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Dental and Medical Problems 2022Wearing masks has become an essential safety measure during the coronavirus 2019 (COVID-19) pandemic. Especially clinicians in dental clinics should focus on infection...
BACKGROUND
Wearing masks has become an essential safety measure during the coronavirus 2019 (COVID-19) pandemic. Especially clinicians in dental clinics should focus on infection control. However, there is currently no data regarding the frequency of replacement of the masks used in hospitals. Hence, it is necessary for dental clinic staff, who deal with many patients in an aerosol-producing environment, to have precise mask-wearing guidelines.
OBJECTIVES
The aim of this study was to evaluate the contamination on the inner surface of the masks used by clinicians in dental clinics and provide basic data to describe hospital infection control guidelines in greater detail.
MATERIAL AND METHODS
For Study I,12 participants were recruited. The experiment was conducted indoors. After wearing the mask, the temperature and the humidity inside the mask were measured at the set time points (immediately after wearing the mask, and 10 min, 30 min, 1 h, 2 h, and 4 h after wearing the mask). During the experiment, talking was not allowed. For Study II, 23 clinicians from dental clinics were recruited. After wearing the mask, the temperature, the humidity and the number of colony-forming units (CFU) inside the mask were measured at the set time points. Finally, 15 samples were selected for the study based on a survey. Bacterial identification was conducted using the 16S rDNA sequencing.
RESULTS
The temperature and the humidity inside the mask increased significantly relative to room temperature and room humidity, respectively. Bacteria were found in all the masks worn for more than 10 min and the CFU values increased with the mask-wearing time. Bacteria belonging to the genera Staphylococcus, Bacillus and Roseomonas were detected in the used mask.
CONCLUSIONS
A mask should not be worn for more than 2 h; however, the frequency of mask replacement can vary, depending on the number of patients encountered and the working environment.
Topics: Bacteria; COVID-19; Dental Clinics; Humans; Pandemics
PubMed: 35761755
DOI: 10.17219/dmp/143544 -
Cureus Jun 2023species has been associated with infections in both immunocompetent and immunocompromised hosts, manifesting as peritonitis, bacteremia, catheter-related bacteremia,...
species has been associated with infections in both immunocompetent and immunocompromised hosts, manifesting as peritonitis, bacteremia, catheter-related bacteremia, endophthalmitis, spondylitis, and endocarditis. Here we present a man in his 60s who was brought to our institution for sudden onset of aphasia, right-sided paresthesia, and new onset tonic-clonic seizure episodes. At presentation, he was found to have severe lactic acidosis, acute kidney failure, bilateral hydronephrosis, elevated prostate-specific antigen (PSA), and an enlarged prostate. Blood cultures obtained on admission later grew species for which he was started on meropenem. A trans-esophageal echocardiogram (TEE) showed multiple very thin mobile densities on the ventricular side of the aortic valve; magnetic resonance imaging (MRI) of the brain revealed an 11 mm acute/subacute hemorrhage. The patient was discharged in stable condition on Ertapenem intravenous therapy for six weeks. can be a cause of endocarditis. The antimicrobial resistance profile of suggests that carbapenems, fluoroquinolones or aminoglycosides are the drugs of choice for Roseomonas infections and that infectious diseases involved in cases of infections should be instituted promptly for proper management.
PubMed: 37448416
DOI: 10.7759/cureus.40318 -
Microbiology Spectrum Aug 2022The genus includes widespread plant-associated bacteria that are abundant in the plant phyllosphere (leaf surfaces), consume plant-secreted methanol, and can produce...
The genus includes widespread plant-associated bacteria that are abundant in the plant phyllosphere (leaf surfaces), consume plant-secreted methanol, and can produce plant growth-promoting metabolites. However, despite the potential to increase agricultural productivity, their impact on host fitness in the natural environment is relatively poorly understood. Here, we conducted field experiments with three traditionally cultivated rice landraces from northeastern India. We inoculated seedlings with native versus nonnative phyllosphere strains and found significant impacts on plant growth and grain yield. However, these effects were variable. Whereas some isolates were beneficial for their host, others had no impact or were no more beneficial than the bacterial growth medium on its own. Host plant benefits were not consistently associated with colonization and did not have altered phyllosphere microbiome composition, changes in the early expression of plant stress response pathways, or bacterial auxin production. We provide the first demonstration of the benefits of phyllosphere for rice yield under field conditions and highlight the need for further analysis to understand the mechanisms underlying these benefits. Given that the host landrace- relationship was not generalizable, future agricultural applications will require careful testing to identify coevolved host-bacterium pairs that may enhance the productivity of high-value rice varieties. Plants are associated with diverse microbes in nature. Do the microbes increase host plant health, and can they be used for agricultural applications? This is an important question that must be answered in the field rather than in the laboratory or greenhouse. We tested the effects of native, leaf-inhabiting bacteria (genus ) on traditionally cultivated rice varieties in a crop field. We found that inoculation with some bacteria increased rice grain production substantially while a nonnative bacterium reduced plant health. Overall, the effect of bacterial inoculation varied across pairs of rice varieties and their native bacteria. Thus, knowledge of evolved associations between specific bacteria hosted by specific rice varieties is necessary to develop ways to increase the yield of traditional rice landraces and preserve these important sources of cultural and genetic diversity.
Topics: Agriculture; Edible Grain; Methylobacterium; Oryza; Plant Leaves
PubMed: 35856668
DOI: 10.1128/spectrum.00810-22 -
Microorganisms Nov 2023Radiation methods are widely used for disinfection and sterilization applications. Microorganisms demonstrate known, variable tolerance levels to inactivation with lower...
Radiation methods are widely used for disinfection and sterilization applications. Microorganisms demonstrate known, variable tolerance levels to inactivation with lower doses of ionizing and non-ionizing radiation based on multiple mechanisms of resistance in their structures and nucleic acid repair mechanisms. The radiation dose required to ensure microbial inactivation during sterilization is typically based on the understanding and routine monitoring of the natural population and resistance of microorganisms on products exposed to radiation sterilization processes. This report describes the isolation of in a device manufacturing environment that was detected during routine device bioburden and dose verification monitoring. Sources of Gram-negative bacteria in the environment were investigated. Non-sterile examination gloves used during manufacturing were found to be a persistent source of and other microbial contaminants. The source of contamination was determined to be from the glove manufacturing process. Maintenance and routine microbiological controls during glove manufacturing, including water systems, are required to reduce the risks of gloves being a source of unexpected microbiological contamination.
PubMed: 38138003
DOI: 10.3390/microorganisms11122859 -
The New Phytologist Jan 2021Plant microbiomes are essential to host health and productivity but the ecological processes that govern crop microbiome assembly are not fully known. Here we examined...
Plant microbiomes are essential to host health and productivity but the ecological processes that govern crop microbiome assembly are not fully known. Here we examined bacterial communities across 684 samples from soils (rhizosphere and bulk soil) and multiple compartment niches (rhizoplane, root endosphere, phylloplane, and leaf endosphere) in maize (Zea mays)-wheat (Triticum aestivum)/barley (Hordeum vulgare) rotation system under different fertilization practices at two contrasting sites. Our results demonstrate that microbiome assembly along the soil-plant continuum is shaped predominantly by compartment niche and host species rather than by site or fertilization practice. From soils to epiphytes to endophytes, host selection pressure sequentially increased and bacterial diversity and network complexity consequently reduced, with the strongest host effect in leaf endosphere. Source tracking indicates that crop microbiome is mainly derived from soils and gradually enriched and filtered at different plant compartment niches. Moreover, crop microbiomes were dominated by a few dominant taxa (c. 0.5% of bacterial phylotypes), with bacilli identified as the important biomarker taxa for wheat and barley and Methylobacteriaceae for maize. Our work provides comprehensive empirical evidence on host selection, potential sources and enrichment processes for crop microbiome assembly, and has important implications for future crop management and manipulation of crop microbiome for sustainable agriculture.
Topics: Bacteria; Microbiota; Plant Roots; Rhizosphere; Soil Microbiology
PubMed: 32852792
DOI: 10.1111/nph.16890 -
Antibiotics (Basel, Switzerland) Sep 2021The discharge of untreated hospital and domestic wastewater into receiving water bodies is still a prevalent practice in developing countries. Unfortunately, because of...
The discharge of untreated hospital and domestic wastewater into receiving water bodies is still a prevalent practice in developing countries. Unfortunately, because of an ever-increasing population of people who are perennially under medication, these wastewaters contain residues of antibiotics and other antimicrobials as well as microbial shedding, the direct and indirect effects of which include the dissemination of antibiotic resistance genes and an increase in the evolution of antibiotic-resistant bacteria that pose a threat to public and environmental health. This study assessed the taxonomic and functional profiles of bacterial communities, as well as the antibiotic concentrations in untreated domestic wastewater (DWW) and hospital wastewater (HWW), using high-throughput sequencing analysis and solid-phase extraction coupled to Ultra-high-performance liquid chromatography Mass Spectrometry (UHPLC-MS/MS) analysis, respectively. The physicochemical qualities of both wastewater systems were also determined. The mean concentration of antibiotics and the concentrations of Cl, F and PO were higher in HWW samples than in DWW samples. The phylum was dominant in DWW with a sequence coverage of 59.61% while was dominant in HWW samples with a sequence coverage of 86.32%. At genus level, the genus (20.65%) and (67.41%) were predominant in DWW and HWW samples, respectively. Several pathogenic or opportunistic bacterial genera were detected in HWW ( and ) and DWW (, and ) samples. Functional prediction analysis indicated the presence of beta-lactam resistance, cationic antimicrobial peptide (CAMP) resistance and vancomycin resistance genes in HWW samples. The presence of these antibiotic resistance genes and cassettes were positively correlated with the presence of pathogens. These findings show the risk posed to public and environmental health by the discharge of untreated domestic and hospital wastewaters into environmental water bodies.
PubMed: 34572642
DOI: 10.3390/antibiotics10091059 -
MBio Feb 2022is a prevalent bacterial genus of the phyllosphere. Despite its ubiquity, little is known about the extent to which its diversity reflects neutral processes like...
is a prevalent bacterial genus of the phyllosphere. Despite its ubiquity, little is known about the extent to which its diversity reflects neutral processes like migration and drift, versus environmental filtering of life history strategies and adaptations. In two temperate forests, we investigated how phylogenetic diversity within is structured by biogeography, seasonality, and growth strategies. Using deep, culture-independent barcoded marker gene sequencing coupled with culture-based approaches, we uncovered a considerable diversity of in the phyllosphere. We cultured different subsets of lineages depending upon the temperature of isolation and growth (20°C or 30°C), suggesting long-term adaptation to temperature. To a lesser extent than temperature adaptation, diversity was also structured across large (>100 km; between forests) and small (<1.2 km; within forests) geographical scales, among host tree species, and was dynamic over seasons. By measuring the growth of 79 isolates during different temperature treatments, we observed contrasting growth performances, with strong lineage- and season-dependent variations in growth strategies. Finally, we documented a progressive replacement of lineages with a high-yield growth strategy typical of cooperative, structured communities in favor of those characterized by rapid growth, resulting in convergence and homogenization of community structure at the end of the growing season. Together, our results show how is phylogenetically structured into lineages with distinct growth strategies, which helps explain their differential abundance across regions, host tree species, and time. This work paves the way for further investigation of adaptive strategies and traits within a ubiquitous phyllosphere genus. is a bacterial group tied to plants. Despite the ubiquity of methylobacteria and the importance to their hosts, little is known about the processes driving community dynamics. By combining traditional culture-dependent and -independent (metabarcoding) approaches, we monitored diversity in two temperate forests over a growing season. On the surface of tree leaves, we discovered remarkably diverse and dynamic communities over short temporal (from June to October) and spatial (within 1.2 km) scales. Because we cultured different subsets of diversity depending on the temperature of incubation, we suspected that these dynamics partly reflected climatic adaptation. By culturing strains under laboratory conditions mimicking seasonal variations, we found that diversity and environmental variations were indeed good predictors of growth performances. Our findings suggest that community dynamics at the surface of tree leaves results from the succession of strains with contrasting growth strategies in response to environmental variations.
Topics: Methylobacterium; Phylogeny; Forests; Plants; Host Specificity; Plant Leaves
PubMed: 35073752
DOI: 10.1128/mbio.03175-21 -
Environmental Science & Technology Jan 2023Bacteria play a crucial role in driving ecological processes in aquatic ecosystems. Studies have shown that bacteria-cyanobacteria interactions contributed significantly...
Bacteria play a crucial role in driving ecological processes in aquatic ecosystems. Studies have shown that bacteria-cyanobacteria interactions contributed significantly to phytoplankton dynamics. However, information on the contribution of bacterial communities to blooms remains scarce. Here, we tracked changes in the bacterial community during the development of a cyanobacterial bloom in an equatorial estuarine reservoir. Two forms of blooms were observed simultaneously corresponding to the lotic and lentic characteristics of the sampling sites where significant spatial variabilities in physicochemical water quality, cyanobacterial biomass, secondary metabolites, and cyanobacterial/bacterial compositions were detected. dominated the upstream sites during peak periods and were succeeded by when the bloom subsided. For the main body of the reservoir, a mixed bloom featuring coccoid and filamentous cyanobacteria (, , , , , and ) was observed. Concentrations of the picocyanobacteria remained high throughout the study, and their positive correlations with cylindrospermopsin and anatoxin-a suggested that they could produce cyanotoxins, which pose more damaging impacts than previously supposed. Succession of different cyanobacteria ( and ) following changes in nutrient composition and ionic strength was demonstrated. The microbiomes associated with blooms were unique to the dominant cyanobacteria. Generic and specialized bloom biomarkers for the and downstream mixed blooms were also identified. Microscillaceae, Chthoniobacteraceae, and were the major heterotrophic bacteria associated with bloom, whereas Phycisphaeraceae and Methylacidiphilaceae were the most prominent groups for the bloom. Collectively, bacterial community can be greatly deviated by the geological condition, monsoon season, cyanobacterial density, and dominant cyanobacteria.
Topics: Microcystis; Synechococcus; Phytoplankton; Microbiota; Water Quality; Lakes
PubMed: 36653016
DOI: 10.1021/acs.est.2c04943 -
Frontiers in Cellular and Infection... 2018Mounting evidence indicates that microbiome plays an important role in the development and progression of cancer. The dogma that urine in healthy individuals must be...
Mounting evidence indicates that microbiome plays an important role in the development and progression of cancer. The dogma that urine in healthy individuals must be sterile has been overturned. Dysbiosis of the urinary microbiome has been revealed responsible for various urological disorders, including prostate cancer. The link between chronic inflammation, microbiome and solid tumors has been established for various neoplastic diseases. However, a detailed and comprehensive analysis of urinary microenvironment of bladder cancer has not been yet reported. We performed this study to characterize the potential urinary microbial community possibly associated with bladder cancer. Mid-stream urine was collected from 31 male patients with bladder cancer and 18 non-neoplastic controls. DNA was extracted from urine pellet samples and processed for high throughput 16S rRNA amplicon sequencing of the V4 region using Illumina MiSeq. Sequencing reads were filtered using QIIME and clustered using UPARSE. We observed increased bacterial richness (Observed Species, Chao 1 and Ace indexes; cancer vs. control; 120.0 vs. 56.0; 134.5 vs. 68.3; and 139.6 vs. 72.9, respectively), enrichment of some bacterial genera (e.g., ) and decrease of some bacterial genera (e.g., , and ) in cancer group when compared to non-cancer group. Significant difference in beta diversity was found between cancer and non-cancer group, among different risk level, but not among different tumor grade. Enrichment of , and was observed in cancer patients with high risk of recurrence and progression, which means these genera maybe potential biomarkers for risk stratification. The PICRUSt showed that various functional pathways were enriched in cancer group, including infection, glycerolipid metabolism and retinol metabolism. To our knowledge, we performed the most comprehensive study to date to characterize the urinary microbiome associated with bladder cancer. A better understanding of the role of microbiome in the development and progression of bladder cancer could pave a new way for exploring new therapeutic options and biomarkers.
Topics: Aged; Biomarkers, Tumor; Carcinoma; China; DNA, Bacterial; Disease Progression; Humans; Male; Microbiota; Middle Aged; RNA, Ribosomal, 16S; Statistics, Nonparametric; Urinary Bladder; Urinary Bladder Neoplasms; Urothelium
PubMed: 29904624
DOI: 10.3389/fcimb.2018.00167 -
Scientific Reports Jan 2021We investigated the nascent application and efficacy of sampling and sequencing environmental DNA (eDNA) in terrestrial environments using rainwater that filters through...
We investigated the nascent application and efficacy of sampling and sequencing environmental DNA (eDNA) in terrestrial environments using rainwater that filters through the forest canopy and understory vegetation (i.e., throughfall). We demonstrate the utility and potential of this method for measuring microbial communities and forest biodiversity. We collected pure rainwater (open sky) and throughfall, successfully extracted DNA, and generated over 5000 unique amplicon sequence variants. We found that several taxa including Mycoplasma sp., Spirosoma sp., Roseomonas sp., and Lactococcus sp. were present only in throughfall samples. Spiroplasma sp., Methylobacterium sp., Massilia sp., Pantoea sp., and Sphingomonas sp. were found in both types of samples, but more abundantly in throughfall than in rainwater. Throughfall samples contained Gammaproteobacteria that have been previously found to be plant-associated, and may contribute to important functional roles. We illustrate how this novel method can be used for measuring microbial biodiversity in forest ecosystems, foreshadowing the utility for quantifying both prokaryotic and eukaryotic lifeforms. Leveraging these methods will enhance our ability to detect extant species, describe new species, and improve our overall understanding of ecological community dynamics in forest ecosystems.
Topics: Biodiversity; Cluster Analysis; Cytophagaceae; DNA Barcoding, Taxonomic; DNA, Environmental; Forests; Fresh Water; Lactococcus; Mycoplasma; RNA, Ribosomal, 16S
PubMed: 33452291
DOI: 10.1038/s41598-020-80602-9