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Frontiers in Microbiology 2023Microbial colonization represents one of the main threats to the conservation of subterranean cultural heritage sites. Recently, the microbial colonization on murals in...
BACKGROUND
Microbial colonization represents one of the main threats to the conservation of subterranean cultural heritage sites. Recently, the microbial colonization on murals in tombs has gradually attracted attention.
METHODS
In this study, a total of 33 samples, including 27 aerosol samples and 6 mural painting samples, were collected from different sites of Xu Xianxiu's Tomb and analyzed using culture-dependent methods. We compared the diversities of culturable bacteria and fungi isolated from the air and murals and explored the potential impacts of microorganisms on the biodeterioration of the murals.
RESULTS
Phylogenetic analyses revealed that the culturable bacteria belonged to Bacillus, Microbacterium, Lysobacter and Arthrobacter. And the most of fungal belonged to the Penicillium, Cladosporium and Aspergillus genera. The composition and structure of airborne bacteria and fungi outside the tomb were both significantly different from that inside the tomb. The variation trends of airborne bacterial and fungal concentrations at different sampling sites were remarkably similar. Bacillus frigoritolerans, Bacillus halotolerans, Bacillus safensis, Exiguobacterium mexicanum, Microbacterium trichothecenolyticum, and Micrococcus yunnanensis were bacterial species commonly isolated from both the mural and air environments. Fungal species commonly isolated from aerosol samples and mural painting samples were Alternaria alternata, Cladosporium cladosporioides, Penicillium brevicompactum, and Peyronellaea glomerata. The prediction of the ecological functions of the bacteria revealed that chemoheterotrophy or aerobic_chemoheterotrophy accounted for substantial relative proportions in all sample types.
CONCLUSION
These results suggest that the aerosol circulation between the inside and outside environments of the tomb was weak and that the outside environment had yet to have an impact on the air microbial community inside the tomb. Selective colonization of microorganisms, which is mediated by interaction between microorganisms and special microenvironmental factors, is an important reason for the biodeterioration of murals.
PubMed: 37954248
DOI: 10.3389/fmicb.2023.1253461 -
Frontiers in Cellular and Infection... 2021Microorganisms in the complex root canal system and the extraradicular regions, including the periapical lesions and extraradicular biofilm may cause root canal...
Microorganisms in the complex root canal system and the extraradicular regions, including the periapical lesions and extraradicular biofilm may cause root canal treatment failures. However, few studies described the difference between the intraradicular and extraradicular infections from the same tooth associated with persistent apical periodontitis. This study aimed to characterize the microbiome present in the root canal, extraradicular biofilm, and periapical lesions associated with persistent apical periodontitis. The microbial communities in the root canal, extraradicular biofilm, and periapical lesions were investigated by Illumina high-throughput sequencing using Illumina Hiseq 2500 platform. The dominant phyla in the extraradicular and intraradicular infections associated with persistent apical periodontitis were , and , and the genera , , and dominated across all samples. Although extraradicular infection sites showed higher OTU richness and β-diversity compared to intraradicular samples, the occurrence of sinus tract rather than the sampling sites demarcated the microbial communities in the infections associated with persistent apical periodontitis. PERMANOVA analysis confirmed that the samples with or without sinus tracts contained significantly different microbial communities. , and were found in significantly higher levels with sinus tracts, whilst and were more abundant in samples without sinus tracts. In conclusion, diverse bacteria were detected in both intraradicular and extraradicular infections associated with persistent apical periodontitis, which might be influenced by the occurrence of the sinus tract. The results may provide new insight into the pathogenesis of persistent apical periodontitis.
Topics: Bacteria; Biofilms; Humans; Microbiota; Periapical Periodontitis; Root Canal Therapy
PubMed: 35096647
DOI: 10.3389/fcimb.2021.798367 -
Scientific Reports Jul 2019The Microbacterium sp. LEMMJ01 isolated from Antarctic soil does not belong to any of the nearest species identified in the RDP database. Under UV radiation (A, B and C...
The Microbacterium sp. LEMMJ01 isolated from Antarctic soil does not belong to any of the nearest species identified in the RDP database. Under UV radiation (A, B and C wavebands) the survival fractions of Microbacterium sp. cells were much higher compared with wild-type E. coli K12A15. Especially remarkable for an Antarctic bacterium, an expressive resistance against high UV-B doses was observed. The increased survival of DNA repair-proficient E. coli grown overnight added of 0.1 mg/ml or 1 mg/ml of the whole pigment extract produced by Microbacterium sp. revealed that part of the resistance of Microbacterium sp. against UV-B radiation seems to be connected with photoprotection by its pigments. Scanning electron microscopy revealed that UV-A and UV-B ensued membrane alterations only in E. coli. The APCI-MS fingerprints revealed the diagnostic ions for neurosporene (m/z 580, 566, 522, 538, and 524) synergism for the first time in this bacterium by HPLC-MS/MS analysis. Carotenoids also were devoid of phototoxicity and cytotoxicity effects in mouse cells and in human keratinocytes and fibroblasts.
Topics: Actinobacteria; Antarctic Regions; Carotenoids; Chromatography, High Pressure Liquid; Dose-Response Relationship, Radiation; Escherichia coli; Fibroblasts; Humans; Keratinocytes; Microbial Viability; Phylogeny; RNA, Ribosomal, 16S; Radiation Tolerance; Tandem Mass Spectrometry; Ultraviolet Rays
PubMed: 31266976
DOI: 10.1038/s41598-019-45840-6 -
Journal of Applied Glycoscience 2023Dextran α-1,2-debranching enzyme (DDE) releases glucose with hydrolyzing α-(1→2)-glucosidic linkages in α-glucans, which are made up of dextran with...
Dextran α-1,2-debranching enzyme (DDE) releases glucose with hydrolyzing α-(1→2)-glucosidic linkages in α-glucans, which are made up of dextran with α-(1→2)-branches and are generated by bacteria. DDE was isolated from (formerly known as sp. M-73) 40 years ago, although the amino acid sequence of the enzyme has not been determined. Herein, we found a gene for this enzyme based on the partial amino acid sequences from native DDE and characterized the recombinant enzyme. DDE had a signal peptide, a glycoside hydrolase family 65 domain, a carbohydrate-binding module family 35 domain, a domain (D-domain) similar to the C-terminal domain of glucodextranase, and a transmembrane region at the C-terminus. Recombinant DDE released glucose from α-(1→2)-branched α-glucans produced by strains B-1299, S-32, and S-64 and showed weak hydrolytic activity with kojibiose and kojitriose. No activity was detected for commercial dextran and B-1355 α-glucan, which do not contain α-(1→2)-linkages. The removal of the D-domain decreased the affinity for α-(1→2)-branched α-glucans but not for kojioligosaccharides, suggesting that D-domain plays a role in α-glucan binding. Genes for putative dextranases, oligo-1,6-glucosidase, sugar-binding protein, and permease were present in the vicinity of the DDE gene, and as a result these gene products may be necessary for the use of α-(1→2)-branched glucans. Our findings shed new light on how actinobacteria utilize polysaccharides produced by lactic acid bacteria.
PubMed: 37033117
DOI: 10.5458/jag.jag.JAG-2022_0013 -
Scientific Reports Oct 2023Composition of pulmonary microbiome of patients with severe pneumonia is poorly known. The aim of this work was to analyse the lung microbiome of patients admitted...
Composition of pulmonary microbiome of patients with severe pneumonia is poorly known. The aim of this work was to analyse the lung microbiome of patients admitted to the intensive care unit (ICU) with severe community acquired pneumonia (CAP) between 2019 and 2021 in comparison with a control group of 6 patients undergoing digestive surgery. As a second objective, the diagnostic capabilities of metagenomics was also studied in a small group of selected patients. The lung microbiome of patients with viral (5 with Influenza A and 8 with SARS-CoV-2) pneumonia at admission showed a similar diversity as the control group (p = 0.140 and p = 0.213 respectively). Contrarily, the group of 12 patients with pneumococcal pneumonia showed a significant lower Simpson´s index (p = 0.002). In the control group (n = 6) Proteobacteria (36.6%), Firmicutes (24.2%) and Actinobacteria (23.0%) were the predominant phyla. In SARS-CoV-2 patients (n = 8), there was a predominance of Proteobacteria (mean 41.6%) (Moraxella and Pelomonas at the genus level), Actinobacteria (24.6%) (Microbacterium) and Firmicutes (22.8%) mainly Streptococcus, Staphylococcus and Veillonella. In patients with Influenza A pneumonia (n = 5) there was a predominance of Firmicutes (35.1%) mainly Streptococcus followed by Proteobacteria (29.2%) (Moraxella, Acinetobacter and Pelomonas). In the group of pneumococcal pneumonia (n = 12) two phyla predominated: Firmicutes (53.1%) (Streptococcus) and Proteobacteria (36.5%) (Haemophilus). In the 7 patients with non-pneumococcal bacterial pneumonia Haemophilus influenzae (n = 2), Legionella pneumophila (n = 2), Klebsiella pneumoniae, Streptococcus pyogenes and Leptospira were detected by metagenomics, confirming the diagnosis done using conventional microbiological techniques. The diversity of the respiratory microbiome in patients with severe viral pneumonia at ICU admission was similar to that of the control group. Contrarily, patients with pneumococcal pneumonia showed a lower grade of diversity. At initial stages of SARS-CoV-2 infection, no important alterations in the pulmonary microbiome were observed. The analysis of bacterial microbiome showed promising results as a diagnostic tool.
Topics: Humans; Pneumonia, Pneumococcal; Influenza, Human; Critical Illness; COVID-19; SARS-CoV-2; Lung; Bacteria; Microbiota; Pneumonia, Viral; Firmicutes; Proteobacteria; Community-Acquired Infections
PubMed: 37853062
DOI: 10.1038/s41598-023-45007-4 -
FEMS Microbiology Ecology Jun 2023Microbacterium sp. C448, isolated from a soil regularly exposed to sulfamethazine (SMZ), can use various sulphonamide antibiotics as the sole carbon source for growth....
Effect of subtherapeutic and therapeutic sulfamethazine concentrations on transcribed genes and translated proteins involved in Microbacterium sp. C448 resistance and degradation.
Microbacterium sp. C448, isolated from a soil regularly exposed to sulfamethazine (SMZ), can use various sulphonamide antibiotics as the sole carbon source for growth. The basis for the regulation of genes encoding the sulphonamide metabolism pathway, the dihydropteroate synthase sulphonamide target (folP), and the sulphonamide resistance (sul1) genes is unknown in this organism. In the present study, the response of the transcriptome and proteome of Microbacterium sp. C448 following exposure to subtherapeutic (33 µM) or therapeutic (832 µM) SMZ concentrations was evaluated. Therapeutic concentration induced the highest sad expression and Sad production, consistent with the activity of SMZ degradation observed in cellulo. Following complete SMZ degradation, Sad production tended to return to the basal level observed prior to SMZ exposure. Transcriptomic and proteomic kinetics were concomitant for the resistance genes and proteins. The abundance of Sul1 protein, 100-fold more abundant than FolP protein, did not change in response to SMZ exposure. Moreover, non-targeted analyses highlighted the increase of a deaminase RidA and a putative sulphate exporter expression and production. These two novel factors involved in the 4-aminophenol metabolite degradation and the export of sulphate residues formed during SMZ degradation, respectively, provided new insights into the Microbacterium sp. C448 SMZ detoxification process.
Topics: Microbacterium; Sulfamethazine; Soil Microbiology; Biodegradation, Environmental; Kinetics; Transcriptome; Proteome; Sulfonamides; Drug Resistance, Bacterial; Anti-Infective Agents; Mixed Function Oxygenases; Dihydropteroate Synthase
PubMed: 37309049
DOI: 10.1093/femsec/fiad064 -
Journal of Applied Microbiology Sep 2013To identify bacterial pathogens of diseased NiIe tilapia Oreochromis niloticus and determine their virulence.
Identification and virulence of Aeromonas dhakensis, Pseudomonas mosselii and Microbacterium paraoxydans isolated from Nile tilapia, Oreochromis niloticus, cultivated in Mexico.
AIMS
To identify bacterial pathogens of diseased NiIe tilapia Oreochromis niloticus and determine their virulence.
METHODS AND RESULTS
Sixteen bacterial isolates were recovered from diseased Nile tilapias (O. niloticus) reared in floating cages in Adolfo Lopez Mateos (ALM), Sanalona and Dique IV dams in Sinaloa, Mexico, from February to May 2009. The bacterial isolates were identified by phenotypic and molecular (rep-PCR and 16S rRNA sequencing) methods and were mostly isolated from the kidneys and the brain of tilapias. Bacterial cells and extracellular products (ECPs) of strains were characterized and used in experimental infections with sole Solea vulgaris and Mozambican tilapia Oreochromis mossambicus. The fish challenged with Aeromonas dhakensis sp. nov. comb nov, Pseudomonas mosselii and Microbacterium paraoxydans (3·1 × 10(6) CFU g(-) 1) exhibited mortality between 40 and 100% starting at 6 h postinoculation. The ECPs displayed gelatinase, haemolytic and cytotoxic activity, causing the total destruction of the HeLa cell lines.
CONCLUSIONS
Aeromonas dhakensis and Ps. mosselii were virulent to O. mossambicus, whereas Mic. paraoxydans displayed virulence to S. vulgaris.
SIGNIFICANCE AND IMPACT OF THE STUDY
This the first time that Aeromonas dhakensis and Ps. mosselii are reported as pathogens to tilapia and Mic. paraoxydans was isolated from fish; then, these fish pathogens could be a threat to farmed Nile tilapia in Mexico.
Topics: Actinomycetales; Aeromonas; Animals; Cichlids; Fish Diseases; HeLa Cells; Humans; Mexico; Pseudomonas; RNA, Ribosomal, 16S; Virulence
PubMed: 23758410
DOI: 10.1111/jam.12280 -
Microbiology Resource Announcements Nov 2022Bacteriophages Clayda5, Gshelby23, Wrigley, and Santhid were isolated from soil samples collected in Iowa, with genomes typical of actinobacteriophages from clusters EB,...
Bacteriophages Clayda5, Gshelby23, Wrigley, and Santhid were isolated from soil samples collected in Iowa, with genomes typical of actinobacteriophages from clusters EB, EM, CY, and DY, respectively. Wrigley and Santhid were isolated on Gordonia terrae and are likely to be temperate. Clayda5 and Gshelby23 were isolated on Microbacterium foliorum.
PubMed: 36214689
DOI: 10.1128/mra.00789-22 -
Frontiers in Microbiology 2023Microbial communities are key players in groundwater ecosystems. In this dark environment, heterotrophic microbes rely on biomass produced by the activity of...
Microbial communities are key players in groundwater ecosystems. In this dark environment, heterotrophic microbes rely on biomass produced by the activity of lithoautotrophs or on the degradation of organic matter seeping from the surface. Most studies on bacterial diversity in groundwater habitats are based on 16S gene sequencing and full genome reconstructions showing potential metabolic pathways used in these habitats. However, molecular-based studies do not allow for the assessment of population dynamics over time or the assimilation of specific compounds and their biochemical transformation by microbial communities. Therefore, in this study, we combined DNA-, phospholipid fatty acid-, and metabolomic-stable isotope probing to target and identify heterotrophic bacteria in the groundwater setting of the Hainich Critical Zone Exploratory (CZE), focusing on 2 aquifers with different physico-chemical conditions (oxic and anoxic). We incubated groundwater from 4 different wells using either C-labeled veratric acid (a lignin-derived compound) (single labeling) or a combination of CO and D-labeled veratric acid (dual labeling). Our results show that heterotrophic activities dominate all groundwater sites. We identified bacteria with the potential to break down veratric acid ( or ). We observed differences in heterotrophic activities between the oxic and anoxic aquifers, indicating local adaptations of bacterial populations. The dual labeling experiments suggested that the serine pathway is an important carbon assimilation pathway and that organic matter was an important source of hydrogen in the newly produced lipids. These experiments also yielded different labeled taxa compared to the single labeling experiments, showing that there exists a complex interaction network in the groundwater habitats.
PubMed: 37901809
DOI: 10.3389/fmicb.2023.1252498 -
Frontiers in Medicine 2023Peritoneal dialysis-related peritonitis (PDRP) caused by . is very rare, with only 9 cases reported to date. In this study, we report the treatment experiences of 7...
INTRODUCTION
Peritoneal dialysis-related peritonitis (PDRP) caused by . is very rare, with only 9 cases reported to date. In this study, we report the treatment experiences of 7 patients at our peritoneal dialysis center.
METHODS
We retrospectively collected clinical characteristics and antibiotic management of all 7 episodes of PDRP caused by . in 7 patients from at our center over 4 years, and reviewed the documented . PDRP in the literature.
RESULTS
Empiric antibiotic therapy was initiated as soon as possible, and consisted of intraperitoneal (IP) gentamicin in combination with vancomycin. After up to 5 days, gentamicin was changed to meropenem if the treatment was not effective. The intended course of antibiotic treatment was 21-day. Totally, 6 episodes were cured (85.7%), which was higher than reported.
CONCLUSION
The 21-day antibiotic therapy program by combining vancomycin and meropenem may benefit the management of . PDRP.
PubMed: 38076234
DOI: 10.3389/fmed.2023.1297296