Search Results (31)

Over several decades, childhood asthma has emerged as a significant global public health concern, with the highest prevalence reported in industrialized countries. The rapid rise in asthma incidence and loss of control when the diagnosis is established can be related to environmental and lifestyle changes, especially during early infancy. Current evidence indicates a potential link to an imbalance in immune system responses, influenced by tobacco smoke, traffic-related air pollution, outdoor and indoor allergens, gut microbiome, viral infection, obesity, sedentary lifestyle and dietary patterns. This narrative review aims to explore the landscape of contemporary environmental risk factors for childhood asthma, with a focus on their interplay and the relative importance. Full article

In this study we evaluated over a 1-year period, the ability of Epipremnum aureum leaves to collect particulate matter (PM)-bound Pb from an indoor environment. Using Illumina MiSeq, we investigated the changes in the phylloplane microbiome connected with the accumulation of this pollutant. Plants were placed in a shooting room, where PM release from each shot was recorded, along with PM_2.5 and PM₁₀ sequestration and leaf element enrichment by ICP. Additionally, black carbon (BC) sequestration was determined, and SEM-EDX was performed on leaves after 12 months of exposure. Our results indicated that ambient air pollution shapes microbial leaf communities by affecting their diversity. At the order level, Pseudomonadales, along with Micrococcales, appeared (at a low relative abundance) after exposure to indoor PM-bound Pb air pollution. This study provides a unique comparison of Epipremnum aureum air filtration performance between a standard office environment and a firearm shooting range. The air filtration approach holds promise for reducing indoor air pollution, but more knowledge about the underlying mechanisms supporting genera capable of coping with airborne pollutants is still required. Full article

The aim of the present study was to evaluate the effect of grazing the low deciduous forest (LDF) vegetation on the diversity of the rumen microbiome in growing lambs and its relationship with volatile fatty acid (VFA) profiles. After a 35-day indoor acclimatization (stabilization period), the lambs were assigned to two groups: housed (CG, n = 4) and grazing (EG, n = 4). The grazing lambs had a 14-day habituation period in the LDF (4 h/day) and a further 30 grazing days when fodder intake was observed. Ruminal samples were collected at the end of the stabilization, on day 14 post-stabilization (14DPS), and on day 44 post-stabilization (44DPS). The ruminal butyrate concentration showed a progressive decrease of approximately 23% over the time (p = 0.0130). The qualitative composition (p = 0.001) and relative proportions of bacteria (p = 0.004) in EG-44DPS exhibited a greater diversity, with 107 total genera and 19 unique, significant abundances in 13 genera with a higher presence of Bacteroidales_RF16_group, Lachnospiraceae_ND3007_group, and WCHB1-41. Moreover, significant functional profiles are associated with key metabolic pathways in bacteria and are interconnected by the need to generate energy and biosynthetic precursors and to manage available nitrogen and carbon. Finally, eight bacterial genera were identified as biomarkers correlated with the increase in VFA in EG-44DPS. Full article

The indoor microbiome is a dynamic ecosystem including pathogens that can impact human health. In this regard, the school environment represents the main living space of humans for many years, and an unhealthy environment can significantly condition students’ health. School rooms can suffer from insufficient ventilation and the use of building materials that may favor pathogen contamination, mostly sanitized by conventional chemical-based methods, which can impact pollution, have temporary effects, and induce the selection of antimicrobial resistance (AMR) in persistent microbes. In the search for sustainable and effective methods to improve the healthiness of the classroom environment, a pre–post case–control study was performed in an Italian high school. Over a year, different interventions were sequentially placed and evaluated for their impact on bioburden and air quality, including the introduction of plants, a mechanical ventilation system, and probiotic-based sanitation (PBS) in substitution for chemical sanitation. Through continuous microbial monitoring of the enrolled school rooms, via culture-dependent and -independent methods, a remarkable bioburden level was detected at baseline (around 12,000 and 20,000 CFU/m², before and after classes, respectively), composed mostly of Staphylococcus spp. and fungi. Some decrease in fungal contamination was observed following the introduction of plants. Still, the most significant decrease in pathogens and associated AMR was detected following the introduction of ventilation and PBS, which decreased pathogen level by >80% (p < 0.001) and AMR by up to 3 Log₁₀ (p < 0.001) compared to controls. Collected data support the use of combined strategies to improve indoor microbial quality and confirm that PBS can effectively control bioburden and AMR spread not only in sanitary environments. Full article

Indoor fungal communities, found in household dust, significantly influence indoor air quality and health. These communities are shaped by environmental, socioeconomic, and household factors. However, studies on indoor mycobiomes, particularly in Croatia, remain limited. This study investigates the relationship between environmental and household factors and indoor fungal communities, focusing on their diversity, composition, and potential health impacts in Croatian households. Dust samples from 66 Croatian households were analyzed using fungal ITS sequencing. Statistical analyses, including alpha diversity measures, were conducted to evaluate the influence of variables such as pet ownership, number of siblings, and cleaning habits on fungal diversity and abundance. Dominant genera included Malassezia, Cladosporium, and the family Didymosphaeriaceae. Pet ownership and sibling presence were linked to higher fungal diversity, with outdoor-associated genera such as Aureobasidium being more abundant in these households. Cleaning practices selectively altered fungal communities, with frequent cleaning reducing diversity, but not eliminating resilient taxa like Malassezia. This study highlights the interplay between environmental, household, and socioeconomic factors in shaping indoor fungal communities. The findings underscore the importance of addressing indoor fungal diversity to improve air quality and health, particularly in households with vulnerable populations. Full article

Background: The role of the indoor microbiome in sick building syndrome (SBS) is well-recognized, yet prior studies have been limited to single-center analyses, limiting a broader understanding and applicability of their findings. Methods: We conducted a multicenter indoor microbiome and metabolome investigation for SBS, involving 1139 middle school students across three regions in Malaysia (Johor Bahru, Terengganu, and Penang). Using high-throughput amplicon sequencing and untargeted LC-MS, indoor microbiome and metabolites were characterized from classroom dust samples. Results: The study found that the prevalence of SBS symptoms was high across all three centers (51.0% to 54.6%). Environmental characteristics, including indoor NO₂ and CO₂ concentrations and total weight of indoor dust, were positively associated with SBS (p < 0.01, linear regression). Curtobacterium in Terengganu was negatively associated with SBS, and Clostridium perfringens in Johor Bahru was positively associated with SBS (p < 0.01, FDR < 0.05). Whereas all identified fungal taxa, including an uncharacterized uc_f_Auriculariaceae_sp., Duportella kuehneroides, and Wallemia mellicola, were positively associated with SBS (p < 0.01, FDR < 0.05) in Johor Bahru and Terengganu. Mediation analysis revealed that the adverse health effects of NO₂ on SBS were partially mediated by the increased abundance of uc_f_Auriculariaceae_sp. (p < 0.05, total effect mediated 51.40%). Additionally, potential protective metabolites (S-adenosylmethionine, N-acetylserotonin, sphinganine, 4-hydroxy-2-quinolone, and (2E,4Z,8E)-Colneleic acid) were mainly derived from environmental microorganisms, conferring protective effects against nasal symptoms and tiredness. In contrast, synthetic chemicals were associated with higher SBS symptoms, inducing eye and nasal symptoms. Conclusions: This study emphasizes both the significance of fostering a balanced indoor microbiome/metabolite and the necessity to reduce exposure to deleterious substances, providing new insights for future targeted intervention strategies. Full article

The pancreas, previously considered a sterile organ, has recently been shown to harbor its own microbiota that may influence tumor biology and patient outcomes. Despite increasing interest in the impact of the microbiome on cancer, the relationship between pancreatic tissue and oral microbiomes in pancreatic ductal adenocarcinoma (PDAC) remains limited. In this study, the oral and pancreas tissue microbiomes of patients with PDAC were compared to patients with other periampullary cancers (DC/AC) and a healthy control group using 16S rRNA gene sequence analysis. The results showed a significant reduction in microbial diversity in the saliva of cancer patients compared to healthy controls, while the PDAC patients exhibited a distinct microbial profile in their pancreatic tissues, consisting predominantly of Firmicutes, Proteobacteria, and Actinobacter, after filtering the microbiome of the indoor environment. Notably, the presence of oral bacteria such as Anoxybacillus, Clostridium, and Bacillus in pancreatic tissues suggests potential translocation from the oral cavity. This study emphasizes the importance of understanding the role of body fluid and tissue microbiota in pancreatic cancer, proposing that oral dysbiosis may contribute to disease progression. Moreover, the results suggest that the microbiome of the indoor environment in which samples are collected and analyzed is also important in microbiota analysis studies. Full article

Sustainable horticulture is crucially based on the greenhouse production of vegetables under controlled conditions. In this study, we wanted to learn how cultivated plants may impact indoor air quality and whether the workers can be exposed to bioaerosols in a similar way in these settings. The study objective was to test the hypothesis that the microbial concentrations, distribution of bioaerosol particle sizes, and composition of the airborne microbiome are specific to greenhouses, polytunnels, and open-air sites. The air samples were collected to assess the concentration of total culturable bacteria (TCB), fungi, actinomycetes, and β-haemolytic bacteria and for the identification of bacterial and fungal strains. Higher concentrations of TCB and fungi were found in the greenhouse (log 3.71 and 3.49 cfu m⁻³, respectively) than in polytunnels (log 2.60–2.48 and 2.51–2.31 cfu m⁻³, respectively) during the vegetation of cucumbers. These airborne microbes were represented by a significant contribution of the respirable fraction with a distinct contribution of fine particles in size below 4.7 µm. Cultivation of cucumbers resulted in the higher emission of airborne microorganisms in contrast with growing herbs such as oregano and basil. In total, 35 different bacteria and 12 fungal species, including pathogenic or allergenic agents, were identified within the studied sites. The workers can be exposed to increased concentrations of TCB and fungi in the greenhouse during the plant vegetation. It might be recommended to properly manage greenhouses and polytunnels, dispose of dust sources, and maintain appropriate ventilation to sustain relevant air quality. Full article

Light intensity primarily drives plant growth and morphogenesis, whereas the ecological impact of light intensity on the phyllosphere (leaf surface and endosphere) microbiome is poorly understood. In this study, garden lettuce (Lactuca sativa L.) plants were grown under low, medium, and high light intensities. High light intensity remarkably induced the leaf contents of soluble proteins and chlorophylls, whereas it reduced the contents of leaf nitrate. In comparison, medium light intensity exhibited the highest contents of soluble sugar, cellulose, and free amino acids. Meanwhile, light intensity resulted in significant changes in the composition of functional genes but not in the taxonomic compositions of the prokaryotic community (bacteria and archaea) in the phyllosphere. Notably, garden lettuce plants under high light intensity treatment harbored more sulfur-cycling mdh and carbon-cycling glyA genes than under low light intensity, both of which were among the 20 most abundant prokaryotic genes in the leaf phyllosphere. Furthermore, the correlations between prokaryotic functional genes and lettuce leaf metabolite groups were examined to disclose their interactions under varying light intensities. The relative abundance of the mdh gene was positively correlated with leaf total chlorophyll content but negatively correlated with leaf nitrate content. In comparison, the relative abundance of the glyA gene was positively correlated with leaf total chlorophyll and carotenoids. Overall, this study revealed that the functional composition of the phyllosphere prokaryotic community and leaf metabolite groups were tightly linked in response to changing light intensities. These findings provided novel insights into the interactions between plants and prokaryotic microbes in indoor farming systems, which will help optimize environmental management in indoor farms and harness beneficial plant–microbe relationships for crop production. Full article

Libraries contain a large amount of organic material, frequently stored with inadequate climate control; thus, mold growth represents a considerable threat to library buildings and their contents. In this essay, we review published papers that have isolated microscopic fungi from library books, shelving, walls, and other surfaces, as well as from air samples within library buildings. Our literature search found 54 published studies about mold in libraries, 53 of which identified fungi to genus and/or species. In 28 of the 53 studies, Aspergillus was the single most common genus isolated from libraries. Most of these studies used traditional culture and microscopic methods for identifying the fungi. Mold damage to books and archival holdings causes biodeterioration of valuable educational and cultural resources. Exposure to molds may also be correlated with negative health effects in both patrons and librarians, so there are legitimate concerns about the dangers of contact with high levels of fungal contamination. Microbiologists are frequently called upon to help librarians after flooding and other events that bring water into library settings. This review can help guide microbiologists to choose appropriate protocols for the isolation and identification of mold in libraries and be a resource for librarians who are not usually trained in building science to manage the threat molds can pose to library holdings. Full article

In this work, we investigated the structure of the airborne bacterial community obtained by 16S rRNA gene sequencing performed on aerosol samples from different indoor and outdoor locations. The 48-h aerosol samples were collected in two laboratories, in the corridors, and on the roof of the Mathematics and Physics Department of the University of Salento (Italy). The investigation was carried out through the application of an innovative compositional data analysis approach, mainly based on a centered log-ratio transformation as a standardization procedure, the Aitchison distance for data ordination, and the principal component analysis via singular value decomposition for data clustering. This methodology allowed us to explore the main relationships among samples, identifying different results between indoor and outdoor samples both at the genus level and at the species level. Bacillus and Pseudomonas represented the most abundant genera identified in the analyzed samples. Out of the 21 identified bacterial species with the highest abundances in the collected aerosol samples, Acinetobacter lwoffii, Propionibacterium acnes, Diplorickettsia massiliensis, and Corynebacterium tuberculostearicum were the only four commonly classified as human opportunistic pathogens. Among the genera mostly associated with indoor environments, Hymenobacter and Arthrobacter could be noted as including many species that are unique in being radiation resistant. Full article

Maintaining a diverse and well-balanced nasal and oral microbiota is vital for human health. However, the impact of indoor microbiome and metabolites on nasal and oral microbiota remains largely unknown. Fifty-six children in Shanghai were surveyed to complete a questionnaire about their personal and environmental characteristics. The indoor microbiome and metabolites from vacuumed indoor dust were profiled via shotgun metagenomics and untargeted liquid chromatography-mass spectrometry (LC–MS). The nasal and oral microbiota in children was characterized using full-length 16S rRNA sequencing from PacBio. Associations between personal/environmental characteristics and the nasal/oral microbiota were calculated using PERMANOVA and regression analyses. We identified 6247, 431, and 342 microbial species in the indoor dust, nasal, and oral cavities, respectively. The overall nasal and oral microbial composition showed significant associations with environmental tobacco smoke (ETS) exposure during pregnancy and early childhood (p = 0.005 and 0.03, respectively), and the abundance of total indoor flavonoids and two mycotoxins (deoxynivalenol and nivalenol) (p = 0.01, 0.02, and 0.03, respectively). Notably, the abundance of several flavonoids, such as baicalein, eupatilin, isoliquiritigenin, tangeritin, and hesperidin, showed positive correlations with alpha diversity and the abundance of protective microbial taxa in nasal and oral cavities (p < 0.02), suggesting their potential beneficial roles in promoting nasal/oral health. Conversely, high carbohydrate/fat food intake and ETS exposure diminished protective microorganisms while augmenting risky microorganisms in the nasal/oral cavities. Further, potential microbial transfer was observed from the indoor environment to the childhood oral cavity (Moraxella catarrhalis, Streptococcus mitis, and Streptococcus salivarius), which could potentially increase virulence factors related to adherence and immune modulation and vancomycin resistance genes in children. This is the first study to reveal the association between the indoor microbiome/metabolites and nasal/oral microbiota using multi-omic approaches. These findings reveal potential protective and risk factors related to the indoor microbial environment. Full article

The black morel Morchella sextelata (Morchellaceae, Pezizales) is a valuable edible mushroom that can be cultivated on a large scale, but a severe yield decline is observed during continuous cropping. The effect of long-term cropping on soil-borne diseases and the dysbiosis of the microbiome and how these biotic factors affect the morel yield are not well understood. To help fill this knowledge gap, we designed an indoor experiment to investigate the influence of black morel cropping regimes on soil physicochemical properties, richness and distribution of fungal community, and morel primordial production. In this study, we employed rDNA metabarcoding and microbial network analysis to evaluate the effect of non-continuous and continuous cropping regimes on the fungal community during three developmental stages of black morel production, namely, the bare soil mycelium, mushroom conidial, and primordial stages. The results showed that during the first year, M. sextelata mycelium overwhelmed the resident soil fungal community by reducing the alpha diversity and niche breadth of soil fungal patterns by a greater amount compared to the continuous cropping regime, leading to high crop yield of 12.39 ± 6.09/quadrat but less complex soil mycobiome. To sustain continuous cropping, exogenous nutrition bags and morel mycelial spawn were consecutively added to the soil. The additional nutrient input stimulated the growth of fungal saprotrophic decomposers. The degrading activity of soil saprotrophs, including M.sextelata, caused a significant increase in soil nutrient content. This led to an inhibitory effect on the formation of morel primordia, resulting in a sharp decline to 0.29 ± 0.25/quadrat and 0.17 ± 0.24/quadrat, respectively, in the final morel cropping. Our findings provided a dynamic overview of the soil fungal community during morel mushroom production, allowing us to identify beneficial and detrimental fungal taxa in the soil mycobiome involved in morel cultivation. The information acquired from this study can be applied to mitigate the adverse impact of continuous cropping on the yield of black morel. Full article

Early childhood is a time of rapid physiological, cognitive, and social development, affected by various environmental factors. The physical environment, including the environmental microbiome (the entire consortium of microorganisms and their theatre of activity in a given environment), plays an essential role in childhood development and can be shaped in ways to support health and wellbeing. In this Perspective article, we present considerations for early childhood education settings that wish to shape their outdoor and indoor environments to optimise human and ecosystem health. This is done in line with the latest evidence base on optimising health-supporting interactions between humans and environmental microbiota, but also in pedagogically and developmentally appropriate ways. Based on the Microbiome-Inspired Green Infrastructure (MIGI) principles, the considerations presented here not only support health through human–nature interactions and a healthier natural environment, but also promote a closer, reciprocal relationship between children and their natural environments. Full article

Indoor spaces exhibit microbial compositions that are distinctly dissimilar from one another and from outdoor spaces. Unique in this regard, and a topic that has only recently come into focus, is the microbiome of hospitals. While the benefits of knowing exactly which microorganisms propagate how and where in hospitals are undoubtedly beneficial for preventing hospital-acquired infections, there are, to date, no standardized procedures on how to best study the hospital microbiome. Our study aimed to investigate the microbiome of hospital sanitary facilities, outlining the extent to which hospital microbiome analyses differ according to sample-preparation protocol. For this purpose, fifty samples were collected from two separate hospitals—from three wards and one hospital laboratory—using two different storage media from which DNA was extracted using two different extraction kits and sequenced with two different primer pairs (V1–V2 and V3–V4). There were no observable differences between the sample-preservation media, small differences in detected taxa between the DNA extraction kits (mainly concerning Propionibacteriaceae), and large differences in detected taxa between the two primer pairs V1–V2 and V3–V4. This analysis also showed that microbial occurrences and compositions can vary greatly from toilets to sinks to showers and across wards and hospitals. In surgical wards, patient toilets appeared to be characterized by lower species richness and diversity than staff toilets. Which sampling sites are the best for which assessments should be analyzed in more depth. The fact that the sample processing methods we investigated (apart from the choice of primers) seem to have changed the results only slightly suggests that comparing hospital microbiome studies is a realistic option. The observed differences in species richness and diversity between patient and staff toilets should be further investigated, as these, if confirmed, could be a result of excreted antimicrobials. Full article