Bacteriophages To Sensitize a Pathogenic New Delhi Metallo β-Lactamase-Positive Escherichia coli to Solar Disinfection

Environ Sci Technol. 2018 Dec 18;52(24):14331-14341. doi: 10.1021/acs.est.8b04501. Epub 2018 Dec 3.

Abstract

Bacteriophages active against a New Delhi metallo beta lactamase (NDM)-positive E. coli PI-7 were isolated from municipal wastewater and tested for their lytic effect against the bacterial host. Bacteriophages were highly specific to E. coli PI-7 when tested for host-range. After determining host-specificity, bacteriophages were tested for their ability to sensitize E. coli PI-7 to solar irradiation. Solar irradiation coupled with bacteriophages successfully reduced the length of the lag-phase for E. coli PI-7 from 4 h to 2 h in buffer solution. The reduction of lag-phase length was also observed in filtered wastewater effluent and chlorinated effluent. Previously, we found through gene expression analysis that cell wall, oxidative stress, and DNA repair functions played a large role in protecting E. coli PI-7 against solar damage. Here, gene expression analysis of bacteriophage-supplemented solar-irradiated E. coli PI-7 revealed downregulation of cell wall functions. Downregulation of functions implicated in scavenging and detoxifying reactive oxygen species, as well as DNA repair genes, was also observed in bacteriophage-supplemented solar-irradiated E. coli PI-7. Moreover, solar irradiation activates recA, which can induce lytic activity of bacteriophages. Overall, the combined treatment led to gene responses that appeared to make E. coli PI-7 more susceptible to solar disinfection and bacteriophage infection. Our findings suggest that bacteriophages show good potential to be used as a biocontrol tool to complement solar irradiation in mitigating the persistence of antibiotic-resistant bacteria in reuse waters.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteriophages*
  • Disinfection
  • Escherichia coli
  • Escherichia coli Infections*
  • Humans
  • beta-Lactamases

Substances

  • beta-Lactamases