Tetracycline- and Macrolide-Resistant Species Isolated from a Mink Farm in the United States.

species are a normal flora of animals and humans. However, life-threatening opportunistic infections can be caused by antimicrobial resistant strains. Fecal ( = 42) and feed ( = 8) samples were obtained from a mink farm and cultured for the enumeration and detection of erythromycin-resistant (a macrolide; ERY)- and tetracycline-resistant (TET) enterococci. ERY and TET enterococci were detected from all fecal (mean concentrations = 6 and 7 logs, respectively) and feed (mean concentrations = 5 and 4 logs, respectively) samples. While and were detected at equal proportions among the fecal TET isolates, predominated among ERY fecal isolates. All ERY and 90% of the TET isolates ( = 50) were multidrug resistant (resistant to three or more antimicrobial classes). Among ERY isolates, while 83% of ( = 12) were positive for (B), 58% of ( = 38) isolates were positive for (C). Among ERY isolates, (M) was detected from 92% of ( = 12) and 97% of ( = 38) isolates. Conversely, however, (B) was detected in 18% of ( = 22) and 33% of ( = 27) TET isolates. Our study provides a baseline for future efforts to reduce antimicrobial resistance and improve antimicrobial stewardship in commercial mink production facilities.