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https://www.readbyqxmd.com/read/28532117/optimization-for-extracellular-biosynthesis-of-silver-nanoparticles-by-penicillium-aculeatum-su1-and-their-antimicrobial-activity-and-cytotoxic-effect-compared-with-silver-ions
#1
Liang Ma, Wei Su, Jian-Xin Liu, Xiao-Xi Zeng, Zhi Huang, Wen Li, Zheng-Chun Liu, Jian-Xin Tang
The present study addresses an eco-friendly and energy-saving method for extracellular biosynthesis of silver nanoparticles (AgNPs) using a cell free filtrate of the fungus strain Penicillium aculeatum Su1 as a reducing agent. Parametric optimization of the biosynthesis process demonstrated different effects on the size, distribution, yield, and synthesis rate of biosynthesized AgNPs. The transmission electron microscopy (TEM) measurements demonstrated that AgNPs were spherical or approximately spherical, with a size between 4 and 55nm...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532116/antibacterial-mechanical-and-surface-properties-of-ag-dlc-films-prepared-by-dual-pld-for-medical-applications
#2
P Písařík, M Jelínek, J Remsa, J Mikšovský, J Zemek, K Jurek, Š Kubinová, J Lukeš, J Šepitka
Silver doped diamond-like carbon layers were deposited by dual pulsed laser deposition using two KrF excimer lasers. The concentration of Ag, determined by XPS and WDS, moved from zero to ~10at%. We found that the sp(2)/sp(3) ratio, film roughness and the number of droplets (SEM and AFM) increased with increasing silver concentration. The sp(3) content measurement (XPS) was influenced by ion cluster surface sputtering and varied from 71.0% (undoped DLC) to 36.2% (for 9.3at% Ag). Transmission was measured on the scale from 200nm to 1100nm, and decreased with increasing silver content...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532093/electrophoretic-deposition-of-organic-inorganic-composite-coatings-containing-zno-nanoparticles-exhibiting-antibacterial-properties
#3
Joanna Karbowniczek, Luis Cordero-Arias, Sannakaisa Virtanen, Superb K Misra, Eugenia Valsami-Jones, Lorena Tuchscherr, Bogdan Rutkowski, Kamil Górecki, Piotr Bała, Aleksandra Czyrska-Filemonowicz, Aldo R Boccaccini
To address one of the serious problems associated with permanent implants, namely bacterial infections, novel organic/inorganic coatings containing zinc oxide nanoparticles (nZnO) are proposed. Coatings were obtained by electrophoretic deposition (EPD) on stainless steel 316L. Different deposition conditions namely: deposition times in the range 60-300s and applied voltage in the range 5-30V as well as developing a layered coating approach were studied. Antibacterial tests against gram-positive Staphylococcus aureus and gram-negative Salmonella enteric bacteria confirmed the activity of nZnO to prevent bacterial growth...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532080/antibiotic-loaded-microspheres-as-antimicrobial-delivery-systems-for-medical-applications
#4
J Szczeblinska, K Fijalkowski, J Kohn, M El Fray
In this paper, we present the preparation and antibiotic loading of polymeric microspheres, composed of copolymers derived from fatty acid/amino acid components, as new polymeric platforms for antibiotic delivery systems. New polymeric materials were used to prepare microspheres with and without immobilized model antibiotics (streptomycin, chloramphenicol and amphotericin B) by a W/O/W double-emulsion/solvent evaporation method, in which chloroform and poly(vinyl alcohol) are used as the solvent and emulsifier, respectively...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532073/fabrication-of-vinyl-organosilicon-poly-n-n-4-5-dihydroxy-1-2-phenylene-bis-methylene-bisacrylamide-core-shell-antibacterial-agent
#5
Zhijia Zhang, Xiaole Zhao, Yingchun Su, Defeng Xing, Xiaojun Han
We demonstrate that antibacterial agent N, N'-[(4, 5-dihydroxy-1, 2-phenylene)bis(methylene)]bisacrylamide (OHABA) can be assembled on the surface of vinyl organosilicon nanospheres (VOSNs) by atom transfer radical polymerization (ATRP). Chemically cross-linked vinyl organosilicon cores were facilely fabricated by sol-gel method as support, which densely grafted poly-OHABA (POHABA) as shells. Antibacterial assessment test results revealed that POHABA-based core@shell structure displayed high antibacterial performance, long-term stability, and kept broad-spectrum antibacterial effect of against Gram-negative and Gram-positive bacteria...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532030/tetracycline-hydrochloride-loaded-electrospun-nanofibers-mats-based-on-pva-and-chitosan-for-wound-dressing
#6
Alex Carvalho Alavarse, Fernanda Waitman de Oliveira Silva, Jandir Telleria Colque, Viviam Moura da Silva, Tatiane Prieto, Everaldo Carlos Venancio, Jean-Jacques Bonvent
Fibrous mats built from biopolymer have been extensively explored for tissue engineering due mainly to their mimic structure to the extracellular matrix. The incorporation of drug in such scaffolds represents a growing interest for control drug delivery system in order to promote the tissue repair. In the present work, we present an experimental investigation of morphological, thermal, mechanical, drug release, antibacterial and cytotoxicity properties of electrospun PVA/Chitosan and PVA/Chitosan/Tetracycline hydrochloride (TCH) mats for wound dressing...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28530279/bifunctional-antimicrobial-conjugates-and-hybrid-antimicrobials
#7
REVIEW
P Klahn, M Brönstrup
Covering: up to the end of 2016Novel antimicrobial drugs are continuously needed to counteract bacterial resistance development. An innovative molecular design strategy for novel antibiotic drugs is based on the hybridization of an antibiotic with a second functional entity. Such conjugates can be grouped into two major categories. In the first category (antimicrobial hybrids), both functional elements of the hybrid exert antimicrobial activity. Due to the dual targeting, resistance development can be significantly impaired, the pharmacokinetic properties can be superior compared to combination therapies with the single antibiotics, and the antibacterial potency is often enhanced in a synergistic manner...
May 22, 2017: Natural Product Reports
https://www.readbyqxmd.com/read/28530195/facile-synthesis-of-silver-nanoparticles-mediated-by-polyacrylamide-reduction-approach-to-antibacterial-application
#8
Hosam I Salaheldin, Meshal H K Almalki, Abd Elhameed M Hezma, Gamal E H Osman
The current time increase in the prevalence of antibiotic resistant 'super-bugs' and the risks associated with food safety have become global issues. Therefore, further research is warranted to identify new and effective antimicrobial substances. Silver nanoparticles (Ag-NPs) were synthesized by autoclaving technique using, different concentrations of Ag salt (AgNO3) solution (1, 5, 10, and 25 mM). Their presence was confirmed by a surface plasmon resonance band at ∼435 nm using UV-Vis absorption spectra...
June 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28530191/green-synthesis-of-silver-nanoparticles-using-bovine-skin-gelatin-and-its-antibacterial-effect-on-clinical-bacterial-isolates
#9
Hosam I Salaheldin, Meshal H K Almalki, Gamal E H Osman
Nanoparticles are being increasingly used in day-to-day life. Therefore, concerns have been raised regarding their interactions with the surrounding environment. This study focused on a simple green method for synthesizing silver nanoparticles (Ag-NPs) in an autoclave at 15 psi (103 kPa) and 121°C. An aqueous solution of AgNO3 as a precursor of Ag-NPs and gelatin (type B) reducing and/or stabilizing (capping) agent were used. The effect of various AgNO3 concentrations of certain gelatin concentration and various gelatin concentrations at constant AgNO3 concentration, and autoclaving time, was studied...
June 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28530189/marinobacter-lipolyticus-from-red-sea-for-lipase-production-and-modulation-of-silver-nanomaterials-for-anti-candidal-activities
#10
Mohammad Oves, Huda A Qari, Nadeen M Felemban, Mohammad Z Khan, Zulfiqar A Rehan, Iqbal M I Ismail
In this study, the bacterial strain CEES 33 was isolated from the coastal area of the Red Sea, Jeddah, Kingdom of Saudi Arabia. The bacterium isolate was identified and characterized by using biochemical and molecular methods. The isolate CEES 33 has been identified as Gram-negative rod shaped and cream pigmented spherical colonies. It also demonstrated a positive result for nitrate reduction, oxidase, catalase, citrate utilization, lipase and exopolysaccharide production. Strain CEES 33 was characterized at the molecular level by partial 16S rRNA sequencing and it has been identified as Marinobacter lipolyticus (EMBL|LN835275...
June 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28530185/effect-of-gnp-functionalisation-and-multiple-n-methylation-of-%C3%AE-amyloid-residue-32-37-on-gram-positive-bacterium
#11
Nanjundaswamy Marishetty Hemmaragala, Heidi Abrahamse, Blassan P George
In the previous report, the authors showed the gold nanoparticle (GNP) functionalised multiple N-methylated fragments of the residue (32-37) of beta (β)-amyloid protein (1-42), CGGIGLMVG and CGGGGGIGLMVG toward disruption of β-amyloid (1-42), the predominant component of senile plaques. Herein the in vitro antimicrobial activities of both normal and multiple N-methylated sequences of CGGIGLMVG and CGGGGGIGLMVG were screened and it was found that all the eight sequences including four (non-functionalised with GNP) to possess activity against both Gram-positive [Staphylococcus aureus (ATCC 43300) and Enterococcus faecalis (ATCC 5129)] and Gram-negative [Escherichia coli (ATCC 35218), Pseudomonas aeruginosa (ATCC 27853) and Klebsiella pneumoniae (ATCC 700603)] bacteria...
June 2017: IET Nanobiotechnology
https://www.readbyqxmd.com/read/28529866/which-orthopaedic-patients-are-infected-with-gram-negative-non-fermenting-rods
#12
Omid Jamei, Shpresa Gjoni, Besa Zenelaj, Benjamin Kressmann, Wilson Belaieff, Didier Hannouche, Ilker Uçkay
Background : 1(st) and 2(nd) generation cephalosporins used for perioperative prophylaxis in orthopaedic surgery do not cover non-fermenting Gram-negative rods (NFR). Methods: Epidemiological cohort study of adult patients operated for orthopedic infections between 2004 and 2014 with perioperative cefuroxim or vancomycin prophylaxis. Exclusion of polyneuropathic ischemic foot infections and septic bursitis cases. Results: Of the total 1840 surgical procedures in the study, 430 grew Gram-negative pathogens (23%), of which 194 (11%) were due to NFR and 143 (8%) to Pseudomonas aeruginosa...
2017: J Bone Jt Infect
https://www.readbyqxmd.com/read/28529729/characterization-of-the-novel-in1059-harbouring-vim-gene-cassette
#13
Dongguo Wang, Jinhong Yang, Meiyu Fang, Wei He, Ying Zhang, Caixia Liu, Dongsheng Zhou
BACKGROUND: VIM-type enzyme encodes the most widely acquired metallo-β-lactamases in Gram- negative bacteria. To obtain current epidemiological data for integrons from enterobacteriae in hospital, the study characterizes the genetic structure in In1059 by comparison with In846 integrons harbouring VIM gene and other class 1 integrons including In37, In62, In843 and In1021 with the aim of identifying the putative mechanisms involved integron mobilization and infer evolution of relevant integrons...
2017: Antimicrobial Resistance and Infection Control
https://www.readbyqxmd.com/read/28529273/septicemic-invasive-klebsiella-pneumoniae-infection-in-a-cynomolgus-monkey-macaca-fascicularis-with-severe-diffused-suppurative-meningoencephalitis
#14
Kazufumi Kasuya, Kou Takayama, Makiko Bito, Natsumi Shimokubo, Ryosuke Kawashima, Tomoyuki Shibahara
A 2-year-old male cynomolgus monkey (Macaca fascicularis) showed neurological symptoms during quarantine for importation into Japan, and was euthanized due to poor prognosis. Gross anatomical examination revealed a hemorrhagic lesion around the lateral ventricle in the cerebrum. Histologically, severe diffused suppurative meningitis and ventriculitis were detected with numerous Gram-negative bacilli in the cerebrum. Immunohistochemically, the bacilli were positively stained with an antibody against Klebsiella pneumoniae...
May 22, 2017: Journal of Veterinary Medical Science
https://www.readbyqxmd.com/read/28529027/management-of-postneurosurgical-meningitis-narrative-review
#15
REVIEW
Khetam Hussein, Roni Bitterman, Ben Shofty, Mical Paul, Ami Neuberger
BACKGROUND: Infections complicating neurosurgery pose unacceptable mortality and morbidity. AIMS: To summarize what is known about the epidemiology, diagnosis and treatment of post-neurosurgical meningitis (PNM). SOURCES: PubMed, references of identified studies and reviews, and personal experience when evidence was lacking. CONTENT: The incidence and pathogen distribution of PNM is highly variable. A shift towards Gram-negative bacteria has been observed with use of antibiotic prophylaxis and antibiotic-coated devices directed mainly against Gram-positive bacteria...
May 18, 2017: Clinical Microbiology and Infection
https://www.readbyqxmd.com/read/28529026/the-use-of-matrix-assisted-laser-desorption-ionization-time-of-flight-mass-spectrometry-maldi-tof-ms-for-rapid-bacterial-identification-in-patients-with-smear-positive-bacterial-meningitis
#16
Boaz Bishop, Yuval Geffen, Adi Plaut, Ola Kassis, Roni Bitterman, Mical Paul, Ami Neuberger
OBJECTIVES: To assess the potential of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in rapid identification of bacteria from smear-positive cerebrospinal fluid (CSF) in a cohort of patients with meningitis. METHODS: Single-center observational study, including adults and children with community-acquired or postneurosurgical bacterial meningitis. Meningitis was defined using established criteria. CSF samples that had a positive CSF Gram stain were directly examined by MALDI-TOF-MS...
May 18, 2017: Clinical Microbiology and Infection
https://www.readbyqxmd.com/read/28528707/molecular-transcriptional-and-functional-insights-into-duplicated-goose-type-lysozymes-from-sebastes-schlegelii-and-their-potential-immunological-role
#17
Jehanathan Nilojan, S D N K Bathige, Roopasingam Kugapreethan, W S Thulasitha, Bo-Hye Nam, Jehee Lee
Black rockfish (Sebastes schlegelii), an important aquaculture species in Korea, has been affected by bacterial diseases leading to a drastic decline in production. Goose-type lysozyme (LysG) is a key enzyme of the innate immune system to eradicate bacterial infections. In this study, two isoforms of LysG from black rockfish, designated as RfLysG1 and RfLysG2, have been identified and characterized at the molecular, transcriptional, and functional levels. The deduced amino acid sequences had the LysG family characteristics and exhibited conserved properties, including active residues and domains...
May 18, 2017: Fish & Shellfish Immunology
https://www.readbyqxmd.com/read/28527130/pulse-generation-in-the-quorum-machinery-of-pseudomonas-aeruginosa
#18
Cicik Alfiniyah, Martin A Bees, A Jamie Wood
Pseudomonas aeruginosa is a Gram-negative bacterium that is responsible for a wide range of infections in humans. Colonies employ quorum sensing (QS) to coordinate gene expression, including for virulence factors, swarming motility and complex social traits. The QS signalling system of P. aeruginosa is known to involve multiple control components, notably the las, rhl and pqs systems. In this paper, we examine the las system and, in particular, the repressive interaction of rsaL, an embedded small regulative protein, employing recent biochemical information to aid model construction...
May 19, 2017: Bulletin of Mathematical Biology
https://www.readbyqxmd.com/read/28526895/three-novel-xenorhabdus-steinernema-associations-and-evidence-of-strains-of-x-khoisanae-switching-between-different-clades
#19
Jonike Dreyer, Antoinette P Malan, Leon M T Dicks
Xenorhabdus species are normally closely associated with entomopathogenic nematodes of the family Steinernematidae. Strain F2, isolated from Steinernema nguyeni, was identified as Xenorhabdus bovienii and strains J194 and SB10, isolated from Steinernema jeffreyense and Steinernema sacchari as Xenorhabdus khoisanae, based on phenotypic characteristics and sequencing of 16S rRNA and housekeeping genes dnaN, gltX, gyrB, infB and recA. All three strains produced antimicrobial compounds that inhibited the growth of Gram-positive and Gram-negative bacteria...
May 19, 2017: Current Microbiology
https://www.readbyqxmd.com/read/28526864/a-broad-spectrum-bactericidal-lipopeptide-with-anti-biofilm-properties
#20
Ohad Meir, Fadia Zaknoon, Uri Cogan, Amram Mor
Previous studies of the oligoacyllysyl (OAK) series acyl-lysyl-lysyl-aminoacyl-lysine-amide, suggested their utility towards generating robust linear lipopeptide-like alternatives to antibiotics, although to date, none exhibited potent broad-spectrum bactericidal activity. To follow up on this premise, we produced a new analog (C14KKc12K) and investigated its properties in various media. Mechanistic studies suggest that C14KKc12K uses a non-specific membrane-disruptive mode of action for rapidly reducing viability of Gram-negative bacteria (GNB) similarly to polymyxin B (PMB), a cyclic lipopeptide used as last resort antibiotic...
May 19, 2017: Scientific Reports
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