title: Novel bioassay using Bacillus megaterium to detect tetracycline in milk.
abstract: Tetracyclines are used for the prevention and control of dairy cattle diseases. Residues of these drugs can be excreted into milk. Thus, the aim of this study was to develop a microbiological method using Bacillus megaterium to detect tetracyclines (chlortetracycline, oxytetracycline and tetracycline) in milk. In order to approximate the limits of detection of the bioassay to the Maximum Residue Limit (100μg/l) for milk tetracycline, different concentrations of chloramphenicol (0, 1000, 1500 and 2000μg/l) were tested. The detection limits calculated were similar to the Maximum Residue Limits when a bioassay using B. megaterium ATCC 9885 spores (2.8×10(8)spores/ml) and chloramphenicol (2000μg/l) was utilized. This bioassay detects 105μg/l of chlortetracycline, 100μg/l of oxytetracycline and 134μg/l of tetracycline in 5h. Therefore, this method is suitable to be incorporated into a microbiological multi-residue system for the identification of tetracyclines in milk.
authors.affiliation: Cátedra de Biofísica, Departamento de Ciencias Básicas, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, R.P.L. Kreder 2804, 3080 Esperanza, Argentina.
authors.forename: Melisa
authors.initials: M
authors.lastname: Tumini
authors.affiliation: Cátedra de Biofísica, Departamento de Ciencias Básicas, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, R.P.L. Kreder 2804, 3080 Esperanza, Argentina.
authors.forename: Orlando G
authors.initials: OG
authors.lastname: Nagel
authors.affiliation: Instituto de Ciencia y Tecnología Animal, Universidad Politécnica de Valencia, Camino de Vera 14, 46071 Valencia, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Molina
authors.affiliation: Cátedra de Biofísica, Departamento de Ciencias Básicas, Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, R.P.L. Kreder 2804, 3080 Esperanza, Argentina. Electronic address: ralthaus@fcv.unl.edu.ar.
authors.forename: Rafael L
authors.initials: RL
authors.lastname: Althaus
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000494:pharmacology; D001118:Argentina; D001410:Bacillus megaterium / Q000187:drug effects* / Q000502:physiology; D001681:Biological Assay / Q000379:methods*; D002701:Chloramphenicol / Q000032:analysis / Q000494:pharmacology; D004350:Drug Residues / Q000032:analysis* / Q000494:pharmacology; D005506:Food Contamination / Q000032:analysis* / Q000331:legislation & jurisprudence; D008452:Maximum Allowable Concentration; D008892:Milk / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013171:Spores, Bacterial / Q000187:drug effects; D013754:Tetracyclines / Q000032:analysis* / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D013754:Tetracyclines; D002701:Chloramphenicol
keywords: Antibiotics; Antibióticos; Bacillus megaterium; Bioassay; Bioensayo; Detección; Detection; Leche; Milk; Tetraciclinas; Tetracyclines