The Experts below are selected from a list of 246 Experts worldwide ranked by ideXlab platform
Ole Bent Samuelsen - One of the best experts on this subject based on the ideXlab platform.
-
pharmacokinetic data show that Oxolinic Acid and flumequine are absorbed and excreted rapidly from plasma and tissues of lumpfish
Frontiers in Veterinary Science, 2019Co-Authors: Gyri Teien Haugland, Karen Obrestad Kverme, Rita Hannisdal, Marielle Kallekleiv, Duncan J Colquhoun, Heidrun I Wergeland, Bjorn Tore Lunestad, Ole Bent SamuelsenAbstract:This study examined the uptake, tissue distribution and elimination of the antibacterial agents Oxolinic Acid and flumequine in lumpfish (Cyclopterus lumpus L.) by use of LC-MS/MS following a single oral administration of 25 mg/kg fish given in feed. Lumpfish are increasingly used as cleaner fish for removal of sea lice on commercially farmed salmon. The production of lumpfish is successful, but there are challenges with bacterial infections and the number of antibacterial treatments has increased in recent years. As the lumpfish is a novel species to farming, there is a need for pharmacokinetic data and establishment of protocols for efficient antibacterial treatment. The current study describes the pharmacokinetic properties of Oxolinic Acid and flumequine in lumpfish. Absorption of Oxolinic Acid was moderate and was characterised by a calculated peak plasma concentration (Cmax) of 2.12 µg/ml after 10.3 hours (Tmax) and an elimination half-life (t1/2) of 21 hours. Area under curve (AUC) and AUC from 0 to 24 hours (AUC0-24h) were calculated to be 60.9 and 34.0 h g/ml, respectively. For flumequine, plasma Cmax was found to be 2.77 µg/ml after 7.7 h (Tmax) with t1/2 of 22 h. The area under the curve (AUC) and AUC from 0 to 24 hours (AUC0-24h) were calculated as 104.3 and 50.3 h g/ml, respectively. Corresponding Cmax values in muscle, liver and head-kidney for Oxolinic Acid were 4.01, 3.04 and 4.68 µg/g respectively and Tmax of 11.1, 9.2 and 10.0 h, respectively. For flumequine, Cmax values of 4.16, 4.01 and 7.48 µg/g were obtained in muscle, liver and head kidney respectively, with corresponding Tmax values of 10.2, 10.3 and 6.0 h. Antimicrobial susceptibility values as determined by minimum inhibitory concentration (MIC) analyses against 28 isolates of Aeromonas salmonicida isolated from diseased lumpfish ranged from 0.06 to 15 µg/ml for Oxolinic Acid and 0.024 to 6.25 µg/ml for flumequine. Bimodal distributions in susceptibility to both Oxolinic Acid and flumequine were observed. The combination of pharmacokinetic properties and MIC data make possible calculation of efficient treatment doses, which are needed to improve the welfare of lumpfish and minimize development of antibiotic resistant bacteria.
-
Multiple dose pharmacokinetic study of Oxolinic Acid in cod, Gadus morhua L.
Aquaculture International, 2006Co-Authors: Ole Bent SamuelsenAbstract:The plasma, muscle and liver distribution and elimination of the antibacterial agent Oxolinic Acid were studied after multiple oral (p.o.) administration of 10 or 20 mg kg^−1 day^−1 to cod ( Gadus morhua ) for 6 days. The fish, held in seawater at 6 and 12°C and weighing 150–250 g were sampled 24 h following last medication. The concentrations in plasma and tissues were clearly dosage and temperature dependent. The distribution from plasma to muscle (muscle/plasma ratio) was higher than that from a single dose study and independent of temperature and dosage. The distribution from plasma to liver (liver/plasma ratio) was lower than the muscle/plasma ratio and according to this study dependent of the administered dosage but independent of temperature. The elimination of Oxolinic Acid from plasma, muscle and liver was considerably faster following multiple administration compared to a single administration.
-
efficacy of orally administered florfenicol and Oxolinic Acid for the treatment of vibriosis in cod gadus morhua
Aquaculture, 2004Co-Authors: Ole Bent Samuelsen, Oivind BerghAbstract:Abstract This study was performed to determine the efficacy of orally administered Oxolinic Acid and florfenicol in the treatment of experimentally induced vibriosis in cod Gadus morhua . The Vibrio anguillarum strain HI-610 was used. This strain has minimum inhibitory concentration (MIC) values of 0.016 mg/l against Oxolinic Acid and 0.5 mg/l against florfenicol. Ten groups of 40 fish each were challenged by bath, 8.5×10 6 cells/ml for 1 h. Three days following challenge, medication with Oxolinic Acid or florfenicol was introduced in eight of the groups. The dosages used were 10 or 20 mg/kg day for both antibacterials and administered at days 1, 2, 4, 6, 8 and 10 following initiation of treatment for Oxolinic Acid and daily for 10 consecutive days for florfenicol. Among challenged unmedicated fish, the mortality started at day 3 post-challenge reaching a final cumulative mortality of 87.5% at day 22 when the experiment was terminated. In the medicated groups, the majority of deaths occurred from days 3 to 5 post-challenge reaching final cumulative mortalities of 34% and 28%, respectively, for the fish treated with 10 and 20 mg/kg of Oxolinic Acid and 31% and 20%, respectively, for the fish treated with 10 and 20 mg/kg of florfenicol. Survival of medicated fish in all groups were significant ( p p >0.1) in survival was however found between groups with parallel treatment or between groups given different drugs, dosages or medication regimens. Twenty-four hours following last medication, fish ( n =5) given a daily dosage of 10 mg/kg of florfenicol had mean plasma and muscle concentrations of 5.0±1.6 mg/l and 4.6±0.9 mg/kg, respectively. Corresponding values for fish given 20 mg/kg day of florfenicol were 6.5±1.3 mg/l (plasma) and 7.0±2.7 mg/kg (muscle). The plasma and muscle concentrations for fish treated with Oxolinic Acid were 0.8±0.2 mg/l and 1.9±0.4 mg/kg, respectively, when administered a dosage of 10 mg/kg day and 1.4±0.6 mg/l and 3.4±1.1 mg/kg, respectively, for the fish given a dosage of 20 mg/kg day.
-
a single dose pharmacokinetic study of Oxolinic Acid and vetoquinol an Oxolinic Acid ester in cod gadus morhua l held in sea water at 8 c and in vitro antibacterial activity of Oxolinic Acid against vibrio anguillarum strains isolated from diseased c
Journal of Fish Diseases, 2003Co-Authors: Ole Bent Samuelsen, Oivind Bergh, A ErvikAbstract:The pharmacokinetic properties of the antibacterial agent Oxolinic Acid and vetoquinol, the carbitol ester of Oxolinic Acid, were studied after intravenous (i.v.) and oral (p.o.) administration to 100- 150 g cod, Gadus morhua L., held in sea water at 8 °C. Following i.v. injection, the plasma drug concentration-time profile showed two distinct phases. The distribution half-life (t 1 / 2 α) was estimated at 1.3 h, the elimination half-life (t 1 / 2 β) as 84 h and the total body clearance (Cl T ) as 0.047 L kg - 1 h - 1 . The volume of distribution at steady state, V d ( s s ) was calculated to be 5.5 L kg - 1 , indicating good tissue penetration of Oxolinic Acid in cod. Following p.o. administration of Oxolinic Acid or vetoquinol, the peak plasma concentrations (C m a x ) of Oxolinic Acid and the time to peak plasma concentrations (T m a x ) were estimated to be 1.2 and 2.5 μg mL - 1 , and 24 and 12 h, respectively. The bioavailabilities of Oxolinic Acid following p.o. administration of Oxolinic Acid and vetoquinol were calculated to be 55 and 72%, respectively. The in vitro minimum inhibitory concentration (MIC) values of Oxolinic Acid against three strains of Vibrio anguillarum isolated from diseased cod were 0.016 μg mL - 1 (HI-610), 0.250 μg mL - 1 (HI- 618) and 0.250 μg mL - 1 (HI-A21). Based on a MIC value of 0.016 μg mL - 1 a single p.o. administration of 25 mg kg - 1 of Oxolinic Acid maintains plasma levels in excess of 0.064 μg mL - 1 , corresponding to four times the MIC-value, for approximately 12 days. The analogous value for a single p.o. dose of 25 mg kg - 1 of Oxolinic Acid administered as vetoquinol was 13 days.
-
A single‐dose pharmacokinetic study of Oxolinic Acid and vetoquinol, an Oxolinic Acid ester, in cod, Gadus morhua L., held in sea water at 8 °C and in vitro antibacterial activity of Oxolinic Acid against Vibrio anguillarum strains isolated from dise
Journal of Fish Diseases, 2003Co-Authors: Ole Bent Samuelsen, Oivind Bergh, A ErvikAbstract:The pharmacokinetic properties of the antibacterial agent Oxolinic Acid and vetoquinol, the carbitol ester of Oxolinic Acid, were studied after intravenous (i.v.) and oral (p.o.) administration to 100- 150 g cod, Gadus morhua L., held in sea water at 8 °C. Following i.v. injection, the plasma drug concentration-time profile showed two distinct phases. The distribution half-life (t 1 / 2 α) was estimated at 1.3 h, the elimination half-life (t 1 / 2 β) as 84 h and the total body clearance (Cl T ) as 0.047 L kg - 1 h - 1 . The volume of distribution at steady state, V d ( s s ) was calculated to be 5.5 L kg - 1 , indicating good tissue penetration of Oxolinic Acid in cod. Following p.o. administration of Oxolinic Acid or vetoquinol, the peak plasma concentrations (C m a x ) of Oxolinic Acid and the time to peak plasma concentrations (T m a x ) were estimated to be 1.2 and 2.5 μg mL - 1 , and 24 and 12 h, respectively. The bioavailabilities of Oxolinic Acid following p.o. administration of Oxolinic Acid and vetoquinol were calculated to be 55 and 72%, respectively. The in vitro minimum inhibitory concentration (MIC) values of Oxolinic Acid against three strains of Vibrio anguillarum isolated from diseased cod were 0.016 μg mL - 1 (HI-610), 0.250 μg mL - 1 (HI- 618) and 0.250 μg mL - 1 (HI-A21). Based on a MIC value of 0.016 μg mL - 1 a single p.o. administration of 25 mg kg - 1 of Oxolinic Acid maintains plasma levels in excess of 0.064 μg mL - 1 , corresponding to four times the MIC-value, for approximately 12 days. The analogous value for a single p.o. dose of 25 mg kg - 1 of Oxolinic Acid administered as vetoquinol was 13 days.
A Ervik - One of the best experts on this subject based on the ideXlab platform.
-
a single dose pharmacokinetic study of Oxolinic Acid and vetoquinol an Oxolinic Acid ester in cod gadus morhua l held in sea water at 8 c and in vitro antibacterial activity of Oxolinic Acid against vibrio anguillarum strains isolated from diseased c
Journal of Fish Diseases, 2003Co-Authors: Ole Bent Samuelsen, Oivind Bergh, A ErvikAbstract:The pharmacokinetic properties of the antibacterial agent Oxolinic Acid and vetoquinol, the carbitol ester of Oxolinic Acid, were studied after intravenous (i.v.) and oral (p.o.) administration to 100- 150 g cod, Gadus morhua L., held in sea water at 8 °C. Following i.v. injection, the plasma drug concentration-time profile showed two distinct phases. The distribution half-life (t 1 / 2 α) was estimated at 1.3 h, the elimination half-life (t 1 / 2 β) as 84 h and the total body clearance (Cl T ) as 0.047 L kg - 1 h - 1 . The volume of distribution at steady state, V d ( s s ) was calculated to be 5.5 L kg - 1 , indicating good tissue penetration of Oxolinic Acid in cod. Following p.o. administration of Oxolinic Acid or vetoquinol, the peak plasma concentrations (C m a x ) of Oxolinic Acid and the time to peak plasma concentrations (T m a x ) were estimated to be 1.2 and 2.5 μg mL - 1 , and 24 and 12 h, respectively. The bioavailabilities of Oxolinic Acid following p.o. administration of Oxolinic Acid and vetoquinol were calculated to be 55 and 72%, respectively. The in vitro minimum inhibitory concentration (MIC) values of Oxolinic Acid against three strains of Vibrio anguillarum isolated from diseased cod were 0.016 μg mL - 1 (HI-610), 0.250 μg mL - 1 (HI- 618) and 0.250 μg mL - 1 (HI-A21). Based on a MIC value of 0.016 μg mL - 1 a single p.o. administration of 25 mg kg - 1 of Oxolinic Acid maintains plasma levels in excess of 0.064 μg mL - 1 , corresponding to four times the MIC-value, for approximately 12 days. The analogous value for a single p.o. dose of 25 mg kg - 1 of Oxolinic Acid administered as vetoquinol was 13 days.
-
A single‐dose pharmacokinetic study of Oxolinic Acid and vetoquinol, an Oxolinic Acid ester, in cod, Gadus morhua L., held in sea water at 8 °C and in vitro antibacterial activity of Oxolinic Acid against Vibrio anguillarum strains isolated from dise
Journal of Fish Diseases, 2003Co-Authors: Ole Bent Samuelsen, Oivind Bergh, A ErvikAbstract:The pharmacokinetic properties of the antibacterial agent Oxolinic Acid and vetoquinol, the carbitol ester of Oxolinic Acid, were studied after intravenous (i.v.) and oral (p.o.) administration to 100- 150 g cod, Gadus morhua L., held in sea water at 8 °C. Following i.v. injection, the plasma drug concentration-time profile showed two distinct phases. The distribution half-life (t 1 / 2 α) was estimated at 1.3 h, the elimination half-life (t 1 / 2 β) as 84 h and the total body clearance (Cl T ) as 0.047 L kg - 1 h - 1 . The volume of distribution at steady state, V d ( s s ) was calculated to be 5.5 L kg - 1 , indicating good tissue penetration of Oxolinic Acid in cod. Following p.o. administration of Oxolinic Acid or vetoquinol, the peak plasma concentrations (C m a x ) of Oxolinic Acid and the time to peak plasma concentrations (T m a x ) were estimated to be 1.2 and 2.5 μg mL - 1 , and 24 and 12 h, respectively. The bioavailabilities of Oxolinic Acid following p.o. administration of Oxolinic Acid and vetoquinol were calculated to be 55 and 72%, respectively. The in vitro minimum inhibitory concentration (MIC) values of Oxolinic Acid against three strains of Vibrio anguillarum isolated from diseased cod were 0.016 μg mL - 1 (HI-610), 0.250 μg mL - 1 (HI- 618) and 0.250 μg mL - 1 (HI-A21). Based on a MIC value of 0.016 μg mL - 1 a single p.o. administration of 25 mg kg - 1 of Oxolinic Acid maintains plasma levels in excess of 0.064 μg mL - 1 , corresponding to four times the MIC-value, for approximately 12 days. The analogous value for a single p.o. dose of 25 mg kg - 1 of Oxolinic Acid administered as vetoquinol was 13 days.
-
absorption tissue distribution and excretion of flumequine and Oxolinic Acid in corkwing wrasse symphodus melops following a single intraperitoneal injection or bath treatment
Journal of Veterinary Pharmacology and Therapeutics, 2001Co-Authors: Ole Bent Samuelsen, A ErvikAbstract:The pharmacokinetic properties of the antibacterial agents Oxolinic Acid and flumequine were studied in corkwing wrasse (Symphodus melops) after either intraperitoneal injection or bath treatment. Following intraperitoneal administration the peak plasma concentrations (Cmax) and the time to peak plasma concentrations (Tmax) were estimated to be 2.0 μg/mL and 12 h, respectively, for Oxolinic Acid and 2.6 μg/mL and 12 h, respectively, for flumequine. In muscle, Cmax and Tmax were estimated to 6.7 μg/g and 12 h, respectively, for Oxolinic Acid with corresponding values of 8.5 μg/g and 13 h, respectively, for flumequine. In liver, Cmax and Tmax were calculated to 7.0 μg/g and 12 h, respectively, for Oxolinic and 12.2 μg/g and 11 h, respectively, for flumequine. Elimination half-lives (t1/2β) of 26, 24 and 29 h, respectively, for plasma, muscle and liver were calculated for flumequine. For Oxolinic Acid two distinct elimination phases were found and calculated to be 16 h (t1/2β) and 57 h (t1/2γ) in plasma, 15 and 59 h, respectively, in muscle and 20 and 72 h, respectively, in liver. Bath treatment using 150 mg/L of flumequine or 200 mg/L of Oxolinic Acid for 72 h resulted in flumequine concentrations of 1.0 μg/mL in plasma, 5.0 μg/g in muscle and 12.4 μg/g in liver. Corresponding values for Oxolinic Acid were 1.0 μg/g in plasma, 2.5 μg/g in muscle and 4.9 μg/g in liver.
-
single dose pharmacokinetic study of Oxolinic Acid and vetoquinol an Oxolinic Acid ester in atlantic salmon salmo salar held in seawater and in vitro antibacterial activity against aeromonas salmonicida
Aquaculture, 2000Co-Authors: Ole Bent Samuelsen, A Ervik, Lisa Pursell, P SmithAbstract:Abstract The pharmacokinetic properties of the antibacterial agent Oxolinic Acid and its carbitol ester (Vetoquinol) were studied after intravenous (Oxolinic Acid) and oral (Oxolinic Acid and Vetoquinol) administration to Atlantic salmon ( Salmo salar ) held in seawater at 10°C. Following intravenous injection of Oxolinic Acid, the plasma drug concentration–time profile showed two distinct phases. The distribution half life ( t 1/2 α) was calculated to be 1 h and the elimination half life ( t 1/2 β) to be 15 h. Total body clearance (Cl T ) was determined to be 0.40 l/kg h and the volume of distribution at steady state, V d(ss) to be 5.7 l/kg indicating good tissue penetration of Oxolinic Acid in Atlantic salmon. The peak plasma concentrations ( C max ) and the time to peak plasma concentrations ( T max ) for Oxolinic Acid were estimated to be 0.5 μg/ml and 19 h, respectively, when administrating Oxolinic Acid and 3.8 μg/ml and 7 h, respectively, following oral administration of Vetoquinol. A bioavailability of 25% was calculated following oral administration of Oxolinic Acid whereas a total bioavailability of 93% (Oxolinic Acid+Vetoquinol) where Oxolinic Acid accounted for 71% was calculated following oral administration of Vetoquinol. In muscle, C max and T max were estimated to 3.2 μg/g and 17 h, respectively, following oral administration of Oxolinic Acid with corresponding values of 4.6 μg/g and 14 h for Oxolinic Acid following oral administration of Vetoquinol. Following oral administration of Oxolinic Acid, C max and T max were estimated to 5.6 μg/g and 10 h, respectively, in liver with corresponding values of 11.5 μg /g and 9 h following oral administration of Vetoquinol. The in vitro minimum inhibitory concentration (MIC) values for Oxolinic Acid and Vetoquinol against 20 strains of Aeromonas salmonicida ranged from 0.0625 to >8 μg/ml for Oxolinic Acid and from 2 to >516 μg/ml for Vetoquinol.
-
a single dose pharmacokinetic study of Oxolinic Acid and vetoquinol an Oxolinic Acid ester in atlantic halibut hippoglossus hippoglossus l held in sea water at 9 c
Journal of Fish Diseases, 1999Co-Authors: Ole Bent Samuelsen, A ErvikAbstract:The pharmacokinetic properties of the antibacterial agent Oxolinic Acid were studied after intravenous, intraperitoneal and oral administration to 1.5–3.0 kg Atlantic halibut, Hippoglossus hippoglossus L., held in sea water at 9 °C. Following intravenous injection, the plasma drug concentration-time profile showed two distinct phases. The terminal elimination half-life was estimated to be 52 h, whereas total body clearance (ClT) was determined to be 0.044 L kg–1 h–1. The volume of distribution at steady state, Vd(ss), was calculated to be 3.0 L kg–1, indicating good tissue penetration of Oxolinic Acid in Atlantic halibut. The peak plasma concentration (Cmax) and the time to peak plasma concentration (Tmax) were estimated to be 1.2 and 2.7 μg mL–1, and 21.5 and 80 h, respectively, following oral administration of medicated feed or intraperitoneal injection. The corresponding bioavailabilities were calculated to be 15% and 92%, respectively. Oral administration of vetoquinol, the carbitol ester of Oxolinic Acid, increased the bioavailability of Oxolinic Acid to 64% and the total bioavailability (Oxolinic Acid + vetoquinol) to 82%, whereas Cmax and Tmax values of 6.7 μg mL–1 and 14.5 h, respectively, for Oxolinic Acid, and 1.0 μg mL–1 and 6.3 h, respectively, for vetoquinol were obtained. Based on a minimum inhibitory concentration (MIC) of 0.0625 μg mL–1 for susceptible strains, a single intraperitoneal injection of 25 mg kg–1 of Oxolinic Acid maintains plasma levels in excess of 0.25 μg mL–1, corresponding to four times the MIC value, for ≈12 days. The corresponding values for a single oral dose of 25 mg kg–1 of Oxolinic Acid and vetoquinol were 5 and 10 days, respectively. For resistant strains with a MIC of 1 μg mL–1, a single oral dose of vetoquinol (25 mg kg–1) maintained plasma levels in excess of 4 μg mL–1 for 34 h.
P Smith - One of the best experts on this subject based on the ideXlab platform.
-
use of indirect conductimetry to establish predictive no effect concentrations of oxytetracycline and Oxolinic Acid in aquatic sediments
Aquaculture, 2001Co-Authors: Aisling Oreilly, P SmithAbstract:Abstract A method based on indirect conductimetry was developed for detecting the minimum effect concentration (MEC) of oxytetracycline and Oxolinic Acid on the metabolic activity of the microflora of freshwater sediments. For each agent, three repeat examinations of separate samples collected from the same river location generated identical MEC values (20 mg/kg for oxytetracycline and 0.63 mg/kg for Oxolinic Acid). Sediment microcosms were employed to determine the impact of these agents on the frequency of resistance in the culturable microflora. The minimum concentration capable of selecting for increased frequencies of resistance (MSC) was determined from resistance profiles constructed by measuring the percentage of resistant colony forming units over a range of selective concentrations. For each agent, the MSC values calculated in three independent analyses were identical to the previously determined MEC values. Comparisons of the resistance profiles generated from impacted and unimpacted microcosms allowed the establishment of empirically justifiable breakpoint concentrations for incorporation into Iso-Sensitest agar. These were 12.5 mg/l for oxytetracycline and 1.56 mg/l for Oxolinic Acid. Arguments are presented that the determination of MEC values for any sediment will allow the determination of no-effect concentrations that can be used in predictive environmental impact studies.
-
single dose pharmacokinetic study of Oxolinic Acid and vetoquinol an Oxolinic Acid ester in atlantic salmon salmo salar held in seawater and in vitro antibacterial activity against aeromonas salmonicida
Aquaculture, 2000Co-Authors: Ole Bent Samuelsen, A Ervik, Lisa Pursell, P SmithAbstract:Abstract The pharmacokinetic properties of the antibacterial agent Oxolinic Acid and its carbitol ester (Vetoquinol) were studied after intravenous (Oxolinic Acid) and oral (Oxolinic Acid and Vetoquinol) administration to Atlantic salmon ( Salmo salar ) held in seawater at 10°C. Following intravenous injection of Oxolinic Acid, the plasma drug concentration–time profile showed two distinct phases. The distribution half life ( t 1/2 α) was calculated to be 1 h and the elimination half life ( t 1/2 β) to be 15 h. Total body clearance (Cl T ) was determined to be 0.40 l/kg h and the volume of distribution at steady state, V d(ss) to be 5.7 l/kg indicating good tissue penetration of Oxolinic Acid in Atlantic salmon. The peak plasma concentrations ( C max ) and the time to peak plasma concentrations ( T max ) for Oxolinic Acid were estimated to be 0.5 μg/ml and 19 h, respectively, when administrating Oxolinic Acid and 3.8 μg/ml and 7 h, respectively, following oral administration of Vetoquinol. A bioavailability of 25% was calculated following oral administration of Oxolinic Acid whereas a total bioavailability of 93% (Oxolinic Acid+Vetoquinol) where Oxolinic Acid accounted for 71% was calculated following oral administration of Vetoquinol. In muscle, C max and T max were estimated to 3.2 μg/g and 17 h, respectively, following oral administration of Oxolinic Acid with corresponding values of 4.6 μg/g and 14 h for Oxolinic Acid following oral administration of Vetoquinol. Following oral administration of Oxolinic Acid, C max and T max were estimated to 5.6 μg/g and 10 h, respectively, in liver with corresponding values of 11.5 μg /g and 9 h following oral administration of Vetoquinol. The in vitro minimum inhibitory concentration (MIC) values for Oxolinic Acid and Vetoquinol against 20 strains of Aeromonas salmonicida ranged from 0.0625 to >8 μg/ml for Oxolinic Acid and from 2 to >516 μg/ml for Vetoquinol.
-
towards the establishment of a breakpoint concentration for the determination of resistance to Oxolinic Acid in marine microflora
Aquaculture, 1998Co-Authors: P SmithAbstract:Abstract A rational framework is presented for establishing valid breakpoint concentrations to be employed in determining the frequency of Oxolinic Acid resistant bacteria in marine environments. There is a shortage of relevant data concerning the sensitivities of truly marine fish pathogens and, therefore, quantitative estimates of appropriate breakpoints have been made by reference to data on the sensitivity of Aeromonas salmonicida . The use of these data may limit the general applicability of the breakpoints established. Consideration of clinical, pharmacokinetic and microbiological data indicate that the incorporation of 0.5 μg/ml Oxolinic Acid in Tryptone Soya Agar (TSA) would provide a suitable breakpoint for selecting resistant strains of A. salmonicida . Arguments are presented that the media currently being employed in studies of the frequency of resistance in the vicinity of marine fish farms are inappropriate. It is suggested that media specifically formulated for work with antimicrobial agents, such as Iso-Sensitest Agar (ISA) and Mueller Hinton Agar (MHA) would be more suitable. Seawater is routinely added to media used to enumerate bacteria from the marine environment. The ions present in seawater, particularly Mg 2+ and Ca 2+ , inhibit the antimicrobial activity of Oxolinic Acid. When 70% artificial seawater is used in preparing ISA, the median percentage bioactivity of Oxolinic Acid is approximately 4.5%. Thus, in this medium Oxolinic Acid concentrations of 10–12 μg/ml will exert a selection equivalent to that exerted by 0.5 μg/ml in standard TSA media.
Goran Bylund - One of the best experts on this subject based on the ideXlab platform.
-
influence of oxytetracycline and Oxolinic Acid on the immune response of rainbow trout oncorhynchus mykiss
Fish & Shellfish Immunology, 1998Co-Authors: Tuula Lunden, Susanna Miettinen, L G Lonnstrom, Esamatti Lilius, Goran BylundAbstract:Abstract Oxytetracycline and Oxolinic Acid were tested for possible immunomodulatory effects on fish. The aim of the study was to follow the kinetics of the immune response after vaccination with simultaneous antibiotic treatment. The fish were immunised with a commercial oil-based divalent (furunculosis/vibriosis) vaccine and were simultaneously given oral antibiotic treatment. The specific immune response was monitored by analysing the levels of specific antibodies with ELISA. As an indicator of the nonspecific immune response, the phagocytic activity of circulating leucocytes was measured by a chemiluminescence assay. Total circulating leucocyte counts and differentials were also monitored. The disease resistance was evaluated by challenge tests at the end of the experiment. The results indicate that both oxytetracycline and Oxolinic Acid significantly suppress antibody production as well as the level of circulating white cells, especially lymphocytes, in rainbow trout when administered in association with immunisation. The phagocytic activity of whole blood leucocytes was stimulated by Oxolinic Acid and slightly suppressed by oxytetra-cycline. The survival after challenge was not significantly affected by the antibiotics in the present tests.
-
temperature related absorption and excretion of Oxolinic Acid in rainbow trout oncorhynchus mykiss
Aquaculture, 1992Co-Authors: Harry Bjorklund, A Eriksson, Goran BylundAbstract:Abstract The absorption and elimination of Oxolinic Acid in serum, bile and tissues of rainbow trout were studied at 5, 10 and 15 °C after a single oral dose of 75 mg/kg. The maximum levels of Oxolinic Acid were obtained in serum within 1, 4 and 6 days at 16, 10 and 5 °C, respectively. The highest drug concentrations were measured in bile followed by liver, kidney, muscle tissue and serum. The higher levels of Oxolinic Acid in tissues compared to serum indicate a good distribution of the drug. The elimination half-life in serum was 24 h at 16 °C, 4.0 days at 10 °C and 6.1 days at 5 °C. With the detection limit of 0.01 μg/g for the Oxolinic Acid HPLC assay, the predicted withdrawal time with 95% confidence for muscle tissue was 28 days at 16 °C, 60 days at 10 °C and 140 days at 5 °C. Results obtained under laboratory conditions were in accordance with results from field trials.
-
residues of Oxolinic Acid and oxytetracycline in fish and sediments from fish farms
Aquaculture, 1991Co-Authors: Harry Bjorklund, C M I Rabergh, Goran BylundAbstract:Abstract The residues of Oxolinic Acid and oxytetracycline were studied in fish and sediments from five fish farms after chemotherapy of the farmed fish. Compared to oxytetracycline, Oxolinic Acid was better absorbed and faster excreted from the treated fish. Oxytetracycline was found persistent in concentrations of 0.8–6.3 μg/g in the sediments under the medicated fish pens. Oxolinic Acid levels of 0.05–0.2 μg/g were measured in the sediments for 5 days after the treatment of the fish. Compared to oxytetracycline, Oxolinic Acid showed a faster loss of antibacterial activity in the fish farm sediments. Fish pathogenic bacteria resistant to oxytetracycline were isolated from the treated fish and from the sediments under fish pens. No fish pathogenic bacteria resistant to Oxolinic Acid were found in this study.
Harry Bjorklund - One of the best experts on this subject based on the ideXlab platform.
-
temperature related absorption and excretion of Oxolinic Acid in rainbow trout oncorhynchus mykiss
Aquaculture, 1992Co-Authors: Harry Bjorklund, A Eriksson, Goran BylundAbstract:Abstract The absorption and elimination of Oxolinic Acid in serum, bile and tissues of rainbow trout were studied at 5, 10 and 15 °C after a single oral dose of 75 mg/kg. The maximum levels of Oxolinic Acid were obtained in serum within 1, 4 and 6 days at 16, 10 and 5 °C, respectively. The highest drug concentrations were measured in bile followed by liver, kidney, muscle tissue and serum. The higher levels of Oxolinic Acid in tissues compared to serum indicate a good distribution of the drug. The elimination half-life in serum was 24 h at 16 °C, 4.0 days at 10 °C and 6.1 days at 5 °C. With the detection limit of 0.01 μg/g for the Oxolinic Acid HPLC assay, the predicted withdrawal time with 95% confidence for muscle tissue was 28 days at 16 °C, 60 days at 10 °C and 140 days at 5 °C. Results obtained under laboratory conditions were in accordance with results from field trials.
-
residues of Oxolinic Acid and oxytetracycline in fish and sediments from fish farms
Aquaculture, 1991Co-Authors: Harry Bjorklund, C M I Rabergh, Goran BylundAbstract:Abstract The residues of Oxolinic Acid and oxytetracycline were studied in fish and sediments from five fish farms after chemotherapy of the farmed fish. Compared to oxytetracycline, Oxolinic Acid was better absorbed and faster excreted from the treated fish. Oxytetracycline was found persistent in concentrations of 0.8–6.3 μg/g in the sediments under the medicated fish pens. Oxolinic Acid levels of 0.05–0.2 μg/g were measured in the sediments for 5 days after the treatment of the fish. Compared to oxytetracycline, Oxolinic Acid showed a faster loss of antibacterial activity in the fish farm sediments. Fish pathogenic bacteria resistant to oxytetracycline were isolated from the treated fish and from the sediments under fish pens. No fish pathogenic bacteria resistant to Oxolinic Acid were found in this study.
-
analysis of Oxolinic Acid in fish by high performance liquid chromatography
Journal of Chromatography B: Biomedical Sciences and Applications, 1990Co-Authors: Harry BjorklundAbstract:Abstract A simple high-performance liquid chromatographic method for assaying Oxolinic Acid, a chemotherapeutic agent, in fish tissues has been developed. Nalidixic Acid is used as an internal standard. The drugs are separated on an internal surface reversed-phase column. The sample clean-up is minimized. Serum samples are analysed by direct injection on the column; muscle and liver samples are analysed after solid-phase extraction. The recoveries of Oxolinic Acid from spiked rainbow trout serum, muscle tissue and liver are 99.7, 87.7 and 83.6%, respectively. The lowest measurable amount of the drug is 0.01 μg/g in all three tissues.
