Transfer of plasmid-mediated resistance to tetracycline in pathogenic bacteria from fish and aquaculture environments

• Published in: FEMS microbiology letters Vol. 293; no. 1; pp. 28 - 34
• Main Authors: Guglielmetti, Elena, Korhonen, Jenni M, Heikkinen, Jouni, Morelli, Lorenzo, von Wright, Atte
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.04.2009; Blackwell Publishing Ltd; Wiley-Blackwell; Oxford University Press
• Subjects: Animals; Antibiotic resistance; Antibiotics; Aquaculture; Bacteria; Bacteriology; Biological and medical sciences; Conjugation; Conjugation, Genetic; Drug resistance; Electroporation; Fish; Fish Diseases - microbiology; Fishes - microbiology; Fundamental and applied biological sciences. Psychology; Gene Transfer, Horizontal; Genetics; Gram-Positive Bacterial Infections - microbiology; Gram-Positive Bacterial Infections - veterinary; horizontal gene transfer; Humans; Intestine; Intestines - microbiology; Lactococcus; Lactococcus - classification; Lactococcus - genetics; Lactococcus garvieae; Lactococcus lactis; Lactococcus spp; Listeria; Listeria monocytogenes; Listeria monocytogenes - genetics; Listeriosis - microbiology; Microbiology; Pathogens; Plasmids - genetics; tetracycline resistance; Tetracycline Resistance - genetics; tetracycline resistance; aquaculture; spp; horizontal gene transfer; Plasmid; Lactococcusspp; Lactococcus garvieae; Antibiotic resistance; Transfer; Listeria monocytogenes; Bacteria; Conjugation; Tetracycline
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2009.01512.x

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.