DefinePK

Abstract

Background: The increasing prevalence of multidrug-resistant (MDR) Escherichia Coli (E. Coli) and Staphylococcus aureus (S. aureus) has become a major public health concern. Traditional antibiotics are losing efficacy, necessitating alternative therapeutic strategies. Phage Therapy (PT), a natural and highly specific bacterial control method, presents a promising solution. This study explores the isolation and efficacy of bacteriophages against these resistant pathogens.
Methods: Thirty environmental samples were collected from hospital sewage, farm sewage, poultry farms, and urban wastewater. Phages were enriched using bacterial cultures and screened via spot tests and plaque assays to confirm their lytic potential. Bacterial inhibition was further assessed through qualitative turbidity comparisons. Additionally, thermal stability tests were conducted at varying temperatures to evaluate phage viability.
Results:
 Phages targeting E. Coli were detected in 30% of samples, the majority from hospital, urban, and agricultural sewage, as well as fecal and manure sources. In contrast, S. aureus phage was found in 26.7% of samples, with notable occurrences in hospital sewage, urban sewage, and poultry environments. Phage activity was most prominent in hospital sewage, where 147 plaques for S. aureus and 32 plaques for E. Coli were observed, corresponding to titters of 1.47 × 10⁸ PFU/mL and 3.2 × 10⁷ PFU/mL, respectively. Among the environmental sources tested, E. Coli-specific phages were most abundant in fresh poultry manure, with 54 plaques and a titer of 5.4 × 10⁷ PFU/mL, followed by farm sewage, which showed 42 plaques and a titer of 4.2 × 10⁷ PFU/mL. Bacterial suppression was observed in cultures treated with phage, and thermal stability tests revealed that lytic activity peaked at temperatures between 20°C and 30°C, diminished at 40°C, and ceased at 50°C.
Conclusion: This study confirms the strong lytic potential of bacteriophages against E. Coli and S. aureus, suggesting PT may be a viable alternative to antibiotics.