Phage therapy against MDR and XDR Salmonella enterica serovars at Basrah Province, Iraq

Salmonella enterica is a significant contributor to infectious diseases, and the proliferation of antibiotic-resistant bacteria has led to considerable public health challenges. Currently, the prevention and control of multidrug-resistant Salmonella contamination face enormous difficulties in food contamination management. Bacteriophages offer a promising approach to managing foodborne pathogens by lysis it. In this study, a lytic Salmonella phage, belonging to the genus Felixounavirus, family Myoviridae, and order Caudovirales, was isolated. This phage exhibited high lytic activity against multi- and extensively drug-resistant Salmonella, with a lytic activity rate of 85.71% (6 out of 7 strains). In comparison 14.29% (1 out of 7 strains) were resistant, showing highly significant differences (P<0.001). The results indicated that a dilution factor of 10-6 yielded the best countable number of plaques and optimal lytic activity at 37°C and pH 7, with decreased activity at pH 4, and no activity at pH 9. These findings suggest that this phage can be used as an antibacterial agent to control multi- and extensively drug-resistant Salmonella.