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Environment International Oct 2020Bioaerosol particles, originated from many different earth ground sources, have unique health impacts, including respiratory infections, allergic reactions, and toxic...
Bioaerosol particles, originated from many different earth ground sources, have unique health impacts, including respiratory infections, allergic reactions, and toxic effects. Here, we applied a portable high-flow sampler HighBioTrap to collect and investigate bioaerosol emissions from 13 different land types (forest, wetland, lake, bare soil, cropland, wastewater treatment facility, street, livestock farm, smeltery and garden) that are heavily or less affected by humans. Plate cultivation, real-time quantitative PCR analysis (q-PCR) and high-throughput gene sequencing analysis were used to characterize bacterial and fungal levels as well as their community structures emitted from different land use types. Results showed that there were statistically significant differences in biological emission levels (up to 100-fold difference) and diversity among different land use types. Cropland, sewage plant street and smeltery heavily affected by human activities were found to exhibit higher bioaerosol emission levels, with Massilia genus detected as the dominant species. In contrast, some land types (lakes, forests, gardens, and wetland) less affected by humans were found to emit lower bioaerosol levels but with higher culturability, e.g., up to 16% for wetland. In addition, the microbiological structures of these land-use types usually had higher species richness and diversity, yet different dominant species. For some land types such as streets in Beijing, the microbial community appeared to be skewed with an over 80% relative abundance of a specific dominant species such as Massilia. Other detected dominant species also included Acinetobacter and Brevundimonas for street, and Sphingomonas for wetland. For fungal community, Naganishia, Alternaria, Penicillium, and Aureobasidium were detected to be most abundant. RDA analysis showed metals and ions could to some extent affect the microbial community structures. This work highlights that the human activities could substantially affect the airborne microbiota, which in turn could affect local human health and ecosystems. On the other hand, the results here provide important references for quantitatively estimating the microbial emissions from the earth into the atmosphere.
Topics: Beijing; Forests; Humans; Soil; Soil Microbiology; Wetlands
PubMed: 32717647
DOI: 10.1016/j.envint.2020.105988 -
Archives of Toxicology Feb 2022The biologically stable and highly toxic organophosphorus nerve agent (OP) VX poses a major health threat. Standard medical therapy, consisting of reactivators and... (Comparative Study)
Comparative Study
The biologically stable and highly toxic organophosphorus nerve agent (OP) VX poses a major health threat. Standard medical therapy, consisting of reactivators and competitive muscarinic receptor antagonists, is insufficient. Recently, two engineered mutants of the Brevundimonas diminuta phosphotriesterase (PTE) with enhanced catalytic efficiency (k/K = 21 to 38 × 10 M min) towards VX and a preferential hydrolysis of the more toxic P(-) enantiomer were described: PTE-C23(R152E)-PAS(100)-10-2-C3(I106A/C59V/C227V/E71K)-PAS(200) (PTE-2), a single-chain bispecific enzyme with a PAS linker and tag having enlarged substrate spectrum, and 10-2-C3(C59V/C227V)-PAS(200) (PTE-3), a stabilized homodimeric enzyme with a double PASylation tag (PAS-tag) to reduce plasma clearance. To assess in vivo efficacy, these engineered enzymes were tested in an anesthetized rat model post-VX exposure (~ 2LD) in comparison with the recombinant wild-type PTE (PTE-1), dosed at 1.0 mg kg i.v.: PTE-2 dosed at 1.3 mg kg i.v. (PTE-2.1) and 2.6 mg kg i.v. (PTE-2.2) and PTE-3 at 1.4 mg kg i.v. Injection of the mutants PTE-2.2 and PTE-3, 5 min after s.c. VX exposure, ensured survival and prevented severe signs of a cholinergic crisis. Inhibition of erythrocyte acetylcholinesterase (AChE) could not be prevented. However, medulla oblongata and diaphragm AChE activity was partially preserved. All animals treated with the wild-type enzyme, PTE-1, showed severe cholinergic signs and died during the observation period of 180 min. PTE-2.1 resulted in the survival of all animals, yet accompanied by severe signs of OP poisoning. This study demonstrates for the first time efficient detoxification in vivo achieved with low doses of heterodimeric PTE-2 as well as PTE-3 and indicates the suitability of these engineered enzymes for the development of highly effective catalytic scavengers directed against VX.
Topics: Animals; Caulobacteraceae; Chemical Warfare Agents; Cholinesterase Inhibitors; Male; Organothiophosphorus Compounds; Phosphoric Triester Hydrolases; Protein Engineering; Rats; Rats, Wistar; Stereoisomerism
PubMed: 34962578
DOI: 10.1007/s00204-021-03199-6 -
Germs Mar 2023spp. are rare and opportunistic pathogens which may cause infections in patients who are immunocompromised or have underlying disease.
INTRODUCTION
spp. are rare and opportunistic pathogens which may cause infections in patients who are immunocompromised or have underlying disease.
CASE REPORT
Two cases with a microbiological diagnosis of and spp. are presented. Both occurred in immunocompromised patients with post-chemotherapy febrile neutropenia for B-type acute lymphoblastic leukemia and hepatoblastoma. Antibiogram findings showed resistance to quinolones, ceftazidime, and intermediate resistance to cefepime, being susceptible to carbapenems and aminoglycosides. The cases responded favorably to the administration of carbapenem.
CONCLUSIONS
The identification of the species and antimicrobial susceptibility profile favor response to infection, denoting the importance of species identification and the performance of an antibiogram to determine the different susceptibility profiles described in the literature on this emerging pathogen.
PubMed: 38023950
DOI: 10.18683/germs.2023.1369 -
PloS One 2022This study explored changes in the microbial community structure during straw degradation by a microbial decomposer, M44. The microbial community succession at different...
This study explored changes in the microbial community structure during straw degradation by a microbial decomposer, M44. The microbial community succession at different degradation periods was analyzed using MiSeq high-throughput sequencing. The results showed that 14 days after inoculation, the filter paper enzyme and endoglucanase activities increased to 2.55 U·mL-1 and 2.34 U·mL-1. The xylanase, laccase, and lignin peroxidase activities rose to 9.86 U·mL-1, 132.16 U·L-1, and 85.43 U·L-1 after 28 d, which was consistent with changes in the straw degradation rate. The degradation rates of straw, lignin, cellulose, and hemicellulose were 31.43%, 13.67%, 25.04%, and 21.69%, respectively, after 28 d of fermentation at 15°C. Proteobacteria, Firmicutes, and Bacteroidetes were the main bacterial species in samples at different degradation stages. The dominant genera included Pseudomonas, Delftia, and Paenibacillus during the initial stage (1 d, 7 d) and the mid-term stage (14 d). The key functional microbes during the late stage (21 d, 28 d) were Rhizobium, Chryseobacterium, Sphingobacterium, Brevundimonas, and Devosia. Changes in the bacterial consortium structure and straw degradation characteristics during different degradation periods were clarified to provide a theoretical basis for the rational utilization of microbial decomposer M44.
Topics: Bacteria; Cellulose; Fermentation; Lignin; Microbial Consortia; Temperature
PubMed: 35802565
DOI: 10.1371/journal.pone.0270162 -
Journal of Aerosol Science Dec 2017This study experimentally assessed bacterial water-to-air partitioning coefficients resulting from showerhead aerosolization of water contaminated with or , and...
This study experimentally assessed bacterial water-to-air partitioning coefficients resulting from showerhead aerosolization of water contaminated with or , and estimated human exposure through inhalation. Dechlorinated tap water was spiked with two cell densities (10 and 10 CFU l) and cycled at three temperatures (10, 25, and 37 or 40ºC) through a full-scale shower system. For reproducibility, spiked water concentrations were intentionally higher than found in natural environments. Three types of samplers measured size distribution and viable concentrations throughout the system. Results indicate low levels of respirable bioaerosols were generated. The ratio of bacterial contaminant that was effectively aerosolized (bacterial water-to-air partitioning coefficient, ) was low - averaging 1.13×10 L m for and 8.31×10 L m for . However, the respirable fraction of aerosolized organisms was high, averaging above 94% (in shower) and above 99% (downstream) for both organisms. This study found no significant difference in bioaerosol load for a forward facing versus reverse facing individual. Further, for the average hot shower (33-43°C) the total number of respirable bioaerosols is higher, but the observed culturability of those aerosolized cells is lower when compared to lower temperatures. Bacterial water to air partitioning coefficients were calculated to predict microbial air concentration and these empirical parameters may be used for assessing inhalation as a route of exposure to pathogens in contaminated waters.
PubMed: 30319141
DOI: 10.1016/j.jaerosci.2017.08.008 -
PloS One 2017The Caulobacter crescentus cell extension known as a stalk represents an unusual bacterial morphology. C. crescentus produces stalks under multiple nutrient conditions,...
The Caulobacter crescentus cell extension known as a stalk represents an unusual bacterial morphology. C. crescentus produces stalks under multiple nutrient conditions, but the length of the stalk is increased in response to phosphate starvation. However, the exact function of the stalk is not known, nor is it known how much stalk biogenesis or function is conserved with other stalked bacteria. Work presented here shows that many organisms in the Caulobacter genus and the next closest genus (Brevundimonas) generally do not synthesize stalks in the relatively-rich PYE growth medium, suggesting that the synthesis of a stalk under nutrient-rich conditions by C. crescentus may be the exception instead of the norm among its phylogenetic group. Brevundimonas subvibrioides can be induced to synthesize stalks by genetically mimicking phosphate starvation conditions, indicating stalk synthesis in this organism may be performed on an as-need basis. This mutation, however, does not appear to increase the incidence of holdfast synthesis. While B. subvibrioides stalks appear to be synthesized with the same polarity with respect to holdfast as C. crescentus stalks, evidence is presented that suggests B. subvibrioides may disassemble stalks when they are no longer needed. Many homologs of C. crescentus genes encoding stalk-associated proteins are absent in the B. subvibrioides genome, and B. subvibrioides PstA-GFP as well as C. crescentus StpX-GFP are able to enter the B. subvibrioides stalk compartment, calling into question the level of compartmentalization of the B. subvibrioides stalk. In summary, this work begins to address how much the C. crescentus model for this unusual morphological adaptation can be extended to related organisms.
Topics: Alphaproteobacteria; Caulobacter crescentus; Evolution, Molecular; Gene Deletion; Mutation; Nutritional Physiological Phenomena; Phosphate-Binding Proteins
PubMed: 28886080
DOI: 10.1371/journal.pone.0184063 -
Scientific Reports Apr 2022We analysed the human milk microbiome in a cohort of 80 lactating women and followed the dynamics in taxa over the course of lactation from birth to 6 months. Two...
We analysed the human milk microbiome in a cohort of 80 lactating women and followed the dynamics in taxa over the course of lactation from birth to 6 months. Two hundred and thirty one milk samples were collected from full-term lactating women at 1, 4, 8 and 24 weeks following birth and analysed for microbiota composition using 16S rRNA sequencing. A significant decrease in milk microbiota diversity was observed throughout the first 6 months of lactation, with the greatest difference seen between week 8 and week 24. Nine genera predominated in milk over lactation from week 1 to week 24, comprising of Staphylococcus, Streptococcus, Pseudomonas, Acinetobacter, Bifidobacterium, Mesorhizobium, Brevundimonas, Flavobacterium, and Rhodococcus; however, fluctuations in these core genera were apparent over time. There was a significant effect of stage of lactation on the microbiome, while no effect of birth mode, infant sex and maternal BMI was observed throughout lactation. Streptococcus had the highest mean relative abundance at week 1 and 24 (17.3% and 24% respectively), whereas Pseudomonas predominated at week 4 (22%) and week 8 (19%). Bifidobacterium and Lactobacillus had the highest mean relative abundance at week 4 (5% and 1.4% respectively), and occurred at a relative abundance of ≤ 1% at all other time points. A decrease in milk microbiota diversity throughout lactation was also observed. This study concluded that lactation stage was the primary driving factor in milk microbiota compositional changes over lactation from birth to 6 months, while mode of delivery was not a factor driving compositional changes throughout human lactation.
Topics: Breast Feeding; Female; Humans; Infant; Lactation; Microbiota; Milk, Human; RNA, Ribosomal, 16S
PubMed: 35379843
DOI: 10.1038/s41598-022-09009-y -
Frontiers in Plant Science 2022Crocins are high-value soluble pigments that are used as colorants and supplements, their presence in nature is extremely limited and, consequently, the high cost of...
Crocins are high-value soluble pigments that are used as colorants and supplements, their presence in nature is extremely limited and, consequently, the high cost of these metabolites hinders their use by other sectors, such as the pharmaceutical and cosmetic industries. The carotenoid cleavage dioxygenase 2L () is the key enzyme in the biosynthetic pathway of crocins in . In this study, was introduced into and for the production of crocins. In addition, a chimeric construct containing the sp. β-carotene hydroxylase (), the mutant gene (), and was also introduced into . Quantitative and qualitative studies on carotenoids and apocarotenoids in the transgenic plants expressing alone showed higher crocin level accumulation in transgenic plants, reaching almost 400 μg/g DW in leaves, while in 36 μg/g DW was obtained. In contrast, plants coexpressing , , and accumulated, 3.5-fold compared to plants only expressing . Crocins with three and four sugar molecules were the main molecular species in both host systems. Our results demonstrate that the production of saffron apocarotenoids is feasible in engineered species and establishes a basis for the development of strategies that may ultimately lead to the commercial exploitation of these valuable pigments for multiple applications.
PubMed: 35350302
DOI: 10.3389/fpls.2022.861140 -
Food Research International (Ottawa,... Dec 2022Metabolic syndrome (MS) is a common metabolic disorder characterized by obesity, insulin resistance, cardiovascular disease and gut microbiota dysbiosis. Pu-erh tea and...
Metabolic syndrome (MS) is a common metabolic disorder characterized by obesity, insulin resistance, cardiovascular disease and gut microbiota dysbiosis. Pu-erh tea and its ingredient theabrownin have known functions on the reduction of body weight gain and fat accumulation. However, few studies systematicly analyze the different contributions and mechanisms of their anti-metabolic syndrome functions through multi-omics combination analysis. Here, we used metagenomics, transcriptomics and metabolomics technology to investigate the anti-metabolic syndrome mechanism of Pu-erh tea and theabrownin in MS mice. Our results suggested that Pu-erh tea and theabrownin interventions could improve the physiological functions of liver, jejunum and adipose tissues in MS mice. Hepatic transcriptome revealed that both interventions could regulate the circadian rhythm pathway. Glycerophospholipid and linoleic acid metabolism were also modulated by both interventions through serum and brain metabolome analysis. Faecal metagenome demonstrated that both interventions could increase the relative abundance of Clostridiales bacterium 42_27, Blautia coccoides and Firmicutes bacterium ASF500, but decrease the relative abundance of Brevundimonas vesicularis. Otherwise, compared with Pu-erh tea, theabrownin markedly upregulated the levels of hepatic antioxidants (i.e., SOD, GSH), prominently downregulated hepatic inflammatory factors (i.e., IL-1, IL-6, TNF-α) and malondialdehyde oxidant, but modestly reduced obesity-associated short-chain fatty acids in faeces in MS mice. Taken together, our data provided insights into the homogeneous and heterogeneous natural biological functions of theabrownin and Pu-erh tea in the treatment of metabolic syndrome.
Topics: Animals; Mice; Gastrointestinal Microbiome; Liver; Metabolic Syndrome; Brain; Obesity; Tea
PubMed: 36461373
DOI: 10.1016/j.foodres.2022.112176 -
Microbiology Spectrum Feb 2023Phyllosphere bacterial communities play important roles in plant fitness and growth. The objective of this study was to characterize the epiphytic and endophytic...
Phyllosphere bacterial communities play important roles in plant fitness and growth. The objective of this study was to characterize the epiphytic and endophytic bacterial communities of boxwood shoots and determine how they may respond to commonly used fungicides. In early summer and early fall, shoot samples were collected immediately before and 1, 7, and 14 days after three fungicides containing chlorothalonil and/or propiconazole were applied to the canopy. Total genomic DNA from shoot surface washings and surface-sterilized shoot tissues was used as the template for 16S rRNA metabarcoding, and the amplicons were sequenced on a Nanopore MinION sequencer to characterize the epiphytic and endophytic communities. The bacterial communities were phylogenetically more diverse on the boxwood shoot surface than in the internal tissue, although the two communities shared 12.7% of the total 1,649 identified genera. The most abundant epiphytes were and , while and were the dominant endophytes. Fungicide treatments had strong impacts on epiphytic bacterial community structure and composition. Analysis of compositions of microbiomes with bias correction (ANCOM-BC) and analysis of variance (ANOVA)-like differential expression (ALDEx2) together identified 312 and 1,362 epiphytes changed in abundance due to fungicide treatments in early summer and early fall, respectively, and over 50% of these epiphytes were negatively impacted by fungicide. The two chlorothalonil-based contact fungicides demonstrated more marked effects than the propiconazole-based systemic fungicide. These results are foundational for exploring and utilizing the full potential of the microbiome and fungicide applications and developing a systems approach to boxwood health and production. Agrochemicals are important tools for safeguarding plants from invasive pathogens, insects, mites, and weeds. How they may affect the plant microbiome, a critical component of crop health and production, was poorly understood. Here, we used boxwood, an iconic low-maintenance landscape plant, to characterize shoot epiphytic and endophytic bacterial communities and their responses to contact and systemic fungicides. This study expanded our understanding of the above-ground microbiome in ornamental plants and is foundational for utilizing the full benefits of the microbiome in concert with different fungicide chemistries to improve boxwood health. This study also sets an example for a more thorough evaluation of these and other agrochemicals for their effects on boxwood microbiomes during production and offers an expanded systems approach that could be used with other crops for enhanced integrated pest management.
PubMed: 36853063
DOI: 10.1128/spectrum.04163-22