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Microorganisms Apr 2023is broadly distributed in terrestrial and aquatic environments and has various biological activities. In this study, we found that exhibited nematicidal activity...
is broadly distributed in terrestrial and aquatic environments and has various biological activities. In this study, we found that exhibited nematicidal activity against the plant root-knot nematode, . A total of 42 volatile organic compounds (VOCs) from were identified using gas chromatography-mass spectrometry (GC-MS). The nematicidal activity of the 10 main VOCs was tested against . Butyl butanoate (4 µL) caused the mortality of 80.13% of after 4 h. The nematicidal activity of an additional 38 butyl-butyrate-like volatile esters was also investigated. Of these, seven had strong nematicidal activity against , five of which showed egg-hatching inhibitory activity. This study is the first to report that butyl butanoate, ethyl 2-methylbutanoate, ethyl 4-methylpentanoate, ethyl pent-4-enoate, and methyl undecanoate have nematicidal activity against . The results indicated that could serve as a candidate microorganism for the biocontrol of plant root-knot nematodes, showing that volatile esters have great potential as nematicides.
PubMed: 37110389
DOI: 10.3390/microorganisms11040966 -
International Journal of Environmental... Mar 2022Lake Vostok is the deepest lake of Antarctica but has poor accessibility for study due to a thick glacial cover, however, water samples of this lake have become...
Lake Vostok is the deepest lake of Antarctica but has poor accessibility for study due to a thick glacial cover, however, water samples of this lake have become available for study just recently. Previously, only the microbiome of the ice cover samples was characterized. Here we report results of bacteriological seeding with subsequent identification of the heterotrophic microorganisms (bacteria and micellar fungi) present by 16S rDNA sequencing as well as results of a direct molecular study of the water microbiome. Surprisingly, the data obtained gave evidence of a predominant occurrence of common chemoorganotrophs that were rather psychrotolerant than psychrophilic. We isolated and described strains belonging to eight heterotrophic microbial species able to grow in a rich medium: six bacterial strains belonging to the species and , , , sp. and ; and two fungal strains belonging to sp. and . Direct study of 16S rDNA purified water samples confirmed the predominance of the , , and () .
Topics: Antarctic Regions; DNA, Ribosomal; Lakes; Microbiota; Sphingomonadaceae; Water; Water Microbiology
PubMed: 35409708
DOI: 10.3390/ijerph19074025 -
Frontiers in Microbiology 2023Microbial inoculation with plant growth-promoting microorganisms (PGPMs) is one of the most promising technologies to solve the current global challenges. Co-inoculants...
Microbial inoculation with plant growth-promoting microorganisms (PGPMs) is one of the most promising technologies to solve the current global challenges. Co-inoculants is more efficient and stable than mono-inoculants. However, the growth promoting mechanism of co-inoculants in complex soil system is still poorly understood. In this study, the effects on rice, soil and the microbiome of the mono-inoculant FH-1 (F) and NYM3 (N) and the co-inoculant FN obtained in previous works were compared. Correlation analysis and PLS-PM were used to explore the primary mechanism of different inoculants promoting rice growth. We hypothesized that inoculants promoted plant growth (i) by themselves, (ii) by improving soil nutrient availability or (iii) by regulating the rhizosphere microbiome in complex soil system. We also assumed that different inoculants had different ways of promoting plant growth. The results showed that FN significantly promoted rice growth and nitrogen absorption and slightly increased soil total nitrogen and microbial network complexity compared with F, N and the control (CK). FH-1 and NYM3 interfered with each other's colonization in FN. FN increased the complexity of the microbial network compared to F and N. The bacterial community of FN was quite different from CK and N, while the fungal community was not significantly different from other treatments. The species and functions enriched or inhibited by FN are part of F. The correlation analysis and PLS-PM results showed that inoculants (F/N/FN) promoted the growth of rice mainly by regulating the rhizosphere microbiome rather than by themselves or by improving soil nutrient availability. Co-inoculant FN promotes rice growth specifically by enhancing microbial nitrification function through enriching related species compared with F or N. This may provide theoretical guidance for the construction and application of co-inoculants in the future.
PubMed: 36846752
DOI: 10.3389/fmicb.2023.1101773 -
BMJ Case Reports May 2021, a non-fermenting gram-negative bacterium, is emerging as an important multidrug resistant opportunistic pathogen. It has been described in cases of bacteremia,...
, a non-fermenting gram-negative bacterium, is emerging as an important multidrug resistant opportunistic pathogen. It has been described in cases of bacteremia, pleuritis, keratitis and peritoneal dialysis-associated peritonitis. We describe, for the first time, a case of pyogenic liver abscess caused by coinfection of and , and briefly review pyogenic liver abscesses and the literature regarding .
Topics: Caulobacteraceae; Coinfection; Humans; Liver Abscess, Pyogenic; Streptococcus anginosus
PubMed: 33975829
DOI: 10.1136/bcr-2020-236235 -
Bioinformation 2022Microbial dynamics of the domestic environment and their antibiotic-resistant properties have been poorly characterized. We surveyed the microbial community and their...
Microbial dynamics of the domestic environment and their antibiotic-resistant properties have been poorly characterized. We surveyed the microbial community and their antibiotic profiling located in the rural and urban areas of Meerut city, Uttar Pradesh, India. Results show that bacterial community load across all samples had more than 100-fold higher than fungal community (all p<0.05.). Based on population load, the kitchen of both rural (Fungal: 4.16±1.81 vs Bacteria: 160.5±27.13) and urban areas (Fungal: 6.2±1.02 vs Bacteria: 205.46±30.9) were more contaminated than living rooms (rural area-Fungal: 2.13±0.74 vs Bacteria: 62.17±20.68 and urban area- Fungal: 4.75±1.68 vs Bacteria: 74.88±7.53). Six bacteria, namely sps; sps; ; Brevundimonas diminuta; Bacillus megaterium; and pneumonia, showed dominance on all other bacterial and fungal sp hence, only these six bacteria were subjected to antibiotic sensitivity test (AST). In AST, pneumoniae, , Bacillus megaterium, were resistant to more than three antibiotics. The most sensitive strain for Ciprofloxacin, Streptomycin was sp. However, sp was found sensitive only to Amoxillin. Brevundimonas diminuta is found most sensitive to all antibiotics. Plasmid profiling of selected bacteria suggests that antibiotic resistance properties arose from plasmids, not genomic ones. These findings give new insights into the local-scale distribution of MDR bacteria in a household environment.
PubMed: 36518135
DOI: 10.6026/97320630018293 -
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 -
Microbiology Spectrum Feb 2023Microbial communities in coastal waters are diverse and dynamic and play important roles in ecosystem functions and services. Despite the ecological impact of...
Microbial communities in coastal waters are diverse and dynamic and play important roles in ecosystem functions and services. Despite the ecological impact of bacterioplankton or pathogens, little is known about whether bacterioplankton and pathogen communities exhibit similar patterns. Here, using 16S RNA gene amplicon sequencing, the geographic patterns and assembly processes of bacterioplankton and pathogen communities in 30 subtropical estuaries were studied. Results showed that the estuarine bacterioplankton communities mainly consisted of (49.06%), (17.62%), and (16.33%), among which 31 pathogen genera (186 amplicon sequence variants [ASVs]) were identified. Under the influence of salinity, bacterioplankton and pathogens showed similar biogeographic patterns. Redundancy and correlation analyses indicated that the bacterioplankton communities were strongly correlated with estuarine environmental factors, but potential pathogens were less influenced. Co-occurrence network analysis revealed a close relationship between bacterioplankton and potential pathogens, with two pathogens identified as connectors (i.e., ASV340 [Clostridium perfringens] and ASV1624 [Brevundimonas diminuta]), implying potential impacts of pathogens on structure, function, and stability of estuarine bacterioplankton communities. Null-model analysis revealed that deterministic processes (heterogeneous selection) dominated bacterioplankton community assembly, while stochastic processes (undominated effect) shaped the potential pathogen community. Our findings illustrate the biogeographic patterns and community assembly mechanisms of bacterioplankton and pathogens in estuaries, which should provide guidance and a reference for the control of potential pathogenic bacteria. Bacterioplankton play an important role in estuarine ecosystem functions and services; however, potentially pathogenic bacteria may exhibit infectivity and pose a serious threat to environmental and human health. In this study, geographic patterns and assembly processes of bacterioplankton communities in 30 subtropical estuaries were explored, and potential pathogenic bacteria in the estuaries were detected and profiled. Our results demonstrate here that bacterioplankton and pathogens show similar biogeographic patterns under the influence of salinity. Interestingly, heterogeneous selection dominated bacterioplankton assembly, while stochasticity dominated pathogen assembly. This study provides important information for future risk assessment of potential pathogenic bacteria as well as management in estuarine ecosystems.
Topics: Humans; Ecosystem; Estuaries; Microbiota; Bacteria; Proteobacteria; Aquatic Organisms
PubMed: 36507672
DOI: 10.1128/spectrum.03683-22 -
Cureus Jul 2023Lung abscesses caused by () are a rare occurrence, particularly in immunocompetent adults. We present the case of a 47-year-old male with a history of COPD, bipolar...
Lung abscesses caused by () are a rare occurrence, particularly in immunocompetent adults. We present the case of a 47-year-old male with a history of COPD, bipolar disorder, and seizure disorder, who presented with a productive cough, worsening shortness of breath, yellow sputum, weight loss, and fatigue over a period of three weeks. Clinical examination revealed decreased breath sounds in the left upper lung zones. Laboratory investigations showed an elevated white cell count, while blood cultures identified . Imaging with computed tomography (CT) confirmed the presence of a 4.2x2.0 cm cavitary lesion consistent with a lung abscess. The patient was successfully treated with a combination of Ampicillin/Sulbactam and Azithromycin, followed by a course of oral Augmentin. Given the size of the abscess and favorable response to antibiotic therapy, invasive procedures were deemed unnecessary. This case underscores the importance of considering unusual pathogens in the etiology of lung abscesses, even in immunocompetent individuals, and highlights the successful management with appropriate antibiotic therapy.
PubMed: 37621835
DOI: 10.7759/cureus.42371 -
Frontiers in Microbiology 2023Planetary protection is a guiding principle aiming to prevent microbial contamination of the solar system by spacecraft (forward contamination) and extraterrestrial...
Planetary protection is a guiding principle aiming to prevent microbial contamination of the solar system by spacecraft (forward contamination) and extraterrestrial contamination of the Earth (backward contamination). Bioburden reduction on spacecraft, including cruise and landing systems, is required to prevent microbial contamination from Earth during space exploration missions. Several sterilization methods are available; however, selecting appropriate methods is essential to eliminate a broad spectrum of microorganisms without damaging spacecraft components during manufacturing and assembly. Here, we compared the effects of different bioburden reduction techniques, including dry heat, UV light, isopropyl alcohol (IPA), hydrogen peroxide (HO), vaporized hydrogen peroxide (VHP), and oxygen and argon plasma on microorganisms with different resistance capacities. These microorganisms included spores and spores, , and , all important microorganisms for considering planetary protection. spores showed the highest resistance to dry heat but could be reliably sterilized (i.e., under detection limit) through extended time or increased temperature. spores and were highly resistant to UV light. Seventy percent of IPA and 7.5% of HO treatments effectively sterilized and but showed no immediate bactericidal effect against spores. IPA immediately sterilized spores, but HO did not. During VHP treatment under reduced pressure, viable spores and spores were quickly reduced by approximately two log orders. Oxygen plasma sterilized but did not eliminate spores. In contrast, argon plasma sterilized but not . Therefore, dry heat could be used for heat-resistant component bioburden reduction, and VHP or plasma for non-heat-resistant components in bulk bioburden reduction. Furthermore, IPA, HO, or UV could be used for additional surface bioburden reduction during assembly and testing. The systemic comparison of sterilization efficiencies under identical experimental conditions in this study provides basic criteria for determining which sterilization techniques should be selected during bioburden reduction for forward planetary protection.
PubMed: 38152378
DOI: 10.3389/fmicb.2023.1253436 -
Ultrasonics Sonochemistry Oct 2020Supercritical carbon dioxide (SC-CO) is a novel method for food pasteurization, but there is still room for improvement in terms of the process shortening and its use in...
Supercritical carbon dioxide (SC-CO) is a novel method for food pasteurization, but there is still room for improvement in terms of the process shortening and its use in products with high oil content. This study addressed the effect of high power ultrasound (HPU) on the intensification of the SC-CO inactivation of E. coli and B. diminuta in soybean oil-in-water emulsions. Inactivation kinetics were obtained at different pressures (100 and 350 bar), temperatures (35 and 50 °C) and oil contents (0, 10, 20 and 30%) and were satisfactorily described using the Weibull model. The experimental results showed that for SC-CO treatments, the higher the pressure or the temperature, the higher the level of inactivation. Ultrasound greatly intensified the inactivation capacity of SC-CO, shortening the process time by approximately 1 order of magnitude (from 50 to 90 min to 5-10 min depending on the microorganism and process conditions). Pressure and temperature also had a significant (p < 0.05) effect on SC-CO + HPU inactivation for both bacteria, although the effect was less intense than in the SC-CO treatments. E. coli was found to be more resistant than B. diminuta in SC-CO treatments, while no differences were found when HPU was applied. HPU decreased the protective effect of oil in the inactivation and similar microbial reductions were obtained regardless of the oil content in the emulsion. Therefore, HPU intensification of SC-CO treatments is a promising alternative to the thermal pasteurization of lipid emulsions with heat sensitive compounds.
PubMed: 32339868
DOI: 10.1016/j.ultsonch.2020.105138