title: Heat treatment effects on the antimicrobial activity of macrolide and lincosamide antibiotics in milk.
abstract: Antibiotic residues in milk can cause serious problems for consumers and the dairy industry. Heat treatment of milk may diminish the antimicrobial activity of these antibiotic residues. This study analyzed the effect of milk processing (60 °C for 30 min, 120 °C for 20 min, and 140 °C for 10 s) on the antimicrobial activity of milk samples fortified with three concentrations of three macrolides (erythromycin: 20, 40 and 80 μg/liter; spiramycin: 100, 200, and 400 μg/liter; and tylosin: 500, 1,000, and 2,000 μg/liter) and one lincosamide (lincomycin: 1,000, 2,000, and 4,000 μg/liter). To measure the loss of antimicrobial activity, a bioassay based on the growth inhibition of Micrococcus luteus was done. The data were analyzed using a multiple linear regression model. The results indicate that treatment at 120 °C for 20 min produces inactivation percentages of 93% (erythromycin), 64% (spiramycin), 51% (tylosin), and 5% (lincomycin), while treatment at 140 °C for 10 s results in generally lower percentages (30% erythromycin, 35% spiramycin, 12% tylosin, and 5% lincomycin). The lowest loss or lowest reduction of antimicrobial activity (21% erythromycin and 13% spiramycin) was obtained by treatment at 60 °C for 30 min.
authors.affiliation: Departamento de Producción Agraria, Universidad Pública de Navarra, Campus de Arrosadía, 31006 Pamplona, Spain.
authors.forename: M A
authors.initials: MA
authors.lastname: Zorraquino
authors.forename: R L
authors.initials: RL
authors.lastname: Althaus
authors.forename: M
authors.initials: M
authors.lastname: Roca
authors.forename: M P
authors.initials: MP
authors.lastname: Molina
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D004350:Drug Residues / Q000032:analysis / Q000494:pharmacology; D005511:Food Handling / Q000379:methods*; D006358:Hot Temperature; D006801:Humans; D055231:Lincosamides / Q000032:analysis / Q000494:pharmacology*; D018942:Macrolides / Q000032:analysis / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D008835:Micrococcaceae / Q000187:drug effects*; D008892:Milk / Q000737:chemistry*; D011634:Public Health; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D055231:Lincosamides; D018942:Macrolides