title: Transfer of plasmid-mediated resistance to tetracycline in pathogenic bacteria from fish and aquaculture environments.
abstract: The transferability of a large plasmid that harbors a tetracycline resistance gene tet(S), to fish and human pathogens was assessed using electrotransformation and conjugation. The plasmid, originally isolated from fish intestinal Lactococcus lactis ssp. lactis KYA-7, has potent antagonistic activity against the selected recipients (Lactococcus garvieae and Listeria monocytogenes), preventing conjugation. Therefore the tetracycline resistance determinant was transferred via electroporation to L. garvieae. A transformant clone was used as the donor in conjugation experiments with three different L. monocytogenes strains. To our knowledge, this is the first study showing the transfer of an antibiotic resistance plasmid from fish-associated lactic bacteria to L. monocytogenes, even if the donor L. garvieae was not the original host of the tetracycline resistance but experimentally created by electroporation. These results demonstrate that the antibiotic resistance genes in the fish intestinal bacteria have the potential to spread both to fish and human pathogens, posing a risk to aquaculture and consumer safety.
authors.affiliation: Department of Biosciences, Food and Nutrition Biotechnology, University of Kuopio, Kuopio, Finland. elena.guglielmetti@unicatt.it
authors.forename: Elena
authors.initials: E
authors.lastname: Guglielmetti
authors.forename: Jenni M
authors.initials: JM
authors.lastname: Korhonen
authors.forename: Jouni
authors.initials: J
authors.lastname: Heikkinen
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Morelli
authors.forename: Atte
authors.initials: A
authors.lastname: von Wright
mesh_terms: D000818:Animals; D017756:Aquaculture; D003227:Conjugation, Genetic; D018274:Electroporation; D005393:Fish Diseases / Q000382:microbiology*; D005399:Fishes / Q000382:microbiology; D022761:Gene Transfer, Horizontal; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology / Q000662:veterinary*; D006801:Humans; D007422:Intestines / Q000382:microbiology; D017045:Lactococcus / Q000145:classification / Q000235:genetics*; D008089:Listeria monocytogenes / Q000235:genetics*; D008088:Listeriosis / Q000382:microbiology; D010957:Plasmids / Q000235:genetics*; D013753:Tetracycline Resistance / Q000235:genetics*