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https://www.readbyqxmd.com/read/28826054/photothermal-lysis-of-pathogenic-bacteria-by-platinum-nanodots-decorated-gold-nanorods-under-near-infrared-irradiation
#1
Jie Zhang, Yonghai Feng, Jianli Mi, Yanting Shen, Zhigang Tu, Lei Liu
Photothermal lysis is an effective method for fast removal of pathogenic bacteria from bacterial contaminated environments and human body, irrespective of bacterial drug resistance. In the present work, a highly effective photothermal agent, Au@Pt nanorods (NRs), was prepared by modification of Pt nanodots with particle size of 5nm on the surface of Au NRs with a length of ca. 41nm and a width of ca. 13nm. The LSPR absorbance band of Au@Pt NRs could be tuned from 755 to 845nm by changing the Pt loading from 0...
July 25, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28825218/perspective-of-ions-and-messengers-an-intricate-link-between-potassium-glutamate-and-cyclic-di-amp
#2
REVIEW
Jan Gundlach, Fabian M Commichau, Jörg Stülke
Potassium and glutamate are the most abundant ions in every living cell. Whereas potassium plays a major role to keep the cellular turgor and to buffer the negative charges of the nucleic acids, the major function of glutamate is to serve as the universal amino group donor. In addition, both ions are involved in osmoprotection in bacterial cells. Here, we discuss how bacterial cells maintain the homeostasis of both ions and how adaptive evolution allows them to live even at extreme potassium limitation. Interestingly, positively charged amino acids are able to partially replace potassium, likely by buffering the negative charge of DNA...
August 20, 2017: Current Genetics
https://www.readbyqxmd.com/read/28824881/ask2-bioactive-compound-inhibits-mdr-klebsiella-pneumoniae-by-antibiofilm-activity-modulating-macrophage-cytokines-and-opsonophagocytosis
#3
Cheepurupalli Lalitha, Thiagarajan Raman, Sudarshan S Rathore, Manikandan Ramar, Arumugam Munusamy, Jayapradha Ramakrishnan
The emergence and spread of pathogens harboring extended spectrum beta-lactamase (ESBL) like carbapenem resistant Gram negative bacteria are the major emerging threat to public health. Of particular concern Klebsiella pneumoniae carbapenamase- producing strains have been recorded worldwide. Catheter associated urinary tract infections (CAUTI) caused by K. pneumoniae are significantly associated with morbidity and mortality. Hence the present work was aimed to develop a strategy for addressing these issues through an innovative approach of antibiofilm and immunomodulation...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28824570/dltx-of-bacillus-thuringiensis-is-essential-for-d-alanylation-of-teichoic-acids-and-resistance-to-antimicrobial-response-in-insects
#4
Rita Kamar, Agnès Réjasse, Isabelle Jéhanno, Zaynoun Attieh, Pascal Courtin, Marie-Pierre Chapot-Chartier, Christina Nielsen-Leroux, Didier Lereclus, Laure El Chamy, Mireille Kallassy, Vincent Sanchis-Borja
The dlt operon of Gram-positive bacteria is required for the incorporation of D-alanine esters into cell wall-associated teichoic acids (TAs). Addition of D-alanine to TAs reduces the negative charge of the cell envelope thereby preventing cationic antimicrobial peptides (CAMPs) from reaching their target of action on the bacterial surface. In most gram-positive bacteria, this operon consists of five genes dltXABCD but the involvement of the first ORF (dltX) encoding a small protein of unknown function, has never been investigated...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28822434/-risk-factors-of-bacterial-nosocomial-infection-after-pediatric-liver-transplantation
#5
H Zhu, W Gao
Objective: To analyze the risk factors of nosocomial infection after liver transplantation in children, so as to provide scientific evidence for the prevention and control of nosocomial infection. Method: Clinical data of 223 pediatric patients undergoing liver transplantation between January 2014 and December 2015 were analyzed retrospectively. Univariate and multivariate analyses were carried out to investigate the risk factors of infection after transplantation. Result: Totally 51 children were infected among the 223 patients, the infection rate was 22...
August 2, 2017: Zhonghua Er Ke za Zhi. Chinese Journal of Pediatrics
https://www.readbyqxmd.com/read/28821717/promysalin-is-a-salicylate-containing-antimicrobial-with-a-cell-membrane-disrupting-mechanism-of-action-on-gram-positive-bacteria
#6
Rahul D Kaduskar, Giulia Della Scala, Zaaima J H Al Jabri, Stefania Arioli, Loana Musso, Marco R Oggioni, Sabrina Dallavalle, Diego Mora
Promysalin was previously described as a narrow spectrum molecule with a unique species-specific activity against Pseudomonas aeruginosa. Here we demonstrate that promysalin is active against Gram-positive and Gram-negative bacteria using a microdilution assay. Promysalin acts on Gram-positive bacteria with a mechanism of action involving cell membrane damage with leakage of intracellular components. The evaluation of MICs and MBCs on 11 promysalin analogs, synthesized utilizing diverted total synthesis, allowed the identification of the structural moieties potentially involved in cell membrane interaction and damage...
August 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28821711/genetic-cargo-and-bacterial-species-set-the-rate-of-vesicle-mediated-horizontal-gene-transfer
#7
Frances Tran, James Q Boedicker
Most bacteria release extracellular vesicles (EVs). Recent studies have found these vesicles are capable of gene delivery, however the consequences of vesicle-mediated transfer on the patterns and rates of gene flow within microbial communities remains unclear. Previous studies have not determined the impact of both the genetic cargo and the donor and recipient species on the rate of vesicle-mediated gene exchange. This report examines the potential for EVs as a mechanism of gene transfer within heterogeneous microbial populations...
August 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28821550/crystal-structure-of-the-tetr-family-repressor-alkx-from-dietzia-sp-dq12-45-1b-implicated-in-biodegradation-of-n-alkanes
#8
Jie-Liang Liang, Yuan Gao, Zheng He, Yong Nie, Meng Wang, Jing-Hong JiangYang, Xuejun C Zhang, Wen-Sheng Shu, Xiao-Lei Wu
n-Alkanes are ubiquitous in nature and are widely used by microorganisms as carbon sources. Alkane hydroxylation by alkane monooxygenases is a critical step in the aerobic biodegradation of n-alkanes, which plays important roles in natural alkane attenuation and is used in industrial and environmental applications. The alkane oxidation operon, alkW1-alkX, in an alkane-degrading strain Dietzia sp. DQ12-45-1b, is negatively auto-regulated by the TetR family repressor, AlkX, via a product positive feedback mechanism...
August 18, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28821406/structural-insight-into-lipopolysaccharide-transport-from-the-gram-negative-bacterial-inner-membrane-to-the-outer-membrane
#9
REVIEW
Haohao Dong, Xiaodi Tang, Zhengyu Zhang, Changjiang Dong
Lipopolysaccharide (LPS) is an important component of the outer membrane (OM) of Gram-negative bacteria, playing essential roles in protecting bacteria from harsh environments, in drug resistance and in pathogenesis. LPS is synthesized in the cytoplasm and translocated to the periplasmic side of the inner membrane (IM), where it matures. Seven lipopolysaccharide transport proteins, LptA-G, form a trans‑envelope complex that is responsible for LPS extraction from the IM and transporting it across the periplasm to the OM...
August 15, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28821241/genetic-diversity-and-virulence-potential-of-clinical-and-environmental-aeromonas-spp-isolates-from-a-diarrhea-outbreak
#10
Lívia Christina Alves da Silva, Tereza Cristina Leal-Balbino, Beatriz Souza Toscano de Melo, Carina Lucena Mendes-Marques, Antonio Mauro Rezende, Alzira Maria Paiva de Almeida, Nilma Cintra Leal
BACKGROUND: Aeromonas spp. are gram-negative bacteria that can cause a variety of infections in both humans and animals and play a controversial role in diarrhea outbreaks. Our aim was to identify clinical and environmental Aeromonas isolates associated with a cholera outbreak in a northeast county of Brazil at the species level. We also aimed to determine the genetic structure of the bacterial population and the virulence potential of the Aeromonas isolates. METHODS AND RESULTS: Analysis based on concatenated sequences of the 16S rRNA and gyrB genes suggested the classification of the 119 isolates studied into the following species: A...
August 18, 2017: BMC Microbiology
https://www.readbyqxmd.com/read/28821240/avbd1-nucleotide-polymorphisms-peptide-antimicrobial-activities-and-microbial-colonisation-of-the-broiler-chicken-gut
#11
Kevin Cadwell, Sherko S Niranji, Vanessa L Armstrong, Catherine A Mowbray, Richard Bailey, Kellie A Watson, Judith Hall
BACKGROUND: The importance of poultry as a global source of protein underpins the chicken genome and associated SNP data as key tools in selecting and breeding healthy robust birds with improved disease resistance. SNPs affecting host peptides involved in the innate defences tend to be rare, but three non-synonymous SNPs in the avian β-defensin (AvBD1) gene encoding the variant peptides NYH, SSY and NYY were identified that segregated specifically to three lines of commercial broiler chickens Line X (LX), Line Y(LY) and Line Z...
August 18, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28821119/tailoring-of-temperature-and-ph-responsive-cotton-fabric-with-antimicrobial-activity-effect-of-the-concentration-of-a-bio-barrier-forming-agent
#12
Danaja Štular, Ivan Jerman, Barbara Simončič, Brigita Tomšič
A stimuli-responsive cotton fabric was designed using temperature and pH-responsive poly-N-isopropylacrylamide (poly-NiPAAm) and chitosan (PNCS) microgel as a carrier of antimicrobially active 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (Si-QAC), which forms a bio-barrier on the fibre surface. The influence of Si-QAC on the moisture management and thermoregulation abilities of the PNCS microgel was investigated. Using a pad-dry cure method, Si-QAC was applied to a 100% cotton fabric model in concentrations ranging from 0...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821033/novel-nitroaniline-cellulose-nanohybrids-nitro-radical-photo-release-and-its-antibacterial-action
#13
Prashant Chauhan, Ning Yan
In this study, carboxylated nanocrystalline cellulose is surface functionalized by a chromophoric nitro radical (NO) photodonor via covalent bonding. The resulting new photoactive nanohybrid material displays an effective photogeneration of NO radicals upon illumination by light. The release of NO radicals has been chemically detected by various spectroscopic techniques. The bactericidal activity of the novel nanohybrid is effectively demonstrated against both Gram positive (Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa) bacteria with light...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821027/preparation-characterization-and-antibacterial-activity-of-oxidized-%C3%AE%C2%BA-carrageenan
#14
Mingjin Zhu, Liming Ge, Yongbo Lyu, Yaxin Zi, Xinying Li, Defu Li, Changdao Mu
The oxidized κ-carrageenans with different oxidation levels were prepared through the hydrogen peroxide and copper sulfate redox system. The oxidation level of oxidized κ-carrageenan was successfully controlled by adjusting the dosage of hydrogen peroxide. The results showed that the microtopography of oxidized κ-carrageenan changed from rough granules to smooth flakes, mainly resulting from the easily melting property of oxidized κ-carrageenan induced by introduced carboxyl and aldehyde groups. Especially, the antibacterial activity of oxidized κ-carrageenans against Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) was systematically investigated...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821026/ultrahigh-antibacterial-efficacy-of-meropenem-loaded-chitosan-nanoparticles-in-a-septic-animal-model
#15
Ayat Abdelkader, Mohamed A El-Mokhtar, Ola Abdelkader, Mostafa A Hamad, Mahmoud Elsabahy, Omaima N El-Gazayerly
Antimicrobial resistance is one of the most significant health challenges worldwide. Meropenem is a broad spectrum beta-lactam antibiotic that possesses high activity against Gram-positive and Gram-negative bacteria. However, it has a short plasma half-life, and thus requiring frequent administration of high doses. For the first time, meropenem-loaded chitosan nanoparticles were prepared and evaluated as a potential tool to overcome antimicrobial resistance and to improve pharmacokinetics of the drug. Spherical nanosized particles were prepared and demonstrated ultrahigh encapsulation efficiency of meropenem (i...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28820574/thiol-containing-metallo-%C3%AE-lactamase-inhibitors-resensitize-resistant-gram-negative-bacteria-to-meropenem
#16
Kamaleddin Haj Mohammad Ebrahim Tehrani, Nathaniel I Martin
The prevalence of infections caused by metallo-β-lactamase (MBL) expressing Gram-negative bacteria has grown at an alarming rate in recent years. Despite the fact that MBLs can deactivate virtually all β-lactams antibiotics, there are as of yet no approved drugs available that inhibit their activity. We here examine the ability of previously reported thiol-based MBL inhibitors to synergize with meropenem against a panel of Gram-negative carbapenem-resistant isolates expressing different β-lactamases. Among the compounds tested, thiomandelic acid 3 and 2-merpto-3-phenylpropionic acid 4 were found to efficiently potentiate the activity of meropenem, especially against an IMP producing strain of K...
August 18, 2017: ACS Infectious Diseases
https://www.readbyqxmd.com/read/28820151/a-literature-review-and-update-on-the-incidence-and-microbiology-spectrum-of-postcataract-surgery-endophthalmitis-over-past-two-decades-in-india
#17
REVIEW
Prajna Lalitha, Sabyasachi Sengupta, Ravilla D Ravindran, Savitri Sharma, Joveeta Joseph, Vikas Ambiya, Taraprasad Das
PURPOSE: The purpose of this study was to review the incidence and microbiology of acute postcataract surgery endophthalmitis in India. METHODS: Systematic review of English-language PubMed referenced articles on endophthalmitis in India published in the past 21 years (January 1992-December 2012), and retrospective chart review of 2 major eye care facilities in India in the past 5 years (January 2010-December 2014) were done. The incidence data were collected from articles that described "in-house" endophthalmitis and the microbiology data were collected from all articles...
August 2017: Indian Journal of Ophthalmology
https://www.readbyqxmd.com/read/28820119/blastomonas-fulva-sp-nov-aerobic-photosynthetic-bacteria-isolated-from-a-microcystis-culture
#18
Hyung-Gwan Lee, So-Ra Ko, Jun-Woo Lee, Chang Soo Lee, Chi-Yong Ahn, Hee-Mock Oh, Long Jin
Two Gram-stain-negative, aerobic, non-motile, non-spore-forming and rod-shaped bacteria, designated strains T2T and T5, were isolated from a culture of Microcystis from Daejeon, Republic of Korea. Comparative 16S rRNA gene sequence studies placed the new isolates in the class Alphaproteobacteria and, notably, most closely related to Blastomonasaquatica PE 4-5T, Blastomonas natatoria DSM 3183T and Blastomonas ursincola KR-99T showing 99.4 %, 98.2 % and 97.9 % 16S rRNA gene sequence similarities, respectively...
August 18, 2017: International Journal of Systematic and Evolutionary Microbiology
https://www.readbyqxmd.com/read/28820111/description-of-actinokineospora-acnipugnans-sp-nov-an-actinomycete-isolated-from-soil-showing-potential-uses-in-cosmetics
#19
Ram Hari Dahal, Dong Seop Shim, Jaisoo Kim
During isolation of soil bacteria having antibacterial functions, an aerobic, Gram-stain-positive, oxidase-negative, catalase-positive bacterium, designated strain R434T, was isolated. Strain R434T showed antimicrobial activity against Propionibacterium acnes and Staphylococcus epidermidis and significant enzyme-inhibitory capability. The diagnostic diamino acid of the cell-wall peptidoglycan was meso-diaminopimelic acid, and the whole-cell sugars were galactose, arabinose and glucose. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain R434T formed a lineage within the family Pseudonocardiaceae...
August 18, 2017: International Journal of Systematic and Evolutionary Microbiology
https://www.readbyqxmd.com/read/28820095/proposal-of-henriciella-barbarensis-sp-nov-and-henriciella-algicola-sp-nov-stalked-species-of-the-genus-and-emendation-of-the-genus-henriciella
#20
Wolf-Rainer Abraham, Maira Peres de Carvalho, Thais Souto Paula da Costa Neves, Marina Torquato Memoria, Iago Toledo Tartuci, Marc Vancanneyt, John Smit, Manfred Rohde
Two Gram-negative, heterotrophic, aerobic, prosthecated, marine bacteria, designated strains MCS23T and MCS27T, were isolated from seawater samples. NaCl was required for growth. The major polar lipid detected in strain MCS27T was phosphatidylglycerol, whereas those detected in MCS23T were phosphatidylglycerol, sulfoquinovosyl diacylglycerol and 1,2-diacyl-3-α-d-glucuronopyranosyl-sn-glycerol taurineamide. The most abundant cellular fatty acids were C18 : 1ω7 and C16 : 0, hydroxyl-fatty acids were 3-OH C12 : 0 in both strains and 3-OH C11 : 0 in MCS23T...
August 18, 2017: International Journal of Systematic and Evolutionary Microbiology
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