Proximity to animal or crop operations may be associated with de novo daptomycin-non-susceptible Enterococcus infection.

Daptomycin-non-susceptible enterococci (DNSE) are emerging pathogens. We have previously reported de novo DNSE isolates in patients with agricultural activities and exposure to livestock. We studied the geographical distribution of the residencies of 34 patients with DNSE infections described in a tertiary centre over a 5-year period in an effort to explore the association between patients' residential locations and agricultural and farm lands. Nine patients had no prior exposure to daptomycin (de novo) and seven of these lived in areas with animal or crop operations. Of those living near an animal or crop operation, the mean number of operations in the proximity of the residence of patients with daptomycin-exposed DNSE was 13.8 (range 1-67) compared to 98.6 (3-529) for those patients with de novo DNSE (P = 0.0486). These data are consistent with previous reports that the transport of daptomycin resistance genes between animals and humans may be a possible mechanism for development of de novo daptomycin resistance in enterococci.