Fig. 1

Simplified model structure. The model considers community and hospital settings interconnected by hospitalizations and dismissals. Transmission within each setting is simulated by means of a core model with setting specific parameters. In the core model (right black box), uncolonized individuals can have «normal» (\({S}^{n}\)) and «amplified» (\({S}^{a})\) susceptibility to colonization, reflecting increased risk of colonization associated with antimicrobial therapy (dark, orange arrows). Colonization with ESBL-producing Klebsiella pneumoniae (red arrows) can occur through human-to-human contact locally (within hospitals and the community) and through external sources (e.g., traveling to high-prevalence areas and contaminated food). Colonized individuals are classified into two levels according to their ability to transmit the resistant pathogen: «normal» infectiousness (\({r}_{setting}^{n}\)) and «amplified» infectiousness \({r}_{setting}^{a,\kappa }\) (dark, orange arrows). The model explicitly accounts for infections caused by ESBL producing K. pneumoniae with inadequate antimicrobial treatment \((k=1\), otherwise \(k=0\)). *ESBL-producing K. pneumonia