The Efficacy of a Single Intraperitoneal Injection of Flumequine in the Treatment of Systemic Vibriosis in Corkwing Wrasse Symphodus melops

Abstract

In this investigation, the efficacy of a single intraperitoneal injection of flumequine in the treatment of systemic vibriosis in corkwing wrasse Symphodus melops was examined. In a population of corkwing wrasse that was experiencing daily mortality, the dominant bacterium cultivated from kidney samples of dead fish was tentatively classified as a species of Vibrio resembling V. splendidus. The infected fish were randomly divided into two groups, each of 60 individuals. Group 1 was treated with flumequine (25 mg/kg of fish) administered by a single intraperitoneal injection, whereas the fish from group 2 were injected with saline. The mortality was observed daily for 21 d. The cumulative mortality was significantly (P < 0.005) higher in the control group (58%) compared with the medicated group (11%). Bacterial examination of kidneys from dead and surviving fish of both groups indicated the Vibrio to be quickly and effectively eliminated by the antibacterial agent.

Susceptibility of corkwing wrasse Symphodus melops, goldsinny wrasse Ctenolabrus rupestis, and Atlantic salmon Salmo salar smolt, to experimental challenge with Vibrio tapetis and Vibrio splendidus isolated from corkwing wrasse

“…Significantly higher mortality was observed in the challenged groups than in the control group, and successful re-isolation of the bacteria through bacterial examination of kidney samples was done from the dead fish in the challenged groups, suggesting that the two bacterial strains were the causative agents. Re-isolation of the pathogens confirmed Koch's postulate for both bacterial strains, as both strains had previously been isolated by necropsy from corkwing wrasse that were suffering from systemic vibriosis (Samuelsen et al 2000;Jensen et al 2003). However, the high mortality observed in the control group of corkwing wrasse (33%) raises some questions.…”

“…The mortality in the control group was close to that of the remaining 156 fish (counted the day the challenge experiment started) in the storage tank, which was 36% in the same period. This observation adds to our earlier experience (Samuelsen et al 2000) that corkwing wrasse are difficult to keep healthy during long periods in captivity, despite attempts to minimise stress. For the three subsequent years we kept groups of wild-caught corkwing wrasse in captivity, and, in all cases, high mortality, typically 1-5% of the population per day, started after approximately 1 month.…”

“…For the three subsequent years we kept groups of wild-caught corkwing wrasse in captivity, and, in all cases, high mortality, typically 1-5% of the population per day, started after approximately 1 month. From two different groups of corkwing wrasse, we have been able to isolate one dominating pathogen, leading to the isolation of the opportunistically pathogenic strains LP1 and LP2 (Samuelsen et al 2000;Jensen et al 2003). In other groups, including the present control groups, mixed growth of several Vibrio spp.…”

“…The strain LP1 was isolated from diseased corkwing wrasse in September 1998, as described by Samuelsen et al (2000). A different Vibrio sp., LP2, was isolated from diseased corkwing wrasse in the laboratories of the Institute of Marine Research in September 1999 (Jensen et al 2003).…”

“…Recently, a Vibrio sp. was isolated from captured corkwing wrasse that were suffering high mortality (Samuelsen et al 2000). This strain has later been classified into the species V. splendidus, while a different strain, classified into V. tapetis, was subsequently isolated from another group of captured corkwing wrasse that were also experiencing high mortality (Jensen et al 2003).…”