In U.S. channel catfish (Ictalurus punctatus ) production, bacterial pathogens are primarily responsible for disease within production ponds. Channel catfish virus (CCV) has also played a role in production mortality and mainly impacts fry and fingerling production. In a pond-rearing environment, pathogen coinfections may increase the severity of the constituent pathogens and elevate mortality, thus potentiating economic losses for U.S. producers. A recent study assessed and characterized the effects of bacterial and viral coinfection in juvenile channel catfish. Single immersion infections of F. covae (ALG-00-530) and CCV (2013-CCV-DRB), alongside a mixed coinfected treatment group, were incorporated into the experimental design.
The single virulent F. covae infection resulted in a total cumulative percent mortality (CPM) of 21.3 ± 6.7 %, while the CCV-only group was 77.0 ± 9.2 %. A coinfection (half-dose combination) of each pathogen demonstrated pronounced mortality (100.0 ± 0.0 %) over 13 days following the initial challenge.
Trial results indicate changes in catfish mortality levels and trends from simultaneous exposure to multiple pathogens (Figure 1). Reducing disease outbreaks in catfish farming is critical to enhancing production yields and quality products, and comprehending infection dynamics of pathogens coinfections will provide more insight into targeted control measures for catfish health. A further understanding of the channel catfish immune response via transcriptomic analyses may also elucidate host factors involved in mixed infection exposures. Reducing disease outbreaks in catfish farming is critical to enhancing production yields and quality products , and comprehending infection dynamics of pathogens coinfections will provide more insight into targeted control measures for catfish health.