title: Characterization and in vitro evaluation of new bacteriophages for the biocontrol of Escherichia coli.
abstract: In the present study two new phages (phT4A and ECA2) were characterized and their efficacy was evaluated separately and in cocktail (phT4A/ECA2) to control Escherichia coli. The isolated phages, phT4A and ECA2, belonged to the Myoviridae and Podoviridae family, respectively and both are safe (no integrase and toxin codifying genes) to be used in bacterial control. In general, the increase of multiplicity of infection (MOI) from 1 to 100 promoted a significant increase in the efficiency of phage phT4A and phage cocktail phT4A/ECA2. Both phages were effective against E. coli, but phage phT4A (reduction of 5.8 log CFU/mL after 8h treatment) was more effective than phage ECA2 phage (reduction of 4.7 log CFU/mL after 8h treatment). The use of a cocktail phT4A/ECA2 was significantly more effective (reductions of 6.2 log CFU/mL after 6h treatment) than the use single phage suspensions of phT4A and ECA2 (reductions 5.3 log CFU/mL and 4.9 log CFU/mL, respectively, after 6h treatment). The rate of emergence of phage-resistant mutants was lower for phage phT4A when compared with phage ECA2 and phage cocktail phT4A/ECA2.The results indicate that in addition to the efficacy, the potential development of phage-resistant mutants must also be considered in the design of phage cocktails.
authors.affiliation: Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Pereira
authors.affiliation: Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
authors.forename: Catarina
authors.initials: C
authors.lastname: Moreirinha
authors.affiliation: STAB VIDA-Investigação e Serviços em Ciências Biológicas, Madan Parque, 2825-182 Caparica, Portugal.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Lewicka
authors.affiliation: STAB VIDA-Investigação e Serviços em Ciências Biológicas, Madan Parque, 2825-182 Caparica, Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Almeida
authors.affiliation: STAB VIDA-Investigação e Serviços em Ciências Biológicas, Madan Parque, 2825-182 Caparica, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Clemente
authors.affiliation: Departamento de Microbiología e Parasitología, CIBUS-Facultad de Biologia, Universidade de Santiago de Compostela, Campus Vida s/n., 15782 Santiago de Compostela, Spain.
authors.forename: Jesús L
authors.initials: JL
authors.lastname: Romalde
authors.affiliation: Portuguese Institute for Sea and Atmosphere (IPMA IP), Av. Brasília, 1449-006 Lisbon, Portugal.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Nunes
authors.affiliation: Department of Biology and CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal. Electronic address: aalmeida@ua.pt.
authors.forename: Adelaide
authors.initials: A
authors.lastname: Almeida
mesh_terms: D000595:Amino Acid Sequence; D001433:Bacteriolysis; D001435:Bacteriophages / Q000302:isolation & purification / Q000502:physiology* / Q000648:ultrastructure; D061046:Biological Control Agents; D005075:Biological Evolution; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics / Q000821:virology*; D023061:Gene Order; D056084:Genetic Fitness; D016679:Genome, Viral; D058507:Host Specificity; D009154:Mutation; D016366:Open Reading Frames; D000072417:Protein Domains
chemical_list: D061046:Biological Control Agents
keywords: Bacterial-phage inactivation; Multidrug resistance bacteria; Phage cocktail; Phenotypic resistance