Search Results (130)

Objectives: The aim of this study is to assess the influence of diabetes mellitus on the microbial flora involved in root canal infections through a comparative analysis with that of systemically healthy individuals. Methods: A total of 39 participants, including 21 patients with diabetes mellitus and 18 systemically healthy individuals (controls), were enrolled in the study. In the diabetic group, 12 teeth were diagnosed with secondary/persistent endodontic infections (SEIs) and 9 with primary endodontic infections (PEIs). In the healthy group, 12 teeth presented with SEIs and 6 with PEIs. Root canal samples were obtained using sterile paper points. The V3–V4 hypervariable regions of 16S rDNA from both sample types were amplified and sequenced using the Illumina MiSeq platform. Microbial richness and diversity were assessed using alpha diversity indices and beta diversity metrics. Results: Faith’s Phylogenetic Diversity showed a significant difference between diabetic patients with SEIs and healthy individuals with PEIs (p = 0.02). Both weighted and unweighted UniFrac beta diversity analyses indicated significant differences in microbial composition and phylogenetic structure between diabetic patients with SEIs and healthy individuals with PEIs (p = 0.01 and p = 0.02, respectively). Within the diabetic patient group, significant differences were observed between SEI and PEI groups based on alpha (Fisher’s alpha, p = 0.04) and beta diversity analyses (Bray–Curtis and Weighted UniFrac p = 0.02 and p = 0.01, respectively). Conclusions: Diabetic patients showed different microbial profiles compared to healthy individuals. Full article

Background/Objectives: The effects of geographical origin, alongside age, diet, and drug treatments, on the gut microbiota have not been thoroughly analyzed in African countries. Furthermore, eukaryotic components, including Blastocystis, the most common intestinal protozoan worldwide, require further investigation. This study compares the gut microbiota of Italian subjects with that of two African groups to examine the influence of dietary patterns and the effects of Blastocystis presence and subtypes. Methods: Three cohorts of healthy subjects (Italians residing in Rome, Africans residing in the Côte d’Ivoire, and Africans living in Italy) were compared by sequencing the V3-V4 hypervariable regions of the 16S rDNA gene. Taxa abundance and associations with typical West African and Italian foods were determined using DESeq2. Co-abundant genera were identified with a weighted correlation network analysis (WGCNA). Blastocystis subtypes were determined and correlated with the microbial composition in the three groups. Results: Distinct microbial taxa were associated with specific foods, including palm oil, Cube Maggi, sunflower oil, and olive oil. A Mediterranean diet consumed for over two years did not alter the abundance of Faecalibacterium and Dorea in the Africans living in Italy compared with Africans living in Côte d’Ivoire, whereas differences were observed in the abundance of some Prevotella-9, Bacteroides, and Lachnospiraceae OTUs. Significant associations were identified between palm oil and Subdoligranulum, Cube Maggi and Dorea, sunflower oil and the Ruminococcus torques group, and olive oil and Faecalibacterium. Concerning Blastocystis, alpha and beta diversity analysis showed a significant separation between carriers and non-carriers. Conclusions: This study provides the first comparative analysis of gut microbiota composition between individuals from Côte d’Ivoire and Italians focusing on the influence of distinct dietary patterns. Full article

16S rRNA next-generation sequencing (NGS) has significantly advanced cervicovaginal microbiome profiling, offering insights into the relationship between vaginal dysbiosis and HPV-associated carcinogenesis. However, reliance on a limited set of 16S hypervariable regions introduces inherent biases that impact results. This study developed standardized workflows for 16S/ITS NGS, with a focus on identifying methodological biases that influence microbial abundance and taxonomic specificity. Commercial NGS tools were employed, including the 16S/ITS QIAseq V1–V9 screening panel, ATCC vaginal microbial standard, and CLC Genomics Workbench integrated with a customized database (VAGIBIOTA) for analysis. The microbial communities of 66 cervical cytology samples were characterized. Among the regions tested, V3V4 exhibited the least quantitative bias, while V1V2 offered the highest specificity. Microbial profiles and Community State Types (CST) (I–V) were broadly consistent with prior studies, with Lactobacillus abundance clustering into three states: L.-dominant (CST I–III, V), L.-diminished (CST IV-A), and L.-depleted (CST IV-B). Differential abundance analysis revealed that anaerobic opportunistic pathogens dominant in CST IV-B (dysbiosis) were also enriched in HSIL and HPV-16 positive samples. Our findings revealed distinct differences in species identification across 16S rRNA hypervariable regions, emphasizing the importance of region selection in clarifying microbial contributions to HPV-associated carcinogenesis. Full article

The purpose of this work was to obtain specialized enrichment cultures from an original extreme acidophilic consortium of extremely acidophilic microorganisms and to study their microbial community composition and biotechnological potential. At temperatures of 25, 35, 40 and 50 °C, distinct enrichments of extremely acidophilic microorganisms used in the processes of bioleaching sulfide ores were obtained using nutrient media containing ferrous sulfate, elemental sulfur and a copper sulfide concentrate as nutrient inorganic substrates, with and without the addition of 0.02% yeast extract. The microbial community composition was studied using the sequencing of the V3–V4 hypervariable region of the 16S rRNA genes. The different growth conditions led to changes in the microbial composition and relative abundance of mesophilic and moderately thermophilic, strict autotrophic and mixotrophic microorganisms in members of the genera Acidithiobacillus, Sulfobacillus, Leptospirillum, Acidibacillus, Ferroplasma and Cuniculiplasma. The dynamics of the oxidation of ferrous iron, sulfur, and sulfide minerals (pyrite and chalcopyrite) by the enrichments was also studied in the temperature range of 25 to 50 °C. The study of enrichment cultures using the molecular biological method using the metabarcoding method of variable V3–24 V4 fragments of 16S rRNA genes showed that enrichment cultures obtained under different conditions differed in composition, which can be explained by differences in the physiological properties of the identified microorganisms. Regarding the dynamics of the oxidation of ferrous ions, sulfur, and sulfide minerals (pyrite and chalcopyrite), each enrichment culture was studied at a temperature range of 25 to 50 °C and indicated that all obtained enrichments were capable of oxidizing ferrous iron, sulfur and minerals at different rates. The obtained enrichment cultures may be used in further work to increase bioleaching by using the suitable inoculum for the temperature and process conditions. Full article

The long-term monocropping of red kidney beans in agricultural fields can lead to the occurrence of soil-borne diseases. Alterations in the composition of the soil microbial community are a primary cause of soil-borne diseases and a key factor in continuous cropping obstacles. Research exploring how different cultivation modes can modify the diversity and composition of the rhizosphere microbial community in red kidney beans, and thus mitigate the effects of continuous cropping obstacles, is ongoing. This study employed three cultivation modes: the continuous monocropping of red kidney beans, continuous monocropping of soybeans, and red kidney bean–soybean intercropping. To elucidate the composition and diversity of rhizosphere microbial communities, we conducted amplicon sequencing targeting the V3-V4 hypervariable regions of the bacterial 16S rRNA gene and the ITS1 region of fungal ribosomal DNA across distinct growth stages. The obtained sequencing data provide a robust basis for estimating soil microbial diversity. We observed that, under the intercropping mode, the composition of both bacteria and fungi more closely resembled that of soybean monocropping. The monocropping of red kidney beans increased the richness of rhizosphere bacteria and fungi and promoted the accumulation of pathogenic microorganisms. In contrast, intercropping cultivation and soybean monocropping favored the accumulation of beneficial bacteria such as Bacillus and Streptomyce, reduced pathogenic fungi including Alternaria and Mortierell, and exhibited less microbial variation across different growth stages. Compared to the monocropping of red kidney beans, these systems demonstrated more stable microbial structure and composition. The findings of this study will inform sustainable agricultural practices and soil management strategies. Full article

Beta-thalassemia major is an inherited disorder that requires lifelong blood transfusions, with the risk of complications including poor oral health and dental caries. The objective of this study was to compare the oral microbiome diversity and composition in transfusion-dependent thalassemia patients and relate it to oral hygiene and dental caries. A cross-sectional analysis of 35 patients of beta-thalassemia major aged 6–18 years was performed. The status of oral hygiene was examined through the Oral Hygiene Index—Simplified (OHI-S) and Decayed, Missing, and Filled Teeth (DMFT) index. Saliva was taken for DNA extraction, followed by the 16S rRNA sequencing of V3-V4 hypervariable regions. The bioinformatics pipeline in QIIME2 was utilized for analyzing the comparison of microbial composition and diversity in groups of varying oral hygiene status and severity of caries. Metagenomic analysis revealed 3334 Amplicon Sequence Variants (ASVs), of which the most prevalent genera were Streptococcus, Haemophilus, Veillonella, Rothia, and Prevotella. High-oral-hygiene groups presented increased levels of cariogenic bacteria, while moderate-oral-hygiene groups presented an equilibrated microbiome. No statistically significant differences in microbial diversity were found between the study groups (p > 0.05). This study sheds light on the critical importance of oral hygiene in microbiome diversity in patients with beta-thalassemia major. Full article

Background/Objectives: The evidence regarding the efficacy of probiotics in chronic rhinosinusitis (CRS) is very limited, prompting the EPOS2020 steering group to advise against their use in CRS treatment. Therefore, further research to evaluate the impact of probiotics on microbial communities is particularly important. This study aimed to assess the influence of probiotic nasal rinses on nasal microbiota profiles in patients with primary CRS, granulomatosis with polyangiitis (GPA), and nasal septal perforation (NSP) using 16S rRNA sequencing. Methods: Thirty-six patients with nasal mucosal diseases, including sixteen with primary CRS, eleven with GPA, and nine with NSP, were randomly assigned to either a study group receiving nasal rinses with probiotics containing Lactobacillus plantarum and Bifidobacterium animalis, or a control group using nasal rinses with saline. Metagenomic analysis targeting the V3–V4 hypervariable region of the 16S rRNA gene was performed to characterize bacterial and archaeal populations. Results: At the genus level, the most abundant co-colonizers included Staphylococcus, Streptococcus, and Haemophilus. After one month of probiotic rinsing, a decrease in abundance of the genera Finegoldia (p = 0.010), Haemophilus (p = 0.020), Streptococcus (p = 0.027), Staphylococcus (p = 0.033), Micrococcus (p = 0.035), Corynebacterium (p = 0.049), Gemella (p = 0.055), Rubrobacter (p = 0.055), and Pseudonocardia (p = 0.058) was observed. Conversely, the abundance of probiotic species Lactobacillus plantarum and Bifidobacterium animalis increased. Moreover, increases in the genera Dolosigranulum and Stenotrophomonas were observed, although they did not reach statistical significance. Conclusions: Probiotic nasal rinses may contribute to restoring microbial homeostasis by reducing genera associated with inflammatory dysbiosis in nasal inflammatory diseases, warranting further research on their clinical benefits. Full article

The peripartum period is critical for breeding female donkeys (i.e., jennies) and ensuring the delivery of healthy neonatal foals. The gut microbiota deeply influences the host metabolism. This study aimed to investigate the dynamic changes in the gut microbiome during the peripartum period in jennies. Fresh fecal samples of eight adult jennies were collected at the following seven sampling time points: 21, 7, and 3 days prepartum (G21, G7, and G3) and 1, 3, 7, and 14 days postpartum (L1, L3, L7, and L14). Sequencing of the V4 hypervariable regions of the 16S rRNA genes was carried out using fecal samples to identify the differences in the microbiome across the peripartum period. Bacteroidota and Firmicutes were the most abundant bacterial phyla in the feces. Treponema and Lachnospiraceae XPB1014 group significantly increased in the L3 group compared to the G7 group (q < 0.05), and a decline trend was observed in L1 group around parturition. The genus Clostridium sensu stricto 1, family Clostridiaceae, and order Clostridiales were considered to be biomarkers of the L3 group. Among the 25 functional pathways detected by Kyoto Encyclopedia of Genes and Genomes pathway analysis, beta lactam resistance, insulin resistance, and peptidases were the top three important pathways observed in the gut microbiota during the peripartum period in jennies. The gut microbial structure changed significantly at different time points during the peripartum period in jennies. These results contribute to a better understanding of the gut microbiota to ensure health care during important phases from late pregnancy to early lactation in jennies. Full article

Sustainable agriculture relies on effective soil management, making it crucial to assess soil health, especially in areas of agricultural expansion, such as the Cerrado in the MATOPIBA region. Sustainable strategies, such as integrated production systems (crop–livestock–forestry), are essential to mitigate these impacts. However, little is known about the effects of these systems on soil microbial communities. The objective of this study was to evaluate bacterial communities associated with soils under different integrated production systems in the MATOPIBA region. Soil samples from the 0–10 cm depth layer were collected from the following land use systems: (i) native Cerrado vegetation (NCV), (ii) native Babassu forest (NPV), (iii) no-tillage soybean—regional standard system (NT-S), (iv) crop–forest integration (CFI), (v) crop–livestock integration (CLI), and (vi) livestock–forest integration (LFI). We measured chemical properties and bacterial communities using next-generation sequencing (NGS) of the V3-V4 hypervariable region of the 16S rRNA gene. The results revealed that the integration systems (CFI, CLI, and LFI) resulted in changes in soil chemical properties, which contributed to the modulation of the bacterial communities. The most abundant taxa in integrated production systems shows a positive correlation with soil pH and phosphorus content. Members of the Nitrosomonadaceae and Sphingomonadaceae families are more related to integrated production systems containing a forestry component (CFI and LFI), while Bacillaceae are more evident in crop–livestock integration systems (CLI). Full article

Postlarval shrimp frequently face threats from acute hepatopancreatic necrosis disease (AHPND). Although AHPND affects both postlarval and adult shrimp, abiotic and biotic factors are distinct between life stages, such as rearing water nutrient levels and host life stage-dependent microbiota. The response of postlarvae-associated microbiota to AHPND, however, remains largely unexplored compared with its effects on juvenile and adult shrimp. To address this knowledge gap, a comparative analysis of postlarvae-associated microbiota and the ecological processes underlying AHPND progression was performed by sequencing the bacterial V3–V4 hypervariable region of the 16S rRNA gene. AHPND infection was validated by high copies of pirAB genes (Toxin 1) in diseased shrimp hepatopancreas. Advanced AHPND significantly altered the structure of the postlarvae-associated microbiota, with significant enrichment of Bacilli and Bdellovibrionia species in healthy larvae compared with matched AHPND-infected cohorts, although gut microbiota recovery was observed at the late disease stage, corresponding with the cessation of postlarval mortality. AHPND infection explained 11.0% (p < 0.001) of the variance in community structures, whereas postlarvae days post hatching also significantly influenced bacterial communities (7.1% variance, p < 0.001). AHPND-infected shrimp exhibited reduced homogeneous selection and increased dispersal limitation and drift governing their microbiota. These changes were primarily driven by specific microbial lineages, including enriched Bin36 Rhodobacteraceae and Bin11 Flavobacteriaceae, and suppressed Bin63 Vibrio and Bin9 Bacillus in AHPND-infected shrimp. After excluding shrimp age effect, 13 AHPND-discriminatory taxa were identified, accurately distinguishing infected shrimp from healthy individuals with 100% precision. Furthermore, AHPND outbreak weakened the network complexity and stability, which was driven by the suppressed keystone taxa that were positively associated with network robustness. Collectively, our findings deepen the understanding of the inextricable interplay between postlarval shrimp health, microbiota dynamics, and survival, as well as the underlying ecological mechanisms over AHPND progression. Full article

Pyogenic liver abscesses (PLAs) are serious infections in which doctors often fail in identifying the causative agent due to microbiological limitations. These limitations in detecting uncommon pathogens complicate the treatment and recovery. Molecular techniques, like massive sequencing, enable the detection of uncommon pathogens and highlight the shortcomings of traditional cultures. The aim of this work was to characterise the bacterial composition of PLAs through massive sequencing of the V3-V4 hypervariable region of the 16S rRNA gene in cases where conventional culture methods were negative. Purulent material was collected from three patients with PLAs at Hospital Juárez de México. Classical and molecular microbiological cultures were performed in parallel. Metagenomic DNA was extracted and massively sequenced (16S rRNA gene) using the Illumina MiSeq platform. A bioinformatic analysis was performed to determine the diversity at six different taxa levels and the relative abundances. The culture methods were not sufficient to detect the causative agent of the PLAs. However, the massive sequencing revealed the causative agents of the monomicrobial and polymicrobial infectious foci, with Gardnerella vaginalis, Lactobacillus iners, and Prevotella timonensis as the dominant bacteria. The massive sequencing revealed the presence of unusual pathogens that traditional culture failed to detect. There is an immediate need for molecular or comprehensive microbiological culture techniques to search for unusual bacteria in the diagnosis of PLAs. Full article

The Eurasian griffon vulture (Gyps fulvus), a widely distributed scavenger, plays a crucial role in ecosystem health by consuming decomposing carcasses. Scavengers have adapted to avoid disease from the rotting carrion they feed on, probably through a specialized gut microbiome. This study aimed to characterize the gut microbiome of G. fulvus (n = 8) present in two rehabilitation centers in mainland Portugal and evaluate their potential as reservoirs of pathogens. Samples were studied through high-throughput 16S rDNA amplicon sequencing of the hypervariable V3-V4 regions and further analyzed using the Qiime2 bioinformatics platform. Our results showed that factors such as sex, location, and time of sampling did not significantly affect the gut microbiome of the griffon vulture. Its composition was highly similar to that of phylogenetically closed animals. However, several potential human and veterinary pathogens were identified. In conclusion, the gut microbiome of Gyps fulvus in rehabilitation centers is not significantly altered by stress associated with captivity. Its composition is similar to that of other vultures and scavengers due to their identic diet and needs, suggesting a well-conserved functional gut microbiome, which seems to be influenced by season. The potential risks posed by the identified pathogens to humans and other animals should be further investigated. Full article

Background/Objectives: The prevalence of food allergy (FA) in children is increasing. Dysbiosis of the microbiome has been linked to FA but needs to be better understood. We aimed to characterize the gut and skin microbiome of young food-allergic children over time and within different types of immunoglobulin E (IgE)-mediated FA. Methods: We studied 23 patients, as a pilot study of an ongoing prospective multicenter cohort study including children < 2y with newly diagnosed IgE-mediated FA. Samples (feces/skin swabs) were collected at enrollment and at 1-year follow-up and sequenced for the bacterial 16S rRNA gene (hypervariable v1–v2 region). Results: Gut and skin bacterial diversity was significantly higher in patients compared with controls and increased over time (beta test, Shannon diversity, p < 0.01). Within different types of IgE-mediated FA, bacterial diversity was similar. Community composition differed significantly over time and within IgE-mediated FA types (PERMANOVA: p < 0.01). Several significantly different genus abundances were revealed. We observed a positive correlation between high total IgE and a high abundance of the genus Collinsella in patients with a higher number of allergies/sensitizations (≥3), and patients with tree nut and/or peanut allergy. Conclusions: This study revealed an increased bacterial diversity in children with FA compared with non-atopic children. Importantly, the gut and skin microbiome differed in their composition over time and within different types of IgE-mediated FA. These findings contribute to the understanding of microbiome changes in children with FA and indicate the potential of the genus Collinsella as a biomarker for tree nut and/or peanut allergy and possibly for allergy persistence. Full article

Microbiome studies targeting hypervariable regions of the 16S rRNA gene are suitable for understanding interactions between animals and their associated bacteria. While many studies focus on the gut microbiome, assessments of blood microbiota remain scarce despite the prevalence of blood-borne pathogens in vertebrates. This study aimed to investigate the bacterial community in blood samples from 79 living and 7 road-killed lowland tapirs (Tapirus terrestris), a vulnerable species, sampled in two biomes in midwestern Brazil: Pantanal and Cerrado. Animals were categorized by condition (living or road-killed), sex, age, and biome. V3–V4 16S rRNA fragments were obtained from 86 blood samples and 4 negative controls. After filtering contaminants, 13,742,198 sequences representing 2146 ASVs were analyzed. Alpha diversity significantly differed by condition, while beta diversity differed by condition, site, and age (adults vs. sub-adults). For living animals (79/86 samples), alpha diversity showed no significant differences, but beta diversity differed by age. Different vector-borne bacterial pathogens, including Anaplasmataceae, Bartonella, and Borrelia spp., were detected. Additionally, evidence of transient translocation of microbial communities from other body regions to the bloodstream was observed. Amplification of bacterial 16S rRNA from blood samples of wild T. terrestris provided novel information about the diversity of blood-borne microbiota of lowland tapirs, members of a poorly studied mammalian family. Next-generation sequencing proved to be a valuable tool for screening potential vector-borne pathogens in this host. Full article

Understanding the intricate dynamics of fish microbiota through 16S rRNA amplicon sequencing is pivotal for ecological insights and effective disease management. However, this approach faces challenges including the co-amplification of host mitochondrial sequences and the variability in bacterial composition influenced by the selected 16S rRNA gene regions. To overcome these limitations, we conducted a comprehensive investigation to identify the most suitable 16S rRNA region for bacterial microbial analysis in endangered fish Totoaba macdonaldi, an endemic species of significant ecological and economic importance in Mexico. Targeting four distinct hypervariable regions (V1–V2, V2–V3, V3–V4, and V5–V7) of the 16S rRNA gene, we determined the microbial composition within the distal intestine. A total of 40 microbiomes were sequenced. Our findings underscore the critical impact of region selection on the accuracy of microbiota analysis. The V3–V4 region detected the highest number of bacterial taxa and exhibited significantly higher alpha diversity indices, demonstrating the highest taxonomic resolution. This study emphasizes the necessity of meticulous 16S rRNA region selection for fish microbiota analysis, particularly in native species of ecological and economic significance such as the endangered T. macdonaldi, where information is limited. Such optimization enhances the reliability and applicability of microbiota studies in fisheries management and conservation efforts. Full article