| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4409678 | Chemosphere | 2013 | 7 Pages |
Antibiotic-resistant bacteria are an emerging threat to public health during drinking water consumption and reclaimed water reuse. Several studies have shown that the proportions of antibiotic-resistant bacteria in waters may increase when exposed to low doses of UV light or chlorine. In this study, inactivation of tetracycline-resistant Escherichia coli and antibiotic-sensitive E. coli by UV disinfection and chlorination was compared to determine the tolerance of tetracycline-resistant E. coli to UV light and chlorine, and tetracycline resistance of a tetracycline-resistant E. coli population was studied under different doses of the disinfectants. Our results showed that relative to antibiotic-sensitive E. coli, tetracycline-resistant E. coli had the same tolerance to UV light and a potentially higher tolerance to chlorination. The mortality frequency distributions of tetracycline-resistant E. coli exposed to tetracycline were shifted by both chlorination and UV disinfection. When compared to the hemi-inhibitory concentrations (IC50) of tetracycline-resistant E. coli with no exposure to UV or chlorination, the IC50 of tetracycline-resistant E. coli treated with tetracycline was 40% lower when inactivation by UV light or chlorination reached 3-log but was 1.18 times greater when inactivation by chlorination reached 4.3-log. Chlorination applied to drinking water or reclaimed water treatment may increase the risk of selection for highly tetracycline-resistant E. coli.
► Inactivation of tetracycline-resistant Escherichia coli was compared to that of sensitive one. ► Tetracycline-resistant E. coli did not show any tolerance to UV lights. ► Tetracycline-resistant E. coli showed tolerance to chlorine of high dose. ► UV disinfection did not shift tetracycline-resistant E. coli more tolerant to tetracycline. ► Chlorination with a high dose shifted tetracycline-resistant E. coli more tolerant to tetracycline.
