keyword
MENU ▼
Read by QxMD icon Read
search

Polymyxins

keyword
https://www.readbyqxmd.com/read/29774093/distribution-of-virulence-associated-genes-and-antimicrobial-susceptibility-in-clinical-acinetobacter-baumannii-isolates
#1
Chao Liu, Yaowen Chang, Ying Xu, Yun Luo, Linrong Wu, Zhanjun Mei, Shigang Li, Rui Wang, Xu Jia
Acinetobacter baumannii is undoubtedly one of the most clinically significant pathogens. The multidrug resistance and virulence potential of A. baumannii are responsible for hospital-acquired nosocomial infections. Unlike numerous investigations on the drug-resistant epidemiology of A. baumanni , virulence molecular epidemiology is less studied. Here, we collected 88 A. baumannii clinical isolates, tested their antimicrobial susceptibility to 10 commonly used antibiotics and analyzed the distribution of 9 selected virulence-associated genes, aims to investigate the primary characteristics of the virulence-associated genes that exist in clinically multidrug resistant (MDR) and non-MDR isolates of A...
April 24, 2018: Oncotarget
https://www.readbyqxmd.com/read/29760690/two-new-lytic-bacteriophages-of-the-myoviridae-family-against-carbapenem-resistant-acinetobacter-baumannii
#2
Weilong Zhou, Yu Feng, Zhiyong Zong
Two lytic bacteriophages, WCHABP1 and WCHABP12, were recovered from hospital sewage and were able to infect 9 and 12 out of 18 carbapenem-resistant Acinetobacter baumannii clinical strains, which belonged to different clones. Electron microscopy scan showed that both bacteriophages had the similar morphology as those of the Myoviridae family. Whole genomic sequencing revealed 45.4- or 45.8-kb genome with a 37.6% GC content for WCHABP1 and WCHABP12, both of which showed significant DNA sequence similarity with bacteriophages of the Ap22virus genus within the Myoviridae family...
2018: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29760144/personalizing-polymyxin-b-dosing-using-an-adaptive-feedback-control-algorithm
#3
Elizabeth A Lakota, Cornelia B Landersdorfer, Roger L Nation, Jian Li, Keith S Kaye, Gauri G Rao, Alan Forrest
Polymyxin B is used as an antibiotic of last resort for patients with multidrug-resistant Gram-negative bacterial infections; however, it carries a significant risk of nephrotoxicity. Herein we present a polymyxin B therapeutic window based on target area under the concentration-time curve (AUC) values and an adaptive feedback control algorithm (algorithm) which allows for the personalization of polymyxin B dosing. The upper bound of this therapeutic window was determined through a pharmacometric meta-analysis of polymyxin B nephrotoxicity data, and the lower bound was derived from murine thigh-infection pharmacokinetic/pharmacodynamic studies...
May 14, 2018: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/29760138/co-location-of-the-polymyxin-resistance-gene-mcr-1-and-variant-of-mcr-3-on-a-plasmid-in-escherichia-coli-from-chicken-farm
#4
Rong Xiang, Bi-Hui Liu, An-Yun Zhang, Chang-Wei Lei, Xiao-Lan Ye, Yan-Xian Yang, Yan-Peng Chen, Hong-Ning Wang
A colistin-resistant Escherichia coli from commercial poultry farm in China carried two colistin-resistance genes mcr-1 and variant of mcr-3 in an IncP plasmid. The variant of mcr-3 gene, named mcr-3.11 , encoded two amino acid substitutions compared with the mcr-3 A novel genetic structure, IS Kpn40-mcr-3-dgkA - IS Kpn40 , might be the key element mediating translocation of mcr-3 through the formation of circular form. The mcr-1 and mcr-3 genes co-located on a plasmid might pose huge threat to public health...
May 14, 2018: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/29758020/defining-icr-mo-an-intrinsic-colistin-resistance-determinant-from-moraxella-osloensis
#5
Wenhui Wei, Swaminath Srinivas, Jingxia Lin, Zichen Tang, Shihua Wang, Saif Ullah, Vishnu Goutham Kota, Youjun Feng
Polymyxin is the last line of defense against severe infections caused by carbapenem-resistant gram-negative pathogens. The emergence of transferable MCR-1/2 polymyxin resistance greatly challenges the renewed interest in colistin (polymyxin E) for clinical treatments. Recent studies have suggested that Moraxella species are a putative reservoir for MCR-1/2 genetic determinants. Here, we report the functional definition of ICR-Mo from M. osloensis, a chromosomally encoded determinant of colistin resistance, in close relation to current MCR-1/2 family...
May 14, 2018: PLoS Genetics
https://www.readbyqxmd.com/read/29755727/antimicrobial-resistance-profile-of-e-coli-isolated-from-raw-cow-milk-and-fresh-fruit-juice-in-mekelle-tigray-ethiopia
#6
Haftay Abraha Tadesse, Netsenet Berhe Gidey, Kidane Workelule, Hagos Hailu, Seyfe Gidey, Abrha Bsrat, Habtamu Taddele
Aim: Foodborne illnesses represent a public health problem in developed and developing countries. They cause great suffering and are transmitted directly or indirectly between animals and humans and circulate in the global environment . E. coli are among them, causing a major public health problem. The aim of this study was therefore to study the antimicrobial resistance profile of E. coli from raw cow milk and fruit juice. Materials and Methods: A cross-sectional study was conducted from October 2016 to June 2017 on 258 samples collected from milk shops ( n = 86), dairy farms ( n = 86), and fruit juice ( n = 86) in different subcities of Mekelle...
2018: Veterinary Medicine International
https://www.readbyqxmd.com/read/29746111/novobiocin-enhances-polymyxin-activity-by-stimulating-lipopolysaccharide-transport
#7
Michael D Mandler, Vadim Baidin, James Lee, Karanbir S Pahil, Tristan W Owens, Daniel Kahne
Gram-negative bacteria are challenging to kill with antibiotics due to their impenetrable outer membrane containing lipopolysaccharide (LPS). The polymyxins, including colistin, are the drugs of last resort for treating Gram-negative infections. These drugs bind LPS and disrupt the outer membrane; however, their toxicity limits their usefulness. Polymyxin has been shown to synergize with many antibiotics including novobiocin, which inhibits DNA gyrase, by facilitating their transport across the outer membrane...
May 10, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29739882/gene-expression-kinetics-governs-stimulus-specific-decoration-of-the-salmonella-outer-membrane
#8
Xinyu Hong, H Deborah Chen, Eduardo A Groisman
Lipid A is the innermost component of the lipopolysaccharide (LPS) molecules that occupy the outer leaflet of the outer membrane in Gram-negative bacteria. Lipid A is recognized by the host immune system and targeted by cationic antimicrobial compounds. In Salmonella enterica serovar Typhimurium, the phosphates of lipid A are chemically modified by enzymes encoded by targets of the transcriptional regulator PmrA. These modifications increase resistance to the cationic peptide antibiotic polymyxin B by reducing the negative charge of the LPS...
May 8, 2018: Science Signaling
https://www.readbyqxmd.com/read/29730830/the-epidemiology-evolution-and-treatment-of-kpc-producing-organisms
#9
REVIEW
Ann Marie Porreca, Kaede V Sullivan, Jason C Gallagher
PURPOSE OF REVIEW: The purpose of this review is to investigate the evolution and epidemiology of Klebsiella pneumoniae carbapenemase (KPC)-producing organisms and the current and future treatment options for infections caused by KPC-producing isolates. RECENT FINDINGS: The emergence of resistance in Enterobacteriaceae producing carbapenemases globally has increased the challenges in treating infections caused by these organisms. One of the prominent mechanisms of resistance is the production of KPC enzymes...
May 5, 2018: Current Infectious Disease Reports
https://www.readbyqxmd.com/read/29720352/bacteremia-and-meningitis-caused-by-oxa-23-producing-acinetobacter-baumannii-molecular-characterization-and-susceptibility-testing-for-alternative-antibiotics
#10
Kamile Francine Schuertz, Felipe Francisco Tuon, Jussara Kasuko Palmeiro, Danieli Conte, João Paulo Marochi Telles, Lucas Eduardo Trevisoli, Libera Maria Dalla-Costa
BACKGROUND: Carbapenem-resistant Acinetobacter baumannii infection is a concern in developing countries due to high incidence, few therapeutic options, and increasing costs. OBJECTIVE: Characterize and analyze the antibiotic susceptibility patterns of carbapenem-resistant A. baumannii isolates and evaluate clinical data of meningitis and bacteremia caused by this microorganism. METHODS: Twenty-six A. baumannii isolates from 23 patients were identified by MALDI-TOF and automated methods and genotyped using pulsed field genotyping electrophoresis...
April 24, 2018: Brazilian Journal of Microbiology: [publication of the Brazilian Society for Microbiology]
https://www.readbyqxmd.com/read/29720043/antimicrobial-stewardship-through-telemedicine-and-its-impact-on-multi-drug-resistance
#11
Rodrigo P Dos Santos, Camila H Dalmora, Stephani A Lukasewicz, Otávio Carvalho, Caroline Deutschendorf, Raquel Lima, Tiago Leitzke, Nilson C Correa, Marcelo V Gambetta
Introduction Telemedicine technologies are increasingly being incorporated into infectious disease practice. We aimed to demonstrate the impact of antimicrobial stewardship through telemedicine on bacterial resistance rates. Methods We conducted a quasi-experimental study in a 220-bed hospital in southern Brazil. An antimicrobial stewardship program incorporating the use of telemedicine was implemented. Resistance and antimicrobial consumption rates were determined and analysed using a segmented regression model...
January 1, 2018: Journal of Telemedicine and Telecare
https://www.readbyqxmd.com/read/29713282/synergistic-killing-of-polymyxin-b-in-combination-with-the-antineoplastic-drug-mitotane-against-polymyxin-susceptible-and-resistant-acinetobacter-baumannii-a-metabolomic-study
#12
Thien B Tran, Phillip J Bergen, Darren J Creek, Tony Velkov, Jian Li
Polymyxins are currently used as the last-resort antibiotics against multidrug-resistant Acinetobacter baumannii . As resistance to polymyxins emerges in A. baumannii with monotherapy, combination therapy is often the only remaining treatment option. A novel approach is to employ the combination of polymyxin B with non-antibiotic drugs. In the present study, we employed metabolomics to investigate the synergistic mechanism of polymyxin B in combination with the antineoplastic drug mitotane against polymyxin-susceptible and -resistant A...
2018: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/29706941/novel-polymyxin-combination-with-antineoplastic-mitotane-improved-the-bacterial-killing-against-polymyxin-resistant-multidrug-resistant-gram-negative-pathogens
#13
Thien B Tran, Jiping Wang, Yohei Doi, Tony Velkov, Phillip J Bergen, Jian Li
Due to limited new antibiotics, polymyxins are increasingly used to treat multidrug-resistant (MDR) Gram-negative bacteria, in particular carbapenem-resistant Acinetobacter baumannii , Pseudomonas aeruginosa , and Klebsiella pneumoniae . Unfortunately, polymyxin monotherapy has led to the emergence of resistance. Polymyxin combination therapy has been demonstrated to improve bacterial killing and prevent the emergence of resistance. From a preliminary screening of an FDA drug library, we identified antineoplastic mitotane as a potential candidate for combination therapy with polymyxin B against polymyxin-resistant Gram-negative bacteria...
2018: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29701307/exogenous-fatty-acids-alter-phospholipid-composition-membrane-permeability-capacity-for-biofilm-formation-and-antimicrobial-peptide-susceptibility-in-klebsiella-pneumoniae
#14
Chelsea R Hobby, Joshua L Herndon, Colton A Morrow, Rachel E Peters, Steven J K Symes, David K Giles
Klebsiella pneumoniae represents a major threat to human health due to a combination of its nosocomial emergence and a propensity for acquiring antibiotic resistance. Dissemination of the bacteria from its native intestinal location creates severe, complicated infections that are particularly problematic in healthcare settings. Thus, there is an urgency for identifying novel treatment regimens as the incidence of highly antibiotic-resistant bacteria rises. Recent findings have highlighted the ability of some Gram-negative bacteria to utilize exogenous fatty acids in ways that modify membrane phospholipids and influence virulence phenotypes, such as biofilm formation and antibiotic resistance...
April 27, 2018: MicrobiologyOpen
https://www.readbyqxmd.com/read/29700569/enzyme-oxidation-of-plant-galactomannans-yielding-biomaterials-with-novel-properties-and-applications-including-as-delivery-systems
#15
REVIEW
Yves M Galante, Luca Merlini, Tiziana Silvetti, Paola Campia, Bianca Rossi, Fiorenza Viani, Milena Brasca
New biomaterials from renewable sources and the development of "functionalized biopolymers" are fields of growing industrial interest. Plant polysaccharides represent a valid alternative to traditional synthetic polymers, which are obtained from monomers of fossil, non-renewable origin. Several polysaccharides, either in their natural or chemically/biochemically modified forms, are currently employed in the biomedical, food and feed, and industrial fields, including packaging. Sustainable biochemical reactions, such as enzyme modifications of polysaccharides, open further possibilities for new product and process innovation...
April 26, 2018: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/29688451/genome-scale-metabolic-modeling-of-responses-to-polymyxins-in-pseudomonas-aeruginosa
#16
Yan Zhu, Tobias Czauderna, Jinxin Zhao, Matthias Klapperstueck, Mohd Hafidz Mahamad Maifiah, Mei-Ling Han, Jing Lu, Björn Sommer, Tony Velkov, Trevor Lithgow, Jiangning Song, Falk Schreiber, Jian Li
Background: Pseudomonas aeruginosa often causes multidrug-resistant infections in immunocompromised patients, and polymyxins are often used as the last-line therapy. Alarmingly, resistance to polymyxins has been increasingly reported worldwide recently. To rescue this last-resort class of antibiotics, it is necessary to systematically understand how P. aeruginosa alters its metabolism in response to polymyxin treatment, thereby facilitating the development of effective therapies. To this end, a genome-scale metabolic model (GSMM) was used to analyze bacterial metabolic changes at the systems level...
April 1, 2018: GigaScience
https://www.readbyqxmd.com/read/29686157/antimicrobial-activity-of-murepavadin-tested-against-clinical-isolates-of-pseudomonas-aeruginosa-from-the-united-states-europe-and-china
#17
Helio S Sader, Glenn E Dale, Paul R Rhomberg, Robert K Flamm
Murepavadin (formerly POL7080), a 14-amino-acid cyclic peptide, and comparators were tested by broth microdilution method against 1,219 isolates from 112 medical centers. Murepavadin (MIC50/90 , 0.12/0.12 mg/L) was 4- to 8-fold more active than colistin (MIC50/90 , 1/1 mg/L) and polymyxin B (MIC50/90 , 0.5/1 mg/L) and inhibited 99.1% of isolates at ≤0.5 mg/L. Only 4 isolates (0.3%) exhibited murepavadin MIC >2 mg/L. Murepavadin was equally active against isolates from Europe, the United States, and China...
April 23, 2018: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/29686149/retained-activity-of-an-o25b-specific-monoclonal-antibody-against-mcr-1-producing-escherichia-coli-st131
#18
Luis M Guachalla, Katharina Ramoni, Cecilia Varga, Michele Mutti, Akela Ghazawi, Tibor Pál, Eszter Nagy, Ágnes Sonnevend, Gábor Nagy, Valéria Szijártó
Plasmid-encoded colistin resistance is emerging among extra-intestinal pathogenic Escherichia coli including the epidemic clone ST131-H30. Mcr-1 transfers a phosphoethanolamine to the lipid A portion of LPS conferring resistance to polymyxins. We investigated whether this modification changed the activity of the monoclonal antibody, ASN-4 specific to the O25b side-chain of ST131 LPS. We confirmed that, unlike colistin, ASN-4 retained its bactericidal and endotoxin neutralizing activity and therefore offer a treatment option against extremely drug-resistant ST131 isolates...
April 23, 2018: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/29677669/toxicological-interaction-of-multi-component-mixtures-to-vibrio-qinghaiensis-sp-q67-induced-by-at-least-three-components
#19
Ya-Qian Xu, Shu-Shen Liu, Ye Fan, Kai Li
It has been stated by researchers that the antibiotic polymyxin B sulfate (POL) is a key component inducing time-dependent antagonism in freshwater luminescent bacteria, Vibrio qinghaiensis sp.-Q67, exposed in the ternary mixture system of the ionic liquids, pesticide and antibiotics. However, the previous statement is limited to ternary and quaternary mixtures without considering situations such as the binary system. In order to prove the direct inducing of antagonism by POL in a more complete and systematic way, two categories of experiments (adding POL in non-antagonistic ternary system and decomposing antagonistic ternary system with POL into the binary system) have been conducted in this paper...
April 17, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/29677485/octapeptins-lipopeptide-antibiotics-against-multidrug-resistant-superbugs
#20
Antoine Abou Fayad, Jennifer Herrmann, Rolf Müller
Antimicrobial resistance is increasing at an alarming rate. Polymyxin, one of the few antibiotics of last resort, is heavily affected. In this issue of Cell Chemical Biology, Velkov et al. (2018) present a promising alternative: octapeptin lipopeptide antibiotics active against multidrug- and extensively drug-resistant Gram-negative bacteria, which might help overcoming resistance toward polymyxins.
April 19, 2018: Cell Chemical Biology
keyword
keyword
89847
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"