Search results for "microbial"
showing 10 items of 2041 documents
Metabolic shift of polyphosphate-accumulating organisms with different levels of polyphosphate storage
2012
Previous studies have shown that polyphosphate-accumulating organisms (PAOs) are able to behave as glycogen-accumulating organisms (GAOs) under different conditions. In this study we investigated the behavior of a culture enriched with Accumulibacter at different levels of polyphosphate (poly-P) storage. The results of stoichiometric ratios Gly degraded/HAc uptake, PHB synthesized/HAc uptake, PHV synthesized/HAc uptake and P release/HAc uptake confirmed a metabolic shift from PAO metabolism to GAO metabolism: PAOs with high poly-P content used the poly-P to obtain adenosine tri-phosphate (ATP), and glycogen (Gly) to obtain nicotinamide adenine dinucleotide (NADH) and some ATP. In a test whe…
Impact of biotic interactions on the survival of emerging pathogen Acinetobacter baumannii in aquatic media
2019
Abstract Acinetobacter baumannii is an opportunistic pathogen causing infections in immunocompromised patients. Recent studies recorded its persistence in a variety of abiotic conditions, but data regarding the biotic interactions with other microorganisms are limited. The aim was to assess the interaction of clinically relevant A. baumannii with common faecal bacteria Escherichia coli and Enterococcus faecium. Additionally, the interaction with a bdelloid rotifer Adineta vaga as a potential agent for biological control of A. baumannii was examined. Experiments were conducted in nutrient-poor spring water (SW) and nutrient-rich diluted nutrient broth (DNB) at 22 °C. A. baumannii coexisted w…
Drug resistance patterns of bacteria isolated from patients with nosocomial pneumonia at Tehran hospitals during 2009-2011
2013
Introduction: Nosocomial pneumonia remains an important cause of mortality and morbidity worldwide. Surveillance programs play an important role in the identification of common etiologic agents and local patterns of antimicrobial resistance. Methodology: In this study we determined the frequency and antimicrobial susceptibility of pathogens isolated from patients with nosocomial pneumonia during 2009 to 2011. Results: A total of 642 bacteria were isolated from 516 suspected samples. Acinetobacter baumannii (21.1%, n = 136), was the commonest isolated pathogen followed by Pseudomonas aeruginosa (17.4%, n = 112) , Staphylococcus aureus (15.8%, n = 102) and enterococci (8.4% n = 54). The most …
Cladosins L-O, new hybrid polyketides from the endophytic fungus Cladosporium sphaerospermum WBS017
2019
Abstract The endophytic fungus Cladosporium sphaerospermum WBS017 was obtained from healthy bulbs of Fritillaria unibracteata var. wabuensis. Fermentation of C. sphaerospermum on solid rice medium yielded three new hybrid polyketides, cladosins L−N (1–3), and a known derivative cladodionen (4). Further cultivation of this fungus on white bean medium afforded an additional new hybrid polyketide, cladosin O (5) along with three known analogues (6–8). The structures of the new compounds were elucidated using a combination of NMR and HRESIMS data. The absolute configurations of compounds 2 and 3 were determined by Mosher’s method and TDDFT-ECD calculations. All isolated compounds were evaluated…
High susceptibility of MDR and XDR Gram-negative pathogens to biphenyl-diacetylene-based difluoromethyl-allo-threonyl-hydroxamate LpxC inhibitors
2016
International audience; Inhibitors of uridine diphosphate-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC, which catalyses the first, irreversible step in lipid A biosynthesis) are a promising new class of antibiotics against Gram-negative bacteria. The objectives of the present study were to: (i) compare the antibiotic activities of three LpxC inhibitors (LPC-058, LPC-011 and LPC-087) and the reference inhibitor CHIR-090 against Gram-negative bacilli (including MDR and XDR isolates); and (ii) investigate the effect of combining these inhibitors with conventional antibiotics.MethodsMICs were determined for 369 clinical isolates (234 Enterobacteriaceae and 135 non-fermentati…
Dissemination of a Carbapenem-Resistant Acinetobacter baumannii Strain Belonging to International Clone II/Sequence Type 2 and Harboring a Novel AbaR…
2013
ABSTRACT An outbreak of hospital-acquired Acinetobacter baumannii infections, caused by a bla OXA-23 -positive carbapenem-resistant strain belonging to international clone II/ST2, was detected in Latvia. The strain was partially equipped with the armA gene and the intI1-aacA4-catB8-aadA1-qacE Δ 1 class 1 integron. In addition, the strain carried AbaR25, a novel AbaR4-like resistance island of ∼46,500 bp containing structures similar to the previously described AbaR22 and Tn 6167 islands. AbaR25 was characterized by the occurrence of a second copy of Tn 6022a interrupted by Tn 2006 carrying the bla OXA-23 gene.
Alginate-based coatings charged with hydroxyapatite and quercetin for fresh-cut papaya shelf life
2022
In this study, the effect of alginate-based coatings charged with quercetin glycoside compounds and hydroxyapatite/quercetin glycoside compounds (HA/QUE) on the microbiological quality, and on bioactive compounds of fresh-cut papaya, was evaluated for 14 days at 6 degrees C. Alginate coatings with hydroxyapatite/quercetin showed a high capability to slow down the growth of all microbiological parameters investigated. At the end of cold storage, the total bacteria count in papaya samples covered with HA/QUE alginate coating was 4.8 log CFU g(-1) which is significantly lower (P < 0.05) than 8.3 log CFU g(-1) for uncoated samples. Total carotenoids' percentage decrease, at the end of storag…
Evaluation of Antimicrobial Activity of Triphala Constituents and Nanoformulation
2020
The prevalence of nosocomial infections due to multidrug resistant (MDR) bacterial strains is associated with high morbidity and mortality. Folk medicine and ethnopharmacological data can provide a broad range of plants with promising antimicrobial activity. Triphala, an Ayurvedic formula composed of three different plants: Terminalia chebula Retz., Terminalia bellirica (Gaertn.) Roxb. (Combretaceae), and Phyllanthus emblica L. (Phyllanthaceae), is used widely for various microbial infections. Various extraction techniques were applied in the extraction of the biologically active constituents of Triphala in order to compare their efficiency. Microwave-assisted extraction (MAE) was shown to …
Interleukin-7 or Interleukin-15 Enhances Survival ofMycobacterium tuberculosis-Infected Mice
2000
ABSTRACTBoth antigen-presenting cells and immune effector cells are required to effectively eradicate or containMycobacterium tuberculosis-infected cells. A variety of cytokines are involved to ensure productive “cross talk” between macrophages and T lymphocytes. For instance, infection of macrophages with mycobacteria leads to effective interleukin-7 (IL-7) and IL-15 secretion, and both cytokines are able to maintain strong cellular immune responses of α/β and γ/δ T cells. Here we show that either cytokine is able to enhance survival ofM. tuberculosis-infected BALB/c mice significantly compared to application of IL-2, IL-4, or phosphate-buffered saline (as a control). Enhanced survival cou…
Oral yeast colonization throughout pregnancy
2017
Background Recent studies suggest that placenta may harbour a unique microbiome that may have origin in maternal oral microbiome. Although the major physiological and hormonal adjustments observed in pregnant women lead to biochemical and microbiological modifications of the oral environment, very few studies evaluated the changes suffered by the oral microbiota throughout pregnancy. So, the aim of our study was to evaluate oral yeast colonization throughout pregnancy and to compare it with non-pregnant women. Material and Methods The oral yeast colonization was assessed in saliva of 30 pregnant and non-pregnant women longitudinally over a 6-months period. Demographic information was collec…