Treating experimentally induced vibriosis (Listonella anguillarum) in cod, Gadus morhua L., with florfenicol

Abstract

This study was performed to determine the efficacy of orally administered florfenicol in the treatment of experimentally induced vibriosis (Listonella anguillarum) in cod, Gadus morhua. The L. anguillarum strain HI-610 was used. This strain has a minimal inhibitory concentration value of 0.5 mg L(-1) against florfenicol. Fifteen groups of 40 fish each were challenged by bath with 1.7 x 10(5) CFU mL(-1) for 1 h. Three days following challenge, medication with florfenicol was introduced in 12 of the groups. The dosages used were 10 mg kg(-1) day(-1) for 10 consecutive days in marine or salmonid pellets, 10 mg kg(-1) day(-1) for five consecutive days in marine pellets or administered at days 1, 2, 4, 6 and 8 following initiation of treatment. Among challenged unmedicated fish mortality started at day 3 post-challenge reaching a final cumulative mortality of 77% at day 15. The experiment was terminated at day 26. In the medicated groups, the majority of deaths occurred from days 3-7 post-challenge reaching final cumulative mortalities of 31% and 52%, respectively, for the fish given marine and salmonid pellets for 10 consecutive days. The fish treated with medicated marine pellets for five consecutive days and at days 1, 2, 4, 6 and 8 (sequential feeding) following initiation of treatment had cumulative mortalities of 52% and 38%, respectively. Survival of medicated fish in all groups was significantly (P < 0.005) greater than survival of challenged unmedicated fish. Furthermore, a significant difference (P < 0.001) in survival was found between fish treated for 10 consecutive days using marine pellets and the groups using marine pellets for five consecutive days and salmonid pellets for 10 consecutive days. Twenty four hours following last medication, six fish had mean plasma concentrations of 3.3 +/- 1.7 and 3.5 +/- 2.8 microg mL(-1), respectively, in fish treated for 10 consecutive days using marine and salmonid pellets. Corresponding values for fish treated for five consecutive days and by sequential feeding were 2.2 +/- 2.3 and 1.7 +/- 0.7 microg mL(-1), respectively.

Eficácia do florfenicol e da oxitetraciclina no controle de Aeromonas hydrophila em pacu (Piaractus mesopotamicus)

“…A sobrevivência foi maior em pacu tratado com 10,0mg.kg -1 (100%) do que em salmão para tratar A. salmonicida (87%) (Inglis et al, 1991 A concentração eficaz de 10,0mg.kg -1 de FFC está de acordo com a indicada para I. punctatus para tratar E. ictaluri (Gaikowski et al, 2003;Aquaflor, 2010b); para salmão para tratar furunculoses (Inglis et al, 1991;Nordmo et al, 2006); para G. morhua para tratar vibriose (Seljestokken et al, 2006) e para O. niloticus para tratar A. hydrophila …”

Comparative susceptibility of turbot, halibut, and cod yolk-sac larvae to challenge with Vibrio spp.

“…The bacterial strains and serotypes used are shown in Table 1. Strain HI-610 has previously been used in a range of challenge experiments with cod and halibut (Samuelsen & Bergh 2004, Skjermo & Bergh 2004, Vik-Mo et al 2005, Seljestokken et al 2006, Engelsen et al 2008, Sandlund & Bergh 2008. Strain HI-618 has previously been described by Wiik et al (1989) .…”

Screening and characterisation of potentially pathogenic bacteria associated with Atlantic codGadus morhualarvae: bath challenge trials using a multidish system

“…V. anguillarum strain 610 is known to cause high mortality in various fish species such as Atlantic cod Gadus morhua (Samuelsen & Bergh 2004, Vik-Mo et al 2005, Seljestokken et al 2006 and Atlantic halibut Hippoglossus hippoglossus (Samuelsen et al 1997) and is commonly used in our laboratory during challenge experiments.…”