2,070 results on '"BACTERIUM"'
Search Results
102. No evidence for yaws infection in a small‐scale cross‐sectional serosurvey in Ghanaian monkeys.
- Author
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Adade, Eugene, Roos, Christian, Chuma, Idrissa Shomari, Sylverken, Augustina Angelina, and Knauf, Sascha
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TREPONEMA pallidum ,GHANAIANS ,BLOOD sampling ,INFECTION ,BABOONS - Abstract
Background: Treponema pallidum (TP) is a spirochaete bacterium with subspecies that in humans cause syphilis (subsp. pallidum), bejel (subsp. endemicum) and yaws (subsp. pertenue; TPE). The latter is target for eradication which requires detailed information on yaws epidemiology. It has been shown that African nonhuman primates (NHPs) are infected with TPE strains that are closely related to the human infecting yaws bacterium. While human yaws infection is known to be endemic in Ghana, there is a paucity of information regarding TPE infection of Ghana's native NHPs. Objectives: The objective was to perform a small‐scale cross‐sectional serological screening for antibodies against TPE in Ghanaian monkeys. Due to the reports of TPE‐infected NHPs from neighbouring Côte d'Ivore, we hypothesised that monkeys in Ghana are infected with TPE and, therefore, are seropositive for antibodies against‐Treponema. Methods: We sampled blood from 37 NHPs representing four species: Erythrocebus patas (16/37) 43.2%, Papio anubis (15/37) 40.5%, Chlorocebus sabaeus (3/37) 8.1% and Cercopithecus mona (3/37) 8.1%. Samples were tested using the NHP validated treponemal test ESPLINE TP. Results: All 37 animals were seronegative for yaws infection. Conclusions: We cannot exclude yaws infection in NHPs in Ghana at this point. Our study, in combination with the absence of reports of clinically infected NHPs in a yaws endemic country is, however, supportive for the current thinking that interspecies infection with TPE is extremely rare. This is an important finding for the current ongoing yaws eradication campaign. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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103. Wolbachia Endosymbiont and Mosquito Vectors, with Emphasis on Lymphatic Filariasis Elimination
- Author
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Sunish, I. P. and Tyagi, Brij Kishore, editor
- Published
- 2021
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104. Ultradense Electrochemical Chips with Arrays of Nanostructured Microelectrodes to Enable Sensitive Diffusion-Limited Bioassays.
- Author
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Pimentel GJC, Ayres LB, Costa JNY, Paschoalino WJ, Whitehead K, Kubota LT, de Oliveira Piazzetta MH, Gobbi AL, Shimizu FM, Garcia CD, and Lima RS
- Subjects
- Humans, Diffusion, Biological Assay instrumentation, Biosensing Techniques instrumentation, Biosensing Techniques methods, Microelectrodes, Staphylococcus aureus drug effects, Electrochemical Techniques instrumentation, Electrochemical Techniques methods, Nanostructures chemistry, Gold chemistry
- Abstract
Nanostructured microelectrodes (NMEs) are an attractive alternative to yield sensitive bioassays in unprocessed samples. However, although valuable for different applications, nanoporous NMEs usually cannot boost the sensitivity of diffusion-limited analyses because of the enlarged Debye length within the nanopores, which reduces their accessibility. To circumvent this limitation, nanopore-free gold NMEs were electrodeposited from 45 μm SU-8 apertures, featuring nanoridged microspikes on a recessed surface of gold thin film while carrying interconnected crown-like and spiky structures along the edge of a SU-8 passivation layer. These structures were grown onto ultradense, vertical array chips that offer a promising strategy for translating reproducible, high-resolution, and cost-effective sensors into real-world applications. The NMEs yielded reproducible analyses, while machine learning allowed us to predict the analytical responses from NME electrodeposition data. By taking advantage of the high surface area and accessible structure of the NMEs, these structures provided a sensitivity for [Fe(CN)
6 ]3-/4- that was 5.5× higher than that of bare WEs while also delivering a moderate antibiofouling property in undiluted human plasma. As a proof of concept, these electrodes were applied toward the fast (22 min) and simple determination of Staphylococcus aureus by monitoring the oxidation of [Fe(CN)6 ]4- , which acted as a cellular respiration rate redox reporter. The sensors also showed a wide dynamic range, spanning 5 orders of magnitude, and a calculated limit of detection of 0.2 CFU mL-1 .- Published
- 2025
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105. The Role of Phenotypic Plasticity and Within-Environment Trait Variability in the Assembly of the Nectar Microbiome and Plant-Microbe-Animal Interactions.
- Author
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Quevedo-Caraballo S and Álvarez-Pérez S
- Abstract
The study of the rules that govern the relationship between phenotypic plasticity, genetic structure, and ecological success has traditionally focused on animals, plants, and a few model microbial species, whereas non-model microorganisms have received much less attention in this regard. The floral nectar of angiosperms is an ephemeral, island-like habitat for different highly adapted yeasts and bacteria. The growth of microorganisms in floral nectar depends on their ability to efficiently use the available nutrients and tolerate challenging physicochemical conditions, including high osmotic pressures, unbalanced carbon-to-nitrogen ratios, and the presence of diverse defensive compounds of plant origin. The production of alternative phenotypic states in response to environmental cues (i.e., phenotypic plasticity) or independently from these (within-environment trait variability) might be particularly relevant in floral nectar, in which rapid growth is needed for population persistence and to improve the chance of animal-mediated dispersal. In this article, we use the nectar microbiome as an example to encourage further research on the causes and ecological consequences of phenotypic plasticity and within-environment trait variability of microbes. We review previous work on the mechanisms and potential ecological significance of the phenotypic plasticity and within-environment trait variability displayed by nectar yeasts and bacteria. Additionally, we provide an overview of some topics that require further attention, including potential trade-offs between different traits that are relevant for adaptation to dynamic nectar environments and the direct and indirect effects of phenotypic variability on the fitness of plants, flower-visiting animals, and other nectar microbes. We conclude that further research on the causes and ecological consequences of phenotypic plasticity and within-environment trait variability of microbes is essential to get a better understanding of community assembly and the establishment of ecological interactions in floral nectar and other similar highly dynamic and strongly selective microbial habitats., Competing Interests: The authors declare no conflicts of interest., (© 2025 The Author(s). Ecology and Evolution published by John Wiley & Sons Ltd.)
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- 2025
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106. High-dimensional spectral flow cytometry of activation and phagocytosis by peripheral human polymorphonuclear leukocytes.
- Author
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Lamb ER, Glomski IJ, Harper TA, Solga MD, and Criss AK
- Abstract
Polymorphonuclear leukocytes (PMNs) are terminally differentiated phagocytes with pivotal roles in infection, inflammation, tissue injury, and resolution. PMNs display a breadth of responses to diverse endogenous and exogenous stimuli, making understanding of these innate immune responders vital yet challenging to achieve. Here, we report a 22-color spectral flow cytometry panel to profile primary human PMNs for surface marker expression of activation, degranulation, phagocytosis, migration, chemotaxis, and interaction with fluorescently labeled cargo. We demonstrate the surface marker response of PMNs to phorbol ester stimulation compared to untreated controls in an adherent PMN model with additional analysis of intra- and inter-subject variability. PMNs challenged with the Gram-negative bacterial pathogen Neisseria gonorrhoeae revealed infectious dose-dependent changes in surface marker expression in bulk, population-level analysis. Imaging flow cytometry complemented spectral cytometry, demonstrating that fluorescence signal from labeled bacteria corresponded with bacterial burden on a per-cell basis. Spectral flow cytometry subsequently identified surface markers which varied with direct PMN-bacterium association as well as those which varied in the presence of bacteria but without phagocytosis. This spectral panel protocol highlights best practices for efficient customization and is compatible with downstream approaches such as spectral cell sorting and single-cell RNA-sequencing for applicability to diverse research questions in the field of PMN biology., (© The Author(s) 2025. Published by Oxford University Press on behalf of Society for Leukocyte Biology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
- Published
- 2025
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107. SNARE-Mediated Membrane Fusion Probed Using a Synthetic Organelle in the Living Bacterium.
- Author
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Vannier C and Galli T
- Subjects
- Cell Membrane metabolism, Escherichia coli metabolism, Escherichia coli genetics, Plasmids genetics, Organelles metabolism, SNARE Proteins metabolism, SNARE Proteins genetics, Membrane Fusion
- Abstract
Studies on the mechanisms and regulation of functional assemblies of SNARE proteins mediating membrane fusion essentially make use of recombinant proteins and artificial phospholipid bilayers. We have developed an easy-to-use in vivo system reconstituting membrane fusion in living bacteria. It relies on the formation of caveolin-dependent intracytoplasmic cisternae followed by the controlled synthesis of members of the synaptic SNARE machinery. Only when a SNARE complex is formed with its intact components does the docking and subsequent fusion occur between the cisternae and the plasma membrane that is accompanied by the disappearance of the former. The phenotypic response of the bacterial cell to fusion events is a remarkable increase in cell body length due to an expansion of the plasma membrane. Therefore, such an easy-to-observe phenotype makes this system amenable to structure-function studies of SNAREs. We describe here the specific ways to produce caveolin and the SNARE proteins from compatible plasmids upon bacterial transformation and to obtain the elongated cell phenotype. We also provide protocols to carry out the preparation of cell culture samples suitable for biochemical and light microscopy analysis., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2025
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108. Rich resource environment of fish farms facilitates phenotypic variation and virulence in an opportunistic fish pathogen
- Author
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Katja Pulkkinen, Tarmo Ketola, Jouni Laakso, Johanna Mappes, and Lotta‐Riina Sundberg
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aquaculture ,bacterium ,colony type ,fish diseases ,phenotypic variation ,Evolution ,QH359-425 - Abstract
Abstract Phenotypic variation is suggested to facilitate the persistence of environmentally growing pathogens under environmental change. Here, we hypothesized that the intensive farming environment induces higher phenotypic variation in microbial pathogens than natural environment, because of high stochasticity for growth and stronger survival selection compared to the natural environment. We tested the hypothesis with an opportunistic fish pathogen Flavobacterium columnare isolated either from fish farms or from natural waters. We measured growth parameters of two morphotypes from all isolates in different resource concentrations and two temperatures relevant for the occurrence of disease epidemics at farms and tested their virulence using a zebrafish (Danio rerio) infection model. According to our hypothesis, isolates originating from the fish farms had higher phenotypic variation in growth between the morphotypes than the isolates from natural waters. The difference was more pronounced in higher resource concentrations and the higher temperature, suggesting that phenotypic variation is driven by the exploitation of increased outside‐host resources at farms. Phenotypic variation of virulence was not observed based on isolate origin but only based on morphotype. However, when in contact with the larger fish, the less virulent morphotype of some of the isolates also had high virulence. As the less virulent morphotype also had higher growth rate in outside‐host resources, the results suggest that both morphotypes can contribute to F. columnare epidemics at fish farms, especially with current prospects of warming temperatures. Our results suggest that higher phenotypic variation per se does not lead to higher virulence, but that environmental conditions at fish farms could select isolates with high phenotypic variation in bacterial population and hence affect evolution in F. columnare at fish farms. Our results highlight the multifaceted effects of human‐induced environmental alterations in shaping epidemiology and evolution in microbial pathogens.
- Published
- 2022
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109. Use of sulfate-reducing bacteria and different organic fertilizer for bioremediation of ex-nickel mining soils
- Author
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Karina Paredes Páliz, Ana M. Cunachi, and Edwin Licta
- Subjects
bioaugmentation ,biodegradation ,total petroleum hydrocarbons ,efficiency ,bacterium ,Environmental technology. Sanitary engineering ,TD1-1066 ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
This research focuses on the bioaugmentation with Pseudomonas sp. (native) and Pseudomonas aeruginosa (commercial) for the biodegradation of total petroleum hydrocarbons (TPH) of the environmental soil samples of the AqLab laboratory in Orellana, Ecuador. Two treatments of sterilized soil (one inoculated with the native strain and the other inoculated with the commercial strain), where used for physical- -chemical analyzes as well as the degradation of TPH. They were evaluated every 20 days for a total period of 80–100 days. The native bacterium was isolated from the laboratory agglomerates in a selective culture medium specific for Pseudomonas sp. The biodegradation of the TPH exhibited a positive result after 80 and 100 days of treatment, with a reduction of 84 and 96% of initial TPH after the bacterial inoculation. The comparison between the two strains evaluated, commercial and native, showed a greater efficiency of biodegradation by the native strain isolated directly from the agglomerates, suggesting working with native strains of the place that have a greater adaptability to the contaminated environment that would ensure bioremediation processes faster and more efficient, low cost and environmentally friendly.
- Published
- 2022
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110. Biophysics of helices : devices, bacteria and viruses
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Katsamba, Panayiota and Lauga, Eric
- Subjects
571.4 ,helix ,bacteria ,virus ,phage ,bacteriophage ,microswimmer ,filament ,slender ,selective control ,magnetic actuation ,propulsion ,application-driven design ,elasticity ,elastohydrodynamics ,fluid-structure interaction ,constriction ,complex conduit ,adaptive design ,deformation ,nut-and-bolt mechanism ,flagellotropic ,flagellum ,bacterium ,translocation ,microscale ,fluid mechanics ,artificial-microswimmer ,deformation feedback to kinematics ,swimming ,device ,targeted-drug delivery ,microfluidics ,micromanipulation ,minimally-invasive medical applications ,biophysics ,mechanics ,biomechanics - Abstract
A prevalent morphology in the microscopic world of artificial microswimmers, bacteria and viruses is that of a helix. The intriguingly different physics at play at the small scale level make it necessary for bacteria to employ swimming strategies different from our everyday experience, such as the rotation of a helical filament. Bio-inspired microswimmers that mimic bacterial locomotion achieve propulsion at the microscale level using magnetically actuated, rotating helical filaments. A promising application of these artificial microswimmers is in non-invasive medicine, for drug delivery to tumours or microsurgery. Two crucial features need to be addressed in the design of microswimmers. First, the ability to selectively control large ensembles and second, the adaptivity to move through complex conduit geometries, such as the constrictions and curves of the tortuous tumour microvasculature. In this dissertation, a mechanics-based selective control mechanism for magnetic microswimmers is proposed, and a model and simulation of an elastic helix passing through a constricted microchannel are developed. Thereafter, a theoretical framework is developed for the propulsion by stiff elastic filaments in viscous fluids. In order to address this fluid-structure problem, a pertubative, asymptotic, elastohydrodynamic approach is used to characterise the deformation that arises from and in turn affects the motion. This framework is applied to the helical filaments of bacteria and magnetically actuated microswimmers. The dissertation then turns to the sub-bacterial scale of bacteriophage viruses, 'phages' for short, that infect bacteria by ejecting their genetic material and replicating inside their host. The valuable insight that phages can offer in our fight against pathogenic bacteria and the possibility of phage therapy as an alternative to antibiotics, are of paramount importance to tackle antibiotics resistance. In contrast to typical phages, flagellotropic phages first attach to bacterial flagella, and have the striking ability to reach the cell body for infection, despite their lack of independent motion. The last part of the dissertation develops the first theoretical model for the nut-and-bolt mechanism (proposed by Berg and Anderson in 1973). A nut being rotated will move along a bolt. Similarly, a phage wraps itself around a flagellum possessing helical grooves, and exploits the rotation of the flagellum in order to passively travel along and towards the cell body, according to this mechanism. The predictions from the model agree with experimental observations with respect to directionality, speed and the requirements for succesful translocation.
- Published
- 2018
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111. Study of bacterium associated with maize and nematode, Pseudomonas fragi using 16S rDNA from Rustenburg, North West Province, South Africa
- Author
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Aminisarteshnizi, Mehrnoush
- Published
- 2021
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112. Study of bacterium associated with maize and nematode, Pandoraea using 16S rDNA from Rustenburg, North West Province, South Africa
- Author
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Aminisarteshnizi, Mehrnoush
- Published
- 2021
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113. Invasive Ageratina adenophora can maintain its ecological advantages over time through releasing its autotoxicity by accumulating a bacterium Bacillus cereus
- Author
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Ai-Ping Wu, Zhong-Xi Bai, Jian Li, Hui Liu, Fa-Lin Chen, Man-Yun Zhang, Yan-Hong Wang, Mohamed Abdelaziz Balah, and Ji-Hui Wen
- Subjects
Autotoxicity ,Bacterium ,Detoxification ,Invasion ,Advantage ,Release ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Plant invasive success is attributed to invaders’ ecological advantages over their native neighbors. However, increasing evidence suggests that these advantages are expected to attenuate over time because of natural enemy accumulation, ecological evolution of native species and autotoxicity. We determined how an invasive Ageratina adenophora could remain its competitive advantages over time by avoiding its autotoxicity. Our results highlighted that the autotoxicity of A. adenophora in its invaded soil was reduced by some microbes. Moreover, an autotoxic allelochemical, 2-coumaric acid glucoside, detected in the invaded soil, demonstrated distinctly autotoxic effects on its seed germination and seedling growth. However, the autotoxic effects were greatly alleviated by a bacterium Bacillus cereus, accumulated by A. adenophora. Furthermore, the allelochemical could be almost completely degraded by B. cereus within 96 h. Accordingly, we speculate that A. adenophora could aggregate B. cereus to release its autotoxicity maintaining its competitive advantages over time.
- Published
- 2023
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114. Antibacterial Activity of Different Plant Extracts and Phenolic Phytochemicals Tested on Paenibacillus Larvae Bacteria
- Author
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Liviu Mărghitaș, Daniel Dezmirean, Flore Chirilă, Nicodim Fiț, and Otilia Bobiș
- Subjects
bacterium ,basil ,paenibacillus larvae ,phenolic pyhtochemicals ,nettle ,thyme ,yarrow ,Agriculture ,Technology ,Science - Abstract
Paenibacillus larvae, a Gram-positive and spore-forming bacterium is responsible for American foulbrood disease in bees. The antimicrobial activity of different plant extracts and phenolic phytochemical was evaluated on Paenibacillus larvae bacteria. In addition possible correlation with antioxidant activity of the same plant extracts was studied. Extracts of the following plants were utilized: Achillea millefolium (yarrow), Ocimum basilicum (basil), Thymus vulgaris (thyme) and Urtica dioica (nettle). The extracts that showed antimicrobial activity were later tested to determine the Minimal Inhibitory Concentration (MIC). Although nettle present the lowest polyphenolic content compared with the other plant extracts, exhibit the highest antimicrobial activity, measured as the inhibition zone using Mueller-Hinton agar plates. Basil presented both polyphenolic content and antimicrobial activity at higher levels, while thyme had the lowest antimicrobial activity, even it present high amount of polyphenols.
- Published
- 2023
115. Weeds are survival niches of Xanthomonas campestris pv. campestris in São Paulo state, Brazil
- Author
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da Silva, João César Lourencetti, da Silva Júnior, Tadeu Antônio Fernandes, do Nascimento, Daniele Maria, de Melo, Luana Laurindo, Oliveira, Letícia Rodrigues, Girotto, Karine Teles, Junior, Vilson Eburneo, Soman, José Marcelo, Sartori, Maria Márcia Pereira, and Maringoni, Antonio Carlos
- Published
- 2023
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116. Immunization with a tri-antigen syphilis vaccine significantly attenuates chancre development, reduces bacterial load, and inhibits dissemination of Treponema pallidum.
- Author
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Lukehart, Sheila A., Molini, Barbara, Gomez, Alloysius, Godornes, Charmie, Hof, Rebecca, Fernandez, Mark C., Pitner, Ragan A., Gray, Sean A., Carter, Darrick, Giacani, Lorenzo, and Cameron, Caroline E.
- Subjects
- *
TREPONEMA pallidum , *SYPHILIS , *IMMUNIZATION , *PUBLIC health , *NEUROSYPHILIS - Abstract
Syphilis continues to be a significant public health concern worldwide. The disease is endemic in many low- and middle-income countries, and rates have risen sharply in high-income countries over the last decade. The continued prevalence of infectious and congenital syphilis worldwide highlights the need for the development of an effective syphilis vaccine to complement public health measures for syphilis control. The complex, multi-stage course of syphilis infection necessitates a holistic approach to the development of an effective vaccine, in which immunization prevents both the localized stage of infection (typified by the highly infectious chancre) and the disseminated stages of infection (typified by the secondary rash, neurosyphilis, and destructive tertiary lesions, as well as congenital syphilis). Inhibiting development of the infectious chancre would reduce transmission thus providing community- level protection, while preventing dissemination would provide individual-level protection by reducing serious sequelae and may also provide community level protection by reducing shedding during secondary syphilis. In the current study we build upon prior investigations which demonstrated that immunizations with individual, well characterized T. pallidum TprK, TprC, and Tp0751 peptides elicits partial protection against infection in the animal model. Specifically, we show here that immunization with a TprC/TprK/Tp0751 tri-antigen cocktail protects animals from progressive syphilis lesions and substantially inhibits dissemination of the infection. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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117. Molecular characters of Enterobcater using 16S rDNA isolated from tomato, Limpopo Province, South Africa.
- Author
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AMINISARTESHNIZI, MEHRNOUSH
- Subjects
RECOMBINANT DNA ,GRAM-negative bacteria ,ANAEROBIC bacteria ,TOMATOES ,PATHOGENIC bacteria - Abstract
Enterobacter species are gram negative, motile, non-spore forming, rod shaped, facultatively anaerobic bacteria of the Enterobacteriaceae family. It is also described as non-spore-forming, flagella-containing, urease positive, and lactose fermenting. Enterobacter includes several species which can be a risky pathogenic bacteria to the vegetables, including tomato, and therefore have an impact on the fresh production of tomato. This study was conducted to isolate and identify Enterobacter from a tomato field, in Limpopo Province, South Africa. Therefore, this molecular study was conducted in 2022 at the Limpopo University to identify the bacterium associated with tomato filed from South Africa's soils using 16S rDNA marker. The DNA was extracted using the chelex method. The bacterium was identified as Enterobacter. The Nblast analysis showed South African Enterobacter has 97% similarity with a population from Korea (KC355340). Phylogenetic analysis using maximum likelihood placed this species with those molecularly identified as Enterobacter in the same clade with highly supported (100) bootstrap values. In conclusion, this species is identified using 16S rDNA properly. However, using other DNA markers for a better understanding of Enterobacter phylogeny is recommended. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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118. Identification of the Kinetic Parameters of Thermal Micro-Organisms Inactivation.
- Author
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Bondarchuk, Ivan, Perevozkin, Valery, Bondarchuk, Sergey, and Vorozhtsov, Alexander
- Subjects
BACTERIAL spores ,MICROORGANISMS ,STERILIZATION (Disinfection) ,PARAMETER identification ,BACTERIAL inactivation - Abstract
A mathematical model for estimating the characteristics of the process of thermal inactivation of vegetative bacterial cells and their spores is presented. The model relates the change rate of the number of living cells as a nonlinear kinetic dependence of the p-th order, and the temperature constant of their inactivation rate is the Arrhenius function. A method for solving the inverse kinetic problem of identifying the parameters of this model from experimental data is proposed. The method is implemented through the minimization of the original functional, which reduces the number of variable parameters. The solution results of inverse problems for determining the kinetic model parameters based on the experimental data of thermal inactivation of bacterial spores B. subtilis and B. anthracis are presented. The obtained parameters are used to solve the direct problems of the dynamics of micro-organism inactivation. The calculation results represent the dependence on the time of the change number of inactivated micro-organisms, and the thermal exposure time for 99% of their deaths at different temperatures. A comparison of the results with other authors' calculations and experimental data confirms the adequacy of the model, the high accuracy of the new solution method and the algorithm for its implementation. The developed model of thermal sterilization can be used for the selective deactivation of pathogens in the food products. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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119. Numerical simulation of the mechanics of oblique interaction of a bacterium with a flat surface.
- Author
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Jasevičius, Raimondas
- Subjects
- *
COMPUTER simulation , *BACTERIA , *DISCRETE element method - Abstract
Looking from the mechanical point of view the suspension containing the bacteria may be considered as a system of living active ultrafine particles. Here a model is developed for the interaction of the bacterium in an oblique direction during contact. The model considers an adhesive bacterium moving through a fluid, acting with appropriate specific forces, such as steric, electrostatic double layer and hydrodynamic forces. To understand the influence of the latter hydrodynamic forces on the bacterium, numerical experiments using DEM are carried out with this force and without it. A comparison of these two cases shows the difference in movement. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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120. Transcriptome profiling of lung immune responses potentially related to acute respiratory distress syndrome in forest musk deer.
- Author
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Tang, Jie, Suo, Lijuan, Li, Feiran, Bian, Kun, Yang, Chao, and Wang, Yan
- Subjects
ADULT respiratory distress syndrome ,LUNGS ,DEER ,RESPIRATORY organs ,IMMUNE response ,LUNG development ,MYCOSES - Abstract
Background: Forest musk deer is an endangered species globally. The death of captive forest musk deer can be caused by certain respiratory system diseases. Acute respiratory distress syndrome (ARDS) is a huge threat to the life of forest muck deer that breed in our department. Methods: Lung histopathologic analysis was conducted by hematoxylin and eosin (HE) staining. The lung gene changes triggered by ARDS were examined by RNA sequencing and related bioinformatics analysis in forest musk deer. The potential functions of unigenes were investigated by NR, SwissProt KOG, GO, and KEGG annotation analyses. Vital biological processes or pathways in ARDS were examined by GO and KEGG enrichment analyses. Results: A total of 3265 unigenes were differentially expressed (|log
2 fold-change|> 2 and adjusted P value < 0.01) in lung tissues of 3 forest musk deer with ARDS compared with normal lung tissues of the non-ARDS group. These differentially expressed unigenes (DEGs) played crucial roles in immunity and defense responses to pathogens. Moreover, we identified the DEGs related to one or more of the following biological processes: lung development, immunity, and bacterial/viral/fungal infection. And six DEGs that might be involved in lung injury caused by immune dysregulation or viral/fungal infection were identified. Conclusion: ARDS-mediated lung gene alterations were identified in forest musk deer. Moreover, multiple genes involved in lung development and lung defense responses to bacteria/viruses/fungi in ARDS were filtered out in forest musk deer. [ABSTRACT FROM AUTHOR]- Published
- 2022
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121. Impact of maintenance techniques for woody crops (olive trees and vines) on the bacterial and fungal biomass of the soil, in the region of "Las Vegas of Madrid".
- Author
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Álvarez, Belén, Navas, Mariela, Antón, Omar, Borrego, Adrián, García, Andrés, Bienes, Ramón, and Sastre, Blanca
- Subjects
SOIL compaction ,SOIL porosity ,TILLAGE ,MULTIVARIATE analysis ,SOIL chemistry - Abstract
Copyright of Revista de Ciências Agrárias is the property of Sociedade de Ciencias Agrarias de Portugal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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122. Possibilities of inhalation bacteriophage therapy in treatment of children with acute tonsillitis
- Author
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Sh. T. Turdieva, G. R. Nasirova, and D. K. Ganiyeva
- Subjects
acute tonsillitis ,children ,tonsils ,bacterium ,bacteriophage ,Medicine - Abstract
Introduction. At the same time, in the last decade, pediatricians have increased interest in the study of the therapeutic effect of bacteriophages in infectious diseases of rhinolaryngological organs.Objective. The analysis of results of the use of inhalation bacteriophage therapy in children with acute tonsillitis, on an outpatient basis.Materials and methods. Examined 212 children from 4 to 15 years old with acute tonsillitis. Conducted general clinical research, pharyngoscopy, bacteriological examination of a smear of tonsils. Bacteriophage therapy carried out using the Pyobacteriophage complex liquid (PCL).Results. In the course of an objective clinical analysis, on the day of seeking outpatient care, patients noted asthenovegetative disorders in all patients (100%), in the form of general weakness (96.8%), loss of appetite (94.8%), and headache (92.5%). During the examination, cervical lymphadenopathy (98.6%), tonsil hyperemia and hyperplasia (98.1%), and exudates (48.1%) noted. It revealed that the main causative agents of acute tonsillitis in children were the bacteria Streptococcus pyogenes, Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae, with different relative proportions (from 24.2% to 59%). Inhalation bacteriophage therapy carried out from the first days of the disease. Against the background of therapy, it was noted - a decrease in swelling in the tonsils by 2-3 days with a decrease in general intoxication signs. On the 6th day from the beginning of bacteriophage therapy, asthenovegetative disorders stopped 2.2 times faster in relation to patients who did not receive bacteriophage therapy, against the background of a decrease in the manifestation of objective clinical signs of the disease.Conclusion. The use of inhalation bacteriophage therapy as part of the conservative treatment of acute tonsillitis in children contributes 1.4 times to the fastest relief of the acute period and an improvement in the subjective assessment of well-being is 25% higher concerning the comparison group.
- Published
- 2021
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123. ITRAQ-based quantitative proteomics analysis of forest musk deer with pneumonia
- Author
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Jie Tang, Lijuan Suo, Feiran Li, Chao Yang, Kun Bian, and Yan Wang
- Subjects
forest musk deer ,pneumonia ,proteomics ,bacterium ,immunity ,Veterinary medicine ,SF600-1100 - Abstract
Pneumonia can seriously threaten the life of forest musk deer (FMD, an endangered species). To gain a comprehensive understanding of pneumonia pathogenesis in FMD, iTRAQ-based proteomics analysis was performed in diseased (Pne group) lung tissues of FMD that died of pneumonia and normal lung tissues (Ctrl group) of FMD that died from fighting against each other. Results showed that 355 proteins were differentially expressed (fold change ≥ 1.2 and adjusted P-value < 0.05) in Pne vs. Ctrl. GO/KEGG annotation and enrichment analyses showed that dysregulated proteins might play vital roles in bacterial infection and immunity. Given the close association between bacterial infection and pneumonia, 32 dysregulated proteins related to Staphylococcus aureus infection, bacterial invasion of epithelial cells, and pathogenic Escherichia coli infection were screened out. Among these 32 proteins, 13 proteins were mapped to the bovine genome. Given the close phylogenetic relationships of FMD and bovine, the protein-protein interaction networks of the above-mentioned 13 proteins were constructed by the String database. Based on the node degree analysis, 5 potential key proteins related to pneumonia-related bacterial infection in FMD were filtered out. Moreover, 85 dysregulated proteins related to the immune system process were identified given the tight connection between immune dysregulation and pneumonia pathogenesis. Additionally, 12 proteins that might function as crucial players in pneumonia-related immune response in FMD were screened out using the same experimental strategies described above. In conclusion, some vital proteins, biological processes, and pathways in pneumonia development were identified in FMD.
- Published
- 2022
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124. Effects of a fully enclosed hollow-fiber centrifugal ultrafiltration technique for laboratory biosafety improvement
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Jing Yang, Weigang Wang, Cuixin Qiang, Yanan Niu, Zhirong Li, Mengqiang Zhao, Ye Jiang, Jing Cao, Xiaoran Niu, Xiaoxuan Liu, and Jianhong Zhao
- Subjects
bacterium ,centrifuge tube ,fully enclosed hollow fiber centrifugal ultrafiltration ,laboratory-acquired infections ,laboratory biosafety ,virus ,Biology (General) ,QH301-705.5 - Abstract
Laboratory biosafety has become a core focus in biological analysis, owing to the frequent occurrence of laboratory-acquired infections caused by the leakage of pathogenic microorganisms. For this purpose, the authors developed a safe pretreatment device combining a sealing technique with a direct injection technique. In this study, several bacteria and viruses were used to validate the filtration effect of the invention. Data show that the new device can completely filter bacteria and that the filtration rates for hepatitis B virus and hepatitis C virus reached 94% and 96%, respectively. The results show that the new preparation device can effectively block these pathogens and can improve biological safety and provide powerful protection for technicians.
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- 2021
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125. Insights into the interaction mechanisms between Microcystin-degrading bacteria and Microcystis aeruginosa.
- Author
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Peng, Tangjian, Tang, Yanqing, Cai, Danping, Gu, Yuqing, Wei, Jia, Zhang, Jiajia, Ni, Juan, Liu, Jun, Ren, Xiaoya, Pan, Jiafeng, Long, Xizi, Wang, Hui, and Yang, Fei
- Subjects
- *
CYANOBACTERIAL blooms , *TOXICOLOGICAL interactions , *BACTERIAL growth , *OXIDATIVE stress , *CYANOBACTERIAL toxins , *MICROCYSTINS , *MICROCYSTIS aeruginosa - Abstract
• Interactions between a MCs-degrading bacterium and toxic M. aeruginosa were studied. • The two species mutually affected each other's growth. • The two species' interactions influenced MC-LR synthesis and degradation. • Alleviation of oxidative stress and EPS play roles in the interspecies interactions. Interactions between bacteria and cyanobacteria influence the occurrence and development of harmful cyanobacterial blooms (HCBs). Bloom-forming cyanobacteria and cyanotoxin-degrading bacteria are essential in HCBs, nonetheless, their interactions and the underlying mechanisms remain unclear. To address this gap, a typical microcystin-LR (MC-LR)-degrading bacterium and a toxic Microcystis aeruginosa strain were co-cultivated to investigate their interactions. The cyanobacterial growth was enhanced by 24.8 %-44.3 % in the presence of the bacterium in the first 7 days, and the cyanobacterium enhanced the bacterial growth by 59.2 %-117.5 % throughout the growth phases, suggesting a mutualistic relationship between them. The presence of the bacterium increased cyanobacterial intracellular MC-LR content on days 4, 8, and 10 while reducing the extracellular MC-LR concentration, revealing the dual roles of the bacterium in enhancing cyanotoxin production and degrading cyanotoxins. The bacterium alleviated the oxidative stress, which may be crucial in promoting cyanobacterial growth. Critical functional genes related to cyanobacterial photosynthesis and MC-LR synthesis, and bacterial MC-LR degradation were up-regulated in the presence of the bacterium and cyanobacterium, respectively. Moreover, extracellular polymeric substances (EPS) were produced at the cell interface, implying EPS play a role in cyanobacterial-bacterial interactions. This study is the first to unveil the interaction mechanisms between cyanotoxin-degrading bacteria and bloom-forming cyanobacteria, shedding light on the dynamics of HCBs. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2024
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126. Key genomes, transcriptomes, proteins, and metabolic factors involved in the detoxification/tolerance of TNT and its intermediates by bacteria in anaerobic/aerobic environments.
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Yang, Xu, Yin, Mao-ling, Zhu, Yong-bing, Zhao, San-ping, and Xi, Hai-ling
- Subjects
- *
AMINO acid metabolism , *PHOSPHATE metabolism , *BACTERIAL genomes , *CARBOHYDRATE metabolism , *ANAEROBIC bacteria , *METABOLIC detoxification - Abstract
Novel microbial strains capable of efficient degradation of TNT and typical intermediates (2-ADNT and 4-ADNT) in aerobic/anaerobic environment were screened and isolated from ammunition-contaminated sites. The key genomes, transcriptomes, proteins, and metabolic factors for microbial detoxification/tolerance to pollutants in anaerobic and aerobic environments were analyzed for the first time. The bacterial genome, which is rich in metabolism and environmental information-processing functional genes, provides transcriptional and translational-related proteins for detoxifying/tolerating pollutants. At the transcriptional level, bacteria significantly expressed genes related to inositol phosphate metabolism for regulating membrane transport, maintaining the cytoskeleton, and signal transduction. At the protein level, genes involved in antioxidation, fat metabolism, sugar synthesis/degradation, and pyruvate metabolism were significantly expressed. At the metabolic level, riboflavin metabolism, which regulates membrane integrity, protects against oxidative stress, and maintains the sugar–protein–fat balance, showed significant responses. Bacteria simultaneously regulate amino acid metabolism, carbohydrate metabolism, and N/P/S cycles to maintain homeostatic cellular energy supplies. The key pathway for pollutant degradation in bacteria is nitrotoluene degradation. The molecular mechanism of bacterial tolerance to pollutants involves the regulation of oxidative phosphorylation and basic cycle pathways to maintain gene transcription, protein translation, and metabolic cycles. [Display omitted] • Bacillus cereus degrades TNT, 2-ADNT and 4-ADNT efficiently in anaerobic/aerobic environment. • The key regulatory elements on the surface of bacterial membrane are N and Na. • Metabolism and Environmental Information Processing genes affect the detoxification level. • Amino acid metabolism, Carbohydrate metabolism and N/P/S cycles are involved in maintaining homeostasis. • The key pathway for pollutant degradation by the bacteria was nitrotoluene degradation. [ABSTRACT FROM AUTHOR]
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- 2024
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127. Galectins in Host Defense Against Microbial Infections
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Li, Fang-Yen, Wang, Sheng-Fan, Bernardes, Emerson S., Liu, Fu-Tong, Crusio, Wim E., Series Editor, Lambris, John D., Series Editor, Radeke, Heinfried H., Series Editor, Rezaei, Nima, Series Editor, and Hsieh, Shie-Liang, editor
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- 2020
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128. 膜处理对酱腌菜卤汁中微生物和营养成分的影响.
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杨云, 卢海超, 高颖, 李军, 高志芳, 姜国庆, 鲁绯, and 纪凤娣
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BACTERIAL spores ,MEMBRANE separation ,SEPARATION (Technology) ,MICROFILTRATION ,AMINO acids - Abstract
Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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129. Microbial Fertilization Improves Soil Health When Compared to Chemical Fumigation in Sweet Lily.
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Li, Hui, Yang, Hongyu, Calderón-Urrea, Alejandro, Li, Yuanpeng, Zhang, Lipeng, Yu, Yanlin, Ma, Jiayi, and Shi, Guiying
- Subjects
- *
LILIES , *SOIL fumigation , *FUMIGATION , *SOIL degradation , *BACTERIAL diversity , *FUSARIUM oxysporum , *FERTILIZERS , *RHIZOSPHERE - Abstract
Lanzhou Lily(Lilium davidii) var. unicolor, which is also known as sweet lily in China, is used as a type of food. This lily is distributed in narrow regions, propagates asexually, cultivates perennially, and cultivates commonly in serious consecutive replant problems (CRPs). Soil fumigation is commonly used to control soil-borne disease to alleviate crops' consecutive replant problems (CRPs). However, due to the improper fumigation application, it is common to cause chemical hazard to crops. In this study, we designed a two-factor experiment to explore the bacterial and fungal community structure and some specific microbial groups in the lily rhizosphere soil after chemical versus bacterial fertilizer treatments, by using a metagenomic analysis of the treated soils. The results showed that metham-sodium soil fumigation (SMF treatment) significantly decreased plant growth, as well as it significantly decreased both soil fungal diversity and abundance at the OTUs levels, while Special 8™ microbial fertilizer supplement (MF treatment) significantly improved plant growth and increased fungal diversity and abundance. Under FM treatment, Chao1 richness and Shannon's diversity increased by 6.70% and 35.09% compared to CK (no treatment). However, the bacterial diversity and abundance were not significantly changed among these treatments. The fungal and bacterial community structure were different in all treatments. In SMF treatment, the pathogenic fungal species Fusarium oxysporum increased compared to CK, but it significantly decreased in MF treatment; in MF and MMF treatments, some beneficial bacteria groups such as the bacterial phylum Proteobacteria and its member genus Sphingomonas, as well as the fungal genus Mortierella, increased compared to CK and SFM treatments, but the harmful bacterial genera Gemmatimona was decreased, as well as the harmful fungal genus Cryptococcus. Thus, we concluded that under chemical fumigation conditions, both fungal diversity loss and overall microorganism reduction, which impair multiple ecosystem function, in conjunction with the increase of harmful fungal species such as Fusarium oxysporum, are causes for soil degradation. On the other hand, under microbial fertilizer supplement, it was the fungal diversity increase, as well as these beneficial microorganisms groups' accumulation, together with those harmful groups' depletion, played important roles in restoring and improving soil health that suffered from the chemical fumigant hazard. In addition, the bacterial phylum Proteobacteria and its member genus Sphingomonas are involved in soil health recovery and promotion. The results also emphasized that whether soil is chemically fumigated or not, beneficial microorganism supplementary is effective in ensuring soil productivity. [ABSTRACT FROM AUTHOR]
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- 2022
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130. 再造烟叶生产过程物料微生物群落结构分析.
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张 登, 杨春雪, 马 慧, 廖祥儒, and 管政兵
- Abstract
Copyright of Tobacco Science & Technology is the property of Tobacco Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
131. Fertilization integrated with microbial inoculants improves bell pepper production.
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Tanwar, Anju, Singh, Ajay, Aggarwal, Ashok, Badda, Neetu, Kaur, Rubdeep, and Kumar, Ravindra
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- *
MICROBIAL inoculants , *BELL pepper , *CAPSICUM annuum , *FERTILIZERS , *PLANT growth , *PSEUDOMONAS fluorescens , *AGRICULTURAL intensification - Abstract
Increased use of fertilizers under intensive agriculture has the possibility of environmental contamination. The use of microbial inoculants may be effective in sustaining crop productivity, soil health, and supplementing chemical fertilizers. The investigation evaluated responses of arbuscular mycorrhizal (AM) fungi, Glomus mosseae (G) and Acaulospora laevis (A) and the bacterium Pseudomonas fluorescens (Pf) on bell pepper (Capsicum annuum L.) when provided superphosphate at F1 = 60 kg ha−1 (0.45 g/pot), F2 = 120 kg ha−1 (0.90 g/pot), or F3 = 240 kg ha−1 (1.80 g/pot). Plant growth, nutrient content, and yield 120 days after transplanting (DAT) were determined. Plants responded best to F1 followed by F2, while F3 produced inhibitory effects. The highest AM colonization and spore numbers were with G + A+ Pf, resulting in an increase in chlorophyll content, root phosphatase activity, shoot fresh weight, early fruit formation, number of fruit/plant, fruit size, weight, and early ripening. Inoculation with G. mosseae alone increased leaf area, photosynthesis, plant height, root freshness and dry weight. The G+ Pf commonly produced highest shoot fresh weight and fruit nutrient content. The effectiveness of these inoculants on bell pepper growth and yield was highest; 60 and 120 kg ha−1P-fertilizer level when amended with G + A+ Pf. Use of AM or micro-inoculants may reduce fertilizer input and enhance nutrient utilization efficiency, which positively affected qualitative characteristics, nutrient uptake, and resistance to suboptimal conditions, but has few or little effect on quantitative characteristics. More work is needed to determine optimum rates of the materials tested to produce marketable size fruit. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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132. Smittspridning ombord på fartyg : En studie om hantering av smittspridning ombord på fartyg och rederiers smittskyddsplaner
- Author
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Djurberg, Fabian, Danielsson, Mak, Djurberg, Fabian, and Danielsson, Mak
- Abstract
År 2020 drabbades världen av Covid-19. Spridningen av viruset resulterade i att många länder upprättade en lockdown. Detta påverkade sjöfartsbranschen negativt och ställde till med problem när folk blev sjuka. Detta är på grund av den unika miljön som finns ombord på fartyg. Syftet med studien var att analysera och utvärdera hur olika fartyg och rederier agerade under covid-19-pandemin med fokus på effektivitet, framgång och problem när det kommer till smittskydd. Studiens frågeställningar berörde hur rederiers existerande smittskyddsplaner såg ut och huruvida de kan förbättras, vilka lärdomar som kan dras om smittspridning ombord på fartyg och huruvida en förbättrad smittskyddsplan kan konstrueras utifrån de som redan existerar. En kvalitativ metod i form av granskning och inläsning av studier i området smittspridning i allmänhet samt studier om utbrott av covid-19 ombord på fartyg. Smittskyddsplaner samlades in genom ett mailutskick till svenska rederier. Resultatet visar att rederierna efterlevde många av WHO:s riktlinjer där de även implementerade egna tillägg till den ombordhavna smittskyddsplanen. Vi kom även fram till att landbaserad assistans är en viktig komponent för att kunna bekämpa smittspridning ombord., In 2020, the world was struck by Covid-19. The spread of the virus resulted with many countries establishing lockdowns. This negatively affected the shipping industry and caused problems when people got sick. This is because of the unique environment that exists on board ships. The purpose of the study was to analyze and evaluate how different ships and shipping companies acted during the COVID-19 pandemic with a focus on efficiency, success and problems when it came to controlling the spread of infections. The study's questions concerned how shipping companies' infection control plans were complied with and whether they can be improved, what lessons can be learned about the spread of infections on board ships and whether an improved infection control plan can be constructed from those that already exist. A qualitative method of reviewing and reading studies in the field of infection control in general and studies on COVID-19 outbreaks on board ships. Infection control plans were collected through a mailing to Swedish shipping companies. The results showed that the shipping companies complied with many of the WHO's guidelines where they also implemented their own additions to the on-board infection control plan. We also came to the conclusion that land-based assistance is an important component for combating the spread of infections on board.
- Published
- 2024
133. Viruses in Marine Invertebrate Holobionts: Complex Interactions Between Phages and Bacterial Symbionts
- Author
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Zhou, Kun, Zhang, Ting, Chen, Xiao-Wei, Xu, Ying, Zhang, Rui, Qian, Pei-Yuan, Zhou, Kun, Zhang, Ting, Chen, Xiao-Wei, Xu, Ying, Zhang, Rui, and Qian, Pei-Yuan
- Abstract
Marine invertebrates are ecologically and economically important and have formed holobionts by evolving symbiotic relationships with cellular and acellular microorganisms that reside in and on their tissues. In recent decades, significant focus on symbiotic cellular microorganisms has led to the discovery of various functions and a considerable expansion of our knowledge of holobiont functions. Despite this progress, our understanding of symbiotic acellular microorganisms remains insufficient, impeding our ability to achieve a comprehensive understanding of marine holobionts. In this review, we highlight the abundant viruses, with a particular emphasis on bacteriophages; provide an overview of their diversity, especially in extensively studied sponges and corals; and examine their potential life cycles. In addition, we discuss potential phage-holobiont interactions of various invertebrates, including participating in initial bacterial colonization, maintaining symbiotic relationships, and causing or exacerbating the diseases of marine invertebrates. Despite the importance of this subject, knowledge of how viruses contribute to marine invertebrate organisms remains limited. Advancements in technology and greater attention to viruses will enhance our understanding of marine invertebrate holobionts. © 2024 Annual Reviews Inc.. All rights reserved.
- Published
- 2024
134. Variations in nutrients and microbes during the occurrence and extinction of algal blooms: A mesocosm experiment with the addition of marine aquaculture sediment
- Author
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Yuanmin Sun, Kunxian Tang, Yong Ma, Xuan Zhu, Heyang Li, Fei Zhang, Shan Chen, and Haiping Huang
- Subjects
algal bloom ,nutrient ,bacterium ,virus ,mesocosm experiment ,marine aquaculture sediment ,Science ,General. Including nature conservation, geographical distribution ,QH1-199.5 - Abstract
The release of pollutants in sediment often causes secondary pollution of seawater. In this paper, marine aquaculture sediment was added to seawater in a coastal land–based mesocosm, and the changes in microbial and physicochemical parameters were measured to study the influence of sediment disturbance on seawater. The results showed that sediment disturbance had adverse effects on seawater. After adding and stirring the aquaculture sediment, the concentration of dissolved oxygen (DO) gradually decreased, and those of nutrients gradually increased; in particular, the concentrations of ammonia and dissolved inorganic phosphorus (DIP) increased most sharply. After day 9, a bloom dominated by Chaetoceros occurred. Concentrations of chlorophyll a (Chl-a) increased, and two obvious Chl-a peaks were observed; the trends of DO and pH were similar to that of Chl-a during the bloom period; and DIP and ammonia were exhausted during periods of Chl-a peaks. During the extinction of algal blooms, the concentrations of Chl-a and DO decreased, whereas those of DIP and ammonia increased. The variation trends of bacteria and viruses were similar to that of Chl-a, with two obvious peaks, which were later than those of Chl-a. There were close connections between Chl-a and nutrients, bacteria and viruses and they showed a trend of changes in turn from nutrients to phytoplankton to bacteria to viruses during the experiment. We concluded that bloom formation was mainly affected by nutrients and weather, and the main reason for bloom decline was the depletion of nutrients. The increase in zooplankton, bacteria, and virus abundance was the ecological effect after the occurrence of algal blooms, and they affected the development of algal blooms.
- Published
- 2022
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135. Morphological, biochemical and molecular identification of the wild strain of Agrobacterium tumefaciens from crown gall infected mango tree
- Author
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Mst. Lailatul Ferdous, Md. Najmul Hossain, Md. Osman Ali, Md. Shahidul Islam, and Sabina Yasmin
- Subjects
disease ,bacterium ,confirmation ,mango tree ,Agriculture - Abstract
BACKGROUND: Mango (Mangifera indica) is a very important fruit and it is attractive for its delicious aroma and flavor. Mango is susceptible to various types of pathogens that result in decline of its fruit production. An important pathogen, Agrobacterium tumefaciens attacks on mango plant and it causes crown gall disease. The present study was conducted to isolate and identify Agrobacterium tumefaciens from crown gall samples. METHODOLOGY: These samples were collected from BAU campus, Mymensingh. The bacterium was isolated and characterized by morphological, microscopic, biochemical, and confirmed by molecular test. KEY FINDINGS: The morphological, microscopic and biochemical tests initially revealed that all the bacterial isolates are gram negative. Pathogenicity test: a carrot disc bioassay showed tumors in the plant because T-DNA of the bacteria was transferred and integrated into each of carrot disc. Antibiotic sensitivity tests revealed that the resistance to antibiotic. Moreover, DNA was isolated from infected tissue and after gel electrophoresis of PCR product, DNA band with expected 184bp was found and therefore, it was finally confirmed that the isolates were Agrobacterium tumefaciens. CONCLUSION: This bacterium has ability to alter hosts genome, thus, is considered in plant biotechnology as one of the natures best genetic engineer, antitumor studies and researches other purposes. [Fundam Appl Agric 2021; 6(1.000): 43-49]
- Published
- 2021
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136. Oral microbiota in children with acute tonsillitis
- Author
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Shokhida Tolkunovna Turdieva and Gulmira Ramzitdinovna Nasirova
- Subjects
acute tonsillitis ,bacterium ,children ,microbiota ,oral cavity ,Biotechnology ,TP248.13-248.65 - Abstract
Background: More recently, the human oral microbiota has attracted attention in epidemiological research on health and disease. Against this background, changes in the oral microbiota in acute diseases of the upper respiratory tract are of interest in modern pediatrics and epidemiology. The composition of the bacterial flora is one of the main premorbid backgrounds that determine the clinical course of acute tonsillitis in children. However, the prevalence of bacterial flora and its impact on the clinical course of patients with acute diseases remains unclear. Aims: The aims are to study the state of the oral cavity microbiota in children with acute tonsillitis. Methods: The microbiota of the oral cavity was studied in 221 children aged 3–14 years with acute tonsillitis. General clinical examinations and pharyngoscopy were performed. Bacteriological examination of the oral microbiota was carried out according to the standard method. Results: Colonization by the following was most frequently observed in patients: Staphylococcus aureus (42.2%), Streptococcus pneumoniae (32.0%), Haemophilus influenzae (24.2%), Haemophilus parainfluenzae (18.8%), Streptococcus anginosus (10.9%), Moraxella catarrhalis (9.4%), Streptococcus dysgalactiae ssp. equisimilis (8.6%), and Streptococcus agalactiae (3.1%), which most often occurred as symbionts. Conclusions: In children with acute tonsillitis, colonization of the tonsils by pathogenic bacterial flora increases, changing the composition of the oral microbiota. The most common causes of oral microbiota imbalance in children with acute tonsillitis were S. aureus, Streptococcus pyogenes, and H. influenzae, with varying relative proportions.
- Published
- 2021
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137. 艾滋病患者细菌性血流感染病原菌分布及耐药情况.
- Author
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田波, 刘俊, 李海雯, 宋炜, 陈海云, and 孙建军
- Abstract
Objective: To explore the prevalence of bacterial bloodstream infection in AIDS patients, and to learn the pathogen species drug resistance among AIDS patients . Methods: We retrospectively collected the data of AIDS patients with bacteria isolated from blood culture in Shanghai Public Health Clinical Center from 2015 to 2020. The species of pathogenic bacteria and the antibiotic resistance were analyzed, and the proportion of multiple resistance was also calculated. Results: The positive rate of bacteria in bloodstream between 2015 and 2020 was 4.48% in AIDS patients. 128 strains (59.3%) of gram-positive bacteria were detected, 83 strains were reported to be resistant to penicillin, and the resistance rate to erythromycin was 94% and 91.4% No Linezolide, Tigecycline, Vancomycin, Quinolputin/ Dapoptine resistance were detected. The multiple drug resistance rate was 38.6%, and 39.7% of the bacteria were resistant to more than 5 classes of antibiotics. Gram-negative bacteria were detected in 88 patients (40.7%), and drug resistance was reported in 70 patients, the resistance rate to Ampicillin was 81.6%. Quinolones, Carbopenems and Cephalosperins all had high sensitivity to gram-negative bacteria. The multiple drug resistance rate was 14.4%, and 12.8% of the bacteria were resistant to more than 5 classes of antibiotics. Conclusions: For AIDS patients with bacterial blood flow infection, the multiple drug resistance rate of grampositive bacteria is higher, linezolid, tigecycline, vancomycin and quinuptine/daphoputin can be selected for treatment . Quinolones, Carbopenems, and Cephalosperins all have high sensitivity to gram-negative bacteria. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
138. Assessment of Psyllid Handling and DNA Extraction Methods in the Detection of ' Candidatus Liberibacter Solanacearum' by qPCR.
- Author
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Quintana, María, de-León, Leandro, Cubero, Jaime, and Siverio, Felipe
- Subjects
NUCLEIC acid isolation methods ,CANDIDATUS ,JUMPING plant-lice ,HEMIPTERA - Abstract
'Candidatus Liberibacter solanacearum' (CaLsol) is an uncultured bacterium, transmitted by psyllids and associated with several diseases in Solanaceae and Apiaceae crops. CaLsol detection in psyllids often requires insect destruction, preventing a subsequent morphological identification. In this work, we have assessed the influence on the detection of CaLsol by PCR in Bactericera trigonica (Hemiptera: Psyllidae), of four specimen preparations (entire body, ground, cut-off head, and punctured abdomen) and seven DNA extraction methods (PBS suspension, squashing on membrane, CTAB, Chelex, TRIsure
TM , HotSHOT, and DNeasy® ). DNA yield and purity ratios, time consumption, cost, and residues generated were also evaluated. Optimum results were obtained through grinding, but it is suggested that destructive procedures are not essential in order to detect CaLsol. Although CaLsol was detected by qPCR with DNA obtained by the different procedures, HotSHOT was the most sensitive method. In terms of time consumption and cost, squashed on membrane, HotSHOT, and PBS were the fastest, while HotSHOT and PBS were the cheapest. In summary, HotSHOT was accurate, fast, simple, and sufficiently sensitive to detect this bacterium within the vector. Additionally, cross-contamination with CaLsol was assessed in the ethanol solutions where B. trigonica specimens were usually collected and preserved. CaLsol-free psyllids were CaLsol-positive after incubation with CaLsol-positive specimens. This work provides a valuable guide when choosing a method to detect CaLsol in vectors according to the purpose of the study. [ABSTRACT FROM AUTHOR]- Published
- 2022
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139. Plants and Phytoplasmas: When Bacteria Modify Plants.
- Author
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Bertaccini, Assunta
- Subjects
PHYTOPATHOGENIC microorganisms ,PLANT diversity ,PHYTOPLASMAS ,BACTERIA ,CANDIDATUS ,PLANT diseases - Abstract
Plant pathogen presence is very dangerous for agricultural ecosystems and causes huge economic losses. Phytoplasmas are insect-transmitted wall-less bacteria living in plants, only in the phloem tissues and in the emolymph of their insect vectors. They are able to manipulate several metabolic pathways of their hosts, very often without impairing their life. The molecular diversity described (49 'Candidatus Phytoplasma' species and about 300 ribosomal subgroups) is only in some cases related to their associated symptomatology. As for the other plant pathogens, it is necessary to verify their identity and recognize the symptoms associated with their presence to appropriately manage the diseases. However, the never-ending mechanism of patho-adaptation and the copresence of other pathogens makes this management difficult. Reducing the huge impact of phytoplasma-associated diseases in all the main crops and wild species is, however, relevant, in order to reduce their effects that are jeopardizing plant biodiversity. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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140. Characterization of a Novel Esterase Est33 From an Antarctic Bacterium: A Representative of a New Esterase Family.
- Author
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Liu, Xiaoyu, Zhou, Mingyang, Sun, Rui, Xing, Shu, Wu, Tao, He, Hailun, Chen, Jianbin, and Bielicki, John Kevin
- Subjects
EXTREME environments ,CATALYTIC activity ,BACTERIA ,ETHYLENEDIAMINETETRAACETIC acid - Abstract
Studies of microorganisms from extreme environments can sometimes reveal novel proteins with unique properties. Here, we identified a novel esterase gene (Est33) from an Antarctic bacterium. The protein was expressed and purified for biochemical characterizations. Site-mutation variants including S94A, D205A, and H233A were constructed to explore the structure–function relationship of the catalytic triad of Est33, and we found mutating Ser
94 , Asp205 , and His233 residues lead to a complete loss of enzyme activity. In addition, the catalytic Ser94 located in a conserved pentapeptide motif GVSWG. Phylogenetic analysis showed that Est33 and its closely related homologs belonged to an independent group apart from other known family members, indicating that Est33 represented a new family of esterase. The Est33 enzyme was found to be a cold-active esterase retaining 25%–100% activity from 10°C to 30°C and to have optimal catalytic activity toward p -nitrophenol acetate (30°C and pH7.5). The serine modifying reagent phenylmethylsulfonyl fluoride inhibited the activity of Est33 by 77.34%, while thiol reagents such as dithiol threitol (DTT) activated the enzyme by 3-fold. Metal chelating reagents EDTA had no effects, indicating that Est33 is not a metalloenzyme. Collectively, these results indicate that Est33 constitutes the first member of a novel esterase family XXI that has been identified. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
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141. Evaluation of Bacterial Perpetuation Assays and Plant Biomolecules Antimicrobial Activity against Cotton Blight Bacterium Xanthomonas citri subsp. malvacearum ; An Alternative Source for Food Production and Protection.
- Author
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Naqvi, Syed Atif Hasan, Iqbal, Shehzad, Hafeez-ur-Rehman, Farooq, Umar, Hassan, Muhammad Zeeshan, Shahid, Muhammad Nadeem, Noor Shah, Adnan, Abbas, Aqleem, Mubeen, Iqra, Farooq, Ammara, Ghareeb, Rehab Y., Kalaji, Hazem M., Alrefaei, Abdulwahed Fahad, and Ahmed, Mohamed A. A.
- Subjects
COTTON ,LEMON ,XANTHOMONAS campestris ,PHYTOPATHOGENIC bacteria ,PEPPERMINT ,NEEM ,ANTI-infective agents - Abstract
Cotton (Gossypium hirsutum) is a global cash crop which has gained importance in earning foreign exchange for each country. Bacterial blight caused by Xanthomonascitri subsp. malvacearum (Xcm) has been a seriousdisease in Pakistan's cotton belt on multiple occasions. Bacterium was isolated and identified through various biochemical and diagnostic tests wherehypersensitivity reaction, Gram staining, KOH (potassium hydroxide), catalase, starch hydrolysis, lecithinase and Tween 80 hydrolysis tests confirmed bacterium as Gram-negative and plant pathogenic. Xcm perpetuation assays wereevaluated on various cotton varieties under glasshouse conditions in completely randomized design by three different methods, wherein the scratch method proved to be the best upon CIM-496 and showed 83.33% disease incidence as compared with the other two methods, where Bt-3701 responded with 53.33% incidence via the spray gun method, and 50% with the water splash method on CIM-616, as compared with the control. Similarly, for disease severity percentage, Bt-3701 was pragmatic with 47.21% through scratch method, whereas, in the spray gun method, 45.51% disease severity was noted upon Bt-802, and 31.27% was calculated on Cyto-179 through the water splash method. Owing to the unique antibacterial properties of aqueous plant extracts, the poison food technique showed Aloe vera, Mentha piperita, Syzygiumcumini and Azadirachta indica with 17.77, 29.33, 18.33 and 20.22 bacterial colonies counted on nutrient agarmedium petri plate, respectively, as compared with the control. Measurement of the inhibition zone by disk diffusion technique showed Mentha piperita, Syzygiumcumini, Citrus limon, Moringa oleifera and Syzygium aromaticum to present the most promising results by calculating the maximum diameter of the inhibition zone, viz., 8.58, 8.55, 8.52, 8.49 and 8.41 (mm), respectively, at the highest tested concentration (75 ppm, parts per million) compared with the control. It is probable that the decoction's interaction with the pathogen population on the host plant will need to be considered in future experiments. However, at this moment, more research into the effective management of cotton bacterial blight by plant extracts in terms of concentration determination and development of biopesticides will provide future avenues to avoid environmental pollution. [ABSTRACT FROM AUTHOR]
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- 2022
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142. Citrus Canker—Distribution, Taxonomy, Epidemiology, Disease Cycle, Pathogen Biology, Detection, and Management: A Critical Review and Future Research Agenda.
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Naqvi, Syed Atif Hasan, Wang, Jie, Malik, Muhammad Tariq, Umar, Ummad-Ud-Din, Ateeq-Ur-Rehman, Hasnain, Ammarah, Sohail, Muhammad Aamir, Shakeel, Muhammad Taimoor, Nauman, Muhammad, Hafeez-ur-Rehman, Hassan, Muhammad Zeeshan, Fatima, Maheen, and Datta, Rahul
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CITRUS canker , *CITRUS greening disease , *XANTHOMONAS campestris , *BIOLOGY , *CITRUS fruits , *HOST plants - Abstract
Xanthomonas citri subsp. citri, a causative agent of the citrus canker (CC) disease, belongs to one of the essential groups of the bacterial phytopathogen family, Xanthomonadaceae. It has been a potential threat to the globally significant citrus fruit crop, which has remained under investigation for disease management and epidemiology since the 1980s. In Pakistan, the average yield of citrus is 11 t/ha, which is lower than other countries, including China, Brazil, and India, having average productions of 27, 26, and 22 tons/hectare, respectively. Citrus canker is one of the most devastating diseases, posing a significant threat to crop yield and fruit quality. To date, five distinct types (or forms) of the citrus canker have been recognized; the Asiatic (Canker A) form is most destructive and affects most citrus cultivars. Severe infection outcomes include dieback, defoliation, severely blemished fruit, premature fruit drop, and reduced fruit quality. The infection increases under humid, warm, cloudy climate, wind, and heavy rainfall. The analysis of plasmid and chromosomal DNA of X. citri subsp. citri depicted an evolutionary relationship among pathovars of Xanthomonas. The extensive study on the genome of X. citri subsp. citri has contributed to the current knowledge of plant host recognition of pathogens, host specificities, dissemination, and propagation. Regulatory programs, i.e., quarantine or exclusion, continued to be practiced, prohibiting infected citrus plant material into the existing stock. Other measures include removal of inoculums sources, resistant hosts, protective copper-containing sprays, and windbreak systems. In this review, we explored the latest trends in the areas of epidemiology, pathogenome, detection, host–pathogen interaction, biofilm formation, and management of X. citri subsp. citri. [ABSTRACT FROM AUTHOR]
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- 2022
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143. Bacillus firmus: aplicaciones y potencialidades como probiótico en la acuicultura.
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Mary González-León, Liane, Rizo Porro, Mariela, and Arenal Cruz, Amílcar
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SHRIMPS , *WATER quality management , *PROBIOTICS , *CULTURE , *ECONOMIC sectors , *BACILLUS (Bacteria) , *AQUATIC organisms , *BIOREMEDIATION , *AQUACULTURE , *SHRIMP culture - Abstract
Background: Nowadays, numerous bacterial strains, genus Bacillus, are used as probiotics to promote the growth of cultivated aquatic organisms, particularly in their larval stages. Aim. To conduct a review of the different applications of Bacillus firmus in the industry, with emphasis on their use as a probiotic for aquaculture. Development: B. firmus is a widely used beneficial bacterium as a nematicide to protect crops, the bioremediation of contaminated environments, enzyme production, and as a probiotic for aquaculture. Its potentiality for shrimp culture is outstanding for controlling diseases and water quality management in the pond. Conclusions: Nevertheless, its specific mechanisms for shrimp culture have not been studied broadly, which is particularly interested in providing all the benefits that this bacterium offers to this economic sector. [ABSTRACT FROM AUTHOR]
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- 2022
144. Force spectroscopy of interactions between Yersinia pseudotuberculosis and Yersinia pestis cells and monoclonal antibodies using optical tweezers.
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Byvalov, Andrey, Konyshev, Ilya, Ananchenko, Boris, and Belozerov, Vladislav
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YERSINIA pseudotuberculosis , *OPTICAL tweezers , *YERSINIA pestis , *MICROBIAL cells , *BACTERIAL adhesion - Abstract
The interactions of a microbial cell with host cells and humoral factors play an important role in the development of infectious diseases. The study of these mechanisms contributes to the development of effective methods for the treatment of bacterial infections. One of the possible approaches to studying bacterial adhesion to host cells is based on the use of the optical trap method. The aim of this work was to assess the significance of lipopolysaccharide O-antigen on the adhesiveness of Yersinia pseudotuberculosis using a model system including a bacterial cell captured by a laser beam and monoclonal antibodies (mAbs) bound covalently to a glass substrate. Registered interaction forces between Y. pseudotuberculosis cells and complementary antibodies to the O-antigen of lipopolysaccharide (LPS) or the B antigen outer membrane protein were 5.9 ± 3.3 and 2.0 ± 1.8 pN, respectively. Interaction forces between O-antigen deficient Y. pestis cells and the mentioned mAbs were 4.2 ± 2.9 and 9.6 ± 4.9 pN. The results are qualitatively consistent with earlier data obtained by using a model system based on polymer beads sensitized with LPS from Y. pseudotuberculosis and Y. pestis and surfaces coated by the aforementioned antibodies. This indicates that the immunochemical activity of Y. pseudotuberculosis cells is mediated mainly by the lipopolysaccharide. The model described can be used in similar studies of physicochemical and immunochemical mechanisms of bacterial adhesiveness. [ABSTRACT FROM AUTHOR]
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- 2022
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145. مقایسه تنوع جمعیت باکتریهای همراه بلوط ایرانی در دو روش شناسایی مبتنی بر کشت و مستقل از کشت)متاژنومیکس(
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الهه احمدی, داود آزادفر, مژگان کوثری, غلامرضا صالحی جوزانی, and مسعود توحیدفر
- Abstract
Copyright of Agricultural Biotechnology Journal is the property of Shahid Bahonar University of Kerman & the Iranian Biotechnology Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2022
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146. 不同储藏期浓香型白酒大曲的微生物多样性分析.
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刘延波, 王琳琳, 金尚萍, 韩素娜, 王贤, 孙西玉, 张立新, and 潘春梅
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MICROBIAL diversity ,NUCLEOTIDE sequencing ,BACTERIAL communities ,ENTEROBACTER ,LACTOCOCCUS ,FLAVOR - Abstract
Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2022
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147. mcr-1-carrying Enterobacteriaceae isolated from companion animals in Brazil
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Vanessa C. Kobs, Rafael E. Valdez, Francielle de Medeiros, Patrícia P. Fernandes, Roseneide C. Deglmann, Regina M.M. Gern, and Paulo H.C. França
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mcr-1-carrying Enterobacteriaceae ,companion animals ,Brazil ,bacterium ,polymyxin B ,multiple drug resistance ,MDR genes ,mcr-1 gene ,Veterinary medicine ,SF600-1100 - Abstract
ABSTRACT: Plasmid-mediated polymyxin resistance was first described in 2015, in China, in Escherichia coli carrying the mcr-1 (Mobile Colistin Resistance-1) gene. Since then, it has become a major public health challenge worldwide, representing a major threat to human and animal health. In addition, there are still few reports on the prevalence of mcr-1 in Enterobacteriaceae isolated from humans, animals and food. Therefore, the purpose of the study was to investigate the occurrence of the mcr-1 gene in bacterial isolates with phenotypic resistance to polymyxin B obtained from clinical specimens of companion animals. Phenotypic resistance to polymyxin B were determined by broth microdilution and the susceptibility profile to other antimicrobials (amikacin, amoxicillin/clavulanate, ampicillin, ampicillin/sulbactam, aztreonam, cefazolin, cefepime, cefotaxime, cefoxitin, ceftazidime, ceftriaxone, chloramphenicol, ciprofloxacin, doxycycline, ertapenem, gentamicin, imipenem, marbofloxacin, meropenem, phosphomycin, piperacillin/tazobactam, tetracycline, ticarcillin/clavulanate, tobramycin and trimethoprim/sulfamethoxazole) by disc-diffusion agar method. The extraction of bacterial DNA was performed via heat shock followed by spectrophotometric evaluation. To verify the presence of mcr-1, the Polymerase Chain Reaction was employed using specific primers, followed by agarose gel electrophoresis. The positive isolates had the corresponding amplicons sequenced. In this study, there were identified the first isolates of Escherichia coli, Klebsiella spp. and Enterobacter spp. carrying the mcr-1 gene derived from specimens of companion animals in Brazil. Our results suggest the dissemination of resistance to polymyxins in the community and the environment, highlighting the need for surveillance and optimized treatment guidelines.
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- 2020
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148. Biological products in organic agriculture
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R. Aipova, A. B. Abdykadyrova, and A. A. Kurmanbayev
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complex biological preparations ,nitrogen-fixing ,phosphate and potassium mobilizing microorganisms ,bacterium ,plant growth stimulation ,wheat ,Biotechnology ,TP248.13-248.65 - Abstract
The review presents data on the creation of complex microbial preparations and their application in agricultural practice. According to economists, the turnover in the field of organic agriculture is worth 85-90 billion US dollars a year. Developers of biological products pay great attention to the creation of complex biofertilizers, which contribute to a stable 20-25% increase in yield, with a significant reduction of plant damage by root rot. Among the considered positive effects of plant growth promoting rhizobacteria (PGPR) on plants are the ability to fix molecular nitrogen from the atmosphere, the synthesis of hormonal and fungitoxic substances, and the mobilization of sparingly soluble soil phosphates. The presented data show promise for the use of these microorganisms in the development of eco-friendly farming technologies in order to increase plant productivity and establish biocontrol over the development of plant diseases, reduce the chemical load on the soil, and increase its fertility.
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- 2020
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149. Characterization of a Novel Esterase Est33 From an Antarctic Bacterium: A Representative of a New Esterase Family
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Xiaoyu Liu, Mingyang Zhou, Rui Sun, Shu Xing, Tao Wu, Hailun He, Jianbin Chen, and John Kevin Bielicki
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esterase ,Antarctic ,bacterium ,soil ,new esterase family XXI ,Microbiology ,QR1-502 - Abstract
Studies of microorganisms from extreme environments can sometimes reveal novel proteins with unique properties. Here, we identified a novel esterase gene (Est33) from an Antarctic bacterium. The protein was expressed and purified for biochemical characterizations. Site-mutation variants including S94A, D205A, and H233A were constructed to explore the structure–function relationship of the catalytic triad of Est33, and we found mutating Ser94, Asp205, and His233 residues lead to a complete loss of enzyme activity. In addition, the catalytic Ser94 located in a conserved pentapeptide motif GVSWG. Phylogenetic analysis showed that Est33 and its closely related homologs belonged to an independent group apart from other known family members, indicating that Est33 represented a new family of esterase. The Est33 enzyme was found to be a cold-active esterase retaining 25%–100% activity from 10°C to 30°C and to have optimal catalytic activity toward p-nitrophenol acetate (30°C and pH7.5). The serine modifying reagent phenylmethylsulfonyl fluoride inhibited the activity of Est33 by 77.34%, while thiol reagents such as dithiol threitol (DTT) activated the enzyme by 3-fold. Metal chelating reagents EDTA had no effects, indicating that Est33 is not a metalloenzyme. Collectively, these results indicate that Est33 constitutes the first member of a novel esterase family XXI that has been identified.
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- 2022
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150. High-dimensional spectral flow cytometry of activation and phagocytosis by peripheral human polymorphonuclear leukocytes.
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Lamb ER, Glomski IJ, Harper TA, Solga MD, and Criss AK
- Abstract
Polymorphonuclear lymphocytes (PMNs) are terminally differentiated phagocytes with pivotal roles in infection, inflammation, tissue injury, and resolution. PMNs can display a breadth of responses to diverse endogenous and exogenous stimuli, making understanding of these innate immune responders vital yet challenging to achieve. Here, we report a 22-color spectral flow cytometry panel to profile primary human PMNs on population and single cell levels for surface marker expression of activation, degranulation, phagocytosis, migration, chemotaxis, and interaction with fluorescently labeled cargo. We demonstrate the surface protein response of PMNs to phorbol ester stimulation compared to untreated controls in an adherent PMN model with additional analysis of intra- and inter-subject variability. PMNs challenged with the Gram-negative bacterial pathogen Neisseria gonorrhoeae revealed infectious dose-dependent changes in surface marker expression in bulk, population-level analysis. Imaging flow cytometry complemented spectral cytometry, demonstrating that fluorescence signal from labeled bacteria corresponded with bacterial burden on a per-cell basis. Spectral flow cytometry subsequently identified surface markers which varied with direct PMN-bacterium association as well as those which varied in the presence of bacteria but without phagocytosis. This spectral panel protocol highlights best practices for efficient customization and is compatible with downstream approaches such as spectral cell sorting and single-cell RNA-sequencing for applicability to diverse research questions in the field of PMN biology., Competing Interests: The authors declare no conflicts of interest.
- Published
- 2024
- Full Text
- View/download PDF
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