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Beatus Lyimo, Joram Buza, Murugan Subbiah, Woutrina Smith, Douglas R Call
BACKGROUND: Antimicrobial resistance (AMR) is a growing and significant threat to public health on a global scale. Escherichia coli comprises Gram-negative, fecal-borne pathogenic and commensal bacteria that are frequently associated with antibiotic resistance. AMR E. coli can be ingested via food, water and direct contact with fecal contamination. METHODS: We estimated the prevalence of AMR Escherichia coli from select drinking water sources in northern Tanzania...
November 3, 2016: BMC Microbiology
Jeong-Hwan Hwang, Gee-Wook Shin, Joo-Hee Hwang, Chang-Seop Lee
A 57-year-old man presented with a high fever and diarrhea. A blood culture showed the presence of a Group C nontyphoidal Salmonella isolate. On Salmonella serotyping, the isolate was Salmonella enterica serovar Virchow. Its sequence type was determined to be ST16 by sequence analysis of seven different housekeeping genes. The blaCTX-M group 1 and blaTEM genes were amplified by multiplex PCR assays for detecting ESBL genes. Sequences of both amplicons were respectively identical to CTX-M-15- and TEM-1-encoding genes...
October 31, 2016: Japanese Journal of Infectious Diseases
Dar-Chone Chow, Kacie Rice, Wanzhi Huang, Robert L Atmar, Timothy G Palzkill
The β-lactamase inhibitory protein (BLIP) binds and inhibits a wide range of class A β-lactamases including the TEM-1 β-lactamase (Ki= 0.5 nM), which is widely present in Gram-negative bacteria, and the KPC-2 β-lactamase (Ki= 1.2 nM), which hydrolyzes virtually all clinically useful β-lactam antibiotics. The extent to which the specificity of a protein that binds a broad range of targets can be modified to display narrow specificity was explored in this study by engineering BLIP to bind selectively to KPC-2 β-lactamase...
October 18, 2016: ACS Infectious Diseases
Dominic J Pollard, Joanna C Young, Valentina Covarelli, Silvia Herrera-León, Thomas R Connor, Maria Fookes, Danielle Walker, Aurora Echeita, Nicholas R Thomson, Cedric N Berger, Gad Frankel
Salmonella species utilize type III secretion systems (T3SSs) to translocate effectors into the cytosol of mammalian host cells, subverting cell signaling and facilitating the onset of gastroenteritis. In this study, we compared a draft genome assembly of Salmonella enterica subsp. salamae strain 3588/07 against the genomes of S. enterica subsp. enterica serovar Typhimurium strain LT2 and Salmonella bongori strain 12419. S. enterica subsp. salamae encodes the Salmonella pathogenicity island 1 (SPI-1), SPI-2, and the locus of enterocyte effacement (LEE) T3SSs...
December 2016: Infection and Immunity
Rui Hu, Hong-Kin Yap, Yik-Hong Fung, Yong Wang, Wing-Lam Cheong, Lok-Yan So, Chui-Shan Tsang, Lawrence Yoon Suk Lee, Warrick Ken Cheung Lo, Jian Yuan, Ning Sun, Yun-Chung Leung, Guoqiang Yang, Kwok-Yin Wong
Fluorescent labeling of biomacromolecules to 'light up' biological events through non-invasive methods is of great importance, but is still challenging in terms of fluorophore properties and the labeling methods used. Herein, we designed and synthesized a biocompatible and conformation sensitive tetraphenylethene derivative EPB with aggregation induced emission (AIE) properties. By introducing EPB into TEM-1 β-lactamase (TEM-1 Bla) through a two-step approach, a conformation-dependent fluorescent sensor EPB104-Bla was genetically engineered, which was applied to monitor the protein-protein interaction (PPI) with β-lactamase inhibitor protein (BLIP)...
October 4, 2016: Molecular BioSystems
Wei-Ling Jiang, Luo-Gang Ding, Bing-Jian Yao, Jian-Cheng Wang, Gong-Jun Chen, Yan-An Li, Jian-Ping Ma, Jun Ji, Ying Dong, Yu-Bin Dong
A UiO-66-MOF-based membrane UiO-66-TEM (1) was prepared by the assembly of methacrylamide-decorated UiO-66-NH-Met with a thiol side chain-attached polysiloxane (PSI-SH) via a photoinduced thiol-ene click reaction. The obtained membrane 1 can be a platform to support Au nanoparticles (Au NPs) to generate an Au-MOF-polymer composite membrane Au@UiO-66-TEM (2). 1 and 2 can be used to build highly efficient continuous flow-through membrane reactors for Knoevenagel condensation of 4-nitrobenzaldehyde with malononitrile and 4-nitrophenol (4-NP) reduction at ambient temperature, respectively...
October 3, 2016: Chemical Communications: Chem Comm
C Katvoravutthichai, K Boonbumrung, R Tiyawisutsri
Pseudomonas aeruginosa is one of the most important causes of nosocomial infection and it has increasing resistance to many antimicrobial agents. β-lactamase production is the most frequent mechanism for β-lactam resistance in P. aeruginosa. We evaluated the prevalence of β-lactamase genes in P. aeruginosa for classes A, C, and D by polymerase chain reaction, and investigated clonal diversity by pulsed-field gel electrophoresis (PFGE). We used the disk diffusion method to test 118 non-duplicate clinical isolates of P...
September 23, 2016: Genetics and Molecular Research: GMR
Marion J Skalweit, Mei Li
Genetic screening of Pseudomonas aeruginosa (PSDA) and Acinetobacter baumannii (ACB) reveals genes that confer increased susceptibility to β-lactams when disrupted, suggesting novel drug targets. One such target is lytic transglycosylase. Bulgecin A (BlgA) is a natural product of Pseudomonas mesoacidophila and a lytic transglycosolase inhibitor that works synergistically with β-lactams targeting PBP3 for Enterobacteriaceae. BlgA also weakly inhibits di-Zn(2+) metallo-β-lactamases like L1 of Stenotrophomonas maltophilia...
2016: Drug Design, Development and Therapy
Gabe Haller, David Alvarado, Kevin McCall, Robi D Mitra, Matthew B Dobbs, Christina A Gurnett
Large-scale mutagenesis of target DNA sequences allows researchers to comprehensively assess the effects of single-nucleotide changes. Here we demonstrate the construction of a systematic allelic series (SAS) using massively parallel single-nucleotide mutagenesis with reversibly terminated deoxyinosine triphosphates (rtITP). We created a mutational library containing every possible single-nucleotide mutation surrounding the active site of the TEM-1 β-lactamase gene. When combined with high-throughput functional assays, SAS mutational libraries can expedite the functional assessment of genetic variation...
October 3, 2016: Nature Methods
Yanfei Wang, Ivan J Dmochowski
Molecular imaging holds considerable promise for elucidating biological processes in normal physiology as well as disease states, by determining the location and relative concentration of specific molecules of interest. Proton-based magnetic resonance imaging ((1)H MRI) is nonionizing and provides good spatial resolution for clinical imaging but lacks sensitivity for imaging low-abundance (i.e., submicromolar) molecular markers of disease or environments with low proton densities. To address these limitations, hyperpolarized (hp) (129)Xe NMR spectroscopy and MRI have emerged as attractive complementary methodologies...
October 18, 2016: Accounts of Chemical Research
Carlo Zanotto, Massimiliano Bissa, Elena Illiano, Valeria Mezzanotte, Francesca Marazzi, Andrea Turolla, Manuela Antonelli, Carlo De Giuli Morghen, Antonia Radaelli
The emergence and diffusion of antibiotic-resistant bacteria has been a major public health problem for many years now. In this study, antibiotic-resistance of coliforms and Escherichia coli were investigated after their isolation from samples collected in a municipal wastewater treatment plant in the Milan area (Italy) along different points of the treatment sequence: inflow to biological treatment; outflow from biological treatment following rapid sand filtration; and outflow from peracetic acid disinfection...
December 2016: Chemosphere
Shahram Shahraki-Zahedani, Shahnaz Rigi, Mohammad Bokaeian, Alireza Ansari-Moghaddam, Mehdi Moghadampour
INTRODUCTION: Extended-spectrum beta-lactamases (ESBLs) are bacterial enzymes capable of hydrolyzing beta-lactams. The aim of this study was to describe the prevalence of TEM- and SHV-type ESBL-producing Klebsiella pneumoniae strains in Zahedan, Southeast Iran. METHODS: A total of 170 non-repetitive K. pneumoniae strains were collected from patients referred to three teaching hospitals of Zahedan. Antibiotic susceptibility testing was determined for 17 antibiotics using the Kirby-Bauer disc diffusion method...
July 2016: Revista da Sociedade Brasileira de Medicina Tropical
Yuvaraja Gutha, Venkata Subbaiah Munagapati
A novel crosslinked magnetic chitosan-4-((pyridin-2-ylimino)methyl)benzaldehyde Schiff's Base (m-CSPIB) was prepared by crosslinking of magnetic iron oxide nanoparticles with chitosan-4-((pyridin-2-ylimino)methyl)benzaldehyde schiff's base and used as an biosorbent for the removal of Pb(II) ions from aqueous environment. The biopolymer has been characterized by XRD, FT-IR, SEM, TEM, (1)H NMR and VSM analysis. Kinetic studies were performed, and the data were fitted well with the pseudo-second-order model. The equilibrium data followed Langmuir isotherm model and the maximum monolayer sorption capacity was found to be 104...
August 31, 2016: International Journal of Biological Macromolecules
Hazır Rahman, Madiha Naeem, Il Khan, Jafar Khan, Mohammad Haroon, Fazli Bari, Rahim Ullah, Muhammad Qasim
BACKGROUND/AIM: Extended spectrum beta lactamase (ESBL) production among E. coli is one of the principal mechanisms that augment resistance to antibiotics. In the current study the molecular detection of class A beta lactamases among uropathogenic Escherichia coli was evaluated. MATERIALS AND METHODS: A total of 355 urine samples were collected from a tertiary care hospital in Peshawar. The ESBL production among E. coli isolates was detected by using the disc synergy diffusion method...
2016: Turkish Journal of Medical Sciences
Daniel J O'Shannessy, Michael F Smith, Elizabeth B Somers, Stephen M Jackson, Earl Albone, Brian Tomkowicz, Xin Cheng, Young Park, Danielle Fernando, Andrew Milinichik, Brad Kline, Regan Fulton, Pankaj Oberoi, Nicholas C Nicolaides
Endosialin (Tumor Endothelial Marker-1 (TEM-1), CD248) is primarily expressed on pericytes of tumor-associated microvasculature, tumor-associated stromal cells and directly on tumors of mesenchymal origin, including sarcoma and melanoma. While the function of endosialin/TEM-1 is incompletely understood, studies have suggested a role in supporting tumor growth and invasion thus making it an attractive therapeutic target. In an effort to further understand its role in cancer, we previously developed a humanized anti-endosialin/TEM-1 monoclonal antibody (mAb), called ontuxizumab (MORAb-004) for testing in preclinical and clinical studies...
August 2, 2016: Oncotarget
Yu-Shan Pan, Zhi-Yong Zong, Li Yuan, Xiang-Dang Du, Hui Huang, Xing-Hao Zhong, Gong-Zheng Hu
A 139,622-bp IncI1 ST71 conjugative plasmid pEC012 from an avian Escherichia coli D-ST117 strain was sequenced, which carried five IS26-bracketed resistance modules: IS26-fosA3-orf1-orf2-Δorf3-IS26, IS26-fip-ΔISEcp1-bla CTX-M-65-IS903D-iroN-IS26, IS26-ΔtnpR-bla TEM-1-rmtB-IS26, IS26-oqxAB-IS26, and IS26-floR-aac(3)-IV-IS26. The backbone of pEC012 was similar to that of several other IncI1 ST71 plasmids: pV408, pM105, and pC271, but these plasmids had different arrangements of multidrug resistance region...
2016: Frontiers in Microbiology
Diana Yessenia Calva Delgado, Zorayda Patricia Toledo Barrigas, Sofía Genoveva Ochoa Astutillo, Ana Paulina Arévalo Jaramillo, Alessio Ausili
This work performed a phenotypic and genotypic characterization of 79 clinical isolates of Enterobacteriaceae and Pseudomonadaceae collected in hospitals of Southern Ecuadorin 2013. Our results showed a high incidence of β-lactamases and ESBLs with blaTEM and blaCTX-M as the prevalent genes, respectively. By direct sequencing of PCR amplicons, the different β-lactamases and variants of the genes were also distinguished. Our results revealed a predominance of TEM-1 β-lactamase and the presence of different CTX-M variants with a prevalence of CTX-M-15...
July 30, 2016: Brazilian Journal of Infectious Diseases
Xiaoqiang Liu, Kamoltip Thungrat, Dawn M Boothe
OBJECTIVE: The aim of this study was to explore the occurrence and molecular characterization of extended-spectrum β-lactamases (ESBL), plasmid-mediated AmpC β-lactamase (pAmpC) and carbapenemases among ESBL-producing multidrug resistant (MDR) Escherichia coli from dogs and cats in the United States. METHODS: Of 2443 E.coli isolated from dogs and cats collected between August 2009 and January 2013, 68 isolates were confirmed as ESBL-producing MDR ones. PCR and sequencing were performed to identify β-lactamases and plasmid-mediated quinolone resistance (PMQR) genes, and shed light on the virulence gene profiles, phylogenetic groups and ST types...
2016: Frontiers in Microbiology
Rym Ouertani, Anne Limelette, Thomas Guillard, Lucien Brasme, Yahia Jridi, Farouk Barguellil, Allaaeddin El Salabi, Christophe de Champs, Chedly Chouchani
The aim of this study was to determine the origin of virulence and multiresistance of a Klebsiella pneumoniae isolate from an abdominal wound infection of a patient with a gunshot injury in the thoracoabdominal region. The isolate was identified using biochemical tests and Phoenix™ automated system and was confirmed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). MICs of each antibiotic were determined by Etest. Screening for carbapenemase production was performed by the modified Hodge test and was confirmed by PCR amplification...
March 2016: Journal of Global Antimicrobial Resistance
Michael A Stiffler, Subu K Subramanian, Victor H Salinas, Rama Ranganathan
Site-directed mutagenesis has long been used as a method to interrogate protein structure, function and evolution. Recent advances in massively-parallel sequencing technology have opened up the possibility of assessing the functional or fitness effects of large numbers of mutations simultaneously. Here, we present a protocol for experimentally determining the effects of all possible single amino acid mutations in a protein of interest utilizing high-throughput sequencing technology, using the 263 amino acid antibiotic resistance enzyme TEM-1 β-lactamase as an example...
2016: Journal of Visualized Experiments: JoVE
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