Environmental microbiota represents a natural reservoir for dissemination of clinically relevant metallo-beta-lactamases.

A total of 10 metallo-β-lactamase-producing isolates of six different species, including Brevundimonas diminuta (n = 3), Rhizobium radiobacter (n = 2), Pseudomonas monteilii (n = 1), Pseudomonas aeruginosa (n = 2), Ochrobactrum anthropi (n = 1), and Enterobacter ludwigii (n = 1), were detected in the sewage water of a hospital. The presence of bla(VIM-13) associated with a Tn1721-class 1 integron structure was detected in all but one of the isolates (E. ludwigii, which produced VIM-2), and in two of them (R. radiobacter), this structure was located on a plasmid, suggesting that environmental bacteria represent a reservoir for the dissemination of clinically relevant metallo-β-lactamase genes.