Isolation, Characterization, and Comparative Genomic Analysis of Bacteriophage Ec_MI-02 from Pigeon Feces Infecting Escherichia coli O157:H7

• Published in: International journal of molecular sciences Vol. 24; no. 11; p. 9506
• Main Authors: Sultan-Alolama, Mohamad Ismail, Amin, Amr, Vijayan, Ranjit, El-Tarabily, Khaled A
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30.05.2023; MDPI
• Subjects: Antibiotic resistance; Bacteria; bacteriophage; bio-preservative; Birds; Burst size; characterization; Disinfectants; E coli; E. coli O157:H7; Epidemics; Escherichia coli; Feces; Food industry; Food preservation; Food processing; Food processing industry; Foodborne diseases; Foodborne pathogens; Fruits; Genes; Genomic analysis; Gram-negative bacteria; Gram-positive bacteria; Infections; Laboratories; Latent period; Lysis; phage genome; Phages; Pigeons; Poultry; Preservatives; Propagation; Proteins; Seafood; Serotypes; Vegetables; Virulence; United States > US; phage genome; multiplicity of infection; bio-preservative; phage therapy; E. coli O157:H7; lysis; bacteriophage; characterization
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms24119506

The most significant serotype of Shiga-toxigenic that causes foodborne illnesses is O157:H7. Elimination of O157:H7 during food processing and storage is a possible solution. Bacteriophages have a significant impact on bacterial populations in nature due to their ability to lyse their bacterial host. In the current study, a virulent bacteriophage, Ec_MI-02, was isolated from the feces of a wild pigeon in the United Arab Emirates (UAE) for potential future use as a bio-preservative or in phage therapy. Using a spot test and an efficiency of plating analysis, Ec_MI-02 was found to infect in addition to the propagation host, O157:H7 NCTC 12900, five different serotypes of O157:H7 (three clinical samples from infected patients, one from contaminated green salad, and one from contaminated ground beef). Based on morphology and genome analysis, Ec_MI-02 belongs to the genus Tequatrovirus under the order Caudovirales. The adsorption rate constant (K) of Ec_MI-02 was found to be 1.55 × 10 mL/min. The latent period was 50 min with a burst size of almost 10 plaque forming units (pfu)/host cell in the one-step growth curve when the phage Ec_MI-02 was cultivated using the propagation host O157:H7 NCTC 12900. Ec_MI-02 was found to be stable at a wide range of pH, temperature, and commonly used laboratory disinfectants. Its genome is 165,454 bp long with a GC content of 35.5% and encodes 266 protein coding genes. Ec_MI-02 has genes encoding for rI, rII, and rIII lysis inhibition proteins, which supports the observation of delayed lysis in the one-step growth curve. The current study provides additional evidence that wild birds could also be a good natural reservoir for bacteriophages that do not carry antibiotic resistance genes and could be good candidates for phage therapy. In addition, studying the genetic makeup of bacteriophages that infect human pathogens is crucial for ensuring their safe usage in the food industry.