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Environment International Mar 2024Artificial sweeteners (AS) are extensively utilized as sugar substitutes and have been recognized as emerging environmental contaminants. While the effect of AS on...
Artificial sweeteners (AS) are extensively utilized as sugar substitutes and have been recognized as emerging environmental contaminants. While the effect of AS on aquatic organisms has garnered recent attention, their effects on soil invertebrates and gut microbial communities remain unclear. To address this knowledge gap, we exposed springtails (Folsomia candida) to both single and combined treatments of four typical AS (sucralose [SUC], saccharin [SAC], cyclamate [CYC], and acesulfame [ACE]) at environmentally relevant concentrations of 0.01, 0.1 and 1 mg kg in soil. Following the first-generational exposure, the reproduction of juveniles showed a significant increase under all the AS treatments of 0.1 mg kg. The transcriptomic analysis revealed significant enrichment of several Kyoto Encyclopedia of Gene and Genome pathways (e.g., glycolysis/gluconeogenesis, pentose and glucuronate interconversions, amino sugar, and nucleotide sugar metabolism, ribosome, and lysosome) in springtails under all AS treatments. Analysis of gut bacterial microbiota indicated that three AS (SUC, CYC, and ACE) significantly decreased alpha diversity, and all AS treatments increased the abundance of the genus Achromobacter. After the sixth-generational exposure to CYC, weight increased, but reproduction was inhibited. The pathways that changed significantly (e.g., extracellular matrix-receptor interaction, amino sugar and nucleotide sugar metabolism, lysosome) were generally similar to those altered in first-generational exposure, but with opposite regulation directions. Furthermore, the effect on the alpha diversity of gut microbiota was contrary to that after first-generational exposure, and more noticeable disturbances in microbiota composition were observed. These findings underscore the ecological risk of AS in soils and improve our understanding of the toxicity effects of AS on living organisms.
Topics: Sweetening Agents; Soil; Gastrointestinal Microbiome; Water Pollutants, Chemical; Cyclamates; Amino Sugars; Nucleotides
PubMed: 38359549
DOI: 10.1016/j.envint.2024.108496 -
Urology Apr 2024To determine which bacteria are associated with an increased risk of 90-day complications after urethroplasty. Preoperative bacteriuria is associated with an increased...
OBJECTIVE
To determine which bacteria are associated with an increased risk of 90-day complications after urethroplasty. Preoperative bacteriuria is associated with an increased risk of complications after urethroplasty. However, it remains unclear which specific micro-organisms are the primary drivers of this morbidity.
METHODS
A single-institution, 2-surgeon retrospective review was performed on patients undergoing urethroplasty from 08/2003 to 06/2021. Preoperative bacteriuria was considered significant when the patient had a mixed culture with ≥10 CFU/L or an identifiable micro-organism with ≥10 CFU/L. Descriptive statistics were used to summarize the results and chi-square was used to determine the association between 90-day complications (Clavien ≥2) and clinical characteristics/bacteria.
RESULTS
Out of 1611 patients, 23.2% (373) had significant preoperative bacteriuria. The most common pathogens included coagulase-negative staphylococcus 18.5% (69), mixed growth 15.8% (59), Escherichia coli 10.7% (40), and Enterococcus 14.2% (53). 7.9% (128/1611) experienced a significant 90-day complication (Clavien-Dindo ≥2). Gram-negative bacilli including E coli, Pseudomonas sp, Klebsiella sp, Serratia sp, Citrobacter sp, Achromobacter sp, Stenotrophomonas sp, and Morganella sp were associated with higher rates of postoperative complications (14.2%; P = .01) as well as Enterococcus sp (15.1%; P = .03). However, gram-positive cocci (7.9%; P = .97), gram-positive bacilli (11.8%; P = .47), mixed growth (5.1%; P = .54) and Candida (16.7%; P = .27) were not. Neither escalating concentrations of bacteria (P = .44) or number of strains (P = .08) were associated with increased risk of complications.
CONCLUSION
The main driver of bacteriuria-related complications after urethroplasty are gram-negative bacilli and Enterococcus sp. Patients with bacteriuria related to other micro-organisms can likely proceed with urethroplasty without increased risk of postoperative complications.
Topics: Humans; Bacteriuria; Escherichia coli; Bacteria; Risk Factors; Postoperative Complications; Anti-Bacterial Agents
PubMed: 38354912
DOI: 10.1016/j.urology.2024.01.013 -
The Science of the Total Environment Apr 2024As one of the most commonly used biocidal cationic surfactants, benzalkonium chlorides (BACs) have been an increasing concern as emerging contaminants. Wastewater has...
As one of the most commonly used biocidal cationic surfactants, benzalkonium chlorides (BACs) have been an increasing concern as emerging contaminants. Wastewater has been claimed the main point for BACs to enter into the environment, but to date, it is still largely unknown how the BACs affect the microbes (especially microalgae) in the practical wastewater and how to cost-effectively remove them. In this study, the inhibitory effects of a typical BACs, dodecyl dimethyl benzyl ammonium chloride (DDBAC), on a green microalga Chlorella sp. in oxidation pond wastewater were investigated. The results showed that though a hermetic effect at the first 2 days was observed with the DDBAC at low concentration (<6 mg/L), the algal growth and photosynthesis were significantly inhibited by the DDBAC at all the tested concentrations (3 to 48 mg/L). Fortunately, a new microbial consortium (MC) capable of degrading DDBAC was screened through a gradient domestication method. The MC mainly composed of Wickerhamomyces sp., Purpureocillium sp., and Achromobacter sp., and its maximum removal efficiency and removal rate of DDBAC (48 mg/L) respectively reached 98.1 % and 46.32 mg/L/d. Interestingly, a microbial-microalgal system (MMS) was constructed using the MC and Chlorella sp., and a synergetic effect between the two kinds of microorganisms was proposed: microalga provided oxygen and extracellular polysaccharides as co-metabolic substrates to help the MC to degrade DDBAC, while the MC helped to eliminate the DDBAC-induced inhibition on the alga. Further, by observing the seven kinds of degradation products (mainly including CHOP, CHCH-, and CHN), two possible chemical pathways of the DDBAC degradation were proposed. In addition, the metagenomic sequencing results showed that the main functional genes of the MMS included antibiotic-resistant genes, ABC transporter genes, quorum sensing genes, two-component regulatory system genes, etc. This study provided some theoretical and application findings for the cost-effective pollution prevention of BACs in wastewater.
Topics: Wastewater; Microalgae; Ammonium Chloride; Microbial Consortia; Chlorella; Coculture Techniques; Biomass
PubMed: 38350567
DOI: 10.1016/j.scitotenv.2024.170676 -
Frontiers in Microbiology 2024Endosymbiotic bacteria (ESB) have important effects on their hosts, contributing to its growth, reproduction and biological functions. Although the effects of exogenous...
Endosymbiotic bacteria (ESB) have important effects on their hosts, contributing to its growth, reproduction and biological functions. Although the effects of exogenous bacteria on the trap formation of nematode-trapping fungi (NTF) have been revealed, the effects of ESB on NTF remain unknown. In this study, we investigated the species diversity of ESB in the NTF using high-throughput sequencing and culture-dependent approaches, and compared bacterial profiles to assess the effects of strain source and culture media on . PICRUSt2 and FAPROTAX were used to predict bacterial function. Our study revealed that bacterial communities in displayed high diversity and heterogeneity, with Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria as the dominant phyla. The ESB between groups isolated from different habitats and cultured in the same medium were more similar to each other than the other groups isolated from the same habitat but cultured in different media. Function analysis predicted a broad and diverse functional repertoire of ESB in , and unveiled that ESB have the potential to function in five modules of the nitrogen metabolism. We isolated nitrogen-fixing and denitrifying bacteria from the ESB and demonstrated their effects on trap formation of . Among seven bacteria that we tested, three bacterial species , and were found to be efficient in inducing trap formation. In conclusion, this study revealed extensive ESB diversity within NTF and demonstrated that these bacteria likely play important roles in nitrogen cycling, including nematode trap formation.
PubMed: 38348183
DOI: 10.3389/fmicb.2024.1349447 -
Plant Disease Feb 2024Scrub titi (), broadleaf semi-evergreen shrub, is endemic to central Florida. However, its smaller stature, lustrous, dark-green leaves and abundance of white racemes in...
Scrub titi (), broadleaf semi-evergreen shrub, is endemic to central Florida. However, its smaller stature, lustrous, dark-green leaves and abundance of white racemes in late spring make it a potential candidate for future use in Southeastern U.S. landscapes. Three-years-old container grown plants maintained in a shade house at the Nursery Research Center, McMinnville, TN exhibited black leaf lesions and brown stem lesions (Fig. 1a) in April 2023. The disease severity was 25% of the shoot area and the disease incidence was 10% out of 60 plants. Symptomatic stem and leaf tissues were surface sterilized with 0.525% NaOCl for 1 min. Bacterial colonies were white-colored, opaque, round with smooth edges on lysogen broth agar medium after 2 days of incubation at 28°C. Bacteria were gram-negative and non-fluorescent on King's B. Esculin, catalase, and oxidase tests were positive but arginine dihydrolase and gelatine hydrolysis were negative. Bacterial identity was confirmed by sequencing of DNA from pure cultures (strains FBG5290 and FBG5294). The 16S ribosomal RNA, RNA polymerase sigma factor (), enolase (), and NADH-quinone oxidoreductase subunit L () genes were amplified and sequenced using the primers 8F/1492R (Galkiewicz et al. 2008), rpoDpF/R (Sarkar and Guttman 2004), enoP1/P2 and nuoLP1/P2 (Spilker et al. 2012), respectively. The sequences were deposited in GenBank with acc. nos.: OR689356, OR689357 (16S); OR751366, OR751367 (); OR792456, OR792457 (); and OR792458, OR792459 (). The closest identified species to our two identical strains was (CP054571), showing 99.6%, 95.2%, 96.2%, and 95.0% identity with >99% coverage to the above mentioned gene sequences, respectively. Phylogenetic analysis, using concatenated sequences along with the genome sequences of other closely related taxa (Fig. 2), suggest that is presently the identified species, but given the results of the MLST, it may be that this organism will be classified as new species in the future. The pathogenicity of the strains was confirmed on 1-year-old by inoculating five plants per strain. Stems were inoculated by depositing 15 µl of bacterial suspension (1x10 CFU/mL) into the stem wounded using a scalpel. The inoculation sites were covered with moist cotton and wrapped with Parafilm. Inoculation was also performed on three leaves per plant by using a needleless syringe to infiltrate bacteria into the intercellular spaces (1x10 CFU/mL). Sterile water was used for five control plants. Plants were kept in a greenhouse at 21-23°C, 70% RH, and 16-h photoperiod. All inoculated plants showed brown lesions in stems (Fig. 1b and 1c) and leaves (Fig. 1d) 7-10 days after inoculation, while control plants remained asymptomatic (Fig. 1e and 1f). The bacteria were re-isolated from inoculated plants and confirmed as using morphological and molecular methods. spp. are commonly known as human pathogens, and cross-kingdom pathogenic bacterium in animal (mice) and fungi () (Ye et al. 2018). However, was recently reported as the causal agent of stem rot of in China (Wei et al. 2023). To our knowledge, this is the first report of causing bacterial stem and leaf blight of in Tennessee and the U.S. Identification of this novel disease lays the foundation development of effective management strategies.
PubMed: 38345542
DOI: 10.1094/PDIS-01-24-0005-PDN -
Journal of Hazardous Materials Apr 2024Understanding of the environmental behaviors of microplastics is limited by a lack of knowledge about how photoaging influences biofilm formation on microplastics in...
Understanding of the environmental behaviors of microplastics is limited by a lack of knowledge about how photoaging influences biofilm formation on microplastics in soil. Here, original microplastics (OMPs) and photoaged-microplastics (AMPs) were incubated in soil to study the effect of photoaging on formation and characteristics of biofilm on the poly (butylene succinate) microplastics. Because photoaging decreased the hydrophobicity of the microplastic, the biomass of biofilm on the OMPs was nearly twice that on the AMPs in the early stage of incubation. However, the significance of the substrate on biomass in the biofilm declined as the plastisphere developed. The bacterial communities in the plastisphere were distinct from, and less diverse than, those in surrounding soil. The dominant genera in the OMPs and AMPs plastispheres were Achromobacter and Burkholderia, respectively, indicating that photoaging changed the composition of the bacterial community of biofilm at the genus level. Meantime, photoaging decreased the complexity and stability of the plastisphere bacterial community network. Results of Biolog ECO-microplate assays and functional prediction from amplicons showed that photoaging treatment enhanced the carbon metabolic capacity of the microplastic biofilm. This study provides new insights into the formation of plastispheres in soil.
Topics: Biomass; Microplastics; Plastics; Skin Aging; Microbiota; Biofilms; Soil; Butylene Glycols; Polymers
PubMed: 38341883
DOI: 10.1016/j.jhazmat.2024.133726 -
International Journal of Molecular... Jan 2024Diet plays a crucial role in shaping the gut microbiota and overall health of animals. Traditionally, silkworms are fed fresh mulberry leaves, and artificial diets do...
Diet plays a crucial role in shaping the gut microbiota and overall health of animals. Traditionally, silkworms are fed fresh mulberry leaves, and artificial diets do not support good health. The aim of this study was to explore the relationship between the dietary transition from artificial diets to mulberry leaves and the effects on the gut microbiota and physiological changes in silkworms as a model organism. With the transition from artificial diets to mulberry leaves, the diversity of the silkworm gut microbiota increased, and the proportion of and , the dominant gut bacterial species in silkworms reared on artificial diets, decreased, whereas the abundance of and increased. Dietary transition at different times, including the third or fifth instar larval stages, resulted in significant differences in the growth and development, immune resistance, and silk production capacity of silkworms. These changes might have been associated with the rapid adaptation of the intestinal microbiota of silkworms to dietary transition. This study preliminarily established a dietary transition-gut microbial model in silkworms based on the conversion from artificial diets to mulberry leaves, thus providing an important reference for future studies on the mechanisms through which habitual dietary changes affect host physiology through the gut microbiome.
Topics: Animals; Bombyx; Gastrointestinal Microbiome; Silk; Larva; Morus
PubMed: 38339000
DOI: 10.3390/ijms25031722 -
Journal of Global Antimicrobial... Mar 2024Gram-negative pathogens causing respiratory infection in people with cystic fibrosis and bronchiectasis are becoming progressively more resistant to conventional...
OBJECTIVES
Gram-negative pathogens causing respiratory infection in people with cystic fibrosis and bronchiectasis are becoming progressively more resistant to conventional antibiotics. Although cefiderocol is licenced for the treatment of infections due to Gram-negative organisms, there are limited data on the activity of cefiderocol against pathogens associated with chronic respiratory diseases. The aim of this study was to determine the susceptibility of Gram-negative pathogens from cystic fibrosis and bronchiectasis to cefiderocol and comparator antibiotics.
METHODS
Minimal inhibitory concentrations (MICs) of cefiderocol and 15 comparator antibiotics were determined by broth microdilution against 300 respiratory isolates: Burkholderia spp., Stenotrophomonas spp., Achromobacter spp., Ralstonia spp. and Pandoraea spp., and used to calculate the MIC of each antibiotic required to inhibit 50% (MIC) and 90% (MIC) of isolates.
RESULTS
The MIC and MIC of cefiderocol for all 300 isolates tested was 0.25 and 32 mg/L, with 232 (77.3%) isolates having an MIC value ≤2 mg/L. In addition, cefiderocol demonstrated excellent activity against Stenotrophomonas spp. and Achromobacter spp. isolates, with 86.7% and 87.2%, respectively, exhibiting an MIC of 2 mg/L. Tigecycline also demonstrated good activity against all isolates with an MIC of <0.5 mg/L.
CONCLUSIONS
These in vitro data demonstrated that cefiderocol had greater activity than most comparator antibiotics and could be an alternative treatment option for respiratory infection caused by these pathogens that has not responded to first-line therapy.
Topics: Humans; Cefiderocol; Cephalosporins; Cystic Fibrosis; Gram-Negative Bacteria; Drug Resistance, Multiple, Bacterial; Anti-Bacterial Agents; Bronchiectasis; Respiratory Tract Infections
PubMed: 38336228
DOI: 10.1016/j.jgar.2024.01.023 -
Antonie Van Leeuwenhoek Feb 2024Plant probiotics are live microbial cells or cultures that support plant growth and control plant pathogens through different mechanisms. They have various effects on...
Plant probiotics are live microbial cells or cultures that support plant growth and control plant pathogens through different mechanisms. They have various effects on plants, including plant growth promotion through the production of indole acetic acid (IAA), biological control activity (BCA), and production of cellulase enzymes, thus inducing systemic resistance and increasing the availability of mineral elements. The present work aimed to study the potential of Achromobacter marplatensis and Bacillus velezensis as plant probiotics for the field cultivation of potatoes. In vitro studies have demonstrated the ability of selected probiotics to produce IAA and cellulase, as well as antimicrobial activity against two plant pathogens that infect Solanum tuberosum as Fusarium oxysporum and Ralstonia solanacearum under different conditions at a broad range of different temperatures and pH values. In vivo study of the effects of the probiotics A. marplatensis and B. velezensis on S. tuberosum plants grown in sandy clay loamy soil was detected after cultivation for 90 days. Probiotic isolates A. marplatensis and B. velezensis were able to tolerate ultraviolet radiation (UV) exposure for up to two hours, the dose response curve exhibited that the D values of A. marplatensis and B. velezensis were 28 and 16 respectively. In the case of loading both probiotics with broth, the shoot dry weight was increased significantly from 28 in the control to 50 g, shoot length increased from 24 to 45.7 cm, branches numbers increased from 40 to 70 branch, leaves number increased from 99 to 130 leaf, root dry weight increased from 9.3 to 12.9 g, root length increased from 24 to 35.7 cm, tuber weight increased from 15 to 37.0 g and tubers number increased from 9 to 24.4 tuber, the rot percentage was reduced to 0%. The addition of both probiotic isolates, either broth or wheat grains load separately has enhanced all the growth parameters; however, better results and increased production were in favor of adding probiotics with broth more than wheat. On the other hand, both probiotics showed a remarkable protective effect against potato pathogens separately and reduced the negative impact of the infection using them together.
Topics: Ralstonia solanacearum; Solanum tuberosum; Ultraviolet Rays; Fusarium; Plants; Cellulases; Plant Diseases
PubMed: 38334837
DOI: 10.1007/s10482-024-01928-2 -
Ecology and Evolution Feb 2024Against the backdrop of global warming, marine heatwaves are projected to become increasingly intense and frequent. This trend poses a potential threat to the survival...
Against the backdrop of global warming, marine heatwaves are projected to become increasingly intense and frequent. This trend poses a potential threat to the survival of corals and the maintenance of entire coral reef ecosystems. Despite extensive evidence for the resilience of corals to heat stress, their ability to withstand repeated heatwave events has not been determined. In this study, we examined the responses and resilience of to repeated exposure to marine heatwaves, with a focus on physiological parameters and symbiotic microorganisms. In the first heatwave, from a physiological perspective, showed decreases in the Chl content and endosymbiont density and significant increases in GST, caspase-3, CAT, and SOD levels ( < .05), while the effects of repeated exposure on heatwaves were weaker than those of the initial exposure. In terms of bacteria, the abundance of , with the potential for pathogenicity and intracellular parasitism, increased significantly during the initial exposure. Beneficial bacteria, such as and increased significantly during re-exposure to the heatwave. Overall, these results indicate that might adapt to marine heatwaves through physiological regulation and microbial community alterations.
PubMed: 38322002
DOI: 10.1002/ece3.10869