title: Identification and characterization of tetracycline resistance in Lactococcus lactis isolated from Polish raw milk and fermented artisanal products.
abstract: To assess the occurrence of antibiotic-resistant Lactic Acid Bacteria (LAB) in Polish raw milk and fermented artisanal products, a collection comprising 500 isolates from these products was screened. Among these isolates, six strains (IBB28, IBB160, IBB161, IBB224, IBB477 and IBB487) resistant to tetracycline were identified. The strains showing atypical tetracycline resistance were classified as Lactococcus lactis: three of them were identified as L. lactis subsp. cremoris (IBB224, IBB477 and IBB487) and the other three (IBB28, IBB160, IBB161) were identified as L. lactis subsp. lactis. The mechanism involving Ribosomal Protection Proteins (RPP) was identified as responsible for tetracycline resistance. Three of the tested strains (IBB28, IBB160 and IBB224) had genes encoding the TetS protein, whereas the remaining three (IBB161, IBB477 and IBB487) expressed TetM. The results also demonstrated that the genes encoding these proteins were located on genetic mobile elements. The tet(S) gene was found to be located on plasmids, whereas tet(M) was found within the Tn916 transposon.
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Zycka-Krzesinska
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland; Department of Biochemistry and Molecular Biology, The Centre of Postgraduate Medical Education, Marymoncka 99, 01-813 Warsaw, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Boguslawska
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland.
authors.forename: Tamara
authors.initials: T
authors.lastname: Aleksandrzak-Piekarczyk
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland.
authors.forename: Jakub
authors.initials: J
authors.lastname: Jopek
authors.affiliation: Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106 Warszawa, Poland. Electronic address: jacek@ibb.waw.pl.
authors.forename: Jacek K
authors.initials: JK
authors.lastname: Bardowski
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D019149:Bioreactors / Q000382:microbiology; D003611:Dairy Products / Q000382:microbiology*; D005285:Fermentation; D013294:Lactococcus lactis / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D008892:Milk / Q000382:microbiology*; D010957:Plasmids / Q000187:drug effects; D011044:Poland; D013752:Tetracycline / Q000494:pharmacology*; D013753:Tetracycline Resistance
chemical_list: D000900:Anti-Bacterial Agents; D013752:Tetracycline
keywords: Antibiotic resistance; Lactococcus lactis; Tetracycline; tet(M); tet(S)