Isolation of Lytic Bacteriophages against MDR-Klebsiella pneumoniae and MDR-Enterobacter aerogenes from Sewage Samples: A Potential Tool for Medical Purposes

Abstract

Background and Aim: This study aimed to isolate phages able to lyse some strains of multiple drug-resistant (MDR)-Klebsiella pneumoniae (named vB_Kp1 and vB_Kp2) and Enterobacter aerogenes (named vB_Ea1) from swage. Materials and Methods: Different K. pneumoniae and E. aerogenes strains were isolated from clinical specimens during January-September 2018 in three hospitals of Amol, Mazandaran, Iran. Kirby-Bauer disc diffusion method was used to determine the resistance profiles of these isolates using different antibiotics. The MDR strains were selected for investigating the effect of isolated phages from wastewater and hospital sewage. The presence of phage was confirmed by plaque formation. The isolated bacteriophages were enriched, concentrated, and stained. Afterwards, a transmitting electron microscope (TEM) was applied to observe the morphology of the bacteriophages. Phage identification tests, including host range and one-step growth, were performed. Results: The TEM analysis revealed that three phages had an icosahedral capsid and long contractile tail being classified as a member of the Myoviridae family. Phages were able to lyse 14 (56%) of the 25 MDR isolated bacterial strains. The one-step growth curve showed large bursts and short latent times. Conclusion: The formation of clear plaques demonstrates the high lyse power of phages. Therefore, they have good potential for further analysis for clinical use as a therapeutic agent in the future.