In late 2015, the first example of a transferrable polymyxin resistance mechanism in Gram-negative pathogens, MCR-1, was reported. Since that report, MCR-1 has been described to occur in many Gram-negative pathogens, and the mechanism of MCR-1-mediated resistance was rapidly determined: an ethanolamine is attached to lipid A phosphate groups, rendering the membrane more electropositive and repe...

Background: Antibiotic resistance being the critical issue faced by medical field, especially Gram negative bacteria. It is a great threat in case of both hospitals acquired and community infections. They possess various mechanisms for their survival. The widespread bacteria has necessitated evaluation use older antimicrobials such as polymyxins. Polymyxins are disfavoured owing to potential cl...

The current pandemic El Tor biotype of O1 Vibrio cholerae is resistant to polymyxins, whereas the previous pandemic strain of the classical biotype is polymyxin sensitive. The almEFG operon found in El Tor V. cholerae confers >100-fold resistance to polymyxins through the glycylation of lipopolysaccharide. Here, we present the mechanistic determination of initial steps in the AlmEFG pathway. We...

Polymyxins are the last line of defense against lethal infections caused by multidrug resistant Gram-negative pathogens. Very recently, the use of polymyxins has been greatly challenged by the emergence of the plasmid-borne mobile colistin resistance gene (mcr-1). However, the mechanistic aspects of the MCR-1 colistin resistance are still poorly understood. Here we report the comparative genomi...

The lack of novel antibiotics against gram-negative bacteria has reinstated polymyxins as the drugs of last resort to treat serious infections caused by extremely multiresistant gram-negative organisms. However, polymyxins are nephrotoxic, and this feature may complicate therapy or even require its discontinuation. Like that of aminoglycosides, the nephrotoxicity of polymyxins might be related ...

Polymyxins were developed approximately 60 years ago, but their use was discontinued in the 1980s (the exception being patients with cystic fibrosis) due to concerns with DOI: 10.5935/0101-2800.2015007

To the editor: The foregoing letter by Lentz et al. examined the occurrence of the mcr-1 gene in Escherichia coli isolates recovered from chicken cloacal swabs collected between August and October of 2015, from a poultry slaughterhouse in southern Brazil [1], providing valuable additional data on the epidemiology of this novel gene. Of 343 animals screened, 10 (3%) different chickens belonging ...