title: Liposome-Encapsulated Bacteriophages for Enhanced Oral Phage Therapy against Salmonella spp.
abstract: Bacteriophages UAB_Phi20, UAB_Phi78, and UAB_Phi87 were encapsulated in liposomes, and their efficacy in reducing Salmonella in poultry was then studied. The encapsulated phages had a mean diameter of 309 to 326 nm and a positive charge between +31.6 and +35.1 mV (pH 6.1). In simulated gastric fluid (pH 2.8), the titer of nonencapsulated phages decreased by 5.7 to 7.8 log units, whereas encapsulated phages were significantly more stable, with losses of 3.7 to 5.4 log units. The liposome coating also improved the retention of bacteriophages in the chicken intestinal tract. When cocktails of the encapsulated and nonencapsulated phages were administered to broilers, after 72 h the encapsulated phages were detected in 38.1% of the animals, whereas the nonencapsulated phages were present in only 9.5%. The difference was significant. In addition, in an in vitro experiment, the cecal contents of broilers promoted the release of the phages from the liposomes. In broilers experimentally infected with Salmonella, the daily administration of the two cocktails for 6 days postinfection conferred similar levels of protection against Salmonella colonization. However, once treatment was stopped, protection by the nonencapsulated phages disappeared, whereas that provided by the encapsulated phages persisted for at least 1 week, showing the enhanced efficacy of the encapsulated phages in protecting poultry against Salmonella over time. The methodology described here allows the liposome encapsulation of phages of different morphologies. The preparations can be stored for at least 3 months at 4°C and could be added to the drinking water and feed of animals.
authors.affiliation: Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Colom
authors.affiliation: Institut Catala de Nanociencia i Nanotecnologia, Bellaterra, Spain.
authors.forename: Mary
authors.initials: M
authors.lastname: Cano-Sarabia
authors.affiliation: Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Otero
authors.affiliation: Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Cortés
authors.affiliation: Institut Catala de Nanociencia i Nanotecnologia, Bellaterra, Spain Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain daniel.maspoch@icn.cat montserrat.llagostera@uab.es.
authors.forename: Daniel
authors.initials: D
authors.lastname: Maspoch
authors.affiliation: Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain daniel.maspoch@icn.cat montserrat.llagostera@uab.es.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Llagostera
mesh_terms: D000818:Animals; D001691:Biological Therapy / Q000295:instrumentation / Q000379:methods; D002645:Chickens; D008081:Liposomes / Q000737:chemistry; D011201:Poultry Diseases / Q000382:microbiology / Q000628:therapy*; D012475:Salmonella / Q000502:physiology / Q000821:virology*; D012481:Salmonella Infections, Animal / Q000382:microbiology / Q000628:therapy*; D012483:Salmonella Phages / Q000737:chemistry* / Q000502:physiology*
chemical_list: D008081:Liposomes