The regulation of antibiotic use has the objectives of guaranteeing the safety and efficacy of the drugs for the animals treated and protecting the health of consumer. As with other drugs, antibiotic use assumes the existence of some potential undesirable effects.
These can include the promotion of resistance to antimicrobial agents, interference with the normal micro flora of the treated animals, residues in animal tissues destined for human consumption, potential toxic effects on the cells and tissues of animals, adverse effects due to interactions with other drugs or diseases, and allergic phenomena. Because of such effects, antibiotics are regulated by sanitary authorities.

European Union (E.U.) Legislation On Antibiotics

In the European Union, the entity responsible for the evaluation of medical drugs is the Committee for Medicinal Veterinary Products (CVMP) of the European Agency for the Evaluation of Medicinal Products. Current legislation is based on Regulation No. 2377/90 of the council, dated June 26, 1990 and its later modifications.
The lists (1) of antibiotics that are authorized by the E.U. for use in aquaculture. Some are specifically authorized for fish species, while most are approved for use in all species destined for human consumption. Also included are prohibited antibiotics whose use is not authorized in any species destined for human consumption.

U.S. Use of Antibiotics

The United States establishes norms, ensures they are followed, and punishes infractions through the Food and Drug Administration (FDA). Through the Center for Veterinary Medicine, FDA is in charge of regulating the studies that pharmaceutical companies must present to obtain approval for drugs to be used in food animals.
This system contemplates the establishment of maximum levels for residues that are innocuous to consumers and the necessary requisites to establish the withdrawal period or waiting time between the administration of a drug to animals and its clearance from their systems.
The lists (2) of antibiotics prohibited by FDA for use in animals destined for human consumption. The lists (3) of the tolerated residue levels established by FDA for aquatic organisms.

List (1) Antibiotics authorized and prohibited by the European Union (E.U.).

[A] Sulfamides and Diaminopyrimidines

Antibiotic : Sulfamides
Species : All
MRL : 100 ug/kg
Target Tissues : Muscle

Antibiotic : Trimethoprim
Species : All
MRL : 50 ug/kg
Target Tissues : Muscle and skin in natural proportions

[B] Penicillins

Antibiotic : Amoxicillin, Ampicillin, Benzylpenicillin
Species : All
MRL : 50 ug/kg
Target Tissues : Muscle, liver, kidney and fat

Antibiotic : Cloxacillin, Dicloxacillin, Oxacillin
Species : All
MRL : 300 ug/kg
Target Tissues : Muscle, liver, kidney and fat

[C] Tetracycilnes

Antibiotic : Chlortetracycline, Oxytetracycline, Tetracycilnes
Species : All
MRL : 100ug/kg
Target Tissues : Muscle and skin in natural proportions
MRL : 300ug/kg
Target Tissues : liver
MRL : 600ug/kg
Target Tissues : kidney

[D] Aminoglucosides

Antibiotic : Neomicine
Species : All
MRL : 500 ug/kg
Target Tissues : Muscle and skin in natural proportions, liver and fat
MRL : 5,000 ug/kg
Target Tissues : Kidney

Antibiotic : Paromomicine
Species : All
MRL : 500 ug/kg
Target Tissues : Muscle and skin in natural proportions
MRL : 1,500 ug/kg
Target Tissues : Liver and kidney

Antibiotic : Espectinomycin
Species : All
MRL : 300 ug/kg
Target Tissues : Muscle and skin in natural proportions
MRL : 500 ug/kg
Target Tissues : Fat
MRL : 1,000 ug/kg
Target Tissues : Liver
MRL : 5,000 ug/kg
Target Tissues : Kidney

[E] Chloramphenicol and Derivatives

Antibiotic : Florfenicol
Species : Fishes
MRL : 1,000 ug/kg
Target Tissues : Muscle and skin in natural proportions

Antibiotic : Chloramphenicol
Species : Prohibited

[F] Macrolides, Lincosamides, Streptogramins and Pleuromutilines

Antibiotic : Erythromycine
Species : All
MRL : 200 ug/kg
Target Tissues : Muscle and skin in natural proportions, liver, kidney and fat

Antibiotic : Tilmicosin
Species : All
MRL : 50 ug/kg
Target Tissues : Muscle and skin in natural proportions, fat
MRL : 1,000 ug/kg
Target Tissues : Liver and kidney

Antibiotic : Tylosin
Species : All
MRL : 100 ug/kg
Target Tissues : Muscle and skin in natural proportions, liver, kidney and fat

Antibiotic : Lincomycin
Species : All
MRL : 50 ug/kg
Target Tissues : Fat
MRL : 100 ug/kg
Target Tissues : Muscle and skin in natural proportions
MRL : 500 ug/kg
Target Tissues : Liver
MRL : 1,500 ug/kg
Target Tissues : Kidney

[G] Quinolones and Fluoroquinolones

Antibiotic : Danofloxacin
Species : All
MRL : 50 ug/kg
Target Tissues : Fat
MRL : 100 ug/kg
Target Tissues : Muscle and skin in natural proportions
MRL : 200 ug/kg
Target Tissues : Liver and kidney

Antibiotic : Difloxacin
Species : All
MRL : 100 ug/kg
Target Tissues : Fat
MRL : 300 ug/kg
Target Tissues : Muscle and skin in natural proportions
MRL : 600 ug/kg
Target Tissues : Kidney
MRL : 800 ug/kg
Target Tissues : Liver

Antibiotic : Enrofloxacin
Species : All
MRL : 100 ug/kg
Target Tissues : Muscle and skin in natural proportions, fat
MRL : 200 ug/kg
Target Tissues : Liver and kidney

Antibiotic : Flumequine
Species : Fishes
MRL : 600 ug/kg
Target Tissues : Muscle and skin in natural proportions

Antibiotic : Oxalinic acid
Species : Fishes
MRL : 1,300 ug/kg
Target Tissues : Muscle and skin in natural proportions

Antibiotic : Sarafloxacin
Species : Salmonids
MRL : 30 ug/kg
Target Tissues : Muscle and skin in natural proportions

[H] Nitrofurans

Antibiotic : Furazolidone
Species : Prohibited

[I] Nitroimidazoles

Antibiotic : Dimetridazole
Species : Prohibited

Antibiotic : Metronidazole
Species : Prohibited

[J] Other Compounds

Antibiotic : Colistin (Polymyxin)
Species : All
MRL : 150 ug/kg
Target Tissues : Muscle and skin in natural proportions, kidney and fat
MRL : 200 ug/kg
Target Tissues : Kidney

* MRL = Maximum residue limit, All = Species consumed

List (2) Antimicrobials prohibited by the U.S. Food and Drug Administration for use in animals destined for human consumption.

Antibiotic:

Chloramphenicol
Dimetridazole
Ipronidazole
Other nitroimidazoles
Furazolidone
Nitrofurazone
Fluoroquinolones
Glucopeptides

List (3) Residues tolerated by the U.S. Food and Administration for aquatic organisms.

[A] Antibiotic : Sulfamerazine
Species : Trout
Withdrawal Period (days) : 21
Maximum Residue Limit in Flesh (ppm) : 0

[B] Antibiotic : Sulfadimethoxine + Ormetroprim
Species : Salmonids
Withdrawal Period (days) : 42
Maximum Residue Limit in Flesh (ppm) : 0.1
Species : Catfisht
Withdrawal Period (days) : 3
Maximum Residue Limit in Flesh (ppm) : 0.1

[C] Antibiotic : Oxytetracycline
Species : Pacific salmon
Withdrawal Period (days) : 7
Maximum Residue Limit in Flesh (ppm) : 2
Species : Salmonids
Withdrawal Period (days) : 21
Maximum Residue Limit in Flesh (ppm) : 2
Species : Catfish
Withdrawal Period (days) : 21
Maximum Residue Limit in Flesh (ppm) : 21
Species : Lobster
Withdrawal Period (days) : 30
Maximum Residue Limit in Flesh (ppm) : 2

Article by : Victoria Alday de Graindorge, Ph.D.
INVE Technologies NV Oeverstraat 7
B-9200 Baasrode, Belgium
E-mail : v.alday-sanz@inve.be

Coauthor : Ignacio de Blas, Ph.D.
Veterinary Faculty
University of Zaragoza
Zaragoza, Spain

Article copied from : Global Aquaculture
June 2004, Pg.29-30