Polymorphism in gyrA is associated to quinolones resistance in Chilean Piscirickettsia salmonis field isolates

Comprehensive antibiotic susceptibility profiling of Chilean Piscirickettsia salmonis field isolates

“…Concerning the mechanisms underlying resistance to antibiotics, we previously presented experimental evidence on P. salmonis quinolone‐resistant types and their association with a polymorphism found in gyrA (Henriquez et al . ). Although in this work we did not address the genetic basis of the resistance to quinolones, our ongoing research suggests that the reported polymorphism is present in QUI‐resistant isolates analysed to date.…”

Complete genome sequence of Piscirickettsia salmonis LF-89 (ATCC VR-1361) a major pathogen of farmed salmonid fish

“…Although, several prophylactic approaches have been tested, the high frequency of new epizootic events indicates that alternative strategies are required to prevent SRS. The limited effectiveness of vaccine treatments has favored therapies based primarily on the use of high doses of antibiotics, which have generated antibiotic resistance and strong criticisms to the industry (Henriquez et al, 2015). Hence, the knowledge of genome sequence and structure may be essential to develop effective P. salmonis vaccines.…”

Comparative Genome Analysis of Two Isolates of the Fish Pathogen Piscirickettsia salmonis from Different Hosts Reveals Major Differences in Virulence-Associated Secretion Systems

“…Using a similar approach, we identified EM-90-like isolates in Atlantic salmon only (our unpublished data), suggesting a common genogroup. These isolates were found to be susceptible to quinolones presenting a particular gyrA genotype ( 8 ). Moreover, their mucoid texture is quite different from the “sticky” phenotype shown by LF-89-like colonies.…”