Evaluating Indigenous Lytic Bacteriophages for Activity Against Multi-Resistant Enterobacteriaceae

The widespread and indiscriminate use of antibiotics is increasing drug resistance. The authors isolated, characterized, and assessed the bioactivity of bacteriophages against some multi-resistant Enterobacteriaceae. Using standard protocols, eight wastewater samples were obtained and used to isolate and characterize potential host enteric bacteria and bacteriophages. The wound-healing effect of the phage cocktail (PC) was evaluated by treating coinfected incision 4-cm wounds in animal groups. One hundred bacterial isolates were obtained. Six: U1, U2, S1, S2, P1, and P2, resulted in polyvalent bacteriophages. The cocktailing increased the host range to seventeen. Morphologically, the six bacterial colony sizes ranged from 1 to 6 mm and exhibited different responses to biochemical tests. The PC characterization indicated the presence of constituent phages of the host bacteria. The observed plaque morphology included small, medium, and large-sized plaques, as well as diffuse and clear plaques. The PC concentrations ranged from 3.6 × 103 to 5 × 105 PFU/ml. The adsorption times ranged from 9 to >10 min, with different burst sizes and latent periods. The bacterial isolates showed high resistance, with high multi-antibiotic resistance indices. The host bacteria were identified as Klebsiella aerogenes (U1), Citrobacter freundii (U2), Salmonella enterica (S1 and S2), and Escherichia coli (P1 and P2). Phage therapy with the PC showed significant differences in wound size (p = 0.000), with the PC groups outperforming the negative control groups. The study provides promising evidence for the potential use of phages as alternatives to antibiotics, though further research and clinical trials are necessary to establish their efficacy and safety.