Next Article in Journal
Presence of Shiga Toxin-Producing Escherichia coli (STEC) in Fresh Beef Marketed in 13 Regions of ITALY (2017)
Previous Article in Journal
The Isolation and Identification of Bacteria on Feathers of Migratory Bird Species
Article Menu
Issue 4 (December) cover image

Export Article

Open AccessArticle
Microorganisms 2018, 6(4), 125;

Sequential Combined Effect of Phages and Antibiotics on the Inactivation of Escherichia coli

Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
Author to whom correspondence should be addressed.
Received: 12 November 2018 / Revised: 28 November 2018 / Accepted: 3 December 2018 / Published: 5 December 2018
Full-Text   |   PDF [2052 KB, uploaded 13 December 2018]   |  


The emergence of antibiotic resistance in bacteria is a global concern. The use of bacteriophages (or phages) alone or combined with antibiotics is consolidating itself as an alternative approach to inactivate antibiotic-resistant bacteria. However, phage-resistant mutants have been considered as a major threat when phage treatment is employed. Escherichia coli is one of the main responsible pathogens for moderate and serious infections in hospital and community environments, being involved in the rapid evolution of fluoroquinolones and third-generation cephalosporin resistance. The aim of this study was to evaluate the effect of combined treatments of phages and antibiotics in the inactivation of E. coli. For this, ciprofloxacin at lethal and sublethal concentrations was added at different times (0, 6, 12 and 18 h) and was tested in combination with the phage ELY-1 to inactivate E. coli. The efficacy of the combined treatment varied with the antibiotic concentration and with the time of antibiotic addition. The combined treatment prevented bacterial regrowth when the antibiotic was used at minimum inhibitory concentration (MIC) and added after 6 h of phage addition, causing less bacterial resistance than phage and antibiotic applied alone (4.0 × 10−7 for the combined treatment, 3.9 × 10−6 and 3.4 × 10−5 for the antibiotics and the phages alone, respectively). Combined treatment with phage and antibiotic can be effective in reducing the bacterial density and it can also prevent the emergence of resistant variants. However, the antibiotic concentration and the time of antibiotic application are essential factors that need to be considered in the combined treatment. View Full-Text
Keywords: Phage therapy; ciprofloxacin; combination therapies; Escherichia coli; resistance Phage therapy; ciprofloxacin; combination therapies; Escherichia coli; resistance

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Lopes, A.; Pereira, C.; Almeida, A. Sequential Combined Effect of Phages and Antibiotics on the Inactivation of Escherichia coli. Microorganisms 2018, 6, 125.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Microorganisms EISSN 2076-2607 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top