Antibiotics and Phage Sensitivity as Interventions for Controlling Escherichia coli Isolated from Clinical Specimens

Abstract

Escherichia coli is considered one of the most frequent causative agents of common bacterial infections worldwide. In addition, effective treatment and prevention measures are still in demand due to the rise of antibiotic resistance and the emergence of new virulent strains. In this work, we evaluated antibiotics and bacteriophages as interventions for controlling pathogenic E. coli. A total of 15 E. coli isolates were included in this study. The automated identification system, namely Vitek 2, has been utilized for the identification. Antibiotics susceptibility profiles of all isolates were confirmed by disc diffusion method. All strains exhibited resistance at least to one antibiotic (ampicillin) while 13 strains were resistant to Ampicillin/Sulbactam, Cefazolin, and Ceftriaxone. Except for two strains, no resistance to Amikacin was observed. On the other hand, bacteriophages designated øEU-3 and øEU-4 were isolated by single plaque isolation and investigated as antimicrobial agents against pathogenic E. coli. Phages morphology, determined by transmission electron microscopy, revealed a structure comprised of a head diameter (71.42 nm) and a tail length (214.28 nm). These features placed the øEU-3 phage in the family Siphoviridae while øEU-4 belonged to family Myoviridae with a head diameter (66.6 nm) and a contractile tail length (108.3nm). Phages susceptibilities were determined by spot test to fifteen E. coli isolates. Coliphage øEU-3 and øEU-4 had narrow host range. This work described the efficacy of antibiotics and bacteriophages as intervention strategies to control pathogenic E. coli and paved the way for depth studies to broaden the antimicrobial spectrum of øEU-3 and øEU-4 phages.

Keywords

• escherichia coli
• antibiotic resistance
• coliphage
• siphoviridae
• myoviridae.