Piscirickettsia salmonis forms a biofilm on nylon surface using a CDC Biofilm Reactor

Abstract

Research into Piscirickettsia salmonis biofilms on materials commonly used in salmon farming is crucial for understanding its persistence and virulence. We used the CDC Biofilm Reactor to investigate P. salmonis (LF-89 and EM-90) biofilm formation on Nylon, Stainless steel (316L), Polycarbonate and High-Density Polyethylene (HDPE) surfaces. After 144 h of biofilm visualization by scanning confocal laser microscopy under batch growth conditions, Nylon coupons generated the greatest biofilm formation and coverage compared to Stainless steel (316L), Polycarbonate and HDPE.Additionally, P. salmonis biofilm formation on Nylon was significantly greater (p ≤ .01) than Stainless steel (316L), Polycarbonate and HDPE at 288 h. We used Nylon coupons to determine the kinetic parameters of the planktonic and biofilm phases of P. salmonis. The two strains had similar latencies in the planktonic phase; however, LF-89 maximum growth was 2.5 orders of magnitude higher (Log cell ml −1 ). Additionally, LF-89 had a specified growth rate (µmax) of 0.0177 ± 0.006 h −1 and a generation time of 39.2 h. This study contributes to a deeper understanding of the biofilm formation by P. salmonis and elucidates the impact of the biofilm on aquaculture systems.

Collective behavior and virulence arsenal of the fish pathogen Piscirickettsia salmonis in the biofilm realm

“…Despite recent research focused on biofilm formation by P . salmonis ( Vidal et al., 2022 ), the significance of biofilm biology for piscirickettsiosis pathogenesis, as well as for many other aquatic animal diseases, has received little to no attention when compared with its notoriety in field of terrestrial animal diseases ( Clutterbuck et al., 2007 ; Jacques et al., 2010 ). Many studies on bacterial pathogens have reached generalizations on biofilms and their relationship with virulence considering a limited number of traits ( Gajdács et al., 2021 ) and genes ( Wang et al., 2011 ).…”

“…Rozas-Serri (2022) proposed an interesting conceptual framework for understanding the infectious setting of piscirickettsiosis -P. salmonis mainly exploits skin and gill pathways to invade fish hosts. Later, adhered bacteria can develop microcolony-like aggregates in vivo on the surface of the external epithelial cells of the skin and gills of fish host, as well as on goblet and skeletal muscular cells (Smith et al, 2015).…”

Subinhibitory concentrations of florfenicol increase the biofilm formation of Piscirickettsia salmonis

“…Isolates of P. salmonis can attach to solid materials and form biofilms in vitro (Levipan et al, 2020; Santibañez et al, 2020). P. salmonis preferentially forms biofilms on Nylon surfaces using a standard ASTM‐approved method and the CDC Biofilm Reactor (Vidal et al, 2022). Additionally, P. salmonis produces a quorum‐sensing signal molecule N‐acetyl‐L‐homoserine lactone, which could be related to the biofilm formation process (Ruiz et al, 2021).…”

Effect of florfenicol on Piscirickettsia salmonis biofilm formed in materials used in salmonid nets, nylon and high‐density polyethylene

“…In addition, we previously reported that this strain generates less biofilm formation compared to the ATCC LF‐89 strain. This also correlates with specific biofilm formation index reported for both genogroups, where a P. salmonis EM‐90‐like strain showed a general temporal decline in the specific biofilm formation index (Vidal et al, 2022). Conversely, other authors described that the biofilms formed by P. salmonis LF‐89 T showed an opposing pattern (Levipan et al, 2022).…”

“…Furthermore, HDPE possesses a smooth surface structure, which have the potential to retard the onset of biofouling and facilitate cleaning (Edwards et al, 2015). Importantly, we recently reported that P. salmonis is capable of forming biofilms on Nylon and HDPE surfaces (Vidal et al, 2022). Thus, the purpose of the current study was to evaluate the effect of FLO, the most commonly antimicrobial used in the aquaculture industry in Chile, in the exposure to and the formation of P. salmonis biofilm on the Nylon and HDPE surfaces, the most common materials used in the fish farmers facilities in the sea water.…”