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e coli plasmid strain development

Gabhan Chalmers, Kelly M Rozas, Raghavendra G Amachawadi, Harvey Morgan Scott, Keri N Norman, Tiruvoor G Nagaraja, Mike D Tokach, Patrick Boerlin
Copper is used as an alternative to antibiotics for growth promotion and disease prevention. However, bacteria developed tolerance mechanisms for elevated copper concentrations, including those encoded by the pco operon in Gram-negative bacteria. Using cohorts of weaned piglets, this study showed that the supplementation of feed with copper concentrations as used in the field did not result in a significant short-term increase in the proportion of pco -positive fecal Escherichia coli . The pco and sil (silver resistance) operons were found concurrently in all screened isolates, and whole-genome sequencing showed that they were distributed among a diversity of unrelated E...
October 18, 2018: Genes
Brian M Forde, Hosam M Zowawi, Patrick N A Harris, Leah Roberts, Emad Ibrahim, Nissar Shaikh, Anand Deshmukh, Mazen A Sid Ahmed, Muna Al Maslamani, Kyra Cottrell, Ella Trembizki, Lana Sundac, Heidi H Yu, Jian Li, Mark A Schembri, David M Whiley, David L Paterson, Scott A Beatson
Resistance to last-line polymyxins mediated by the plasmid-borne mobile colistin resistance gene ( mcr-1 ) represents a new threat to global human health. Here we present the complete genome sequence of an mcr-1 -positive multidrug-resistant Escherichia coli strain (MS8345). We show that MS8345 belongs to serotype O2:K1:H4, has a large 241,164-bp IncHI2 plasmid that carries 15 other antibiotic resistance genes (including the extended-spectrum β-lactamase bla CTX-M-1 ) and 3 putative multidrug efflux systems, and contains 14 chromosomally encoded antibiotic resistance genes...
October 10, 2018: MSphere
Cameron J Reid, Matthew Z DeMaere, Steven P Djordjevic
We recently identified clonal complex 10 (CC10) Escherichia coli as the predominant clonal group in two populations of healthy Australian food-production pigs. CC10 are highly successful, colonizing humans, food-production animals, fresh produce and environmental niches. Furthermore, E. coli within CC10 are frequently drug resistant and increasingly reported as human and animal extra-intestinal pathogens. In order to develop a high-resolution global phylogeny and determine the repertoire of antimicrobial-resistance genes, virulence-associated genes and plasmid types within this clonal group, we downloaded 228 publicly available CC10 short-read genome sequences for comparison with 20 porcine CC10 we have previously described...
October 10, 2018: Microbial Genomics
Mariana Blanco Massani, Jochen Klumpp, Madeleine Widmer, Christian Speck, Marc Nisple, Rainer Lehmann, Markus Schuppler
The rise of antibiotic resistance in pathogenic bacteria is endangering the efficacy of antibiotics, which consequently results in greater use of silver as a biocide. Chromosomal mapping of the Cus system or plasmid encoded Sil system and their relationship with silver resistance was studied for several gram-negative bacteria. However, only few reports investigated silver detoxification mediated by the Sil system integrated in Escherichia coli chromosome. Accordingly, this work aimed to study the Sil system in E...
October 4, 2018: Biometals: An International Journal on the Role of Metal Ions in Biology, Biochemistry, and Medicine
Maryam Boshtam, Seddigheh Asgary, Ilnaz Rahimmanesh, Shirin Kouhpayeh, Jamal Naderi, Zahra Hejazi, Hoda Mohammad-Dezashibi, Ina Laura Pieper, Hossein Khanahmad
Monocyte chemoattractant protein-1 (MCP-1/CCL2) is a protein that is secreted immediately upon endothelial injury, and thereby it plays a key role in inflammation via recruitment of leucocytes to the site of inflammation at the beginning and throughout the inflammatory processes. Aim of this study was to develop two separate cell lines displaying either human MCP-1 (HMCP-1) or rabbit MCP-1 (RMCP-1) on their surface. A DNA fragment containing HMCP-1- or RMCP-1-encoding sequence was inserted into a pcDNA plasmid...
October 2018: Research in Pharmaceutical Sciences
Matthew E Falagas, Florentia Athanasaki, Georgios L Voulgaris, Nikolaos A Triarides, Konstantinos Z Vardakas
Fosfomycin has been used for the treatment of infections due to susceptible and multi-drug resistant (MDR) bacteria. It inhibits bacterial cell wall synthesis at a step prior to that of β-lactams through a unique mechanism of action. Fosfomycin enters the bacterium through membrane channels/transporters and inhibits MurA, which initiates peptidoglycan biosynthesis (PG) of the bacterial cell wall. Several bacteria display inherent resistance to fosfomycin mainly through MurA mutations. Acquired resistance involves, with decreasing frequency, modifications of membrane transporters that prevent fosfomycin from entering the bacterial cell, acquisition of plasmid encoded genes that inactivate fosfomycin, and MurA mutations...
September 27, 2018: International Journal of Antimicrobial Agents
G Royer, J W Decousser, C Branger, M Dubois, C Médigue, E Denamur, D Vallenet
Plasmid prediction may be of great interest when studying bacteria of medical importance such as Enterobacteriaceae as well as Staphylococcus aureus or Enterococcus. Indeed, many resistance and virulence genes are located on such replicons with major impact in terms of pathogenicity and spreading capacities. Beyond strain outbreak, plasmid outbreaks have been reported in particular for some extended-spectrum beta-lactamase- or carbapenemase-producing Enterobacteriaceae. Several tools are now available to explore the 'plasmidome' from whole-genome sequences with various approaches, but none of them are able to combine high sensitivity and specificity...
September 2018: Microbial Genomics
Ping Yu, Kaifei Chen, Xingxing Huang, Xinxin Wang, Qian Ren
The compound γ-aminobutyric acid (GABA) has many important physiological functions. The effect of glutamate decarboxylases and the glutamate/GABA antiporter on GABA production was investigated in Escherichia coli. Three genes, gadA, gadB, and gadC were cloned and ligated alone or in combination into the plasmid pET32a. The constructed plasmids were transformed into Escherichia coli BL21(DE3). Three strains, E. coli BL21(DE3)/pET32a-gadA, E. coli BL21(DE3)/pET32a-gadAB and E. coli BL21(DE3)/pET32a-gadABC were selected and identified...
September 28, 2018: Preparative Biochemistry & Biotechnology
Minjia Shen, Ziyan Chen, Xudan Mao, Lin Wang, Jingyi Liang, Qingyuan Huo, Xiaoyu Yin, Juanping Qiu, Dongchang Sun
Accompanied by benefits from horizontally transferred genes, bacteria have to face the risk of the invasion of dangerous genes. Bacteria often use the restriction-modification (R-M) system, which is consisted of methyl transferase (MEase) and restrictase (REase), to protect self-DNA and defend against foreign DNA. Paenibacillus polymyxa, widely used as growth promoting rhizobacteria in agriculture, can also produce compounds of medical and industrial interests. It is unclear whether R-M systems exist in P. polymyxa...
October 12, 2018: Biochemical and Biophysical Research Communications
Fuzhou Xu, Ximin Zeng, Atsushi Hinenoya, Jun Lin
Extensive use of colistin in food animals is deemed a major driving force for the emergence and transmission of mcr-1 However, a non-colistin usage factor(s) contributing to mobile colistin resistance may also exist in animal production systems. Given that polymyxin, a bacterium-derived peptide antibiotic, has been successfully used as a surrogate to study bacterial resistance to antimicrobial peptides (AMPs), acquisition of MCR-1 may confer cross-resistance to the unrelated AMPs implicated in practical applications...
September 5, 2018: MSphere
Laurent Dortet, Remy A Bonnin, Ivana Pennisi, Lauraine Gauthier, Agnès B Jousset, Laura Dabos, R Christopher D Furniss, Despoina A I Mavridou, Pierre Bogaerts, Youri Glupczynski, Anais Potron, Patrick Plesiat, Racha Beyrouthy, Frédéric Robin, Richard Bonnet, Thierry Naas, Alain Filloux, Gerald Larrouy-Maumus
Background: Polymyxins are currently considered a last-resort treatment for infections caused by MDR Gram-negative bacteria. Recently, the emergence of carbapenemase-producing Enterobacteriaceae has accelerated the use of polymyxins in the clinic, resulting in an increase in polymyxin-resistant bacteria. Polymyxin resistance arises through modification of lipid A, such as the addition of phosphoethanolamine (pETN). The underlying mechanisms involve numerous chromosome-encoded genes or, more worryingly, a plasmid-encoded pETN transferase named MCR...
September 1, 2018: Journal of Antimicrobial Chemotherapy
Daniel E Deatherage, Dacia Leon, Álvaro E Rodriguez, Salma K Omar, Jeffrey E Barrick
Unwanted evolution of designed DNA sequences limits metabolic and genome engineering efforts. Engineered functions that are burdensome to host cells and slow their replication are rapidly inactivated by mutations, and unplanned mutations with unpredictable effects often accumulate alongside designed changes in large-scale genome editing projects. We developed a directed evolution strategy, Periodic Reselection for Evolutionarily Reliable Variants (PResERV), to discover mutations that prolong the function of a burdensome DNA sequence in an engineered organism...
September 28, 2018: Nucleic Acids Research
Michelle N Chamoun, Matthew J Sullivan, Glen C Ulett
Uropathogenic Escherichia coli (UPEC) cause the majority of community-acquired urinary tract infections (UTIs). Quantitation of bacteriuria (the number of bacteria in urine) is important for diagnostic approaches and in diverse research applications. Most UPEC strains express hemolysin, the expression of which has been correlated with the severity of UTI in murine models of infection. In this study, we sought to develop and optimise a quantitative Polymerase Chain Reaction (qPCR) assay for enumeration of hemolysin-positive UPEC in urine...
September 2018: Journal of Microbiological Methods
Seon Young Park, Robert M Binkley, Won Jun Kim, Mun Hee Lee, Sang Yup Lee
Astaxanthin is a reddish keto-carotenoid classified as a xanthophyll found in various microbes and marine organisms. As a powerful antioxidant having up to 100 times more potency than other carotenoids such as β-carotene, lutein, and lycopene, astaxanthin is a versatile compound utilized in animal feed, food pigment, health promotion and cosmetic industry. Here, we report development of metabolically engineered Escherichia coli capable of producing astaxanthin to a high concentration with high productivity...
August 7, 2018: Metabolic Engineering
Johana E Dominguez, Leandro M Redondo, Roque A Figueroa Espinosa, Daniela Cejas, Gabriel O Gutkind, Pablo A Chacana, José A Di Conza, Mariano E Fernández Miyakawa
The use of antimicrobial growth promoters (AGPs) in sub-therapeutic doses for long periods promotes the selection of resistant microorganisms and the subsequent risk of spreading this resistance to the human population and the environment. Global concern about antimicrobial resistance development and transference of resistance genes from animal to human has been rising. The goal of our research was to evaluate the susceptibility pattern to different classes of antimicrobials of colistin-resistant Escherichia coli from poultry production systems that use AGPs, and characterize the resistance determinants associated to transferable platforms...
2018: Frontiers in Microbiology
Ye Li, Shuai Qian, Rachel Dunn, Patrick C Cirino
Triacetic acid lactone (TAL) (4-hydroxy-6-methyl-2-pyrone) can be upgraded into a variety of higher-value products, and has potential to be developed into a renewable platform chemical through metabolic engineering. We previously developed an endogenous TAL sensor based on the regulatory protein AraC, and applied it to screen 2-pyrone synthase (2-PS) variant libraries in E. coli, resulting in the identification of variants conferring up to 20-fold improved TAL production in liquid culture. In this study, the sensor-reporter system was further optimized and used to further improve TAL production from recombinant E...
September 2018: Journal of Industrial Microbiology & Biotechnology
Mehreen Anjum, Jonas Stenløkke Madsen, Carmen Espinosa-Gongora, Bimal Jana, Maria Wiese, Dennis Sandris Nielsen, Søren Johannes Sørensen, Arshnee Moodley, Valeria Bortolaia, Luca Guardabassi
IncI1 plasmids play a central role in the transfer of antimicrobial resistance genes among Enterobacteriaceae in animals and humans. Knowledge on the dynamics of IncI1 plasmid transfer is limited, mainly due to lack of culture-independent methods that can quantify donor strain survival and plasmid transfer in complex microbial communities. The aim of this study was to develop a culture-independent method to study the dynamics of IncI1 plasmids transfer by fluorescence-activated cell sorting. We genetically modified three wild-type Escherichia coli of animal (n = 2) and human (n = 1) origin carrying blaCMY-2 or blaCTX-M-1 on two epidemic IncI1 plasmids (pST12 and pST7)...
September 2018: Journal of Microbiological Methods
Eveline Brodl, Johannes Niederhauser, Peter Macheroux
There is a considerable number of bacterial species capable of emitting light. All of them share the same gene cluster, namely the lux operon. Despite this similarity, these bacteria show extreme variations in characteristics like growth behavior, intensity of light emission or regulation of bioluminescence. The method presented here is a newly developed assay that combines recording of cell growth and bioluminescent light emission intensity over time utilizing a plate reader. The resulting growth and light emission characteristics can be linked to important features of the respective bacterial strain, such as quorum sensing regulation...
June 28, 2018: Journal of Visualized Experiments: JoVE
Emilie Racine, Patrice Nordmann, Lucile Pantel, Matthieu Sarciaux, Marine Serri, Jessica Houard, Philippe Villain-Guillot, Anthony Demords, Carina Vingsbo Lundberg, Maxime Gualtieri
Antibacterial activity screening of a collection of Xenorhabdus strains led to the discovery of the odilorhabdins, a new antibiotic class with broad-spectrum activity against Gram-positive and Gram-negative pathogens. Odilorhabdins inhibit bacterial translation by a new mechanism of action on ribosomes. A lead optimization program identified NOSO-502 as a promising candidate. NOSO-502 has MIC values ranging from 0.5 to 4 μg/ml against standard Enterobacteriaceae strains and carbapenem-resistant Enterobacteriaceae (CRE) isolates that produce KPC, AmpC, or OXA enzymes and metallo-β-lactamases...
September 2018: Antimicrobial Agents and Chemotherapy
Bin Xiong, Zhongkang Li, Li Liu, Dongdong Zhao, Xueli Zhang, Changhao Bi
Background: Ralstonia eutropha is an important bacterium for the study of polyhydroxyalkanoates (PHAs) synthesis and CO2 fixation, which makes it a potential strain for industrial PHA production and attractive host for CO2 conversion. Although the bacterium is not recalcitrant to genetic manipulation, current methods for genome editing based on group II introns or single crossover integration of a suicide plasmid are inefficient and time-consuming, which limits the genetic engineering of this organism...
2018: Biotechnology for Biofuels
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