considerable attention due to its extensive use in areas of catalysis and electronics and other technological domains. In this study we report, for the first time, evidence for Pd(II) reduction by the highly corrosive Desulfovibrio ferrophilus IS5 strain to form surface attached Pd nanoparticles, as well as rapid formation of Pd(0) coated microbial nanowires. These filaments reached up to 8 µm in length and led to the formation of a tightly bound group of interconnected cells with enhanced ability to attach to a low carbon steel surface. Moreover, when supplied with high concentrations of Pd (≥ 100 mmol Pd(II) g dry cells), both Desulfovibrio desulfuricans and D. ferrophilus IS5 formed bacteria/Pd hybrid porous microstructures comprising millions of cells. These three-dimensional structures reached up to 3 mm in diameter with a dose of 1200 mmol Pd(II) g dry cells. Under suitable hydrodynamic conditions during reduction, two-dimensional nanosheets of Pd metal were formed that were up to several cm in length. Lower dosing of Pd(II) for promoting rapid synthesis of metal coated nanowires and enhanced attachment of cells onto metal surfaces could improve the efficiency of various biotechnological applications such as microbial fuel cells. Formation of biologically stimulated Pd microstructures could lead to a novel way to produce metal scaffolds or nanosheets for a wide variety of applications.
Topics: Palladium; Desulfovibrio desulfuricans; Desulfovibrio; Catalysis
PubMed: 36396027
DOI: 10.1016/j.nbt.2022.11.001 -
Protein Science : a Publication of the... Dec 2015Nitrate reductases (NR) belong to the DMSO reductase family of Mo-containing enzymes and perform key roles in the metabolism of the nitrogen cycle, reducing nitrate to... (Review)
Review
Nitrate reductases (NR) belong to the DMSO reductase family of Mo-containing enzymes and perform key roles in the metabolism of the nitrogen cycle, reducing nitrate to nitrite. Due to variable cell location, structure and function, they have been divided into periplasmic (Nap), cytoplasmic, and membrane-bound (Nar) nitrate reductases. The first crystal structure obtained for a NR was that of the monomeric NapA from Desulfovibrio desulfuricans in 1999. Since then several new crystal structures were solved providing novel insights that led to the revision of the commonly accepted reaction mechanism for periplasmic nitrate reductases. The two crystal structures available for the NarGHI protein are from the same organism (Escherichia coli) and the combination with electrochemical and spectroscopic studies also lead to the proposal of a reaction mechanism for this group of enzymes. Here we present an overview on the current advances in structural and functional aspects of bacterial nitrate reductases, focusing on the mechanistic implications drawn from the crystallographic data.
Topics: Bacteria; Bacterial Proteins; Catalytic Domain; Cell Membrane; Crystallography, X-Ray; Cytoplasm; Models, Molecular; Nitrate Reductase; Periplasm
PubMed: 26362109
DOI: 10.1002/pro.2801 -
Microorganisms Jan 2023belongs to Sulfate-reducing bacteria (SRB), which are widely present in anaerobic environments, including the human gut. has been associated with many human diseases,...
belongs to Sulfate-reducing bacteria (SRB), which are widely present in anaerobic environments, including the human gut. has been associated with many human diseases, including chronic liver disease. However, the characteristics and difference of from fecal samples of healthy volunteers (HV) and patients with liver cirrhosis (LC) have not been fully elucidated. Here, we isolated from the feces of 6 HV and 9 LC, and 88 strains were obtained. In the feces of HV, 55% of isolated strains were , followed by (15%), D. (11%), (9%), (4%), (4%) and (2%). However, only (60%) and (40%) were isolated from fecal samples of patients with LC. Our results suggest that there was a significant difference in the desulfurization ability and the HS production ability of different . . Furthermore, we found that isolated from the patients with LC generally had a higher hydrogen sulfide production capacity, gastrointestinal tolerance, and levels of antibiotic resistance than the same species isolated from HV. Our findings suggested that may be associated with the occurrence and development of liver cirrhosis.
PubMed: 36838242
DOI: 10.3390/microorganisms11020276 -
Biophysical Reviews Oct 2023The processes of microbiological destruction of toxic and large-tonnage waste are the most attractive processes for protecting the environment. The review considers the... (Review)
Review
The processes of microbiological destruction of toxic and large-tonnage waste are the most attractive processes for protecting the environment. The review considers the results of studies of microbial decomposition of nitrate esters, including hardly decomposable nitrocellulose. The published data show that specific microorganisms are able to degrade nitrated cellulose compounds under both anaerobic and aerobic conditions. The most promising microorganisms in terms of the efficiency of the nitrocellulose degradation process are bacteria belonging to genera, fungi and , as well as their co-cultivation. Recently, the first information about the enzymes involved in the process of nitrocellulose degradation, possible mechanisms of reactions carried out by these enzymes, and the effect of electron donors and acceptors adding to the process have been obtained. Contamination of industrial wastewater with nitrocellulose leads to treatment necessity by using cost-effective, harmless methods. A combined aerobic-anaerobic system, including both bacteria and fungi, has shown hopeful results.
PubMed: 37974989
DOI: 10.1007/s12551-023-01159-1 -
Applied and Environmental Microbiology Jun 2022The growth of sulfate-reducing bacteria (SRB) and associated hydrogen sulfide production can be problematic in a range of industries such that inhibition strategies are...
The growth of sulfate-reducing bacteria (SRB) and associated hydrogen sulfide production can be problematic in a range of industries such that inhibition strategies are needed. A range of SRB can reduce metal ions, a strategy that has been utilized for bioremediation, metal recovery, and synthesis of precious metal catalysts. In some instances, the metal remains bound to the cell surface, and the impact of this coating on bacterial cell division and metabolism has not previously been reported. In this study, Desulfovibrio desulfuricans cells (1g dry weight) enabled the reduction of up to 1500 mmol (157.5 g) palladium (Pd) ions, resulting in cells being coated in approximately 1 μm of metal. Thickly coated cells were no longer able to metabolize or divide, ultimately leading to the death of the population. Increasing Pd coating led to prolonged inhibition of sulfate reduction, which ceased completely after cells had been coated with 1200 mmol Pd gdry cells. Less Pd nanoparticle coating permitted cells to carry out sulfate reduction and divide, allowing the population to recover over time as surface-associated Pd diminished. Overcoming inhibition in this way was more rapid using lactate as the electron donor, compared to formate. When using formate as an electron donor, preferential Pd(II) reduction took place in the presence of 100 mM sulfate. The inhibition of important metabolic pathways using a biologically enabled casing in metal highlights a new mechanism for the development of microbial control strategies. Microbial reduction of sulfate to hydrogen sulfide is highly undesirable in several industrial settings. Some sulfate-reducing bacteria are also able to transform metal ions in their environment into metal phases that remain attached to their outer cell surface. This study demonstrates the remarkable extent to which Desulfovibrio desulfuricans can be coated with locally generated metal nanoparticles, with individual cells carrying more than 100 times their mass of palladium metal. Moreover, it reveals the effect of metal coating on metabolism and replication for a wide range of metal loadings, with bacteria unable to reduce sulfate to sulfide beyond a specific threshold. These findings present a foundation for a novel means of modulating the activity of sulfate-reducing bacteria.
Topics: Bacteria; Cell Division; Desulfovibrio; Desulfovibrio desulfuricans; Formates; Hydrogen Sulfide; Oxidation-Reduction; Palladium; Sulfates; Sulfides
PubMed: 35638843
DOI: 10.1128/aem.00580-22 -
Annals of Translational Medicine May 2021Emerging evidence demonstrates that the salivary microbiome could serve as a biomarker for various diseases. To date, the oral microbiome's role in the diagnosis of...
BACKGROUND
Emerging evidence demonstrates that the salivary microbiome could serve as a biomarker for various diseases. To date, the oral microbiome's role in the diagnosis of colorectal cancer (CRC) has not been fully elucidated. We aimed to illustrate the salivary microbiome's role in diagnosing and predicting the risk of CRC.
METHODS
We collected preoperational saliva from 237 patients [95 healthy controls (HCs) and 142 CRC patients] who underwent surgical resections or colorectal endoscopy in Renji Hospital from January 2018 to January 2020. Clinical demographics, comorbidities, and oral health conditions were obtained from medical records or questionnaires. Salivary microbial biomarkers were detected using quantitative polymerase chain reaction (qPCR) after DNA extraction. Multivariate logistic regression analysis was employed to analyze the risk factors for CRC. A predictive model for the risk of developing CRC was constructed based on logistic regression analysis. Predictive accuracy was internally validated by bootstrap resampling. A clinical nomogram was constructed to visualize the predictive model.
RESULTS
Logistic regression analysis demonstrated that the risk factors associated with CRC included age at diagnosis, male sex, poor oral hygiene, and relative salivary abundance. The predictive model had good discriminative (0.866) and calibration abilities (0.834) after bias correction.
CONCLUSIONS
The model based on age, sex, oral hygiene index (OHI), and the salivary level, which is visualized by a clinical nomogram, can predict the risk of CRC. Developing good oral hygiene habits might reduce the risk of CRC.
PubMed: 34268367
DOI: 10.21037/atm-20-8168 -
Bioresources and Bioprocessing Apr 2022Sulfate-containing wastewater has a serious threat to the environment and human health. Microbial technology has great potential for the treatment of sulfate-containing...
Sulfate-containing wastewater has a serious threat to the environment and human health. Microbial technology has great potential for the treatment of sulfate-containing wastewater. It was found that nano-photocatalysts could be used as extracellular electron donors to promote the growth and metabolic activity of non-photosynthetic microorganisms. However, nano-photocatalysts could also induce oxidative stress and damage cells. Therefore, the interaction mechanism between photosynthetic nanocatalysts and non-photosynthetic microorganisms is crucial to determine the regulatory strategies for microbial wastewater treatment technologies. In this paper, the mechanism and regulation strategy of cadmium sulfide nanoparticles (CdS NPs) on the growth of sulfate-reducing bacteria and the sulfate reduction process were investigated. The results showed that the sulfate reduction efficiency could be increased by 6.4% through CdS NPs under light conditions. However, the growth of Desulfovibrio desulfuricans C09 was seriously inhibited by 55% due to the oxidative stress induced by CdS NPs on cells. The biomass and sulfate reduction efficiency could be enhanced by 6.8% and 5.9%, respectively, through external addition of humic acid (HA). At the same time, the mechanism of the CdS NPs strengthening the sulfate reduction process by sulfate bacteria was also studied which can provide important theoretical guidance and technical support for the development of microbial technology combined with extracellular electron transfer (EET) for the treatment of sulfate-containing wastewater.
PubMed: 38647594
DOI: 10.1186/s40643-022-00523-5 -
Emerging Infectious Diseases Aug 2023An 84-year-old man in Japan who had undergone endovascular aortic repair 9 years earlier had an infected aneurysm develop. We detected Desulfovibrio desulfuricans MB at...
An 84-year-old man in Japan who had undergone endovascular aortic repair 9 years earlier had an infected aneurysm develop. We detected Desulfovibrio desulfuricans MB at the site. The patient recovered after surgical debridement, artificial vessel replacement, and appropriate antimicrobial therapy. Clinicians should suspect Desulfovibrio spp. infection in similar cases.
Topics: Male; Humans; Aged, 80 and over; Desulfovibrio desulfuricans; Aneurysm; Japan
PubMed: 37486321
DOI: 10.3201/eid2908.230403