Assessment of Aquaflor^®, copper sulphate and potassium permanganate for control of Aeromonas hydrophila and Flavobacterium columnare infection in sunshine bass, Morone chrysops female × Morone saxatilis male

Abstract

Two experiments were conducted to test the effectiveness of different therapeutants against a mixed infection of Aeromonas hydrophila and Flavobacterium columnare in sunshine bass. Experiment 1 evaluated copper sulphate, florfenicol‐medicated feed and potassium permanganate (KMnO4) against a natural mixed infection. Experiment 2 further evaluated copper sulphate as a treatment to control an experimental mixed infection. In experiment 1, naturally infected untreated fish had the lowest final survival per cent, at 71%, while florfenicol‐medicated feed at 15 mg kg−1 body weight for 10 days or copper sulphate at 2.1 mg L−1 (1% of the total alkalinity) for 24 h produced the highest final survivals, at 90% and 88%, respectively. The final survival of the naturally infected fish administered florfenicol‐medicated feed was significantly different (P < 0.1) from the untreated fish. The survival curves for the florfenicol and the copper sulphate at 2.1 mg L−1 were significantly improved from the untreated fish. In experiment 2, fish were challenged by waterborne exposure to A. hydrophila and F. columnare and either not treated or treated with copper sulphate at 2.1 mg L−1. At the end of experiment 2, the per cent survival of the challenged fish treated with copper sulphate (99%) was significantly higher (P < 0.05) than the non‐treated (61%). The results illustrate clear benefit of florfenicol and copper sulphate against a mixed infection of A. hydrophila and F. columnare.

White bass Morone chrysops is less susceptible than its hybrid to experimental infection with Flavobacterium columnare

“…Darwish et al (2012) evaluated the efficacy of different therapeutants in HSB exposed to a mixed infection of Aeromonas hydrophila and F. columnare during both natural and experimental infections. In a study to evaluate the im munocompetency of HSB fed test diets with varying levels of vitamin E, Trushenski & Kohler (2008) reported an incidental F. columnare outbreak in test fish, which was presumably a contaminant in a stock culture of Streptococcus iniae, the intended pathogen to be tested.…”

Columnaris disease in fish: a review with emphasis on bacterium-host interactions

“…Different media were used to cultivate the bacteria, including Hsu-Shotts or modified Hsu-Shotts medium [79,114], Ordal’s medium [115], Anacker and Ordal’s medium also referred to as “Cytophaga medium” [94], F. columnare growth medium broth [115] and Shieh or modified Shieh medium [12,23,43-45,105]. The bacteria were mostly grown on a shaker [43-45,75,109-111].…”

“…Gaunt et al demonstrated the efficacy of florfenicol in the feed against columnaris disease in channel catfish [136]. Darwish et al also illustrated the clear benefit of florfenicol against a mixed infection of A. hydrophila and F. columnare in Sunshine bass (hybrid striped bass, Morone chrysops female × Morone saxatilis male) [115]. The excessive use of antimicrobial agents to withstand F. columnare has its negative attributes though [20].…”

Draft Genome Sequences of Three Flavobacterium psychrophilum Strains Isolated from Coldwater Disease Outbreaks at Three Production Hatcheries

“…Analysis revealed the presence of efflux and response elements conferring resistance to copper, lead, cadmium, and zinc in all three genomes. Since the exposure of fish to copper sulfate solution is one of the treatments used against F. psychrophilum infection ( 8 ), the presence of these resistance elements in these outbreak-causing strains might be conferring resistance. Genes conferring resistance to fluoroquinolones and beta-lactam antibiotics were also detected in all three genomes.…”