Assessment of Potential Efficacy of Coliphage Therapy on Multidrug Resistant Clinical Isolates of Escherichia coli

Abstract

Coliphages are the bacteriophages that attack and lyse Escherichia coli, a bacterium emerging as multidrug-resistant, thereby posing a serious public health challenge. Thus, searching for alternative therapies, one of which is coliphage therapy, is timely. The work was aimed at screening clinical isolates of E. coli for the ability to host the coliphage and to determine the cytopathic effect of the coliphages against the multidrug-resistant E. coli hosts. Eight (8) clinical isolates of E. coli were reconfirmed using both conventional and PCR techniques. The isolates were used for the detection and enumeration of the coliphage. The lowest plaque-forming unit (PFU/µL) dilution of each of the 5 samples collected was determined using the double agar overlay method. The isolates that successfully hosted the growth of the phage were further screened against 8 commonly used antibiotics using the disc diffusion method. Out of the 8 clinical isolates collected, 5 (62.5%) were confirmed as E. coli, out of which 3 (60%) supported the growth of the coliphage. The lowest PFU dilution was 1:10⁸, and all the 3 isolates of E. coli that supported the growth of the coliphages were found to be multidrug-resistant (MDR) and were all (100%) lysed by the coliphages. Phage therapy was found to be effective against even the MDR bacteria and, as such, can be considered an alternative therapy. However, a cocktail of the phages may be necessary to ensure absolute adsorption and successful lysis of the pathogens.