15,831 results match your criteria bacteria absent


Piccolo is essential for the maintenance of mouse retina but not cochlear hair cell function.

Aging (Albany NY) 2021 Apr 21;13. Epub 2021 Apr 21.

School of Life Science and Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong University, Jinan 250100, China.

Piccolo is a presynaptic protein with high conservation among different species, and the expression of Piccolo is extensive in vertebrates. Recently, a small fragment of Piccolo (Piccolino), arising due to the incomplete splicing of intron 5/6, was found to be present in the synapses of retinas and cochleae. However, the comprehensive function of Piccolo in the retina and cochlea remains unclear. Read More

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Aim2 and Nlrp3 Are Dispensable For Vaccine-Induced Immunity Against Live Vaccine Strain.

Infect Immun 2021 Apr 19. Epub 2021 Apr 19.

Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, New York, USA

() is a facultative intracellular, Gram-negative bacterium that causes a fatal disease known as tularemia. Due to its extremely high virulence, ease of spread by aerosolization, and the potential to be used as a bioterror agent, is classified by the CDC as a Tier 1 Category A Select Agent. Previous studies have demonstrated the roles of inflammasome sensors; absent in melanoma 2 (AIM2) and NLRP3, in the generation of innate immune responses to infection. Read More

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Developing Cyclic Peptomers as Broad-Spectrum Gram-negative Bacterial Type III Secretion System Inhibitors.

Antimicrob Agents Chemother 2021 Apr 19. Epub 2021 Apr 19.

Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA 95064.

Antibiotic resistant bacteria are an emerging global health threat. New antimicrobials are urgently needed. The injectisome type III secretion system (T3SS), required by dozens of Gram-negative bacteria for virulence but largely absent from non-pathogenic bacteria, is an attractive antimicrobial target. Read More

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Fungal endophytes from the leaves and twigs of Quercus ilex L. from England, Majorca and Switzerland.

New Phytol 1994 May;127(1):133-137

International Mycological Institute, Bakeham Lane, Egham, Surrey, TW20 9TY, UK.

Leaves of Quercus ilex taken from sites in England, Majorca and Switzerland have been studied to detect the influence of the geographic position of the host within and outside its native range on the composition of its endophytic fungal assemblages. Samples of stem tissue of Q. ilex collected from the Swiss trees were also studied to confirm tissue-specific differences. Read More

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Clinical and Pathologic Presentation of Primary Ocular Surface Tumors among Zambians.

Ocul Oncol Pathol 2021 Mar 21;7(2):108-120. Epub 2021 Jan 21.

Nebraska Center for Virology and the School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.

Aim: This study aimed to characterize the clinical and pathologic presentation of ocular surface tumors (OSTs) and to more precisely differentiate the grades of ocular surface squamous neoplasia (OSSN) and benign lesions among Zambians.

Methods: Two-hundred sixty-five Zambian patients presenting with ocular surface growths, suspicious for OSSN, were recruited between November 2017 and November 2019 to a cross-sectional study to investigate their lesions. Sociodemographic data were collected, HIV infection status and vision tests were performed, and lesions were measured and documented. Read More

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Nitric oxide sensing revisited.

Trends Plant Sci 2021 Apr 16. Epub 2021 Apr 16.

Department of Chemistry, Biology, and Biotechnology, University of Perugia, I-06121 Perugia, Italy.

Nitric oxide (NO) sensing is an ancient trait enabled by hemoproteins harboring a highly conserved Heme-Nitric oxide/OXygen (H-NOX) domain that operates throughout bacteria, fungi, and animal kingdoms including in humans, but that has long thought to be absent in plants. Recently, H-NOX-containing plant hemoproteins mediating crucial NO-dependent responses such as stomatal closure and pollen tube guidance have been reported. There are indications that the detection method that led to these discoveries will uncover many more heme-based NO sensors that operate as regulatory sites in complex proteins. Read More

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Bacterial resistance to minocycline after adjunctive minocycline microspheres during periodontal maintenance: randomized clinical trial.

J Periodontol 2021 Apr 18. Epub 2021 Apr 18.

Department of Basic and Translational Sciences, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA, USA.

Background: Despite widespread use, the impact of minocycline HCl microspheres on the shifts of oral bacterial species resistant to minocycline remains unknown. This study aimed at examining the percentage (%) and taxonomy of minocycline-resistant isolates in saliva and subgingival plaque samples before and after minocycline microspheres application in periodontitis patients during maintenance.

Methods: Patients received supra- and subgingival debridement with (test) or without (control) minocycline microspheres application to sites with pocket depth (PD) > 4mm and were clinically monitored at baseline, 1, 3 and 6 months. Read More

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Resistance-guided isolation and characterization of antibiotic-producing bacteria from river sediments.

BMC Microbiol 2021 Apr 17;21(1):116. Epub 2021 Apr 17.

Department of Pharmacy, University of Rajshahi, Rajshahi, Bangladesh.

Background: To tackle the problem of antibiotic resistance, an extensive search for novel antibiotics is one of the top research priorities. Around 60% of the antibiotics used today were obtained from the genus Streptomyces. The river sediments of Bangladesh are still an unexplored source for antibiotic-producing bacteria (APB). Read More

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Human breast microbiome correlates with prognostic features and immunological signatures in breast cancer.

Genome Med 2021 Apr 16;13(1):60. Epub 2021 Apr 16.

Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA.

Background: Currently, over half of breast cancer cases are unrelated to known risk factors, highlighting the importance of discovering other cancer-promoting factors. Since crosstalk between gut microbes and host immunity contributes to many diseases, we hypothesized that similar interactions could occur between the recently described breast microbiome and local immune responses to influence breast cancer pathogenesis.

Methods: Using 16S rRNA gene sequencing, we characterized the microbiome of human breast tissue in a total of 221 patients with breast cancer, 18 individuals predisposed to breast cancer, and 69 controls. Read More

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A noncanonical heme oxygenase specific for the degradation of c-type heme.

J Biol Chem 2021 Apr 13:100666. Epub 2021 Apr 13.

Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA. Electronic address:

Heme oxygenases (HOs) play a critical role in recouping iron from the labile heme pool. The acquisition and liberation of heme iron is especially important for the survival of pathogenic bacteria. All characterized HOs, including those belonging to the HugZ superfamily, preferentially cleave free b-type heme. Read More

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Anatomical and biochemical studies of Spartium junceum infected by Xylella fastidiosa subsp. multiplex ST 87.

Protoplasma 2021 Apr 15. Epub 2021 Apr 15.

Dipartimento di Biologia, Università degli studi di Firenze, via P.A. Micheli 3, 50121, Firenze, Italy.

Spartium junceum L. is a typical species of Mediterranean shrubland areas, also grown in gardens and parks as an ornamental. In recent years in Europe, S. Read More

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Novel Mouse Model Reveals That Serine Phosphorylation of L-Plastin Is Essential for Effective Splenic Clearance of Pneumococcus.

J Immunol 2021 May 15;206(9):2135-2145. Epub 2021 Apr 15.

Division of Infectious Diseases, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO; and

Asplenia imparts susceptibility to life-threatening sepsis with encapsulated bacteria, such as the pneumococcus. However, the cellular components within the splenic environment that guard against pneumococcal bacteremia have not been defined. The actin-bundling protein L-plastin (LPL) is essential for the generation of marginal zone B cells and for anti-pneumococcal host defense, as revealed by a mouse model of genetic LPL deficiency. Read More

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Systematic review and meta-analysis of in vitro efficacy of antibiotic combination therapy against carbapenem-resistant Gram-negative bacilli.

Int J Antimicrob Agents 2021 Apr 12:106344. Epub 2021 Apr 12.

Division of Infectious Diseases, Department of Diagnostic and Public Health, University of Verona, P.Le L.A. Scuro 10, 37134, Verona, Italy; Division of Infectious Diseases, Department of Internal Medicine I, German Center for Infection Research, University of Tübingen, Otfried Müller Straße 12, 72074 Tübingen, Germany;; German Centre for Infection Research (DZIF), Clinical Research Unit for healthcare associated infections, Tübingen, Germany.. Electronic address:

Background: The superiority of combination therapy for carbapenem-resistant Gram-negative bacilli (CR-GNB) remains controversial. In vitro models may predict the efficacy of antibiotic regimens against CR-GNB.

Methods: A systematic review and meta-analysis were performed including pharmacokinetic/pharmacodynamic (PK/PD) and time-kill (TK) studies examining in vitro efficacy of antibiotic combinations against CR-GNB. Read More

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Genomic plasticity and antibody response of Bordetella bronchiseptica strain HT200, a natural variant from a thermal spring.

FEMS Microbiol Lett 2021 Apr 15. Epub 2021 Apr 15.

Institute of Life Sciences, Nalco Square, Bhubaneswar-751023, India.

Classical Bordetella species are primarily isolated from animals and humans causing asymptomatic infection to lethal pneumonia. However, isolation of these bacteria from any extra-host environmental niche has not been reported so far. Here, we have characterized the genomic plasticity and antibody response of B. Read More

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Tissue resident-like CD4+ T cells secreting IL-17 control Mycobacteria tuberculosis in the human lung.

J Clin Invest 2021 Apr 13. Epub 2021 Apr 13.

School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.

T cell immunity is essential for the control of tuberculosis (TB), an important disease of the lung, and is generally studied in humans using peripheral blood cells. Mounting evidence, however, indicates that tissue resident memory T cells (Trm) are superior at controlling many pathogens, including Mycobacterium tuberculosis (Mtb), and can be quite different from those in circulation. Using freshly resected lung tissue, from individuals with active or previous TB, we identified distinct CD4 and CD8 Trm-like clusters within TB diseased lung tissue that were functional and enriched for IL-17 producing cells. Read More

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Characterization of Clinical Isolates of Mycobacterium simiae Using Drug Susceptibility Tests and Molecular Analyses.

Curr Microbiol 2021 Apr 13. Epub 2021 Apr 13.

Mycobacteriology Research Center (MRC), National Research Institute of Tuberculosis and Lung Disease (NRITLD), World Health Organization Collaborating Centre, Shahid Beheshti University of Medical Sciences (Medical Campus), Darabad, PO 19575/154, Tehran, 19556, Iran.

Mycobacterium simiae is an emerging nontuberculous mycobacterium (NTM) and an opportunistic pathogen which is described mainly in Asia and presents in the environment that can cause pulmonary infection. The objective of this study is to characterize M. simiae clinical isolates using mycobacterial interspersed repetitive unit variable-number tandem repeats (MIRU-VNTR) typing for the differentiation of the strains. Read More

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The Archaeal Elongation Factor EF-2 Induces the Release of aIF6 From 50S Ribosomal Subunit.

Front Microbiol 2021 24;12:631297. Epub 2021 Mar 24.

Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy.

The translation factor IF6 is a protein of about 25 kDa shared by the Archaea and the Eukarya but absent in Bacteria. It acts as a ribosome anti-association factor that binds to the large subunit preventing the joining to the small subunit. It must be released from the large ribosomal subunit to permit its entry to the translation cycle. Read More

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Thermal Stress Interacts With Surgeonfish Feces to Increase Coral Susceptibility to Dysbiosis and Reduce Tissue Regeneration.

Front Microbiol 2021 25;12:620458. Epub 2021 Mar 25.

Department of Microbiology, Oregon State University, Corvallis, OR, United States.

Dysbiosis of coral microbiomes results from various biotic and environmental stressors, including interactions with important reef fishes which may act as vectors of opportunistic microbes via deposition of fecal material. Additionally, elevated sea surface temperatures have direct effects on coral microbiomes by promoting growth and virulence of opportunists and putative pathogens, thereby altering host immunity and health. However, interactions between these biotic and abiotic factors have yet to be evaluated. Read More

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Soil bacterial communities and their associated functions for forest restoration on a limestone mine in northern Thailand.

PLoS One 2021 8;16(4):e0248806. Epub 2021 Apr 8.

Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.

Opencast mining removes topsoil and associated bacterial communities that play crucial roles in soil ecosystem functioning. Understanding the community composition and functioning of these organisms may lead to improve mine-rehabilitation practices. We used a culture-dependent method, combined with Illumina sequencing, to compare the taxonomic richness and composition of living bacterial communities in opencast mine substrates and young mine-rehabilitation plots, with those of soil in adjacent remnant forest at a limestone mine in northern Thailand. Read More

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Genetic diversity and the presence of circular plasmids in Bacillus cereus isolates of clinical and environmental origin.

Arch Microbiol 2021 Apr 8. Epub 2021 Apr 8.

Faculty of Health Sciences, University of Ljubljana, Zdravstvena pot 5, 1000, Ljubljana, Slovenia.

The diversity of 61 Bacillus cereus strains isolated from different clinical specimens, food including raw milk and milk products, and water was evaluated. PFGE analysis could discriminate 61 distinct pulsotypes with similarity levels from 25 to 82%, which were divided into 13 clonal complexes. The similarity between clonal complexes was at least 40%. Read More

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Effect of Non-hydrogen Peroxide on Antibacterial Activity of Malaysian Honey against .

J Pharm Bioallied Sci 2020 Nov 5;12(Suppl 2):S831-S835. Epub 2020 Nov 5.

Department of Microbiology, Umaru Musa Yar'adua University Katsina, Katsina, Nigeria.

Introduction: Stingless bee is an insect that belongs to the family Apidae. Its name is based on its disability of stinging. It has a high product of honey and propolis by which are commonly referred to as stingless bee honey and stingless bee propolis. Read More

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November 2020

Mutations in two component system (PhoPQ and PmrAB) in colistin resistant Klebsiella pneumoniae from North Indian tertiary care hospital.

J Antibiot (Tokyo) 2021 Apr 5. Epub 2021 Apr 5.

Department of Education and Research, Artemis Hospitals, Sector 51, Gurgaon, Haryana, 122001, India.

Colistin resistance in Gram negative bacteria is mainly attributed to chromosomal mutations in Two Component Systems(TCS) PhoPQ and PmrAB and plasmid-borne genes(mcr and its variants). The aim of this study was to understand the molecular basis of colistin resistance in Klebsiella pneumoniae and determine clonal transmission, in a North Indian tertiary care hospital over a 2.5 year period. Read More

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Lack of Excitation Energy Transfer from the Bacteriochlorophyll Soret Band to Carotenoids in Photosynthetic Complexes of Purple Bacteria.

J Phys Chem B 2021 04 5;125(14):3538-3545. Epub 2021 Apr 5.

Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia.

The excitation energy transfer (EET) from the bacteriochlorophyll (BChl) Soret band to the second excited state(s) (S) of carotenoids in pigment-protein complexes of purple bacteria was investigated. The efficiency of EET was determined, based on fluorescence excitation and absorption spectra of chromatophores, peripheral light-harvesting complexes (LH2), core complexes (LH1-RC), and pigments in solution. Carotenoid-containing and carotenoid-less samples were compared: LH1-RC and LH2 from , , and chromatophores from and wild type and carotenoid-free strains R-26 and G9. Read More

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Ultrasound-Guided Periprosthetic Biopsy in Failed Total Hip Arthroplasty: A Novel Approach to Test Infection in Patients With Dry Joint.

J Arthroplasty 2021 Mar 17. Epub 2021 Mar 17.

Hip Department, IRCCS Istituto Ortopedico Galeazzi, Milan, Italy.

Background: To diagnose periprosthetic joint infection (PJI) preoperatively, ultrasound-guided joint aspiration (US-JA) may not be performed when effusion is minimal or absent. We aimed to report and investigate the diagnostic performance of ultrasound-guided periprosthetic biopsy (US-PB) of synovial tissue to obtain joint samples in patients without fluid around the implants.

Methods: One-hundred nine patients (55 men; mean age: 68 ± 13 years) with failed total hip arthroplasty (THA) who underwent revision surgery performed preoperative US-JA or US-PB to rule out PJI. Read More

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Symbiont dynamics during the blood meal of Ixodes ricinus nymphs differ according to their sex.

Ticks Tick Borne Dis 2021 Mar 18;12(4):101707. Epub 2021 Mar 18.

INRAE, Oniris, BIOEPAR, 44300, Nantes, France. Electronic address:

Ticks harbour rich and diverse microbiota and, among the microorganisms associated with them, endosymbionts are the subject of a growing interest due to their crucial role in the biology of their arthropod host. Midichloria mitochondrii is the main endosymbiont of the European tick Ixodes ricinus and is found in abundance in all I. ricinus females, while at a much lower density in males, where it is even absent in 56 % of the individuals. Read More

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African horse sickness virus NS4 protein is an important virulence factor and interferes with JAK-STAT signaling during viral infection.

Virus Res 2021 Jun 1;298:198407. Epub 2021 Apr 1.

Deltamune (Pty) Ltd, Moraine House - The Braes, 193 Bryanston Drive, Bryanston, Gauteng, 2191, South Africa; Department of Biochemistry, Focus Area for Human Metabolomics, North-West University, Potchefstroom, South Africa. Electronic address:

African horse sickness virus (AHSV) non-structural protein NS4 is a nucleocytoplasmic protein that is expressed in the heart, lung, and spleen of infected horses, binds dsDNA, and colocalizes with promyelocytic leukemia nuclear bodies (PML-NBs). The aim of this study was to investigate the role of AHSV NS4 in viral replication, virulence and the host immune response. Using a reverse genetics-derived virulent strain of AHSV-5 and NS4 deletion mutants, we showed that knockdown of NS4 expression has no impact in cell culture, but results in virus attenuation in infected horses. Read More

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Virtualized clinical studies to assess the natural history and impact of gut microbiome modulation in non-hospitalized patients with mild to moderate COVID-19 a randomized, open-label, prospective study with a parallel group study evaluating the physiologic effects of KB109 on gut microbiota structure and function: a structured summary of a study protocol for a randomized controlled study.

Trials 2021 Apr 2;22(1):245. Epub 2021 Apr 2.

Kaleido Biosciences, Inc, Lexington, MA, USA.

Objectives: These 2 parallel studies (K031 and K032) aim to evaluate the safety of KB109 in addition to supportive self-care (SSC) compared with SSC alone in outpatients with mild to moderate coronavirus disease 2019 (COVID-19). KB109 is a novel synthetic glycan that was formulated to modulate the gut microbiome composition and metabolic output in order to increase beneficial short-chain fatty acid (SCFA) production in the gut. The K031 study is designed to evaluate the safety of KB109 and characterize its impact on the natural progression of COVID-19 in patients with mild to moderate disease. Read More

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Composite P(3HB-3HV)-CS Spheres for Enhanced Antibiotic Efficiency.

Polymers (Basel) 2021 Mar 23;13(6). Epub 2021 Mar 23.

Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, 91-95 Splaiul Independentei, 050095 Bucharest, Romania.

Natural-derived biopolymers are suitable candidates for developing specific and selective performance-enhanced antimicrobial formulations. Composite polymeric particles based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and chitosan, P(3HB-3HV)-CS, are herein proposed as biocompatible and biodegradable delivery systems for bioproduced antibiotics: bacitracin (Bac), neomycin (Neo) and kanamycin (Kan). The stimuli-responsive spheres proved efficient platforms for boosting the antibiotic efficiency and antibacterial susceptibility, as evidenced against Gram-positive and Gram-negative strains. Read More

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Three-Dimensional Tumor Spheroids as a Tool for Reliable Investigation of Combined Gold Nanoparticle and Docetaxel Treatment.

Cancers (Basel) 2021 Mar 23;13(6). Epub 2021 Mar 23.

Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2, Canada.

Radiotherapy and chemotherapy are the gold standard for treating patients with cancer in the clinic but, despite modern advances, are limited by normal tissue toxicity. The use of nanomaterials, such as gold nanoparticles (GNPs), to improve radiosensitivity and act as drug delivery systems can mitigate toxicity while increasing deposited tumor dose. To expedite a quicker clinical translation, three-dimensional (3D) tumor spheroid models that can better approximate the tumor environment compared to a two-dimensional (2D) monolayer model have been used. Read More

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Effective Small Molecule Antibacterials from a Novel Anti-Protein Secretion Screen.

Microorganisms 2021 Mar 13;9(3). Epub 2021 Mar 13.

Laboratory of Molecular Bacteriology, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium.

The increasing problem of bacterial resistance to antibiotics underscores the urgent need for new antibacterials. Protein export pathways are attractive potential targets. The Sec pathway is essential for bacterial viability and includes components that are absent from eukaryotes. Read More

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