| Summary: | <i>Salmonella</i> causes a range of diseases in humans and livestock of considerable public health and economic importance. Widespread antimicrobial use, particularly in intensively produced livestock (e.g., poultry and pigs) may contribute to the rise of multidrug-resistant <i>Salmonella</i> strains. Alternative treatments such as bacteriophages have shown promise when used to reduce the intestinal carriage of <i>Salmonella</i> in livestock. However, the digestive enzymes and low pH encountered in the monogastric GI tract can significantly reduce phage viability and impact therapeutic outcomes. This study deployed alginate–carrageenan microcapsules with and without CaCO<sub>3</sub> to protect a genomically diverse set of five <i>Salmonella</i> bacteriophages from simulated gastrointestinal conditions. None of the unprotected phage could be recovered following exposure to pH < 3 for 10 min. Alginate–carrageenan encapsulation improved phage viability at pH 2–2.5 after exposure for 10 min, but not at pH 2 after 1 h. Including 1% (<i>w</i>/<i>v</i>) CaCO<sub>3</sub> in the formulation further reduced phage loss to <0.5 log<sub>10</sub> PFU/mL, even after 1 h at pH 2. In all cases, phage were efficiently released from the microcapsules following a shift to a neutral pH (7.5), simulating passage to the duodenum. In summary, alginate–carrageenan-CaCO<sub>3</sub> encapsulation is a promising approach for targeted intestinal delivery of genomically diverse <i>Salmonella</i> bacteriophages.
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