(2014) Science of the Total Environment_Transfer of antibiotic resistance plasmids in pure and activated sludge cultures in the presence of environmentally representative micro-contaminant concentrations

Kim S., Yun Z., Ha U.-H., Lee S., Park H., Kwon E.E., Cho Y., Choung S., Oh J., Medriano C.A., Chandran K.

(Elsevier) Science of the Total Environment ISSN: 489697 Vol.468-469 Issue. Article No. DOI: 10.1016/j.scitotenv.2013.08.100

The presence of antibiotics in the natural environment has been a growing issue. This presence could also account for the influence that affects microorganisms in such a way that they develop resistance against these antibiotics. The aim of this study was to evaluate whether the antibiotic resistant gene (ARG) plasmid transfer can be facilitated by the impact of 1) environmentally representative micro-contaminant concentrations in ppb (part per billion) levels and 2) donor-recipient microbial complexity (pure vs. mixed). For this purpose, the multidrug resistant plasmid, pB10, and Escherichia coli DH5α were used as a model plasmid and a model donor, respectively. Based on conjugation experiments with pure (. Pseudomonas aeruginosa PAKexoT) and mixed (activated sludge) cultures as recipients, increased relative plasmid transfer frequencies were observed at ppb (μg/L) levels of tetracycline and sulfamethoxazole micro-contaminant exposure. When sludge, a more complex community, was used as a recipient, the increases of the plasmid transfer rate were always statistically significant but not always in P. aeruginosa. The low concentration (10. ppb) of tetracycline exposure led to the pB10 transfer to enteric bacteria, which are clinically important pathogens. © 2013 Elsevier B.V.

This research was equally supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (No. 2012-0003505 ) and by Korea Ministry of Environment as “Global Top Project” (Project no.: GT-11-B-01-005-1 ).