Fems Microbiology Letters最新文献

The diagnosis of extrapulmonary tuberculosis (EPTB) poses a significant challenge, with controversies surrounding the accuracy of IFN-γ release assays (IGRAs). This study aimed to assess the diagnostic accuracy of RD1 immunodominant T-cell antigens, including ESAT-6, CFP-10, PE35, and PPE68 proteins, for immunodiagnosis of EPTB. Twenty-nine patients with EPTB were enrolled, and recombinant PE35, PPE68, ESAT-6, and CFP-10 proteins were evaluated in a 3-day Whole Blood Assay. IFN-γ levels were measured using a Human IFN-γ ELISA kit, and the QuantiFERON-TB Gold Plus (QFT-Plus) test was performed. Predominantly, the patients were of Afghan (62%, n = 18) and Iranian (38%, n = 11) nationalities. Eighteen individuals tested positive for QFT-Plus, accounting for 62% of the cases. The positivity rate for IGRA, using each distinct recombinant protein (ESAT-6, PPE68, PE35, and CFP-10), was 72% (n = 21) for every protein tested. Specifically, among Afghan patients, the positivity rates for QFT-Plus and IGRA using ESAT-6, PPE68, PE35, and CFP-10 were 66.7%, 83.3%, 83.3%, 77.8%, and 88.9%, respectively. In contrast, among Iranian patients, the positivity rates for the same antigens were 54.5%, 54.5%, 54.5%, 63.6%, and 45.5%, respectively. In conclusion, our study highlights the potential of IGRA testing utilizing various proteins as a valuable diagnostic tool for EPTB. Further research is needed to elucidate the underlying factors contributing to these disparities and to optimize diagnostic strategies for EPTB in diverse populations.

Biogenic coalbed methane (CBM) is a developing clean energy source. However, it is unclear how the mechanisms of bio-methane production with different sizes of coal. In this work, pulverized coal (PC) and lump coal (LC) were used for methane production by mixed fungi-methanogen microflora. The lower methane production from LC was observed. The aromatic carbon of coal was degraded slightly by 2.17% in LC, while 11.28% in PC. It is attributed to the proportion of lignin-degrading fungi, especially Penicillium, which was reached 67.57% in PC on the 7th day, higher than that of 11.38% in LC. The results suggested that the limited interaction area in LC led to microorganisms hardly utilize aromatics. It also led the accumulation of aromatic organics in the fermentation broth in PC. Increasing the reaction area of coal and facilitating the conversion of aromatic carbon are suggested means to increase methane production in situ.

Autism spectrum disorder (ASD) is estimated to influence as many as 1% children worldwide, but its etiology is still unclear. It has been suggested that gut microbiomes play an important role in regulating abnormal behaviors associated with ASD. A de facto standard analysis on the microbiome-associated diseases has been diversity analysis, and nevertheless, existing studies on ASD-microbiome relationship have not produced a consensus. Here, we perform a comprehensive analysis of the diversity changes associated with ASD involving alpha-, beta-, and gamma-diversity metrics, based on 8 published data sets consisting of 898 ASD samples and 467 healthy controls (HC) from 16S-rRNA sequencing. Our findings include: (i) In terms of alpha-diversity, in approximately 1/3 of the studies cases, ASD patients exhibited significantly higher alpha-diversity than the HC, which seems to be consistent with the "1/3 conjecture" of diversity-disease relationship (DDR). (ii) In terms of beta-diversity, the AKP (Anna Karenina principle) that predict all healthy microbiomes should be similar, and every diseased microbiome should be dissimilar in its own way seems to be true in approximately 1/2 to 3/4 studies cases. (iii) In terms of gamma-diversity, the DAR (diversity-area relationship) modeling suggests that ASD patients seem to have large diversity-area scaling parameter than the HC, which is consistent with the AKP results. However, the MAD (maximum accrual diversity) and RIP (ratio of individual to population diversity) parameters did not suggest significant differences between ASD patients and HC. Throughout the study, we adopted Hill numbers to measure diversity, which stratified the diversity measures in terms of the rarity-commonness-dominance spectrum. It appears that the differences between ASD patients and HC are more propounding on rare-species side than on dominant-species side. Finally, we discuss the apparent inconsistent diversity-ASD relationships among different case studies and postulate that the relationships are not monotonic.

Microbial extracellular enzymatic activities (EEAs) produced by microbes to degrade biopolymers are the 'gatekeeper' of carbon cycle in the marine ecosystem. It is usually assumed that these extracellular enzymes are actively secreted by microbes. However, biopolymer-degrading enzymes also exist in the intracellular space. Cell lysis will passively release these enzymes into the environments and contribute to the total EEAs. However, to what extent the cell lysis can contribute to the total EEAs are still unclear. Here, using extreme cell lysis method, we evaluated the maximum contribution of cell lysis to total EEAs in culturable marine bacteria and coastal seawater. For carbohydrate-processing enzymes (β-glucosidase, alginate lyase, and chitinase), the release of intracellular enzymes could contribute positively (up to 56.1% increase for β-glucosidase in seawater) to the total EEAs. For protease and leucine aminopeptidase, the cell lysis did not increase and even decreased the total EEAs. For alkaline phosphatase, the intracellular enzymes generally had no contribution to the total EEAs. These results showed that passively released intracellular enzymes could substantially increase the total extracellular activities of carbohydrate-processing enzymes, which should be considered in building the link between the EEAs and organic carbon cycle in the ocean.

It is estimated that one in seven individuals, more than 15% of the population in the UK, are neurodivergent. In recent years, there has been a notable increase in university students disclosing disabilities, specific learning difficulties, or mental health conditions. Despite this, students with disabilities and learning differences often experience lower levels of well-being compared to their peers, and their completion rates are significantly lower. Two years ago, I was tasked with creating a training program for academic staff to enhance their support for neurodivergent students. In this commentary, I share reflections on what I have learned while developing this training, and I outline effective strategies and approaches that can be implemented in the design and delivery of educational content. I advocate a collaborative approach to training development with neurodivergent students and with colleagues with various roles. The commentary draws upon the Universal Design for Learning framework to advocate for an educational environment that is welcoming and accommodating to all learners. It champions strength-based practices, steering clear of the traditional deficit-focused narratives. My goal with this reflection is to prompt educators to reflect on their teaching methodologies, engage in conversations with their students, and to consider substantial pedagogical changes that prioritize inclusivity over reasonable adjustments.

Rice blast fungus (Pyricularia oryzae) is a heterothallic ascomycete that causes the most destructive disease in cultivated rice worldwide. This fungus reproduces sexually and asexually, and its mating type is determined by the MAT1 locus, MAT1-1 or MAT1-2. Interestingly, most rice-infecting field isolates show a loss of female fertility, but the MAT1 locus is highly conserved in female-sterile isolates. In this study, we performed a functional analysis of MAT1 using the CRISPR/Cas9 system in female- and male-fertile isolates and female-sterile (male-fertile) isolates. Consistent with a previous report, MAT1 was essential for sexual reproduction but not for asexual reproduction. Meanwhile, deletion mutants of MAT1-1-1, MAT1-1-2, and MAT1-1-3 exhibited phenotypes different from those of other previously described isolates, suggesting that the function of MAT1-1 genes and/or their target genes in sexual reproduction differs among strains or isolates. The MAT1 genes, excluding MAT1-2-6, retained their functions even in female-sterile isolates, and deletion mutants lead to loss or reduction of male fertility. Although MAT1 deletion did not affect microconidia (spermatia) production, microconidia derived from the mutants could not induce perithecia formation. These results indicated that MAT1 is required for microconidia-mediated male fertility in addition to female fertility in P. oryzae .

Methane-oxidizing bacteria (methanotrophs) play an important role in mitigating methane emissions in various ecological environments, including cold regions. However, the response of methanotrophs in these cold environments to extreme temperatures above the in-situ temperature has not been thoroughly explored. Therefore, this study collected soil samples from Longxiazailongba (LXZ) and Qiangyong (QY) glacier forelands and incubated them with 13CH4 at 35°C under different soil water conditions. The active methanotroph populations were identified using DNA stable isotope probing (DNA-SIP) and high throughput sequencing techniques. The results showed that the methane oxidation potential in LXZ and QY glacier foreland soils was significantly enhanced at an unusually high temperature of 35°C during microcosm incubations, where abundant substrate (methane and oxygen) was provided. Moreover, the influence of soil water conditions on this potential was observed. Interestingly, Methylocystis, a type II and mesophilic methanotroph, was detected in the unincubated in-situ soil samples and became the active and dominant methanotroph in methane oxidation at 35°C. This suggests that Methylocystis can survive at low temperatures for a prolonged period and thrive under suitable growth conditions. Furthermore, the presence of mesophilic methanotrophs in cold habitats could have potential implications for reducing greenhouse gas emissions in warming glacial environments.

Biological soil crusts (BSCs), a vital component of ecosystems, are pivotal in carbon sequestration, nutrient enrichment, and microbial diversity conservation. However, their impact on soil microbiomes in alpine regions remains largely unexplored. Therefore, this study aimed to determine the influence of BSCs on alpine grassland soil microbiomes, by collecting 24 pairs of soils covered by biological and physical crusts along a transect on the Qinghai-Tibetan Plateau. We found that BSCs significantly increased the contents of soil moisture, organic carbon, total nitrogen, and many available nutrients. They also substantially altered the soil microbiomes. Specifically, BSCs significantly increased the relative abundance of Cyanobacteria, Verrucomicrobiota, and Ascomycota, while decreasing the proportions of Gemmatimonadota, Firmicutes, Nitrospirae, Mortierellomycota, and Glomeromycota. By contrast, microbial abundance and α-diversity demonstrated low sensitivity to BSCs across most study sites. Under the BSCs, the assembly of prokaryotic communities was more affected by homogeneous selection and drift, but less affected by dispersal limitation. Conversely, soil fungal community assembly mechanisms showed an inverse trend. Overall, this study provides a comprehensive understanding of the effects of BSCs on soil properties and microbial communities, offering vital insights into the ecological roles of BSCs.

This study explores the relationship between microbial diversity and disease status in human lung cancer tissue microbiomes, using a sample size of 1212. Analysis divided the data into primary tumour (PT) and normal tissue (NT) categories. Differences in microbial diversity between PT and NT were significant in 57% of comparisons, although dataset dependence was a factor in the diversity levels. Shared species analysis (SSA) indicated no significant differences between PT and NT in over 90% of comparisons. Network diversity assessments revealed significant differences between NT and PT regarding species relative abundances and network link abundances for q = 0-3. Additionally, significant variations were found between NT and lung squamous cell carcinoma (LUSC) at q = 0. in network link probabilities, illustrating the diversity in species interactions. Our findings suggest a stable overall microbiome diversity and composition in lung cancer patients' lung tissues despite patients with diagnosed lung tumours, indicating modified microbial interactions within the tumour. These results highlight an association between altered microbiome interaction patterns and lung tumours, offering new insights into the ecological dynamics of lung cancer microbiomes.

The genus Flavobacterium comprises a diversity of species, including fish pathogens. Multiple techniques have been used to identify isolates of this genus, such as phenotyping, polymerase chain reaction genotyping, and in silico whole-genome taxonomy. In this study, we demonstrate that whole-genome-based taxonomy, using average nucleotide identity and molecular phylogeny, is the most accurate approach for Flavobacterium species. We obtained various isolated strains from official collections; these strains had been previously characterized by a third party using various identification methodologies. We analyzed isolates by PCR genotyping using previously published primers targeting gyrB and gyrA genes, which are supposedly specific to the genus Flavobacterium and Flavobacterium psychrophilum, respectively. After genomic analysis, nearly half of the isolates had their identities re-evaluated: around a quarter of them were re-assigned to other genera and two isolates are new species of flavobacteria. In retrospect, the phenotyping method was the least accurate. While gyrB genotyping was accurate with the isolates included in this study, bioinformatics analysis suggests that only 70% of the Flavobacterium species could be appropriately identified using this approach. We propose that whole-genome taxonomy should be used for accurate Flavobacterium identification, and we encourage bacterial collections to review the identification of isolates identified by phenotyping.