Emergence of dominant multidrug-resistant bacterial clades: Lessons from history and whole-genome sequencing

Abstract

Antibiotic resistance in bacteria has emerged as a global challenge over the past 90 years, compromising our ability to effectively treat infections. There has been a dramatic increase in antibiotic resistance-associated determinants in bacterial populations, driven by the mobility and infectious nature of such determinants. Bacterial genome flexibility and antibiotic-driven selection are at the root of the problem. Genome evolution and the emergence of highly successful multidrug-resistant clades in different pathogens have made this a global challenge. Here, we describe some of the factors driving the origin, evolution, and spread of the antibiotic resistance genotype.

Keywords: bacteria; emergence; evolution; multidrug resistance.

Fig. 1.

Disruption of the gut mucosa can lead to systemic infections by MDR bacteria following antibiotic treatment of immunocompromised patients. MDR bacteria are represented by red rod-shapes. (A) Healthy gut. The mucosa is intact, the microbiota is normal, and the growth of the MDR bacteria is restricted: they cannot spread systemically and are shed at very low levels. (B) With antibiotic treatment: the epithelial barrier is damaged, the microbiota has been disrupted or is dysbiotic and can no longer exert growth restriction on the MDR bacteria that consequently overgrow, spread systemically, and are shed at higher levels.