Author
Edward P. Abraham
Bio: Edward P. Abraham is an academic researcher from University of Oxford. The author has contributed to research in topics: Cephalosporin C & Cephalosporin. The author has an hindex of 42, co-authored 134 publications receiving 6732 citations.
Topics: Cephalosporin C, Cephalosporin, Penicillin, Tripeptide, Bacitracin
Papers published on a yearly basis
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TL;DR: It is confirmed that the growth of B. coli and a number of other bacteria belonging to the colityphoid group was not inhibited by penicillin, and the cause of the resistance of these organisms to the action of Penicillin is found.
Abstract: FLEMING1 noted that the growth of B. coli and a number of other bacteria belonging to the colityphoid group was not inhibited by penicillin. This observation has been confirmed. Further work has been done to find the cause of the resistance of these organisms to the action of penicillin.
1,193 citations
242 citations
TL;DR: The cloning, characterization and expression in Escherichia coli of the gene encoding the IPS protein in Cephalosporium acremonium is reported, and a new protein co-migrating with authentic IPS as the major protein of the cell.
Abstract: The enzyme isopenicillin N synthetase (IPS) catalyses the oxidative condensation of δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine (LLD-ACV) to isopenicillin N, which is a central reaction in the pathway to clinically important penicillins and cephalosporins. Here we report the cloning, characterization and expression in Escherichia coli of the gene encoding the IPS protein in Cephalosporium acremonium. The IPS gene was identified by purifying IPS protein, determining the first 23 amino-terminal amino acids, preparing a set of synthetic oligonucleotides encoding a portion of the determined amino-acid sequence, and probing a cosmid genome library with the mixed oligonucleotides. A cosmid hybridizing with the probe was isolated and the IPS gene was localized and sequenced. The IPS gene encodes a polypeptide of relative molecular mass (Mr) 38,416. When this open reading frame was cloned into an E. coli expression vector and inserted into E. coli, the recombinant E. coli produced a new protein co-migrating with authentic IPS as the major protein of the cell (∼20% of cell protein). Crude cell extracts condensed LLD-ACV to a penicillinase-sensitive molecule whose antibacterial activity indicated that it was isopenicillin N.
222 citations
214 citations
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TL;DR: Sucrose gradient centrifugation is found to be a suitable method for determining sedimentation coefficients of enzymes in protein mixtures and the sedimentation behavior of several of the enzymes in the pathway of histidine biosynthesis in S. typhimurium has been determined.
5,232 citations
TL;DR: A review of antibiotic resistance development over the past half-century can be found in this article, with the oft-restated conclusion that it is time to act and to restore the therapeutic applications of antibiotics.
Abstract: Antibiotics have always been considered one of the wonder discoveries of the 20th century. This is true, but the real wonder is the rise of antibiotic resistance in hospitals, communities, and the environment concomitant with their use. The extraordinary genetic capacities of microbes have benefitted from man's overuse of antibiotics to exploit every source of resistance genes and every means of horizontal gene transmission to develop multiple mechanisms of resistance for each and every antibiotic introduced into practice clinically, agriculturally, or otherwise. This review presents the salient aspects of antibiotic resistance development over the past half-century, with the oft-restated conclusion that it is time to act. To achieve complete restitution of therapeutic applications of antibiotics, there is a need for more information on the role of environmental microbiomes in the rise of antibiotic resistance. In particular, creative approaches to the discovery of novel antibiotics and their expedited and controlled introduction to therapy are obligatory.
4,364 citations
Princeton University1, Center for Disease Dynamics, Economics & Policy2, Public Health Foundation of India3, University of the Witwatersrand4, Aga Khan University5, University of Oxford6, Food and Drug Administration7, Institute of Tropical Medicine Antwerp8, Aberdeen Royal Infirmary9, University of Antwerp10, National Veterinary Institute11, Duke University12, Karolinska Institutet13, St. John's University of Tanzania14, University of Cuenca15, Wellcome Trust16, St George's, University of London17, McMaster University18, Uppsala University19
TL;DR: The global situation of antibiotic resistance, its major causes and consequences, and key areas in which action is urgently needed are described and identified.
Abstract: The causes of antibiotic resistance are complex and include human behaviour at many levels of society; the consequences affect everybody in the world. Similarities with climate change are evident. Many efforts have been made to describe the many different facets of antibiotic resistance and the interventions needed to meet the challenge. However, coordinated action is largely absent, especially at the political level, both nationally and internationally. Antibiotics paved the way for unprecedented medical and societal developments, and are today indispensible in all health systems. Achievements in modern medicine, such as major surgery, organ transplantation, treatment of preterm babies, and cancer chemotherapy, which we today take for granted, would not be possible without access to effective treatment for bacterial infections. Within just a few years, we might be faced with dire setbacks, medically, socially, and economically, unless real and unprecedented global coordinated actions are immediately taken. Here, we describe the global situation of antibiotic resistance, its major causes and consequences, and identify key areas in which action is urgently needed.
3,181 citations
TL;DR: Recent advances in understanding of the mechanisms by which bacteria are either intrinsically resistant or acquire resistance to antibiotics are reviewed, including the prevention of access to drug targets, changes in the structure and protection of antibiotic targets and the direct modification or inactivation of antibiotics.
Abstract: Antibiotic-resistant bacteria that are difficult or impossible to treat are becoming increasingly common and are causing a global health crisis. Antibiotic resistance is encoded by several genes, many of which can transfer between bacteria. New resistance mechanisms are constantly being described, and new genes and vectors of transmission are identified on a regular basis. This article reviews recent advances in our understanding of the mechanisms by which bacteria are either intrinsically resistant or acquire resistance to antibiotics, including the prevention of access to drug targets, changes in the structure and protection of antibiotic targets and the direct modification or inactivation of antibiotics.
2,837 citations
TL;DR: A group of antibacterial proteins produced by gram-positive bacteria have attracted great interest in their potential use as food preservatives and as antibacterial agents to combat certain infections due to gram- positive pathogenic bacteria.
2,819 citations