Florfenicol depletion in edible tissue of rainbow trout, Oncorhynchus mykiss (Walbaum), and sea bream, Sparus aurata L.

Abstract

An increase in fish production has consequently brought an increase in infectious diseases in fish farms. The use of chemotherapic drugs is the most effective instrument against common bacterial agents. The number of registered drugs for use in aquaculture is limited and often veterinary practitioners resort to the off-label use of chemotherapic agents authorized for different food-producing animal species. Florfenicol is well known for its outstanding effect against various pathogenic bacteria affecting fish, and therefore, it may be a useful drug for off-label use in aquaculture. The aim of this study was to evaluate the depletion of florfenicol and its major metabolite, florfenicol amine, from the edible tissue of two fish species, rainbow trout and sea bream, following treatment with medicated feed at a dosage of 10 mg kg(-1) of bw day(-1) , for 10 consecutive days. At prefixed time points after the end of administration (0.25, 1, 2, 3, 4, 6, 7, 10, 14 and 21 days after treatment), edible tissues (muscle plus adherent skin) from 15 individuals in each group were collected and analysed by HPLC, to determine concentration of the drug in the tissue. On the basis of the obtained concentrations, withdrawal times of florfenicol in the two species were calculated. The results indicate that a drug withdrawal time of 500 °C-day, as established by Directive 2004/28/EC, for off-label drug use is more than satisfactory to guarantee the healthiness of fish products against the risk of drug residues.

Depletion study and estimation of withdrawal periods for florfenicol and florfenicol amine in pacu (Piaractus mesopotamicus)

“…It is worth emphasizing that the methods reported in the literature for use in residue depletion studies are all based on high performance liquid chromatography with ultraviolet detection, which lacks selectivity. Some studies included an acid hydrolysis step to convert florfenicol and related metabolites to florfenicol amine (Di Salvo et al., ; Gaikowski et al., ; Kosoff et al., and Wrzesinski et al., ). It is also important to highlight that the use of the surrogate florfenicol‐d 3 improved the quality of the data for florfenicol, since this internal standard corrected for the matrix effects associated with the use of mass spectrometry.…”

“…Several studies have reported the pharmacokinetics of florfenicol and florfenicol amine in fish tissues and plasma after florfenicol administration (Di Salvo et al., ; Feng & Jia, ; Feng et al., ; Gaikowski et al., ; Gaunt et al., ; Wrzesinski et al., ). However, no reports were found concerning the pharmacokinetics or depletion of florfenicol in pacu, with most studies having been performed using Nile tilapia.…”

“…In fish, the depletion of florfenicol has been evaluated in Atlantic salmon (Horsberg, Martinsen & Varma, ), Rainbow trout ( Oncorhynchus mykiss ) and sea bream ( Sparus aurata L.) (Di Salvo, Della Rocca, Terzetti & Malvisi, ), olive flounder ( Paralichthys olivaceus ) (Lim et al., ), channel catfish ( Ictalurus puncatus ) (Gaunt et al., ; Wrzesinski et al., ), Nile tilapia ( O. niloticus ) and hybrid tilapia (Feng & Jia, ; Feng, Jia & Li, ; Gaikowski et al., ), walleye ( Stizostedion vitreum ), and hybrid striped bass ( Morone saxatilis ) (Kosoff et al., ). The absorption, distribution, metabolism and excretion of 14 C‐labelled florfenicol in Atlantic salmon was evaluated by Horsberg et al.…”

Determination of selected antibiotics in farmed fish species using LC-MS/MS

“…This could be attributed to some factors related to changes in pharmacodynamics and pharmacokinetics of drugs in different fish species and also changes in environmental factors such as salt and temperature level of waters (He et al . ; Di Salvo, della Rocca, Terzetti & Malvisi ). In addition to species‐dependent factors, He et al .…”

“…Important differences in the frequency and concentration of residues were observed among the fish species tested. This could be attributed to some factors related to changes in pharmacodynamics and pharmacokinetics of drugs in different fish species and also changes in environmental factors such as salt and temperature level of waters (He et al 2012;Di Salvo, della Rocca, Terzetti & Malvisi 2013). In addition to species-dependent factors, He et al (2012) noted that a variety of other factors such as administration routes, period and dosage of antibiotics as well as quantity and harvesting time of fishes may be involved.…”