Salmon aquaculture, Piscirickettsia salmonis virulence, and one health: Dealing with harmful synergies between heavy antimicrobial use and piscine and human health comment on Cabello and Godfrey (2019)

Cabello and Godfrey (2019) recently published the review “Salmon aquaculture, Piscirickettsia salmonis virulence, and One Health: Dealing with harmful synergies between heavy antimicrobial use and piscine and human health,” in Aquaculture. Several gaps in the review hinder readers from understanding the complexity of P. salmonis and the bacterium-host interaction. This is in addition to omitting essential information that, in my opinion, should be reported because erroneous policy, economic, and social decisions could be made and could notably impact the Chilean aquaculture industry. For example, P. salmonis is not an opportunistic pathogen with poor virulence/pathogenicity, and the literature instead widely supports several pathogenic mechanisms (e.g., iron uptake) and virulence capacity in vitro and in vivo. Furthermore, P. salmonis is not an emerging pathogen – P. salmonis was described 31 years ago, is currently the primary cause for salmonid mortalities in Chile, and is even officially monitored as a national health threat. Yet other examples reveal gross bias, such as indicating that quinolones are a current treatment for P. salmonis. In reality, the use of quinolones have drastically decreased since 2015 according to official government reports (<1% total volume depending on the year), and prior use is not only against piscirickettsiosis but also the bacterium responsible for bacterial kidney disease. The scope of this commentary addresses all of these issues in Cabello and Godfrey's (2019) review.