REPLY

Abstract

Katsunuma and colleagues respond: First, Silley et al. state that ‘avoparcin was drawn from the European market in 1997 prior to the European Union withdrawal of the authorizations of human‐use classes of antimicrobial agents with performance claims effective July 1999, and so on’. We had received the document, which reported such facts. However, as the introduction in our paper (Katsunuma et al. 2007) became too long, we were unable to describe the documentation concerning such facts. Second, it was necessary to cite the report that avilamycin (AVM) still has no human‐use counterpart and therefore does not pose any medical risk due to resistance in enterococci (Shryock 2001), as suggested by Silley et al. Third, we admit Silley et al.’s statement that our citation of Delsol et al. (2005) was inappropriate. Namely, we had to cite other literatures (MAFF 1998; van den Bogaard et al. 2000; DANMAP 2002; Ministry of Food 2001). As stated by Silley et al., it was necessary to describe Delsol et al.’s (2005) findings that although AVM selects for resistance in the native enterococci population of pigs, no resistant isolates were detected beyond 1 week post‐treatment. Additionally, Silley et al. state that we showed no evidence of increased antimicrobial resistance in the Escherichia coli, Salmonella and Campylobacter populations. Because it is accepted that AVM is active almost exclusively against gram‐positive bacteria (Avcare 2003), we did not investigate the increased antimicrobial resistance in the E. coli, Salmonella and Campylobacter populations. In fact, Delsol et al. (2005) showed that Salmonella Typhimurium and E. coli were intrinsically resistant to AVM.