A New Phage Cocktail Against Multidrug, ESBL-Producer Isolates of and with Highly Efficient Bacteriolytic Activity.

The globally increasing incidence of antibiotic resistance in pathogenic microorganisms such as , a cause of human acute gastrointestinal infections, calls for developing effective alternatives. In this study, the antibiotic resistance pattern, extended-spectrum β-lactamase (ESBL)-production, and molecular characteristics of 70 multidrug-resistant isolates belong to the two most frequent species of genus, that is, (44 isolates) and (26 isolates) were investigated. These isolates were used to evaluate both specificity and activity of -specific bacteriophages, vB_SflS-ISF001, vB_SsoS-ISF002, and a cocktail of both. Twelve out of the 21 tested resistance genes were detected in the isolates. About 59% of and 46% of isolates were identified as ESBL producers. The bacteriophages showed a high efficiency of plating (EOP ≥0.5) in about 75% of the isolates. Moreover, the growth of >85% of the isolates was inhibited by the phage cocktail of vB_SflS-ISF001 and vB_SsoS-ISF002. The phage cocktail was effective against a wide range of ESBL-positive and -negative isolates of and . Therefore, this phage cocktail has the potential to inhibit or significantly decrease the spread of drug-resistant in humans, food chains, and water/wastewater sanitation systems.