Abstract
The occurrence and spreading of multi-resistant, as well as pan-resistant bacterial isolates, presents a global problem of modern medicine. Narrowed therapeutic options actualized the use of old antibiotics such as polymyxins. The use of polymyxins in human medicine has been reduced since the 1960s due to the discovery of safer antibiotics. Modern researches provided a better understanding of their pharmacokinetics and pharmacodynamics, as well as dosing regimens with minimum side effects. However, the increased usage in therapy consequently led to the occurrence of resistance to these last-line antibiotics. Most of polymyxin resistant bacterial isolates carried chromosomally mediated resistance, but the discovery of the plasmid mcr-1 gene in 2015 in China changed the paradigm of the origin and spreading of polymyxin resistance. Animals are the main reservoirs of bacteria carrying plasmid with the mcr-1 gene, because of widespread polymyxins application in veterinary medicine and in food industry, as well. Many studies confirmed the transfer of polymyxins resistance genes from animal bacterial isolates to human isolates, as well as between different bacterial species in vivo or in vitro. These findings indicated the need for more detailed epidemiological research and surveillance, as the European Centre for Disease Prevention and Control recommended.
Highlights
Brkić S. et al Polymyxins – Antibacterial Activity, Resistance Mechanisms and Epidemiology of Plasmid Mediated Resistance
Polymyxins, neutralize endotoxin effects by binding to LPS released from the bacterial wall after cell death [5]
The presence of the mcr-1 and the mcr-2 was not detected among colistin resistant Klebsiella pneumoniae isolates of human origin in Serbia [36]
Summary
Polymyxins are cyclic, hydrophilic, cationic peptides, very similar to antimicrobial peptides of eukaryotic cells (e.g. defensins). One of the most important mutations of Encouraged by these data, Xavier et al screened colistin the mgrB gene, described in Klebsiella spp., is the transpo- resistant, mcr-1 negative animal isolates of Escherichia coli sition of extended-spectrum beta-lactamases (ESBLs) or in Belgium, and discovered the mcr-2 gene on IncX4 placarbapenemase genes. The role MCR-2 protein shares considerable similarity with lipid of efflux pump (AcrAB and KpnEF) and hyperproduction phosphatase, the product of insertion sequence IS1595 of capsule have been described in some polymyxins resi- gene This phosphatase has a high degree of similarity stant strains of Klebsiella pneumoniae. Releasing of anio- with phosphatase of Moraxella spp. strains, intrinsicanic capsular polysaccharides from the cell surface captures lly resistant to polymyxins This homology indicates the possibility of transmission of resistance genes between different species in conditions of cohabitation in animals, humans or in other environments [21]. The presence of the mcr-1 and the mcr-2 was not detected among colistin resistant Klebsiella pneumoniae isolates of human origin in Serbia [36]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
