keyword
MENU ▼
Read by QxMD icon Read
search

Polymyxin resistance

keyword
https://www.readbyqxmd.com/read/28202493/a-klebsiella-pneumoniae-antibiotic-resistance-mechanism-that-subdues-host-defences-and-promotes-virulence
#1
Timothy J Kidd, Grant Mills, Joana Sá-Pessoa, Amy Dumigan, Christian G Frank, José L Insua, Rebecca Ingram, Laura Hobley, José A Bengoechea
Klebsiella pneumoniae is an important cause of multidrug-resistant infections worldwide. Recent studies highlight the emergence of multidrug-resistant K. pneumoniae strains which show resistance to colistin, a last-line antibiotic, arising from mutational inactivation of the mgrB regulatory gene. However, the precise molecular resistance mechanisms of mgrB-associated colistin resistance and its impact on virulence remain unclear. Here, we constructed an mgrB gene K. pneumoniae mutant and performed characterisation of its lipid A structure, polymyxin and antimicrobial peptide resistance, virulence and inflammatory responses upon infection...
February 15, 2017: EMBO Molecular Medicine
https://www.readbyqxmd.com/read/28180225/rediscovering-the-octapeptins
#2
REVIEW
Tony Velkov, Kade D Roberts, Jian Li
Covering: 1975 up to the end of 2016The decline in the discovery and development of novel antibiotics has resulted in the emergence of bacteria that are resistant to almost all available antibiotics. Currently, polymyxin B and E (colistin) are being used as the last-line therapy against life-threatening infections, unfortunately resistance to polymyxins in both the community and hospital setting is becoming more common. Octapeptins are structurally related non-ribosomal lipopeptide antibiotics that do not exhibit cross-resistance with polymyxins and have a broader spectrum of activity that includes Gram-positive bacteria...
February 9, 2017: Natural Product Reports
https://www.readbyqxmd.com/read/28167564/multiclonal-expansion-of-klebsiella-pneumoniae-isolates-producing-ndm-1-in-rio-de-janeiro-brazil
#3
Caio Augusto Martins Aires, Polyana Silva Pereira, Carlos Felipe Machado de Araujo, Thiago Pavoni Gomes Chagas, Jane Cleide Oliveira, Sibelle Nogueira Buonora, Rodolpho Mattos Albano, Ana Paula D'Alincourt Carvalho-Assef, Marise Dutra Asensi
We characterized NDM-1-producing Klebsiella spp. isolates from Rio de Janeiro, Brazil. PCR was applied for resistance and virulence determinants. The genetic context of blaNDM was determined by S1 PFGE and hybridization. The genotyping were performed by PFGE and MLST. Most isolates carried multiple resistance genes and remained susceptible to amikacin, fosfomycin/trometamol, polymyxin B and tigecycline. The spread of NDM-1-producing K. pneumoniae was not associated with a clonal expansion and appears to be associated with Tn3000...
February 6, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28167549/polymyxin-b-based-triple-combinations-wage-war-against-kpc-2-producing-klebsiella-pneumoniae-new-dosing-strategies-for-old-allies
#4
Zackery P Bulman, Michael J Satlin, Liang Chen, Barry N Kreiswirth, Beom Soo Shin, Thomas J Walsh, Patricia N Holden, Alan Forrest, Roger L Nation, Jian Li, Brian T Tsuji
Pharmacodynamics of a polymyxin B, meropenem and rifampin triple combination were examined against Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) ST258. In time-kill experiments against three KPC-Kp isolates, triple combination generated 8.14, 8.19 and 8.29 log10CFU/mL reductions within 24h. In the hollow fiber infection model, the triple combination caused maximal killing of 5.16 log10CFU/mL at 78h and time required for regrowth was more than doubled versus 2-drug combinations...
February 6, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28163137/resistance-to-polymyxins-in-gram-negative-organisms
#5
Katy Jeannot, Arnaud Bolard, Patrick Plésiat
Polymyxins have recently been re-introduced into the therapeutic arsenal to combat infections caused by multidrug-resistant Gram-negative bacteria. However, the emergence of strains resistant to these last-resort drugs is becoming a critical issue in a growing number of countries. Both intrinsic and transferable mechanisms of polymyxin resistance have been characterised. These mechanisms as well as the epidemiological data regarding four relevant bacterial pathogens (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa) are considered in this review...
February 3, 2017: International Journal of Antimicrobial Agents
https://www.readbyqxmd.com/read/28159445/serratia-marcescens-harboring-sme-4-in-brazil-a-silent-threat
#6
Rodrigo Cayô, Rodrigo Cuiabano Paes Leme, Ana Paula Streling, Adriana Pereira Matos, Carolina Silva Nodari, Jessica Reis Esteves Chaves, Jorge Luiz Ferreira Brandão, Maíra Fernandes de Almeida, Valério Carrareto, Marco Aurélio de Castro Pereira, Jean Pierre Aquino de Almeida, Demian Candido Ferreira, Ana Cristina Gales
The intrinsic polymyxin resistance displayed by Serratia marcescens makes the acquisition of carbapenemase encoding genes a worrisome event. This study report a SME-4-producing S. marcescens isolate causing septic shock in Brazil. The insertion of novel resistance determinants and their consequent spread in our territory is noteworthy.
January 20, 2017: Diagnostic Microbiology and Infectious Disease
https://www.readbyqxmd.com/read/28150578/resistotyping-phenotyping-and-genotyping-of-new-delhi-metallo-%C3%AE-lactamase-ndm-among-gram-negative-bacilli-from-iranian-patients
#7
Dariush Shokri, Mohammad Rabbani Khorasgani, Seyed Masih Fatemi, Abbas Soleimani-Delfan
PURPOSE: The purpose of this study was investigation of New Delhi metallo-β-lactamase (NDM) production among gram negative bacilli. METHODOLOGY: Antibiogram-Resistotyping and detection of NDM in clinical isolates of Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa and comparative evaluation of the diagnostic performance of three phenotypic methods for NDM detection considering PCR as gold standard were performed. Minimum Inhibitory Concentration (MIC) of antibiotics against NDM positive strains by E-test and clonal relationship analysis using Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) in these strains were determined...
February 1, 2017: Journal of Medical Microbiology
https://www.readbyqxmd.com/read/28139543/antibiotic-resistance-pathogen-profile-in-ventilator-associated-pneumonia-in-a-tertiary-care-hospital-in-india
#8
Abhijit Chaudhury, A Shobha Rani, Usha Kalawat, Sachin Sumant, Anju Verma, B Venkataramana
BACKGROUND & OBJECTIVES: Ventilator-associated pneumonia (VAP) is an important hospital-acquired infection with substantial mortality. Only a few studies are available from India addressing the microbiological aspects of VAP, which have been done with small study populations. This study was carried out in the intensive care units (ICUs) of a tertiary care hospital to assess the profile of pathogens and to determine the pattern of antimicrobial resistance. METHODS: This was a retrospective study of clinically suspected cases of VAP...
September 2016: Indian Journal of Medical Research
https://www.readbyqxmd.com/read/28139430/prevalence-of-mcr-1-in-escherichia-coli-and-klebsiella-pneumoniae-recovered-from-bloodstream-infections-in-china-a-multicentre-longitudinal-study
#9
Jingjing Quan, Xi Li, Yan Chen, Yan Jiang, Zhihui Zhou, Huichuan Zhang, Lu Sun, Zhi Ruan, Ye Feng, Murat Akova, Yunsong Yu
BACKGROUND: Polymyxin antibiotics are used as last-resort therapies to treat infections caused by multidrug-resistant Gram-negative bacteria. The plasmid-mediated colistin resistance determinant MCR-1 has been identified in Enterobacteriaceae in China. We did this study to investigate the prevalence of the mcr-1 gene in clinical isolates from patients with bloodstream infections in China. METHODS: Clinical isolates of Escherichia coli and Klebsiella pneumoniae were collected from patients with bloodstream infections at 28 hospitals in China, then screened for colistin resistance by broth microdilution and for the presence of the mcr-1 gene by PCR amplification...
January 27, 2017: Lancet Infectious Diseases
https://www.readbyqxmd.com/read/28138370/carbapenem-susceptibility-and-multidrug-resistance-in-pseudomonas-aeruginosa-isolates-in-egypt
#10
Hany Hashem, Amro Hanora, Salah Abdalla, Alaa Shawky, Alaa Saad
BACKGROUND: Resistant Pseudomonas aeruginosa is a serious concern for antimicrobial therapy, as the common isolates exhibit variable grades of resistance, involving beta-lactamase enzymes, beside native defense mechanisms. OBJECTIVES: The present study was designed to determine the occurrence of Metallo-β- Lactamases (MBL) and Amp C harboring P. aeruginosa isolates from Suez Canal university hospital in Ismailia, Egypt. METHODS: A total of 147 P...
November 2016: Jundishapur Journal of Microbiology
https://www.readbyqxmd.com/read/28137807/inhibition-of-pseudomonas-aeruginosa-by-peptide-conjugated-phosphorodiamidate-morpholino-oligomers
#11
James J Howard, Carolyn R Sturge, Dina A Moustafa, Seth M Daly, Kimberly R Marshall-Batty, Christina F Felder, Danniel Zamora, Marium Yabe-Gill, Maria Labandeira-Rey, Stacey M Bailey, Michael Wong, Joanna B Goldberg, Bruce L Geller, David E Greenberg
Pseudomonas aeruginosa is a highly virulent, multidrug-resistant pathogen that causes significant morbidity and mortality in hospitalized patients and is particularly devastating in those with cystic fibrosis (CF). Increasing antibiotic resistance coupled with decreasing numbers of antibiotics in the developmental pipeline demands novel antibacterial approaches. Here we tested peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs), which inhibit translation of complementary mRNA from specific, essential genes in P...
January 30, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28137796/evaluation-of-a-lamp-based-assay-for-the-rapid-detection-of-plasmid-encoded-colistin-resistance-gene-mcr-1-in-enterobacteriaceae-isolates
#12
Can Imirzalioglu, Linda Falgenhauer, Judith Schmiedel, Said-Elias Waezsada, Konrad Gwozdzinski, Nicole Roschanski, Uwe Roesler, Lothar Kreienbrock, Arthur P Schiffmann, Alexandra Irrgang, Annemarie Käsbohrer, Rolf Bauerfeind, Eugen Domann, Trinad Chakraborty
Colistin, which belongs to the class of polypeptide antibiotics known as polymyxins, is a 'last-resort' antibiotic often used for treatment of patients infected with extensively multidrug-resistant (MDR) bacteria such as carbapenem-resistant Enterobacteriaceae….
January 30, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28114348/polymicrobial-ventilator-associated-pneumonia-fighting-in-vitro-candida-albicans-pseudomonas-aeruginosa-biofilms-with-antifungal-antibacterial-combination-therapy
#13
Maria E Rodrigues, Susana P Lopes, Cláudia R Pereira, Nuno F Azevedo, Anália Lourenço, Mariana Henriques, Maria O Pereira
The polymicrobial nature of ventilator-associated pneumonia (VAP) is now evident, with mixed bacterial-fungal biofilms colonizing the VAP endotracheal tube (ETT) surface. The microbial interplay within this infection may contribute for enhanced pathogenesis and exert impact towards antimicrobial therapy. Consequently, the high mortality/morbidity rates associated to VAP and the worldwide increase in antibiotic resistance has promoted the search for novel therapeutic strategies to fight VAP polymicrobial infections...
2017: PloS One
https://www.readbyqxmd.com/read/28103139/endotoxin-neutralization-by-an-o-antigen-specific-monoclonal-antibody-a-potential-novel-therapeutic-approach-against-klebsiella-pneumoniaest258
#14
Valéria Szijártó, Luis M Guachalla, Katharina Hartl, Cecília Varga, Adriana Badarau, Irina Mirkina, Zehra C Visram, Lukas Stulik, Christine A Power, Eszter Nagy, Gábor Nagy
Klebsiella pneumoniae ST258 is a globally distributed multi-drug resistant pathogen responsible for severe invasive infections. In this study, the different virulence potential of K. pneumoniae ST258 isolates in endotoxin susceptible versus resistant animal models was shown. Furthermore, ST258 clinical isolates were found highly sensitive to the bactericidal effect of naive animal and human serum. These observations imply that LPS, released from the rapidly lysed bacteria, may contribute to the high mortality associated with ST258 bacteremia cases...
January 19, 2017: Virulence
https://www.readbyqxmd.com/read/28096166/the-role-of-renal-drug-exposure-in-polymyxin-b-induced-nephrotoxicity
#15
Pooja Manchandani, Jian Zhou, Jessica T Babic, Kimberly R Ledesma, Luan D Truong, Vincent H Tam
Despite dose-limiting nephrotoxic potentials, polymyxin B has re-emerged as the last line of therapy against multidrug-resistant Gram-negative bacterial infections. However, the handling of polymyxin B by the kidneys is still not thoroughly understood. The objectives of this study were to evaluate the impact of renal polymyxin B exposure on nephrotoxicity and to explore the role of megalin in renal drug accumulation. Sprague-Dawley rats (225-250 g) were divided into 3 dosing groups, and polymyxin B was administered (5 mg/kg, 10 mg/kg and 20 mg/kg) subcutaneously once daily...
January 17, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28074057/development-of-new-polymyxin-derivatives-for-multi-drug-resistant-gram-negative-infections
#16
REVIEW
Pamela Brown, Michael J Dawson
Over the last decade, there has been a resurgence of interest in polymyxins owing to the rapid rise in multi-drug resistant Gram-negative bacteria against which polymyxins offer a last-resort treatment. Although having excellent antibacterial activity, the clinical utility of polymyxins is limited by toxicity, especially renal toxicity. There is much interest therefore in developing polymyxin analogues with an improved therapeutic index. This review describes recent work aimed at improving the activity and/or reducing the toxicity of polymyxins...
January 11, 2017: Journal of Antibiotics
https://www.readbyqxmd.com/read/28074004/signaling-by-two-component-system-noncognate-partners-promotes-intrinsic-tolerance-to-polymyxin-b-in-uropathogenic-escherichia-coli
#17
Kirsten R Guckes, Erin J Breland, Ellisa W Zhang, Sarah C Hanks, Navleen K Gill, Holly M S Algood, Jonathan E Schmitz, Charles W Stratton, Maria Hadjifrangiskou
Bacteria use two-component systems (TCSs) to react appropriately to environmental stimuli. Typical TCSs comprise a sensor histidine kinase that acts as a receptor coupled to a partner response regulator that coordinates changes in bacterial behavior, often through its activity as a transcriptional regulator. TCS interactions are typically confined to cognate pairs of histidine kinases and response regulators. We describe two distinct TCSs in uropathogenic Escherichia coli (UPEC) that interact to mediate a response to ferric iron...
January 10, 2017: Science Signaling
https://www.readbyqxmd.com/read/28071053/functional-characterization-of-the-unique-terminal-thioesterase-domain-from-polymyxin-synthetase
#18
Charles A Galea, Kade D Roberts, Yan Zhu, Philip E Thompson, Jian Li, Tony Velkov
Polymyxins remain one of the few antibiotics available for treating antibiotic resistant bacteria. Here we describe polymyxin B thioesterase which performs the final step in polymyxin B biosynthesis. Isolated thioesterase catalyzed cyclization of an N-acetylcystamine polymyxin B analogue to form polymyxin B. The thioesterase contained a catalytic cysteine unlike most thioesterases which possess a serine. Supporting this, incubation of polymyxin B thioesterase with reducing agents abolished enzymatic activity, while mutation of the catalytic cysteine to serine significantly decreased activity...
January 17, 2017: Biochemistry
https://www.readbyqxmd.com/read/28052852/high-dose-ampicillin-sulbactam-combinations-combat-polymyxin-resistant-acinetobacter-baumannii-in-a-hollow-fiber-infection-model
#19
Justin R Lenhard, Nicholas M Smith, Zackery P Bulman, Xun Tao, Visanu Thamlikitkul, Beom S Shin, Roger L Nation, Jian Li, Jürgen B Bulitta, Brian T Tsuji
Acinetobacter baumannii are emerging with resistance to polymyxins. In 24h time-killing experiments, high dose ampicillin/sulbactam in combination with meropenem and polymyxin B achieved additivity or synergy against 10(8)CFU/mL of two clinical A. baumannii isolates resistant to all three drugs (max reductions 1.6 and 3.1 logs). In 14-day hollow-fiber infection models, high dose ampicillin/sulbactam (8/4g q8h) in combination with meropenem (2g q8h) and polymyxin B (1.43 mg/kg q12h with loading dose) achieved rapid eradication (96h)...
January 4, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28044098/polymyxins-facilitate-entry-into-mammalian-cells
#20
Kristina M Hamill, Lisa S McCoy, Ezequiel Wexselblatt, Jeffrey D Esko, Yitzhak Tor
Polymyxin B is an antibiotic used against multi-resistant gram negative infections, despite observed nephrotoxicity. Here we report the synthesis of functionalized derivatives of polymyxin B and its per-guanidinylated derivative in order to further explore the structural requirements necessary to facilitate uptake of the antibiotic into mammalian cells. We also investigate the possibility of using these novel scaffolds as molecular transporters. At nanomolar concentrations, both are capable of delivering large cargo (>300 kDa) into living cells...
August 1, 2016: Chemical Science
keyword
keyword
93866
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"