Community, environment and hospital associated beta-lactamase resistance in Escherichia coli in Salvador, Brazil

The tendency of enteric bacteria to acquire resistance to antibiotics of last resort has placed them at the top of the WHO list of priority pathogens. Their presence as commensal in the human gut also means enterics such as Escherichia coli easily contaminate multiple environments where sanitation is poor. We compared the presence of E. coli resistant to 3rd generation cephalosporins and carbapenem antibiotics across the compartments of fecal carriage, local surface waters and a hospital in the same urban community in Brazil. Species identification and antimicrobial sensitivity profiles were confirmed using MALDI-TOF and Vitek 2. PCR amplification was used to assay 17 β-lactamase genes. Resistance profiles of fecal samples from healthy residents and river water showed most similarity, but samples collected from the river had the highest diversity of β-lactamase genes and presented significant divergence from the other compartments. Hospital isolates had much higher rates of carbapenem resistance. Despite grossly elevated indicators of human fecal contamination, there is not a simple relationship between human fecal carriage, the aquatic resistome and hospital infections. Surface waters in an urban Brazilian site may serve as an environmental reservoir of antimicrobial resistance.