Overview of the global distribution of class 1 integrons carrying metallo-β-lactamases

Abstract

Antibiotic resistance is an increasingly serious global health problem. Bacteria have been able to confront the evolutionary challenge and resist antimicrobial chemotherapy, often acquiring pre-existing resistance determinants from the bacterial genetic pool, such as insertion sequences, transposons, plasmids, integrons, among others. Integrons act as a reservoir of cassette genes, primarily in gram-negative bacteria associated with mobile genetic elements, leading to the spread of antimicrobial resistance among commensal and/or pathogenic bacteria, posing a serious global threat. This study aims to understand the worldwide spread of class 1 integrons carrying metallo-β-lactamases. An in silico search was conducted by analyzing data from the "Integrall Database." The results revealed 30 different species of gram-negative bacilli carrying class 1 integrons, with non-fermenting gram-negative bacilli and Enterobacterales predominating. There was also a high prevalence of two families of metallo-β-lactamases, IMP and VIM. Metallo-β-lactamases in class 1 integrons were found distributed across all five continents, reinforcing that the problem of resistance to β-lactams, including carbapenems mediated by enzymes, is a global issue. This has resulted in real complications for public health worldwide, dramatically impacting morbidity, mortality, and healthcare costs.