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.

Identification and characterization of tetracycline resistance in Lactococcus lactis isolated from Polish raw milk and fermented artisanal products

“…Guglielmetti et al (2009) demonstrated the transfer of tet(S) gene by conjugation from Lactococcus garvieae (fish pathogen) to the human pathogen L. monocytogenes, indicating the possibility of the transfer of tet genes from lactococci to human bacteria. The analysis of the presence of plasmids and the Tn916 transposon in six Tet R L. lactis strains supported these assumptions because most of the tet genes investigated in this study were also identified on mobile elements.…”

Antibiotic Use And Practices In Selected Fish Farms In The Ashanti Region Of Ghana

“…This was also affirmed by the fisheries officers interviewed. Tetracycline is known to be one of the most commonly used antibiotics in fish farms especially in hatcheries [22,23].…”

Antimicrobial resistance profile and resistance genes of Vibrio species isolated from giant freshwater prawn (Macrobrachium rosenbergii) raised in Iran

“…Antibiotic-resistant bacteria may represent a potential threat to human health due to direct transmission through the food chain (Duran and Marshall, 2005) or by transferring the acquired antimicrobial resistance to human pathogens by mobile genetic elements (Angulo, 2000;Serrano, 2005;Guglielmetti et al, 2009). Although several investigations have been conducted in different countries regarding antibiotic resistance in Vibrio spp.…”