title: Antimicrobial effect against different bacterial strains and bacterial adaptation to essential oils used as feed additives.
abstract: The aim of this study was to evaluate the antimicrobial activity and determine the minimum bactericidal concentration (MBC) of the essential oils derived from Origanum vulgare (oregano), Melaleuca alternifolia (tea tree), Cinnamomum cassia (cassia), and Thymus vulgaris (white thyme) against Salmonella Typhimurium, Salmonella Enteritidis, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis. The study also investigated the ability of these different bacterial strains to develop adaptation after repetitive exposure to sub-lethal concentrations of these essential oils. The MBC of the essential oils studied was determined by disc diffusion and broth dilution methods. All essential oils showed antimicrobial effect against all bacterial strains. In general, the development of adaptation varied according to the bacterial strain and the essential oil (tea tree > white thyme > oregano). Therefore, it is important to use essential oils at efficient bactericidal doses in animal feed, food, and sanitizers, since bacteria can rapidly develop adaptation when exposed to sub-lethal concentrations of these oils.
authors.affiliation: Graduate Program in Animal Science, School of Agricultural Sciences and Veterinary Medicine, Pontifícia Universidade Católica do Paraná, BR 376 Km 14, São José dos Pinhais, PR 83010-500, Brazil (Melo, Luciano, Andrade, Costa); School of Veterinary Medicine, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Porto Alegre, RS 91540-000, Brazil (Amaral); Seara Alimentos LTDA, Rua Salgado Filho, 69, Centro, São Miguel do Oeste, SC 89900-000, Brazil (Schaefer); Department of Animal Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA (Rostagno).
authors.forename: Antonio Diego Brandão
authors.initials: AD
authors.lastname: Melo
authors.affiliation: Graduate Program in Animal Science, School of Agricultural Sciences and Veterinary Medicine, Pontifícia Universidade Católica do Paraná, BR 376 Km 14, São José dos Pinhais, PR 83010-500, Brazil (Melo, Luciano, Andrade, Costa); School of Veterinary Medicine, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Porto Alegre, RS 91540-000, Brazil (Amaral); Seara Alimentos LTDA, Rua Salgado Filho, 69, Centro, São Miguel do Oeste, SC 89900-000, Brazil (Schaefer); Department of Animal Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA (Rostagno).
authors.forename: Amanda Figueiredo
authors.initials: AF
authors.lastname: Amaral
authors.affiliation: Graduate Program in Animal Science, School of Agricultural Sciences and Veterinary Medicine, Pontifícia Universidade Católica do Paraná, BR 376 Km 14, São José dos Pinhais, PR 83010-500, Brazil (Melo, Luciano, Andrade, Costa); School of Veterinary Medicine, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Porto Alegre, RS 91540-000, Brazil (Amaral); Seara Alimentos LTDA, Rua Salgado Filho, 69, Centro, São Miguel do Oeste, SC 89900-000, Brazil (Schaefer); Department of Animal Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA (Rostagno).
authors.forename: Gustavo
authors.initials: G
authors.lastname: Schaefer
authors.affiliation: Graduate Program in Animal Science, School of Agricultural Sciences and Veterinary Medicine, Pontifícia Universidade Católica do Paraná, BR 376 Km 14, São José dos Pinhais, PR 83010-500, Brazil (Melo, Luciano, Andrade, Costa); School of Veterinary Medicine, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Porto Alegre, RS 91540-000, Brazil (Amaral); Seara Alimentos LTDA, Rua Salgado Filho, 69, Centro, São Miguel do Oeste, SC 89900-000, Brazil (Schaefer); Department of Animal Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA (Rostagno).
authors.forename: Fernando Bittencourt
authors.initials: FB
authors.lastname: Luciano
authors.affiliation: Graduate Program in Animal Science, School of Agricultural Sciences and Veterinary Medicine, Pontifícia Universidade Católica do Paraná, BR 376 Km 14, São José dos Pinhais, PR 83010-500, Brazil (Melo, Luciano, Andrade, Costa); School of Veterinary Medicine, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Porto Alegre, RS 91540-000, Brazil (Amaral); Seara Alimentos LTDA, Rua Salgado Filho, 69, Centro, São Miguel do Oeste, SC 89900-000, Brazil (Schaefer); Department of Animal Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA (Rostagno).
authors.forename: Carla
authors.initials: C
authors.lastname: de Andrade
authors.affiliation: Graduate Program in Animal Science, School of Agricultural Sciences and Veterinary Medicine, Pontifícia Universidade Católica do Paraná, BR 376 Km 14, São José dos Pinhais, PR 83010-500, Brazil (Melo, Luciano, Andrade, Costa); School of Veterinary Medicine, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Porto Alegre, RS 91540-000, Brazil (Amaral); Seara Alimentos LTDA, Rua Salgado Filho, 69, Centro, São Miguel do Oeste, SC 89900-000, Brazil (Schaefer); Department of Animal Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA (Rostagno).
authors.forename: Leandro Batista
authors.initials: LB
authors.lastname: Costa
authors.affiliation: Graduate Program in Animal Science, School of Agricultural Sciences and Veterinary Medicine, Pontifícia Universidade Católica do Paraná, BR 376 Km 14, São José dos Pinhais, PR 83010-500, Brazil (Melo, Luciano, Andrade, Costa); School of Veterinary Medicine, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9090, Porto Alegre, RS 91540-000, Brazil (Amaral); Seara Alimentos LTDA, Rua Salgado Filho, 69, Centro, São Miguel do Oeste, SC 89900-000, Brazil (Schaefer); Department of Animal Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907, USA (Rostagno).
authors.forename: Marcos Horácio
authors.initials: MH
authors.lastname: Rostagno
mesh_terms: D000821:Animal Feed; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D024881:Drug Resistance, Bacterial; D005503:Food Additives / Q000494:pharmacology*; D009822:Oils, Volatile / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology*; D010944:Plants / Q000737:chemistry / Q000145:classification
chemical_list: D000900:Anti-Bacterial Agents; D005503:Food Additives; D009822:Oils, Volatile; D010938:Plant Oils