Local Antimicrobial Resistance Trends in Madurai, Tamil Nadu: Implications for Antimicrobial Stewardship and Future Bacteriophage Therapy

Abstract

Antimicrobial resistance (AMR) has emerged as a major global public health challenge, particularly in developing countries where empirical antibiotic use and limited antimicrobial stewardship accelerate resistance development. The present study investigated local antimicrobial resistance trends in Madurai, Tamil Nadu, and explored the potential role of bacteriophage therapy as an alternative or adjunct antimicrobial strategy. Thirty microbiology culture and antibiotic susceptibility reports were analyzed to identify resistance patterns among clinically important bacterial pathogens, including Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Pseudomonas aeruginosa, Enterococcus species, and Proteus species. The findings demonstrated widespread resistance to third- and fourth-generation cephalosporins, high resistance to fluoroquinolones, and preserved susceptibility to carbapenems across most Gram-negative isolates, suggesting an ESBL-dominated resistance profile. Experimental bacteriophage assays using T3/T7 coliphages against E. coli confirmed successful bacterial lysis and demonstrated the antibacterial potential of phage therapy. However, bacterial regrowth indicated the possible emergence of phage resistance over time. Combination treatment involving bacteriophages and antibiotics showed enhanced bacterial suppression compared to monotherapy, supporting the concept of phage–antibiotic synergy. The study highlights the urgent need for culture-guided antibiotic therapy, strengthened antimicrobial stewardship, continuous local AMR surveillance, and further research into bacteriophage-based therapeutic strategies to combat multidrug-resistant bacterial infections.