Isolation and characterization of strictly lytic bacteriophages against carbapenem-resistant complex.
Journal
Microbiology spectrum
Journal Volume
13
Journal Issue
11
ISSN
2165-0497
Date Issued
2025-11-04
Author(s)
Bregente, Carl Jay Ballena
Thuy, Tran Thi Dieu
Hidrosollo, Jazon Harl
Cruz-Papa, Donna May Dela
Gutierrez, Tracey Antaeus
Chuang, Yu-Jui
Kao, Cheng-Yen
Abstract
The global surge of carbapenem-resistant Enterobacter cloacae complex (CR-ECC) poses a significant clinical challenge due to limited treatment options. This study aimed to isolate and characterize lytic bacteriophages (phages) targeting CR-ECC. CR-ECC CYEBC080 was used as the bacterial host for isolating lytic phages, and a comprehensive evaluation was conducted on isolated phages, including phage stability under various pH and temperature conditions, host range analysis, killing curves, and therapeutic efficacy in Galleria mellonella larvae and a murine bacteremia model. Twelve lytic phages with distinct random amplified polymorphic DNA patterns were isolated, and transmission electron microscopy confirmed their classification under the Straboviri dae family within the Caudoviricetes class. All phages remained stable across pH 3–11 for up to 90 minutes, with an optimal temperature range of 25°C–37°C. Among them, CYPEBC012 exhibited the broadest host range, lysing 93.75% of 80 CR-ECC isolates, while CYPEBC006 displayed the narrowest, lysing only 65%. Whole-genome sequencing revealed 12 phages with linear double-stranded DNA genomes ranging from 177,624 to 180,648 bp. Phage treatment administered at a multiplicity of infection of 10, 1 hour post-infection, significantly improved larval survival at day 7, reaching ≥80% in most groups, except CYPEBC001 (50%) and CYPEBC004 (60%) treatment groups. In CYEBC080 infected mice, CYPEBC012 treatment resulted in 100% survival by day 3 and 80% survival through day 7. Additionally, phage-treated mice exhibited significantly reduced bacterial loads and high phage titers in blood and liver. This study demonstrates the therapeutic potential of CYPEBC012 as a promising strategy against CR-ECC infections, offering an alternative to conventional antimicrobial treatments.
Subjects
Enterobacter cloacae complex
bacteriophage
carbapenem resistance
multidrug resistance
whole-genome sequencing
Publisher
American Society for Microbiology
Type
journal article