Efficacy of Oxytetracycline Hydrochloride Bath Immersion to Control External Columnaris Disease on Walleye and Channel Catfish Fingerlings

Abstract

The efficacy of oxytetracycline hydrochloride (OTC-HCl) in controlling external columnaris disease caused by Flavobacterium columnare on fingerling walleyes Sander vitreus and channel catfish Ictalurus punctatus was evaluated in two on-site hatchery trials. Microscopic examination of skin scrapings before treatment confirmed the presence of bacteria with characteristics indicative of F. columnare. In separate trials, walleyes (4.4 g) and channel catfish (1.5 g) were exposed to 60-min static bath treatments of OTC-HCl at 0, 10, and 20 mg/L (walleyes) or 0, 10, 20, and 40 mg/L (channel catfish) on three consecutive days. Each treatment regimen was tested in triplicate, and each replicate contained either 30 walleyes or 55 channel catfish. Posttreatment presumptive disease diagnosis indicated that F. columnare was the disease agent causing the mortality in both species of fish. Walleye survival at 10 d posttreatment was greater in the 10-and 20-mg/L treatment groups than in the control group; however, only the 10-mg/L treatment significantly (P , 0.05) increased walleye survival in comparison with controls. In the channel catfish trial, survival at 10 d posttreatment was significantly (P , 0.05) greater for all OTC-HCl treatment groups relative to controls. Results from these trials indicated that OTC-HCl treatments effectively reduced mortality in walleyes (10 mg/L only) and channel catfish infected

Toxicidade aguda e risco ambiental do antibiótico oxitetraciclina para tilápia ( Oreochromis niloticus ), Daphnia magna e Lemna minor

“…This result shows that there is a possibility of acute poisoning of these species with the effective concentration of 20.0 mg L -1 OTC recommended by Kubtiza (1997) and Rach et al (2008). At OTC concentrations of 7.5 and 8.0 mg L -1 fishes behavior changed, the lack of ability to pitch, erratic swimming, increased Arq.…”

“…Kubtiza (1997) and Rach et al (2008) found that a dilution of 20.0mg L -1 OTC in the water satisfactorily controls fish infections. Thus, because of this effectiveness in control of infections, OTC can be prospected for aquaculture use, provided it shows risk to aquatic organisms.…”

“…The risk of acute environmental poisoning posed by Terramycin ® was calculated with the OTC concentration of 20.0 mg L -1 , which is considered effective to control fish infections (Kubtiza, 1997;Rach et al, 2008). Risk assessment was also calculated for half and twice this recommended concentration (10.0 and 40.0 mg L -1 ).…”

Glochidial infection by the endangered Margaritifera margaritifera (Mollusca) increased survival of salmonid host (Pisces) during experimental Flavobacterium disease outbreak

“…However, several studies have found a lowered resistance to bacterial infections in fish that were pre-infected with parasites (Kotob et al 2016). Fish's increased susceptibility to bacterial infection has been shown in co-infection by monogenean gill parasites (Busch et al 2003;Zhang et al 2015), tissuepenetrating trematode metacercaria (Pylkkö et al 2006), fish lice (Bandilla et al 2006;Lhorente et al 2014) and different ciliated ectoparasites (Evans et al 2007;Xu et al 2009Xu et al , 2012Shoemaker et al 2012). A chronic myxosporean parasite infection decreased the resistance of rainbow trout to bacterial disease even 12 months after exposure to the parasite (Densmore et al 2004).…”

“…Flavobacterium columnare strains differ in their virulence (Suomalainen et al 2006 ; Pulkkinen et al 2018 ) and are capable of causing up to 100% mortality in juvenile salmonids (Suomalainen et al 2005 ). Since there is no effective vaccination available for young salmonids (Sundell et al 2014 ), the only treatment against F. columnare is antibiotics (Rach et al 2008 ).…”