Molecular Ecology of Class 1 Integrons in Patagonia as Model System for Understanding the Rise of Antibiotic Resistance Isolates Around the World

The understanding of the molecular basis of the flux of antimicrobial resistance genes (ARG) is a fundamental requirement to develop a comprehensive explanation of how pathogenic strains adapt to extreme resistance phenotypes at a global scale. However, it is difficult to assess how ARG interact with human activities. This constraint led us to seek a suitable biological model system, which has two components: class 1 integrons as the main molecular element of bacterial resistance to antibiotics, and Tierra del Fuego Island as the study area. Both clinical and non-clinical strains were studied from this island for the presence of class 1 integrons. The 30 % of clinical strains and the 11 % of strains isolated from the open environment were intI1 positive, respectively, sharing 3 intI1 “clinical” alleles previously described in nosocomial strains from Europe, Africa, and Asia, depicting an interchange of genes among both habitats, the hospital and the sites close to human activities in Ushuaia City. It is likely that once the intI1-positive clinical strains are released from the hospital, the intI1 genes can be transferred through the mechanisms of lateral genetic transfer to other bacterial species from the open environment where they can be maintained over time.