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Clinical Epigenetics Jun 2024Gastrointestinal malignancies encompass a diverse group of cancers that pose significant challenges to global health. The major histocompatibility complex (MHC) plays a... (Review)
Review
BACKGROUND
Gastrointestinal malignancies encompass a diverse group of cancers that pose significant challenges to global health. The major histocompatibility complex (MHC) plays a pivotal role in immune surveillance, orchestrating the recognition and elimination of tumor cells by the immune system. However, the intricate regulation of MHC gene expression is susceptible to dynamic epigenetic modification, which can influence functionality and pathological outcomes.
MAIN BODY
By understanding the epigenetic alterations that drive MHC downregulation, insights are gained into the molecular mechanisms underlying immune escape, tumor progression, and immunotherapy resistance. This systematic review examines the current literature on epigenetic mechanisms that contribute to MHC deregulation in esophageal, gastric, pancreatic, hepatic and colorectal malignancies. Potential clinical implications are discussed of targeting aberrant epigenetic modifications to restore MHC expression and 0 the effectiveness of immunotherapeutic interventions.
CONCLUSION
The integration of epigenetic-targeted therapies with immunotherapies holds great potential for improving clinical outcomes in patients with gastrointestinal malignancies and represents a compelling avenue for future research and therapeutic development.
Topics: Humans; Gastrointestinal Neoplasms; Epigenesis, Genetic; Major Histocompatibility Complex; Gene Expression Regulation, Neoplastic; Immunotherapy; DNA Methylation; Tumor Escape
PubMed: 38915093
DOI: 10.1186/s13148-024-01698-8 -
The ISME Journal Jan 2024Genome-scale metabolic models (GEMs) are valuable tools serving systems biology and metabolic engineering. However, GEMs are still an underestimated tool in informing... (Review)
Review
Genome-scale metabolic models (GEMs) are valuable tools serving systems biology and metabolic engineering. However, GEMs are still an underestimated tool in informing microbial ecology. Since their first application for aerobic gammaproteobacterial methane oxidizers less than a decade ago, GEMs have substantially increased our understanding of the metabolism of methanotrophs, a microbial guild of high relevance for the natural and biotechnological mitigation of methane efflux to the atmosphere. Particularly, GEMs helped to elucidate critical metabolic and regulatory pathways of several methanotrophic strains, predicted microbial responses to environmental perturbations, and were used to model metabolic interactions in cocultures. Here, we conducted a systematic review of GEMs exploring aerobic methanotrophy, summarizing recent advances, pointing out weaknesses, and drawing out probable future uses of GEMs to improve our understanding of the ecology of methane oxidizers. We also focus on their potential to unravel causes and consequences when studying interactions of methane-oxidizing bacteria with other methanotrophs or members of microbial communities in general. This review aims to bridge the gap between applied sciences and microbial ecology research on methane oxidizers as model organisms and to provide an outlook for future studies.
Topics: Methane; Oxidation-Reduction; Aerobiosis; Metabolic Networks and Pathways; Models, Biological
PubMed: 38861460
DOI: 10.1093/ismejo/wrae102 -
Frontiers in Cellular and Infection... 2024The microbiota-gut-lung axis has elucidated a potential association between gut microbiota and idiopathic pulmonary fibrosis (IPF). However, there is a paucity of...
BACKGROUND
The microbiota-gut-lung axis has elucidated a potential association between gut microbiota and idiopathic pulmonary fibrosis (IPF). However, there is a paucity of population-level studies with providing robust evidence for establishing causality. This two-sample Mendelian randomization (MR) analysis aimed to investigate the causal relationship between the gut microbiota and IPF as well as lung function.
MATERIALS AND METHODS
Adhering to Mendel's principle of inheritance, this MR analysis utilized summary-level data from respective genome-wide association studies (GWAS) involving 211 gut microbial taxa, IPF, and lung function indicators such as FEV, FVC, and FEV/FVC. A bidirectional two-sample MR design was employed, utilizing multiple MR analysis methods, including inverse variance-weighted (IVW), weighted median, MR-Egger, and weighted mode. Multivariable MR (MVMR) was used to uncover mediating factors connecting the exposure and outcome. Additionally, comprehensive sensitivity analyses were conducted to ensure the robustness of the results.
RESULTS
The MR results confirmed four taxa were found causally associated with the risk of IPF. (OR=0.773, 95% CI: 0.610-0.979, p=0.033), (OR=0.773, 95% CI: 0.610-0.979, p=0.033), and (OR=0.793, 95% CI: 0.652-0.965, p=0.020) exerted protective effects on IPF, while (OR=1.349, 95% CI: 1.021-1.783, p=0.035) promote the development of IPF. Several taxa were causally associated with lung function, with those in , and being the most prominent beneficial microbiota, while those in , and were associated with impaired lung function. As for the reverse analysis, MR results confirmed the effects of FEV and FVC on the increased abundance of six taxa (, and ) with a boosted level of evidence. MVMR suggested monounsaturated fatty acids, total fatty acids, saturated fatty acids, and ratio of omega-6 fatty acids to total fatty acids as potential mediating factors in the genetic association between gut microbiota and IPF.
CONCLUSION
The current study suggested the casual effects of the specific gut microbes on the risk of IPF and lung function. In turn, lung function also exerted a positive role in some gut microbes. A reasonable dietary intake of lipid substances has a certain protective effect against the occurrence and progression of IPF. This study provides novel insights into the potential role of gut microbiota in IPF and indicates a possible gut microbiota-mediated mechanism for the prevention of IPF.
Topics: Humans; Mendelian Randomization Analysis; Idiopathic Pulmonary Fibrosis; Gastrointestinal Microbiome; Genome-Wide Association Study; Lung; Respiratory Function Tests; Genetic Predisposition to Disease
PubMed: 38841114
DOI: 10.3389/fcimb.2024.1348685 -
NPJ Biofilms and Microbiomes May 2024Childhood stunting is associated with impaired cognitive development and increased risk of infections, morbidity, and mortality. The composition of the enteric... (Review)
Review
Childhood stunting is associated with impaired cognitive development and increased risk of infections, morbidity, and mortality. The composition of the enteric microbiota may contribute to the pathogenesis of stunting. We systematically reviewed and synthesized data from studies using high-throughput genomic sequencing methods to characterize the gut microbiome in stunted versus non-stunted children under 5 years in LMICs. We included 14 studies from Asia, Africa, and South America. Most studies did not report any significant differences in the alpha diversity, while a significantly higher beta diversity was observed in stunted children in four out of seven studies that reported beta diversity. At the phylum level, inconsistent associations with stunting were observed for Bacillota, Pseudomonadota, and Bacteroidota phyla. No single genus was associated with stunted children across all 14 studies, and some associations were incongruent by specific genera. Nonetheless, stunting was associated with an abundance of pathobionts that could drive inflammation, such as Escherichia/Shigella and Campylobacter, and a reduction of butyrate producers, including Faecalibacterium, Megasphera, Blautia, and increased Ruminoccoccus. An abundance of taxa thought to originate in the oropharynx was also reported in duodenal and fecal samples of stunted children, while metabolic pathways, including purine and pyrimidine biosynthesis, vitamin B biosynthesis, and carbohydrate and amino acid degradation pathways, predicted linear growth. Current studies show that stunted children can have distinct microbial patterns compared to non-stunted children, which could contribute to the pathogenesis of stunting.
Topics: Child, Preschool; Humans; Infant; Infant, Newborn; Bacteria; Feces; Gastrointestinal Microbiome; Growth Disorders; High-Throughput Nucleotide Sequencing
PubMed: 38782939
DOI: 10.1038/s41522-024-00517-5 -
Frontiers in Immunology 2024Increasing evidence indicates the microbial ecology of chronic obstructive pulmonary disease (COPD) is intricately associated with the disease's status and severity, and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Increasing evidence indicates the microbial ecology of chronic obstructive pulmonary disease (COPD) is intricately associated with the disease's status and severity, and distinct microbial ecological variations exist between COPD and healthy control (HC). This systematic review and meta-analysis aimed to summarize microbial diversity indices and taxa relative abundance of oral, airway, and intestine microbiota of different stages of COPD and HC to make comparisons.
METHODS
A comprehensive systematic literature search was conducted in PubMed, Embase, the Web of Science, and the Cochrane Library databases to identify relevant English articles on the oral, airway, and intestine microbiota in COPD published between 2003 and 8 May 2023. Information on microbial diversity indices and taxa relative abundance of oral, airway, and intestine microbiota was collected for comparison between different stages of COPD and HC.
RESULTS
A total of 20 studies were included in this review, involving a total of 337 HC participants, 511 COPD patients, and 154 AECOPD patients. We observed that no significant differences in alpha diversity between the participant groups, but beta diversity was significantly different in half of the included studies. Compared to HC, , , , and of oral microbiota in SCOPD were reduced at the genus level. Most studies supported that , , and were increased, but , , , , and were decreased at the genus level in the airway microbiota of SCOPD. However, the abundance of , and genera exhibited an increase, whereas and showed a decrease in the airway microbiota of AECOPD compared to HC. And of intestine microbiota in SCOPD was reduced at the genus level.
CONCLUSION
The majority of published research findings supported that COPD exhibited decreased alpha diversity compared to HC. However, our meta-analysis does not confirm it. In order to further investigate the characteristics and mechanisms of microbiome in the oral-airway- intestine axis of COPD patients, larger-scale and more rigorous studies are needed.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO (https://www.crd.york.ac.uk/prospero/), identifier CRD42023418726.
Topics: Pulmonary Disease, Chronic Obstructive; Humans; Gastrointestinal Microbiome; Mouth; Microbiota; Bacteria
PubMed: 38779669
DOI: 10.3389/fimmu.2024.1407439 -
Applied Microbiology and Biotechnology May 2024A more optimized culture medium used in vitro to mimic the bacterial composition of original oral flora as similar as possible remains difficult at present, and the goal...
A more optimized culture medium used in vitro to mimic the bacterial composition of original oral flora as similar as possible remains difficult at present, and the goal of this study is to develop a novel oral biofilm medium to restore the original oral microbiome. Firstly, we conducted a systematic literature review by searching PubMed and summarized the current reported culture media in vitro. Seven culture media were found. We used mixed saliva as the origin of oral species to compare the effects of the above media in culturing oral multispecies biofilms. Results indicated that among the seven media brain heart infusion containing 1% sucrose (BHIs) medium, PG medium, artificial saliva (AS) medium, and SHI medium could obviously gain large oral biofilm in vitro. The nutrients contained in different culture media may be suitable for the growth of different oral bacteria; therefore, we optimized several novel media accordingly. Notably, results of crystal violet staining showed that the biofilm cultured in our modified artificial saliva (MAS) medium had the highest amount of biofilm biomass. 16S rRNA gene sequencing showed that the operational taxonomic units (OTUs) and Shannon index of biofilm cultured in MAS medium were also the highest among all the tested media. More importantly, the 16S rRNA gene sequencing analysis indicated that the biofilm cultured in MAS medium was closer to the original saliva species. Besides, biofilm cultured by MAS was denser and produced more exopolysaccharides. MAS supported stable biofilm formation on different substrata. In conclusion, this study demonstrated a novel MAS medium that could culture oral biofilm in vitro closer to the original oral microbiome, showing a good application prospect. KEY POINTS: • We compare the effects of different media in culturing oral biofilms • A novel modified artificial saliva (MAS) medium was obtained in our study • The MAS medium could culture biofilm that was closer to oral microbiome.
Topics: Biofilms; Culture Media; Microbiota; Mouth; Humans; RNA, Ribosomal, 16S; Saliva; Bacteria; Saliva, Artificial
PubMed: 38730049
DOI: 10.1007/s00253-024-13149-8 -
International Journal of Molecular... Apr 2024Molecular methods have become integral to microbiological research for microbial identification. This literature review focuses on the application of molecular methods... (Review)
Review
Molecular methods have become integral to microbiological research for microbial identification. This literature review focuses on the application of molecular methods in examining airborne bacteria and fungi in healthcare facilities. In January 2024, a comprehensive electronic search was carried out in esteemed databases including PubMed, Web of Science, and Scopus, employing carefully selected keywords such as ((bacteria) OR (virus) OR (fungi)) AND (aerosol) AND ((hospital) OR (healthcare) OR (dental office)) AND ((molecular) OR (PCR) OR (NGS) OR (RNA) OR (DNA) OR (metagenomic) OR (microarray)), following the PRISMA protocol. The review specifically targets healthcare environments with elevated concentrations of pathogenic bacteria. A total of 487 articles were initially identified, but only 13 met the inclusion criteria and were included in the review. The study disclosed that the prevalent molecular methodology for appraising aerosol quality encompassed the utilization of the PCR method, incorporating either 16S rRNA (bacteria) or 18S rRNA (fungi) amplification techniques. Notably, five diverse molecular techniques, specifically PFGE, DGGE, SBT, LAMP, and DNA hybridization methods, were implemented in five distinct studies. These molecular tests exhibited superior capabilities compared to traditional bacterial and fungal cultures, providing precise strain identification. Additionally, the molecular methods allowed the detection of gene sequences associated with antibiotic resistance. In conclusion, molecular testing offers significant advantages over classical microbiological culture, providing more comprehensive information.
Topics: Fungi; Aerosols; Bacteria; Air Microbiology; Humans; Health Facilities
PubMed: 38673740
DOI: 10.3390/ijms25084154 -
Brazilian Journal of Microbiology :... Jun 2024In South Africa, basic healthcare centres treat sexually transmitted infections (STIs) using a syndromic approach. In line with Preferred Reporting Items for Systematic... (Review)
Review
In South Africa, basic healthcare centres treat sexually transmitted infections (STIs) using a syndromic approach. In line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, a complete study of all randomised controlled trials and surveillance data relevant to N. gonorrhoeae antibiotic resistance was conducted. To discover papers published between 2002 and 2022, searches were undertaken using PubMed, EMBASE and any other relevant databases. This systematic review extracted a total of 463 articles published between 2002 and 2022 from a variety of online research sources. Seven South African provinces were represented in the studies that were assessed. Mpumalanga and the North West Province did not have any studies that described the identification and monitoring of antimicrobial resistance (AMR). This study presents data obtained from a comprehensive analysis of 2140 isolates, in which we examined the presence of one or more antibiotic resistance. Our findings revealed that out of these samples, 1891 isolates exhibited antimicrobial properties; tetracycline was the antimicrobial resistance that was found the most often (30%), followed by ciprofloxacin (19%) and penicillin (17%). The mean of the isolates was 143, the upper 95% mean was 243, and the standard deviation (SD) was 181.6. All microbiological identification and susceptibility testing processes must be standardised and improved so national organisations can monitor AMR. The nation's health community must address all identified areas of concern to avoid AMR.
Topics: South Africa; Neisseria gonorrhoeae; Gonorrhea; Humans; Anti-Bacterial Agents; Drug Resistance, Bacterial; Microbial Sensitivity Tests
PubMed: 38662152
DOI: 10.1007/s42770-024-01281-6 -
Frontiers in Microbiology 2024Quorum sensing (QS) research stands as a pivotal and multifaceted domain within microbiology, holding profound implications across various scientific disciplines. This...
BACKGROUND
Quorum sensing (QS) research stands as a pivotal and multifaceted domain within microbiology, holding profound implications across various scientific disciplines. This bibliometric analysis seeks to offer an extensive overview of QS research, covering the period from 2004 to 2023. It aims to elucidate the hotspots, trends, and the evolving dynamics within this research domain.
METHODS
We conducted an exhaustive review of the literature, employing meticulous data curation from the Science Citation Index Extension (SCI-E) within the Web of Science (WOS) database. Subsequently, our survey delves into evolving publication trends, the constellation of influential authors and institutions, key journals shaping the discourse, global collaborative networks, and thematic hotspots that define the QS research field.
RESULTS
The findings demonstrate a consistent and growing interest in QS research throughout the years, encompassing a substantial dataset of 4,849 analyzed articles. Journals such as Frontiers in Microbiology have emerged as significant contributor to the QS literature, highlighting the increasing recognition of QS's importance across various research fields. Influential research in the realm of QS often centers on microbial communication, biofilm formation, and the development of QS inhibitors. Notably, leading countries engaged in QS research include the United States, China, and India. Moreover, the analysis identifies research focal points spanning diverse domains, including pharmacological properties, genetics and metabolic pathways, as well as physiological and signal transduction mechanisms, reaffirming the multidisciplinary character of QS research.
CONCLUSION
This bibliometric exploration provides a panoramic overview of the current state of QS research. The data portrays a consistent trend of expansion and advancement within this domain, signaling numerous prospects for forthcoming research and development. Scholars and stakeholders engaged in the QS field can harness these findings to navigate the evolving terrain with precision and speed, thereby enhancing our comprehension and utilization of QS in various scientific and clinical domains.
PubMed: 38646636
DOI: 10.3389/fmicb.2024.1366760 -
Journal of Global Antimicrobial... Jun 2024This study aims to estimate the overall in vitro activity of bedaquiline (BDQ) against clinical isolates of Mycobacterium abscessus complex (MABS) and M. avium complex... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This study aims to estimate the overall in vitro activity of bedaquiline (BDQ) against clinical isolates of Mycobacterium abscessus complex (MABS) and M. avium complex (MAC), considering BDQ as a repurposed drug for non-tuberculous mycobacteria (NTM) infections.
METHODS
We conducted a systematic review of publications in PubMed/ MEDLINE, Web of Science, and Embase up to 15 April 2023. Studies were included if they followed the Clinical and Laboratory Standards Institute (CLSI) criteria for drug susceptibility testing (DST). Using a random effects model, we assessed the overall in vitro BDQ resistance rate in clinical isolates of MABS and MAC. Sources of heterogeneity were analysed using Cochran's Q and the I statistic. All analyses were performed using CMA V3.0.
RESULTS
A total of 24 publications (19 reports for MABS and 11 for MAC) were included. Using 1 µg/mL and 2 µg/mL as the breakpoint for BDQ resistance, the pooled rates of in vitro BDQ resistance in clinical isolates of MABS were found to be 1.8% (95% confidence interval [CI], 0.7-4.6%) and 1.7% (95% CI, 0.6-4.4%), respectively. In the case of MAC, the pooled rates were 1.7% (95% CI, 0.4-6.9%) and 1.6% (95% CI, 0.4-6.8%) for 1 µg/mL and 2 µg/mL, respectively.
CONCLUSION
This study reports the prevalence of BDQ resistance in clinical isolates of MABS and MAC. The findings suggest that BDQ holds potential as a repurposed drug for treating MABS and MAC infections.
Topics: Diarylquinolines; Humans; Microbial Sensitivity Tests; Mycobacterium abscessus; Mycobacterium avium Complex; Mycobacterium Infections, Nontuberculous; Antitubercular Agents; Drug Resistance, Bacterial; Mycobacterium avium-intracellulare Infection
PubMed: 38561143
DOI: 10.1016/j.jgar.2024.03.009