Frontiers in Microbiology

Sewage-and fertilizer-derived nutrients alter the intensity, diversity, and toxicity of harmful cyanobacterial blooms in eutrophic lakes
Gobler CJ, Drinkwater RW, Anthony A, Goleski JA, Famularo-Pecora AME, Wallace MK, Straquadine NRW and Hem R
Cyanobacterial harmful algal blooms (CHABs) are promoted by excessive nutrient loading and, while fertilizers and sewage are the most prevalent external nutrient sources in most watersheds, the differential effects of these nutrient sources on CHABs are unknown. Here, we tracked CHABs and performed experiments in five distinct lakes across the Northern US including Lake Erie. Fertilizers with ammonium and orthophosphate, membrane (0.2 μm)-filtered sewage (dominated by reduced forms of nitrogen) sand-and membrane-filtered sewage (dominated by nitrate), and an inorganic nutrient solution of ammonium and orthophosphate were used as experimental nutrient sources for CHABs at N-equivalent, environmentally realistic concentrations. Phytoplankton communities were evaluated fluorometrically, microscopically, and via high throughput sequencing of the 16S rRNA gene, and levels of microcystin and the δN content of particulate organic nitrogen (δPON) were quantified. Fertilizer and both sources of wastewater increased the abundance of cyanobacteria in all experiments across all five lakes ( < 0.05 for all) whereas effects on eukaryotic phytoplankton were limited. Sand-filtered sewage contained less P, organic matter, and ammonium but more nitrate and had a 25% less potent stimulatory effect on cyanobacteria than membrane-filtered sewage, suggesting nitrification may play a role in reducing CHABs. Fertilizer increased microcystin levels and decreased the δPON whereas wastewater increased δPON ( < 0.05 for all). was the genus most consistently promoted by nutrient sources ( < 0.05 in all experiments), followed by ( < 0.05 in 50% of experiments), with increases in biomass consistently elicited by membrane-filtered wastewater. Collectively, results demonstrate that differing types of sewage discharge and fertilizers can promote CHAB intensity and toxicity, while concurrently altering CHAB diversity and δPON. While membrane-filtered sewage consistently favored , the discharge of sewage through sands muted bloom intensity suggesting sand-beds may represent a tool to remove key nutrients and partially mitigate CHABs.
A transformer-based deep learning model for identifying the occurrence of acute hematogenous osteomyelitis and predicting blood culture results
Xia Y, Kang Q, Gao Y and Su J
Acute hematogenous osteomyelitis is the most common form of osteomyelitis in children. In recent years, the incidence of osteomyelitis has been steadily increasing. For pediatric patients, clearly describing their symptoms can be quite challenging, which often necessitates the use of complex diagnostic methods, such as radiology. For those who have been diagnosed, the ability to culture the pathogenic bacteria significantly affects their treatment plan.
Exploring phyllosphere fungal communities of 29 alpine meadow plant species: composition, structure, function, and implications for plant fungal diseases
Yang F, Pu X, Matthew C, Nan Z and Li X
The phyllosphere of plants hosts diverse fungal microbial communities. Despite the significant impact of plant fungal diseases on productivity and community ecology, the relationship between phyllosphere fungal communities and plant health in natural environments remains poorly understood. This study utilized high-throughput sequencing and field investigations to explore the composition, dynamics, and incidence of fungal diseases across 29 plant species from four functional groups (forbs, grasses, legumes, and sedges) in alpine meadow plant communities of the Qinghai-Tibetan Plateau. We identified Ascomycetes and Basidiomycetes as the predominant phyllosphere fungi. Significant differences were observed in the Shannon diversity index, -diversity, indicator fungi, and hub fungi among the functional groups. With the exception of the sedge group, the incidence of fungal diseases in other groups was positively correlated with the proportion of pathogens in the phyllosphere fungal community. Predictive analyses revealed that was strongly associated with high disease incidence in grasses, in forbs, and in legumes, while was associated with low disease incidence in sedges. These findings enhance our understanding of how plant phyllosphere fungal communities assemble in natural environments and improve our ability to predict and manage foliar fungal diseases in alpine meadows.
Molecular characterization of wheat dwarf virus isolates from Serbia based on complete genome sequences
Stanković I, Zečević K, Ristić D, Vučurović I and Krstić B
Wheat dwarf virus (WDV), the species of the genus in the family , is a cereal virus commonly detected in several European, African and Asian countries that causes economic losses.
Research on gut microbiota characteristics of PBC patients at different ALBI grades based on machine learning
Shi H, Wang Q, Xu B, Liu Y, Zhao J, Yang X, Huang C and Jin R
The Albumin-Bilirubin (ALBI) score and grade are widely used to stratify patients with primary biliary cholangitis (PBC) into different disease statuses and risk levels. Recent studies have increasingly highlighted the role of gut microbiota in autoimmune liver diseases. This study aimed to investigate the differences in gut microbiota among PBC patients with varying ALBI grades.
Recurrence and propagation of past functions through mineral facilitated horizontal gene transfer
Verma T, Hendiani S, Carbajo C, Andersen SB, Hammarlund EU, Burmølle M and Sand KK
Horizontal gene transfer is one of the most important drivers of bacterial evolution. Transformation by uptake of extracellular DNA is traditionally not considered to be an effective mode of gene acquisition, simply because extracellular DNA is degraded in a matter of days when it is suspended in e.g. seawater. Recently the age span of stored DNA was increased to at least 2 Ma. Here, we show that can incorporate 60 bp DNA fragments adsorbed to common sedimentary minerals and that the transformation frequencies scale with mineral surface properties. Our work highlights that ancient environmental DNA can fuel the evolution of contemporary bacteria. In contrast to heritable stochastic mutations, the processes by which bacteria acquire new genomic material during times of increased stress and needs, indicate a non-random mechanism that may propel evolution in a non-stochastic manner.
Thermophilic aerobic digestion using aquaculture sludge from rainbow trout aquaculture facilities: effect of salinity
Chun J, Kim SM, Ko G, Shin HJ, Kim M and Cho HU
The objectives of this study were to evaluate the potential of using thermophilic aerobic digestion (TAD) to hydrolyze aquaculture sludge, and to investigate the hydrolysis efficiency and changes in microbial community structure during TAD at 0, 15, and 30 practical salinity units (psu). As digestion progressed, soluble organic matter concentrations in all reactors increased to their maximum values at 6 h. The hydrolysis efficiency at 6 h decreased as salinity increased: 2.42% at 0 psu, 1.78% at 15 psu, and 1.04% at 30 psu. The microbial community compositions at the genus level prominently differed in the relative abundances of dominant bacteria between 0 psu and 30 psu. The relative abundance of genera and increased significantly as salinity increased. Increase in the salinity at which thermophilic aerobic digestion of aquaculture sludge was conducted altered the microbial community structure, which in turn decreased the efficiency of organic matter hydrolysis.
The respiratory chain of in urine-like conditions: critical roles of NDH-2 and -terminal oxidases
González-Montalvo MA, Sorescu JM, Baltes G, Juárez O and Tuz K
is an opportunistic nosocomial bacterial pathogen that commonly causes urinary tract infections. Over the past decades, strains have acquired resistance to common antibiotics that has led to the rise of multidrug-resistant and even pandrug-resistant strains. Infections produced by these strains are nearly impossible to treat, which makes a global priority to develop new antibiotics and there is an urgent need to identify targets to treat infections against this pathogen. However, very little is known about the metabolism and metabolic adaptations of this bacterium in infection sites. In this work, we investigated the respiratory metabolism of in conditions that resemble human urine, allowing us to identify novel targets for antibiotic development. Here we describe that, unlike other gram-negative pathogens, utilizes the type-2 NADH dehydrogenase (NDH-2) as the main entry point for electrons in the respiratory chain in all growth conditions evaluated. Additionally, in urine-like media, the aerobic metabolism as a whole is upregulated, with significant increases in succinate and lactate dehydrogenase activity. Moreover, our data show that the -I type oxidoreductases are the main terminal oxidases of this microorganism. Our findings support an initial identification of NDH-2 and -I oxidase as attractive targets for the development of new drugs against as they are not found in human hosts.
Banxia-Yiyiren alleviates insomnia and anxiety by regulating the gut microbiota and metabolites of PCPA-induced insomnia model rats
Wang L, Qi X, Wang S, Tian C, Zou T, Liu Z, Chen Q, Chen Y, Zhao Y, Li S, Yang M and Chai N
This study aims to clearly define the effects of Banxia-Yiyiren on the gut microbiota and its metabolites in a para-chlorophenylalanine-induced insomnia model and the possible underlying mechanisms involved.
Role of methanotrophic communities in atmospheric methane oxidation in paddy soils
Zheng Y, Cai Y and Jia Z
Wetland systems are known methane (CH) sources. However, flooded rice fields are periodically drained. The paddy soils can absorb atmospheric CH during the dry seasons due to high-affinity methane-oxidizing bacteria (methanotroph). Atmospheric CH uptake can be induced during the low-affinity oxidation of high-concentration CH in paddy soils. Multiple interacting factors control atmospheric CH uptake in soil ecosystems. Broader biogeographical data are required to refine our understanding of the biotic and abiotic factors related to atmospheric CH uptake in paddy soils. Thus, here, we aimed to assess the high-affinity CH oxidation activity and explored the community composition of active atmospheric methanotrophs in nine geographically distinct Chinese paddy soils. Our findings demonstrated that high-affinity oxidation of 1.86 parts per million by volume (ppmv) CH was quickly induced after 10,000 ppmv high-concentration CH consumption by conventional methanotrophs. The ratios of 16S rRNA to rRNA genes (rDNA) for type II methanotrophs were higher than those for type I methanotrophs in all acid-neutral soils (excluding the alkaline soil) with high-affinity CH oxidation activity. Both the 16S rRNA:rDNA ratios of type II methanotrophs and the abundance of C-labeled type II methanotrophs positively correlated with high-affinity CH oxidation activity. Soil abiotic factors can regulate methanotrophic community composition and atmospheric CH uptake in paddy soils. High-affinity methane oxidation activity, as well as the abundance of type II methanotroph, negatively correlated with soil pH, while they positively correlated with soil nutrient availability (soil organic carbon, total nitrogen, and ammonium-nitrogen). Our results indicate the importance of type II methanotrophs and abiotic factors in atmospheric CH uptake in paddy soils. Our findings offer a broader biogeographical perspective on atmospheric CH uptake in paddy soils. This provides evidence that periodically drained paddy fields can serve as the dry-season CH sink. This study is anticipated to help in determining and devising greenhouse gas mitigation strategies through effective farm management in paddy fields.
Comparative genomic characterization of isolate RVMD1 from Ma'an desert rock varnish challenges systematics
Alnaimat SM, Abushattal S and Dmour SM
Desert environments harbor unique microbial communities. This study focuses on isolate RVMD1, isolated from rock varnish in the Ma'an Desert. Initial identification was achieved using 16S rRNA gene sequencing, followed by whole-genome sequencing (WGS) for comprehensive characterization. The genome comprises 4,264,015 base pairs (857 contigs) with a high G + C content of 74.59%. A total of 4,449 proteins were predicted. Comparative analysis utilizing OrthoANI, ANI, AAI, and dDDH metrics suggests that RVMD1 belongs to the group, with the highest similarity to (97.71% ANI). Phylogenomic analysis of 43 genomes revealed significant heterogeneity within the genus. Our results challenge current systematics, with potentially representing up to 9 distinct genomospecies. Isolate RVMD1 shows genetic adaptations to its desert environment, including genes for denitrification, oxygen and sulfur cycling, and diverse hydrogen metabolism. Pangenomic analysis uncovered a considerable number of unique genes within RVMD1, highlighting its genetic distinctiveness. Gene family expansions suggest evolution in response to stressors like UV radiation and nutrient limitation. This study represents the first whole-genome analysis of a bacterium isolated from Jordanian rock varnish, emphasizing the value of WGS in understanding microbial diversity and adaptation in extreme environments.
Dynamic succession of the quantity and composition of epiphytic microorganisms at different growth stages on rice surface
Huang L, Zhang Z, Mu L, Liu X, Sun R, Gao W and Chen G
The quality of silage is uneven, which is due to the difference of epiphytic microorganisms of raw materials. To improve the quality of fermentation, the quantity and composition of epiphytic microorganisms are usually analyzed to better prepare silage. In this research, plate coating method and 16S high-throughput sequencing were used to analyze the differences in the quantity and composition of rice epiphytic microorganisms during different growth stages. The Lactic acid bacteria (LAB) and aerobic bacteria were the highest at the flowering stage, the yeast was the highest at the milk ripening stage, and the mould was the highest at the full ripening stage. And the growth stage also had a great influence on the composition of epiphytic bacterial community, at the phylum level, it was mainly composed of Proteobacteria. And at the genus level, and were dominanted at the flowering stage; and were dominanted at the milk ripening stage; and were dominanted at the dough stage; and were dominated at the full ripening stage. Overall, the growth stage significantly affected the quantity and composition of rice epiphytic microorganisms. Therefore, rice silage can be modulated reasonably according to the number and composition of epiphytic microorganisms in different growth stages.
The microbiome analysis of ripen grape berries supports the complex etiology of sour rot
Brischetto C, Rossi V and Fedele G
Sour rot (SR) is a grapevine disease complex that is not completely understood in its etiology and epidemiology. Recently, SR has received special attention due to its increasing economic importance due to crop losses and reduced wine quality. In this study, the fungal and bacterial microbiota of healthy (i.e., without rot symptoms) and rotten (i.e., exhibiting visual and olfactory SR symptoms) ripe bunches were characterized across 47 epidemics (39 vineyards in six Italian grape-growing areas) over three years. The 16S rRNA gene, ITS high-throughput amplicon sequencing, and quantitative PCR were used to assess the relative abundance and dynamic changes of microorganisms associated with SR. The estimators of genera richness of fungal communities within samples indicated a significantly different diversity between healthy and rotten bunches. For bacterial communities, the healthy and rotten bunches significantly differed in the total number of species, but not in abundance distribution across species. The bunch status (i.e., healthy and rotten) was a significant source of diversity ( < 0.01) when the community composition between samples was evaluated, indicating that microbiome composition varied between healthy and rotten bunches. In particular, healthy and rotten bunches shared 43.1 and 54.8% of fungal and bacterial genera, respectively; 31.3% (fungal) and 26.2% (bacterial) genera were associated with rotten bunches only. The yeast genera , , , , and and the bacterial genera , , , , and were strongly associated with bunches showing SR symptoms based on a linear discriminant analysis. These microorganisms have been associated with insects in literature. The relationships between the microflora associated with SR-affected bunches and the roles of in SR development need further investigation, which may open perspectives for more effective disease control.
experimental model to test new antimicrobials: a methodological approach
Vidal M, Arch M, Fuentes E and Cardona PJ
Given the increasing concern about antimicrobial resistance among the microorganisms that cause infections in our society, there is an urgent need for new drug discovery. Currently, this process involves testing many low-quality compounds, resulting from the testing, on mammal models, which not only wastes time, resources, and money, but also raises ethical questions. In this review, we have discussed the potential of as an intermediary experimental model in this drug discovery timeline. We have tackled the topic from a methodological perspective, providing recommendations regarding the range of drug concentrations to test based on the mechanism of action of each compound; how to treat , how to monitor that treatment, and what parameters we should consider when designing a drug screening protocol to maximize the study's benefits. We also discuss the necessary improvements needed to establish the model of infection as a standard technique in the drug screening process. Overall, has been demonstrated to be a manageable model for studying broad-spectrum infection treatment. It allows us to obtain valuable information in a cost-effective manner, which can improve the drug screening process and provide insights into our current major concern. This approach is also in line with the 3R policy in biomedical research, in particular on the replacement and reduce the use of vertebrates in preclinical development.
Correlation between oxygenation function and laboratory indicators in COVID-19 patients based on non-enhanced chest CT images and construction of an artificial intelligence prediction model
Kong W, Liu Y, Li W, Yang K, Yu L and Jiao G
By extracting early chest CT radiomic features of COVID-19 patients, we explored their correlation with laboratory indicators and oxygenation index (PaO/FiO), thereby developed an Artificial Intelligence (AI) model based on radiomic features to predict the deterioration of oxygenation function in COVID-19 patients.
Comparative study of endophytic bacterial strains from non-host crops for enhancing plant growth and managing early blight in tomato
Kukreti A, Siddabasappa CB, Krishnareddy PM, Devanna P, Basavapatna Subbanna Y, Channappa M, Reddy NK, Hashem A, Alsayed MF and Abd Allah EF
, , and are potent bacterial endophytes, which typically exhibit host-specific interactions. However, comparative studies of these endophytes and in non-host crops are lacking. Therefore, in this study, we evaluated the potential of endophytes strain HP3d, strain PGSS1, strain A6, and P42, isolated from various crop ecosystems in promoting plant growth and inducing systemic resistance against early blight disease in tomato. , endophytes exhibited 44.44-55.56% and 37.50-87.50% inhibition of in dual culture and volatilome bioassay, respectively. In the glasshouse, individual and combined applications via seed treatment (ST), seedling dip (SD), and foliar spray (FS) significantly enhanced shoot growth (23.63-57.61%), root growth (43.27-118.23%), number of leaves (77.52-93.58%), number of shoots (33.42-45.28%) and root dry matter (42.17-43.86%), reducing early blight (PDI) by 70.95-76.12% compared to uninoculated control. Enzymatic activities, including such as polyphenol oxidase (30-40 fold), peroxidase (65.00-75.00 fold), superoxide dismutase (34.20-37.20 fold) and phenylalanine ammonia-lyase (44.44-45.56 fold) were elevated post-inoculation in endophytes treated tomato plants challenged with compared to control treated only with and declined after the fifth day. The total chlorophyll content declined from the 0th to the 10th day, but endophyte treated plants exhibited lesser reductions (2.03-2.09) than uninoculated control. Field trials confirmed the glasshouse findings, showing reduced early blight and improved growth parameters in tomato where the ST + SD + FS combination emerged as the most effective treatment for all endophytes showing 1.06-1.88 fold increase in fruit yield per plant and 28.92-32.52% decrease in PDI compared to untreated control. Thus, the study highlights the broad-spectrum potential of these strains in promoting plant growth and controlling early blight in tomato, demonstrating non-host specificity. These endophytes offer eco-friendly alternatives to chemical pesticides, supporting sustainable agriculture. Their success in field trials suggests the potential for commercialization and large-scale use across diverse crops and pave the way for further interdisciplinary research to optimize their application in integrated pest management strategies.
Debate on the relationship between infection and inflammatory bowel disease: a bibliometric analysis
Wang Z, Zhao S, Zhong X, Su Y, Song Y, Li J and Shi Y
Inflammatory bowel diseases (IBD) are chronic inflammation conditions affecting the gastrointestinal tract. Studies point out an association between () infection and IBD. This study aims to visually assess the research trends and hotspots in the field of infection and IBD, review mainstream perspectives in this field, and provide a foundation for future research and treatment.
Genome-wide comparative analysis of clinical and environmental strains of the opportunistic pathogen ()
Szuplewska M, Sentkowska D, Lasek R, Decewicz P, Hałucha M, Funk Ł, Chmielowska C and Bartosik D
is the first species in the genus to be implicated in opportunistic infections in humans. As a result, strains provide a valuable model for exploring how bacteria shift from a saprophytic to a pathogenic lifestyle, as well as for investigating the role of horizontally transferred DNA in this transition. In order to gain deeper insights into the unique characteristics of this bacterium and the molecular mechanisms underlying its opportunistic behavior, a comparative physiological and genomic analysis of strains was performed.
Revealing the metabolic potential and environmental adaptation of nematophagous fungus, , derived from hadal sediment
Li Y, Zhang C, Zhong M, Hu S, Cui Y, Fang J and Yu X
The extreme environment shapes fungi in deep-sea sediments with novel metabolic capabilities. The ubiquity of fungi in deep-sea habitats supports their significant roles in these ecosystems. However, there is limited research on the metabolic activities and adaptive mechanisms of filamentous fungi in deep-sea ecosystems. In this study, we investigated the biological activities, including antibacterial, antitumor and nematicidal activity of FDZ8Y1, isolated from sediments of the Mariana Trench. A key feature of FDZ8Y1 was its tolerance to high hydrostatic pressure (HHP), up to 110 MPa. We showed that HHP affected its vegetative growth, development, and production of secondary metabolites, indicating the potential for discovering novel natural products from hadal fungi. Whole-genome sequencing of FDZ8Y1 revealed the metabolic potential of this piezotolerant fungus in carbon (carbohydrate metabolism), nitrogen (assimilatory nitrate reduction and protein degradation) and sulfur cycling processes (assimilatory sulfate reduction). Transcriptomic analysis under elevated HHP showed that FDZ8Y1 may activate several metabolic pathways and stress proteins to cope with HHP, including fatty acid metabolism, the antioxidant defense system, the biosynthetic pathway for secondary metabolites, extracellular enzymes and membrane transporters. This study provides valuable insights into the metabolic potential and adaptation mechanisms of hadal fungi to the challenging conditions of the hadal environment.
First report on the physicochemical and proteomic characterization of outer membrane vesicles under urine-mimicking growth conditions: comparative analysis with
González MJ, Navarro N, Cruz E, Sánchez S, Morales JO, Zunino P, Robino L, Lima A and Scavone P
Uropathogenic bacteria employ multiple strategies to colonize the urinary tract, including biofilm formation, invasion of urothelial cells, and the production of adhesins, toxins, and siderophores. Among the most prevalent pathogens causing urinary tract infections (UTIs) are Uropathogenic and . A notable feature of Gram-negative bacteria is their ability to produce outer membrane vesicles (OMVs), which play critical roles in bacterial survival, virulence, and host-pathogen interactions, including UTIs.
Editorial: New therapeutic strategies against carbapenem-resistant gram-negative bacteria
Mascellino MT, Oliva A, Biswas S and Ceccarelli G