PHAGE-BASED BIOCONTROL OF MULTI-DRUG-RESISTANT BACTERIA IN ISMAILIA CANAL WATER

This study was aimed examined the antibiotic resistance profiles of wild Aeromonas strains isolated from the Ismailia Canal and wastewater treatment plants (WWTPs). Three presumptive Aeromonas strains were identified, with 68.4% verification using 16S-rDNA analysis. The strains included Aeromonas caviae (Ama1), Aeromonas hydrophila (Ama2), and Aeromonas sp. (Ama3), all showing significant drug resistance, indicating their potential as reservoirs for antibiotic resistance genes. Antibiotic sensitivity tests indicated that strains Ama1 and Ama2 showed 100% sensitivity to tetracycline (TE), amikacin (AK), ofloxacin (OFX), and vancomycin (VA), while strain Ama3 was more resistant. A novel aerophage, MK01, was isolated and shown to effectively lyse the Aeromonas strains, with high concentrations detected in the middle section of the Ismailia canal. Characterization of aerophage MK01 indicated that it belongs to the Myoviridae family and maintains stability across temperatures from 4°C to 72°C and pH levels from 4 to 10. Scanning electron microscopy showed that phage significantly reduced multi-drug-resistant (MDR) bacterial growth and impacted biofilm formation. Phage-mediated biocontrol was applied in a batch reactor with mixed cultures. Metagenomic analysis of treated batch reactor samples showed shifts in microbial community structures, with lytic aerophage MK01 decreasing MDR strains from 81.5% to 34.1% in 8 h. Aerophage MK01 effectively improved wastewater quality, resulting in an average increase of 56.45% in dissolved oxygen, alongside reductions in turbidity (80.01%) and biochemical oxygen demand (BOD) (46.15%) compared to batch reactors without the purified phage. The study concludes that phage-based biocontrol offers a promising approach for managing antibiotic-resistant bacteria in wastewater treatment, achieving effective results without producing chemical byproducts and ensuring safe reuse.