A Review on Colistin Resistance: An Antibiotic of Last Resort

Abstract

Antibiotic resistance has emerged as a significant global public health issue, driven by the rapid adaptation of microorganisms to commonly prescribed antibiotics. Colistin, previously regarded as a last-resort antibiotic for treating infections caused by Gram-negative bacteria, is increasingly becoming resistant due to chromosomal mutations and the acquisition of resistance genes carried by plasmids, particularly the mcr genes. The mobile colistin resistance gene (mcr-1) was first discovered in E. coli from China in 2016. Since that time, studies have reported different variants of mcr genes ranging from mcr-1 to mcr-10, mainly in Enterobacteriaceae from various parts of the world, which is a major concern for public health. The co-presence of colistin-resistant genes with other antibiotic resistance determinants further complicates treatment strategies and underscores the urgent need for enhanced surveillance and antimicrobial stewardship efforts. Therefore, understanding the mechanisms driving colistin resistance and monitoring its global prevalence are essential steps in addressing the growing threat of antimicrobial resistance and preserving the efficacy of existing antibiotics. This review underscores the critical role of colistin as a last-choice antibiotic, elucidates the mechanisms of colistin resistance and the dissemination of resistant genes, explores the global prevalence of mcr genes, and evaluates the current detection methods for colistin-resistant bacteria. The objective is to shed light on these key aspects with strategies for combating the growing threat of resistance to antibiotics.

High Prevalence of Colistin-Resistant Encoding Genes Carriage among Patients and Healthy Residents in Vietnam

“…The emergence and spread of colistin resistance pose significant challenges to global public health, particularly in regions where the therapeutic options for multidrug-resistant bacterial infections are limited [11]. In this cross-sectional descriptive study conducted in Vietnam, we investigated the prevalence of colistin-resistant encoding genes among both hospitalized patients and healthy residents.…”

“…Such investigations may uncover nuanced interactions between human activities, environmental factors, and microbial ecology, shedding light on the complex interplay that governs the selection and dissemination of resistant bacteria [10]. Moreover, understanding the epidemiology of colistin resistance in healthy individuals can inform targeted interventions aimed at curbing the transmission of resistant strains and preserving the efficacy of colistin as a last-resort antibiotic [11].…”

Aeromonas dhakensis: A Zoonotic Bacterium of Increasing Importance in Aquaculture

“…In addition, strains of A. dhakensis containing blaCTX-M that confer reduced susceptibility to extended-spectrum β-lactamases (ESBLs) have been reported in aquaculture-derived isolates in Korea [ 143 ], whilst isolates associated with MAS outbreaks in Vietnam contained genes encoding reduced susceptibility to sulphonamide ( sul1 ), tetracycline ( tetA ) and trimethoprim ( dfrA1 ) [ 16 ]. Of particular concern is the detection of the mcr-1 colistin resistance gene in A. dhakensis [ 33 ], which confers resistance against this drug of last resort [ 144 ]. Like other aeromonads, A. dhakensis may carry resistance genes on mobile plasmids [ 145 ] or be integrated into bacterial genomes by class 1 integrons [ 146 ].…”

Colistin: Lights and Shadows of an Older Antibiotic

“…In the last years, renew of older antibiotics such as colistin have created new prospective in treatment of DTR infections [6,8]. However, the emergence of new traits of resistance to this drug and the adverse toxic effects to mammalian cells have mitigated its use in clinical practice [6,7] In this review we discuss the principle of the mode of action, the emerging traits related to the resistance and the use of colistin in clinical practice from a pharmacological and clinical point of views.…”