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Monographs of Topical Drugs that Have Caused Contact Allergy/Allergic Contact Dermatitis
Published in Anton C. de Groot, Monographs in Contact Allergy, 2021
Colistin is a cyclic polypeptide antibiotic derived from Bacillus colistinus; it is composed of polymyxins E1 and E2 (or colistins A, B, and C) which act as detergents on cell membranes. Colistin is less toxic than polymyxin B, but otherwise similar; the methanesulfonate (see Chapter 3.81 Colistimethate) is used orally. Colistin is indicated for the treatment of acute or chronic infections due to sensitive strains of certain gram-negative bacilli, particularly Pseudomonas aeruginosa. In pharmaceutical products, colistin is employed as colistin sulfate (CAS number 1264-72-8, EC number 215-034-3, molecular formula C53H102N16O17S) (1).
LPS/Lipid A–Binding Synthetic Peptides
Published in Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison, Endotoxin in Health and Disease, 2020
Several natural cationic polypeptides of the animal kingdom are known to have antibiotic properties against gram-negative bacteria, at least in part by increasing the permeability of the outer membrane (20). Among these are defensins and defensin-related peptides recently found in human skin, magainins, cecro-pins, melittins, tachyplesins, and rabbit cationic proteins (20–24). The algorithm has, therefore, been applied to these natural polypeptides in order to identify specific sequences as potential binding site for LPS and, if so, their potential use as synthetic anti-LPS antagonist molecules. Indeed, several amino acid sequences with cationic amphipathic characteristics were predicted in the primary sequence of these polypeptide antibiotics (25), and several of these are now under investigation in our laboratories for possible LPS-neutralizing capability. Since natural cationic antibiotic polypeptides seem to contain amino acid sequences with characteristics comparable to those required for binding and neutralizing lipid A, our attention has been also directed toward the investigation of associated complementary activities of these anti-LPS synthetic peptides; that is, the potential antibiotic activity of synthetic peptides designed de novo according to the sequences predicted by the algorithm on gram-negative bacteria (Tables 2 and 3). We have found that several of these synthetic peptides manifest direct antibiotic activity in vitro, as well as synergistic activity with hydrophobic antibiotics like rifampin and erythromycin (26).
Ultraviolet and Light Absorption Spectrometry
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Zoltan M. Dinya, Ferenc J. Sztaricskai
There are also analytical assay methods for the polypeptide antibiotics based on color reactions. For example, the Doulakas method [115] for bacitracin involves oxidation of the α-aminocarboxylic acid moiety of the molecule with sodium hypobromite in alkaline medium and condensation of the resulting aldehyde with phloroglucinol in concentrated hydrochloric acid to yield a pink color that gives an absorbance maximum of 505 nm. Stretton et al. [116] applied the ninhydrin reaction for the determination of bacitracin.
Detection of mobile colistin-resistance gene variants (mcr-1 and mcr-2) in urinary tract pathogens in Bangladesh: the last resort of infectious disease management colistin efficacy is under threat
Published in Expert Review of Clinical Pharmacology, 2021
Bayasrin Ara, Umme Laila Urmi, Tanjum Ara Haque, Shamsun Nahar, Adity Rumnaz, Tamanna Ali, Mohammed Shah Alam, Abu Syed Md. Mosaddek, nor Azlina a Rahman, Mainul Haque, Salequl Islam
Polypeptide antibiotic colistin (Polymyxin E) is considered a last-resort reserved drug for treating severe acute human infections by multidrug-resistant Gram-negative bacteria (GNB) [1]. The drug has been used worldwide in feeding animals for decades for therapeutic and growth promotion purposes [2,3]. Colistin has been banned in some countries as an animal-feed growth promoter to boost farm animals’ weight gains [4,5]. However, in many Asian countries, including Bangladesh, the indiscriminate use of colistin in animal husbandry generates selection pressure to develop antimicrobial resistance (AMR) in pathogens and other diverse commensal microbial populations [6,7].
Antimicrobial resistance and treatment: an unmet clinical safety need
Published in Expert Opinion on Drug Safety, 2018
Matteo Bassetti, Alessandro Russo, Alessia Carnelutti, Alessandro La Rosa, Elda Righi
Polymyxins are “old” polypeptide antibiotics commonly used in the 1950s for the treatment of complicated urinary tract infections (cUTIs) [11]. This class exerts its antibacterial activity through the interaction of a polycationic peptide ring with the lipid A of the lipopolysaccharides, causing disorganization and loss of the membrane integrity and bacterial cell death [11,12]. Due to frequent reports of neurotoxicity and nephrotoxicity associated with their use, polymyxin use was limited in the past years [13–15]. Attempts to generate polymyxin derivatives that are less toxic have been made, but they all lacked a significant antibacterial effect [16].
First report of polymyxin B activity in Klebsiella pneumoniae biofilm
Published in Journal of Chemotherapy, 2019
Karina Marjorie Silva Herrera, Fernanda Kelen da Silva, Michael Eder de Oliveira, Magna Cristina de Paiva, Adriana Cristina Soares, Jaqueline Maria Siqueira Ferreira
Polymyxins are polypeptide antibiotics. Only polymyxins B and E have been used in clinical practice, and the latter, named colistin, has been more extensively studied.11 The effect of colistin on K. pneumoniae biofilm has already been described, in contrast to that of polymyxin B which remains unknown.3,4,10 Thus, this study describes for the first time the polymyxin B activity in K. pneumoniae biofilm, both concerning inhibition of biofilm formation and the disruption of established biofilms, with new perspectives for the clinical use of this compound.