keyword
MENU ▼
Read by QxMD icon Read
search

Lactamase

keyword
https://www.readbyqxmd.com/read/28096978/carriage-of-antibiotic-resistant-enterobacteriaceae-in-hospitalised-children-in-tertiary-hospitals-in-harare-zimbabwe
#1
Marcelyn T Magwenzi, Muchaneta Gudza-Mugabe, Hilda A Mujuru, Mutsa Dangarembizi-Bwakura, Valerie Robertson, Alexander M Aiken
BACKGROUND: Extended-spectrum β-lactamase-producing and gentamicin resistant Enterobacteriaceae are increasingly recognised as a major cause of infection in low-income countries. We assessed the prevalence of gastrointestinal carriage of these bacteria in hospitalised children in Harare, Zimbabwe. METHODS: We conducted a cohort study in paediatric inpatients at two tertiary-referral hospitals between May and July 2015. Rectal swabs and faecal samples were collected within 24 h of admission and further follow-up samples were collected on alternate days during hospitalization...
2017: Antimicrobial Resistance and Infection Control
https://www.readbyqxmd.com/read/28096977/high-rates-of-multidrug-resistance-among-uropathogenic-escherichia-coli-in-children-and-analyses-of-esbl-producers-from-nepal
#2
Narayan Prasad Parajuli, Pooja Maharjan, Hridaya Parajuli, Govardhan Joshi, Deliya Paudel, Sujan Sayami, Puspa Raj Khanal
BACKGROUND: Emergence of Extended-spectrum beta-lactamase producing Escherichia coli causing urinary tract infections (UTI) among pediatric patients is an increasing problem worldwide. However, very little is known about pediatric urinary tract infections and antimicrobial resistance trend from Nepal. This study was conducted to assess the current antibiotic resistance rate and ESBL production among uropathogenic Escherichia coli in pediatric patients of a tertiary care teaching hospital of Nepal...
2017: Antimicrobial Resistance and Infection Control
https://www.readbyqxmd.com/read/28096418/multi-institute-analysis-of-carbapenem-resistance-reveals-remarkable-diversity-unexplained-mechanisms-and-limited-clonal-outbreaks
#3
Gustavo C Cerqueira, Ashlee M Earl, Christoph M Ernst, Yonatan H Grad, John P Dekker, Michael Feldgarden, Sinéad B Chapman, João L Reis-Cunha, Terrance P Shea, Sarah Young, Qiandong Zeng, Mary L Delaney, Diane Kim, Ellena M Peterson, Thomas F O'Brien, Mary Jane Ferraro, David C Hooper, Susan S Huang, James E Kirby, Andrew B Onderdonk, Bruce W Birren, Deborah T Hung, Lisa A Cosimi, Jennifer R Wortman, Cheryl I Murphy, William P Hanage
Carbapenem-resistant Enterobacteriaceae (CRE) are among the most severe threats to the antibiotic era. Multiple different species can exhibit resistance due to many different mechanisms, and many different mobile elements are capable of transferring resistance between lineages. We prospectively sampled CRE from hospitalized patients from three Boston-area hospitals, together with a collection of CRE from a single California hospital, to define the frequency and characteristics of outbreaks and determine whether there is evidence for transfer of strains within and between hospitals and the frequency with which resistance is transferred between lineages or species...
January 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28096155/inhibition-of-the-%C3%AE-lactamase-blamab-by-avibactam-improves-the-in-vitro-and-in-vivo-efficacy-of-imipenem-against-mycobacterium-abscessus
#4
Anne-Laure Lefebvre, Vincent Le Moigne, Audrey Bernut, Carole Veckerlé, Fabrice Compain, Jean-Louis Herrmann, Laurent Kremer, Michel Arthur, Jean-Luc Mainardi
Mycobacterium abscessus pulmonary infections are treated with a macrolide (clarithromycin or azithromycin), an aminoglycoside (amikacin), and a β-lactam (cefoxitin or imipenem). The triple combination is used without any β-lactamase inhibitor despite production of the broad spectrum β-lactamase BlaMab We determine whether inhibition of BlaMab by avibactam improves the activity of imipenem against M. abscessus. Bactericidal activity of drug combinations was assayed in broth and in human macrophages. The in vivo efficacy of the drugs was tested by monitoring the survival of infected zebrafish embryos...
January 17, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28095902/identification-of-positive-selection-in-genes-is-greatly-improved-by-using-experimentally-informed-site-specific-models
#5
Jesse D Bloom
BACKGROUND: Sites of positive selection are identified by comparing observed evolutionary patterns to those expected under a null model for evolution in the absence of such selection. For protein-coding genes, the most common null model is that nonsynonymous and synonymous mutations fix at equal rates; this unrealistic model has limited power to detect many interesting forms of selection. RESULTS: I describe a new approach that uses a null model based on experimental measurements of a gene's site-specific amino-acid preferences generated by deep mutational scanning in the lab...
January 17, 2017: Biology Direct
https://www.readbyqxmd.com/read/28095119/fecal-carriage-of-extended-spectrum-%C3%AE-lactamase-producing-enterobacteriaceae-strains-is-associated-with-worse-outcome-in-patients-hospitalized-in-the-pediatric-oncology-unit-of-beni-messous-hospital-in-algiers-algeria
#6
Chafiaa Medboua-Benbalagh, Abdelaziz Touati, Rachida Kermas, Alima Gharout-Sait, Lucien Brasme, Halima Mezhoud, Djamila Touati, Thomas Guillard, Christophe de Champs
OBJECTIVES: The current study aimed to investigate extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) fecal carriage in children with different cancers admitted in the pediatric oncology unit of Beni-Messous Hospital (Algiers, Algeria). MATERIALS AND METHODS: Rectal swabs from children with cancer were sampled from February 2012 to May 2013 within 48 hours following their admission. After species identification and detection of ESBL production by double-disk synergy test (DD test), antibiotic susceptibility was determined by the standard disk diffusion method...
January 17, 2017: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
https://www.readbyqxmd.com/read/28093116/captive-and-free-living-urban-pigeons-columba-livia-from-brazil-as-carriers-of-multidrug-resistant-pathogenic-escherichia-coli
#7
Clarissa A Borges, Renato P Maluta, Lívia G Beraldo, Marita V Cardozo, Elisabete A L Guastalli, Subhashinie Kariyawasam, Chitrita DebRoy, Fernando A Ávila
Thirty Escherichia coli isolates from captive and free-living pigeons in Brazil were characterised. Virulence-associated genes identified in pigeons included those which occur relatively frequently in avian pathogenic E. coli (APEC) from commercial poultry worldwide. Eleven of 30 E. coli isolates from pigeons, belonging mainly to B1 and B2 phylogenetic groups, had high or intermediate pathogenicity for 1-day-old chicks. The frequency of multi-drug resistant (MDR) E. coli in captive pigeons was relatively high and included one isolate positive for the extended-spectrum β-lactamase (ESBL) gene blaCTX-M-8...
January 2017: Veterinary Journal
https://www.readbyqxmd.com/read/28093102/proteomic-changes-in-the-ileum-of-sheep-infected-with-mycobacterium-avium-subspecies-paratuberculosis
#8
S Pisanu, T Cubeddu, S Uzzau, S Rocca, M F Addis
Johne's disease (JD) is a chronic enteritis of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). To identify the processes activated in the sheep intestine during natural MAP infection, and to provide a panel of differential host and pathogen proteins with diagnostic and prognostic potential, a differential shotgun proteomics workflow, including mass spectrometry, label-free quantisation and pathway analysis, was applied to ileal tissues of ewes with and without JD. Out of 2889 total proteins identified, 384 were differentially expressed and 341 were expressed at a higher level in JD...
January 2017: Veterinary Journal
https://www.readbyqxmd.com/read/28091521/mechanisms-of-intrinsic-resistance-and-acquired-susceptibility-of-pseudomonas-aeruginosa-isolated-from-cystic-fibrosis-patients-to-temocillin-a-revived-antibiotic
#9
Hussein Chalhoub, Daniel Pletzer, Helge Weingart, Yvonne Braun, Michael M Tunney, J Stuart Elborn, Hector Rodriguez-Villalobos, Patrick Plésiat, Barbara C Kahl, Olivier Denis, Mathias Winterhalter, Paul M Tulkens, Françoise Van Bambeke
The β-lactam antibiotic temocillin (6-α-methoxy-ticarcillin) shows stability to most extended spectrum β-lactamases, but is considered inactive against Pseudomonas aeruginosa. Mutations in the MexAB-OprM efflux system, naturally occurring in cystic fibrosis (CF) isolates, have been previously shown to reverse this intrinsic resistance. In the present study, we measured temocillin activity in a large collection (n = 333) of P. aeruginosa CF isolates. 29% of the isolates had MICs ≤ 16 mg/L (proposed clinical breakpoint for temocillin)...
January 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28087769/enzyme-efficiency-but-not-thermostability-drives-cefotaxime-resistance-evolution-in-tem-1-%C3%AE-lactamase
#10
Jennifer Knies, Fei Cai, Daniel M Weinreich
A leading intellectual challenge in evolutionary genetics is to identify the specific phenotypes that drive adaptation. Enzymes offer a particularly promising opportunity to pursue this question, because many enzymes' contributions to organismal fitness depend on a comparatively small number of experimentally accessible properties. Moreover, on first principles the demands of enzyme thermostability stand in opposition to the demands of catalytic activity. This observation, coupled with the fact that enzymes are only marginally thermostable, motivates the widely held hypothesis that mutations conferring functional improvement require compensatory mutations to restore thermostability...
January 12, 2017: Molecular Biology and Evolution
https://www.readbyqxmd.com/read/28087620/e152a-substitution-drastically-affects-ndm-5-activity
#11
Gaurav Kumar, Bagre Issa, Debasish Kar, Sarmistha Biswal, Anindya S Ghosh
New Delhi Metallo beta-lactamase (NDM) is of significant public health concern due to its enormous potential to hydrolyse all major beta-lactams including carbapenems. Amino acid substitutions outside the active site reportedly affect NDM beta-lactamase activities. Here, the effect of amino acid substitutions in the possible omega-like loop region of NDM-5 has been elucidated. Overall, three substitution mutations near active site of NDM-5 were done, namely, E152A, S191A, and D223A and subsequently, the change in antimicrobial resistance was monitored upon expressing each mutant in a suitable host...
January 12, 2017: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/28087584/emergence-of-klebsiella-variicola-positive-for-ndm-9-a-variant-of-new-delhi-metallo-%C3%AE-lactamase-in-an-urban-river-in-south-korea
#12
Doris Y W Di, Jeonghwan Jang, Tatsuya Unno, Hor-Gil Hur
OBJECTIVES: To examine the presence of pathogenic bacteria carrying New Delhi metallo-β-lactamase in the environment and to characterize the genome structures of these strains. METHODS: Phenotypic screening of antimicrobial susceptibility and WGS were conducted on three Klebsiella variicola strains possessing NDM-9 isolated from an urban river. RESULTS: Three carbapenem-resistant K. variicola isolated from Gwangju tributary were found to possess blaNDM-9 genes...
January 12, 2017: Journal of Antimicrobial Chemotherapy
https://www.readbyqxmd.com/read/28081065/notes-from-the-field-pan-resistant-new-delhi-metallo-beta-lactamase-producing-klebsiella-pneumoniae-washoe-county-nevada-2016
#13
Lei Chen, Randall Todd, Julia Kiehlbauch, Maroya Walters, Alexander Kallen
No abstract text is available yet for this article.
January 13, 2017: MMWR. Morbidity and Mortality Weekly Report
https://www.readbyqxmd.com/read/28080212/heterogeneity-of-carbapenem-resistance-mechanisms-among-gram-negative-pathogens-in-lebanon-results-of-the-first-cross-sectional-countrywide-study
#14
Dalal Hammoudi Halat, Carole Ayoub Moubareck, Dolla Karam Sarkis
Carbapenem-resistant Gram-negative pathogens have progressively disseminated to different countries worldwide, presenting a serious public health concern. The aims of this study were to determine the prevalence of carbapenem resistance in Gram-negative bacteria in Lebanon, to elucidate molecular mechanisms, and to identify genetic relatedness of incriminated strains. Carbapenem nonsusceptible Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas were collected from 11 Lebanese hospitals in 2012. Antimicrobial susceptibility was assessed with phenotypic tests, genes encoding carbapenemases were screened via PCR-sequencing, and genetic relatedness was examined by PGFE and ERIC-PCR...
January 12, 2017: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
https://www.readbyqxmd.com/read/28079369/muropeptide-binding-and-the-x-ray-structure-of-the-effector-domain-of-the-transcriptional-regulator-ampr-of-pseudomonas-aeruginosa
#15
David A Dik, Teresa Domínguez-Gil, Mijoon Lee, Dusan Hesek, Byungjin Byun, Jennifer Fishovitz, Bill Boggess, Lance M Hellman, Jed F Fisher, Juan A Hermoso, Shahriar Mobashery
A complex link exists between cell-wall recycling/repair and the manifestation of resistance to β-lactam antibiotics in many Enterobacteriaceae and Pseudomonas aeruginosa. This process is mediated by specific cell-wall-derived muropeptide products. These muropeptides are internalized into the cytoplasm and bind to the transcriptional regulator AmpR, which controls the cytoplasmic events that lead to expression of β-lactamase, an antibiotic-resistance determinant. The effector-binding domain (EBD) of AmpR was purified to homogeneity...
January 17, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28079218/zinc-ion-induced-conformational-changes-in-new-delphi-metallo-%C3%AE-lactamase-1-probed-by-molecular-dynamics-simulations-and-umbrella-sampling
#16
Jianzhong Chen, Jinan Wang, Weiliang Zhu
The hydrolysis of a β-lactam core ring caused by new Delphi metallo-β-lactamase 1 (NDM-1) with the help of two zinc cofactors induces significant resistance toward β-lactam antibiotics. Molecular dynamics (MD) simulations and the umbrella sampling method are integrated to study the conformational change mechanism of NDM-1 mediated by zinc ion binding. The statistical analyses of interaction contacts of the antibiotic ampicillin (AMP) with residues based on MD trajectories suggest that two Zn ions are essential for maintaining the binding of AMP with NDM-1...
January 12, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28078492/first-report-of-bla-ctx-m-15-type-esbl-producing-klebsiella-pneumoniae-in-wild-migratory-birds-in-pakistan
#17
Shahbaz Raza, Mashkoor Mohsin, Waqas Ahmed Madni, Fatima Sarwar, Muhammad Saqib, Bilal Aslam
We investigated wild migratory birds faecal swabs for extended-spectrum β-lactamases-producing Klebsiella pneumoniae (ESBL-K. pneumoniae) from wetland habitats in Pakistan. ESBL-K. pneumoniae were analysed for MDR phenotype, ESBL genotype and genetic diversity. A total of 13 (8.6%) ESBL-K. pneumoniae were recovered. Of these, 8 (61%) isolates were MDR. DNA sequencing confirmed bla CTX-M-15 as the dominant ESBL genotype. BOX-PCR fingerprints showed most of the isolates are unrelated. This study is the first to report the wildlife contamination of CTX-M-15-producing K...
January 11, 2017: EcoHealth
https://www.readbyqxmd.com/read/28077674/population-structure-of-japanese-extraintestinal-pathogenic-escherichia-coli-and-its-relationship-with-antimicrobial-resistance
#18
Yasufumi Matsumura, Taro Noguchi, Michio Tanaka, Toru Kanahashi, Masaki Yamamoto, Miki Nagao, Shunji Takakura, Satoshi Ichiyama
OBJECTIVES: To define the population structure of extraintestinal pathogenic Escherichia coli (ExPEC) in Japan and its relationship with antimicrobial resistance and the major resistance mechanisms for fluoroquinolones and β-lactams, we designed a multicentre prospective study. METHODS: A total of 329 ExPEC isolates were collected at 10 Japanese acute-care hospitals during December 2014. We defined the clonal groups of ExPEC by fumC and fimH sequencing (CH typing)...
January 10, 2017: Journal of Antimicrobial Chemotherapy
https://www.readbyqxmd.com/read/28077672/potentiation-of-ceftazidime-by-avibactam-against-%C3%AE-lactam-resistant-pseudomonas-aeruginosa-in-an-in-vitro-infection-model
#19
Sherwin K B Sy, Luning Zhuang, Marie-Eve Beaudoin, Philipp Kircher, Maria A M Tabosa, Noely C T Cavalcanti, Christian Grunwitz, Sebastian Pieper, Virna J Schuck, Wright W Nichols, Hartmut Derendorf
OBJECTIVES: This study evaluated the in vitro pharmacodynamics of combinations of ceftazidime and the non-β-lactam β-lactamase inhibitor, avibactam, against ceftazidime-, piperacillin/tazobactam- and meropenem-multiresistant Pseudomonas aeruginosa by a quantitative time-kill method. METHODS: MICs of ceftazidime plus 0-16 mg/L avibactam were determined against eight isolates of P. aeruginosa Single-compartment, 24 h time-kill kinetics were investigated for three isolates at 0-16 mg/L avibactam with ceftazidime at 0...
January 10, 2017: Journal of Antimicrobial Chemotherapy
https://www.readbyqxmd.com/read/28076388/risk-factors-for-multi-drug-resistant-pathogens-and-failure-of-empiric-first-line-therapy-in-acute-cholangitis
#20
Philipp A Reuken, Dorian Torres, Michael Baier, Bettina Löffler, Christoph Lübbert, Norman Lippmann, Andreas Stallmach, Tony Bruns
BACKGROUND: Acute cholangitis (AC) requires the immediate initiation of antibiotic therapy in addition to treatment for biliary obstruction. Against a background of an increasing prevalence of multi-drug resistant (MDR) bacteria, the risk factors for the failure of empiric therapy must be defined. METHODS: Using a pathogen-based approach, 1764 isolates from positive bile duct cultures were retrospectively analyzed to characterize the respective pathogen spectra in two German tertiary centers...
2017: PloS One
keyword
keyword
18911
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"