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Published on: December 23, 2022
Large-genome phage vB_Eco_ZCEC15 targets gastrointestinal MDR E. coli: evidence from in vitro and Caco-2 cell models
Kareem Essam1, Amira A Mohamed1, Salsabil Makky1
1Center for Microbiology and Phage Therapy, Zewail City of Science and Technology, Giza, 12578, Egypt.
Background:
Bacterial resistance to traditional antibiotics is spreading at an alarming rate, threatening public health and various industrial applications. Phage therapy has emerged as a promising alternative for combating multidrug-resistant (MDR) bacterial infections. However, most studies have focused on in vitro interactions, often overlooking phage dynamics within human cell environments.
Methodology:
In this study, we characterized MDR stool-derived Escherichia coli isolates and assessed their antibiotic resistance profiles. We then isolated, characterized and evaluated the efficacy of bacteriophage vB_Eco_ZCEC15 (ΦZCEC15) against selected strains under optimized culture conditions (pH 7.3) and acidic conditions mimicking the human gastrointestinal tract. To assess host safety, we tested the impact of ΦZCEC15 on Caco-2 colon carcinoma cells. Furthermore, we explored the effect of bacterial lysis by ΦZCEC15 on Caco-2 cell viability to optimize its therapeutic applications.
Results:
Whole-genome sequencing revealed a large ΦZCEC15 genome (170,313 bp) encoding 272 annotated ORFs, eight tRNAs, and multiple accessory genes. The phage exhibited remarkable stability under diverse physical stressors, including pH 3. Notably, ΦZCEC15 achieved optimal antibacterial activity at a low multiplicity of infection (MOI 0.1), efficiently reducing bacterial titers without compromising eukaryotic host cell viability. In contrast, untreated bacterial infections induced cytotoxic effects in Caco-2 cells.
Conclusion:
These findings highlight the potential of ΦZCEC15 as a safe and effective therapeutic agent against MDR E. coli and encourage the importance of addressing resistance mechanisms to optimize clinical outcomes.
Insights
Bacteriophage ΦZCEC15 effectively targets multidrug-resistant Escherichia coli, showing stability in acidic conditions and safety for human cells. This phage therapy offers a promising solution for bacterial infections.
Area of Science:
- Microbiology
- Molecular Biology
- Biotechnology
Background:
- Antibiotic resistance poses a significant global health threat.
- Phage therapy is a viable alternative for treating multidrug-resistant (MDR) bacterial infections.
- Limited research explores phage behavior within human cellular environments.
Purpose of the Study:
- To characterize bacteriophage vB_Eco_ZCEC15 (ΦZCEC15) and assess its efficacy against MDR Escherichia coli.
- To evaluate ΦZCEC15's stability and safety in conditions mimicking the human gastrointestinal tract.
- To determine the impact of ΦZCEC15-induced bacterial lysis on host cell viability.
Main Methods:
- Whole-genome sequencing of ΦZCEC15.
- Antibacterial efficacy testing under various pH conditions.
- Cytotoxicity assays using Caco-2 colon carcinoma cells.
Main Results:
- ΦZCEC15 possesses a large genome (170,313 bp) with 272 annotated ORFs.
- The phage is stable at low pH (pH 3) and demonstrates optimal activity at MOI 0.1.
- ΦZCEC15 reduced bacterial titers without harming Caco-2 cells, unlike untreated infections.
Conclusions:
- ΦZCEC15 shows potential as a safe and effective therapeutic agent against MDR E. coli.
- Understanding resistance mechanisms is crucial for optimizing phage therapy outcomes.
- Further research into phage dynamics in human cell environments is warranted.
