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Updated: Jan 13, 2026

Following Cell-fate in E. coli After Infection by Phage Lambda
Published on: October 14, 2011
新規巨大溶菌性エルメニア・ダケンス菌バクテリオファージP19とそのエンドリシン
Farhat Ansari1,2, Vandan Nagar1,2
1Food Technology Division, Bhabha Atomic Research Centre, Mumbai, India.
Abstract:
Aeromonas dhakensis is an emerging multidrug-resistant (MDR) bacterial pathogen that presents significant threats to public health and aquaculture. This study reports the isolation and comprehensive characterisation of jumbo bacteriophage P19. It is a lytic phage with a long, contractile tail and is placed in the genus Ceceduovirus of the family Straboviridae. P19 possesses a large genome typical of jumbo phages, which likely contributes to its enhanced replication efficiency and adaptability. P19 exhibited strong lytic activity with a high efficiency of plating (EOP) against multiple A. dhakensis strains, a burst size of approximately 50 plaque-forming units (PFU) per cell, and a latent period of 30 min. It remained highly stable across pH 6-10 and temperatures up to 60°C. Genomic analysis revealed a 228 kb genome with 414 open reading frames (ORFs) and absence of genes related to lysogeny, antibiotic resistance or virulence, indicating its potential for safe therapeutic and biocontrol applications. ORF_358 encodes a stable and soluble T4-type lysozyme endolysin (molecular weight 18.8 kDa) belonging to the glycoside hydrolase family 24. Molecular docking analysis demonstrated strong binding affinity (-6.4 kcal/mol) between P19_358 and the peptidoglycan NAG-NAM dimer. Recombinant P19_358 endolysin exhibited 99.98% relative lytic activity against Gram-positive bacterium Bacillus subtilis at a concentration of 75 μg/mL without EDTA pre-treatment; whereas, it showed broad-spectrum antibacterial activity against several Gram-negative pathogens, including A. dhakensis, Shigella flexneri, Salmonella Typhimurium, Pseudomonas aeruginosa and Escherichia coli, with relative activity ranging from 71% to 97% following pre-treatment with 100 mM EDTA. These findings collectively indicate that phage P19 and its endolysin P19_358 possess potent lytic activity and favourable stability profiles, supporting their development as promising antimicrobial agents against MDR Gram-negative pathogens.
関連する概念動画
Lytic Cycle of Bacteriophages
Viral Replication: Lytic Cycle
Viral Replication: Lysogenic Cycle
DNA Bacteriophages
Lysogenic Cycle of Bacteriophages

