SalmonellaEnteritidis bacteriophage candidates for phage therapy of poultry

Abstract

Aims: Salmonella is a worldwide foodborne pathogen causing acute enteric infections in humans. In the recent years, the use of bacteriophages has been suggested as a possible tool to combat this zoonotic pathogen in poultry farms. This work aims to isolate and perform comparative studies of a group of phages active against a collection of specific Salmonella Enteritidis strains from Portugal and England. Also, suitable phage candidates for therapy of poultry will be selected. Methods and Results: The Salm. Enteritidis strains studied were shown to have a significantly high occurrence of defective (cryptic) prophages; however, no live phages were found in the strains. Bacteriophages isolated from different environments lysed all except one of the tested Salm. Enteritidis strains. The bacteriophages studied were divided into different groups according to their genetic homology, RFLP profiles and phenotypic features, and most of them showed no DNA homology with the bacterial hosts. The bacteriophage lytic efficacy proved to be highly dependent on the propagation host strain. Conclusions: Despite the evidences shown in this work that the Salm. Enteritidis strains used did not produce viable phages, we have confirmed that some phages, when grown on particular hosts, behaved as complexes of phages. This is most likely because of the presence of inactive phage‐related genomes (or their parts) in the bacterial strains which are capable of being reactivated or which can recombine with lytic phages. Furthermore, changes of the bacterial hosts used for maintenance of phages must be avoided as these can drastically modify the parameters of the phage preparations, including host range and lytic activity. Significance and Impact of the Study: This work shows that the optimal host and growth conditions must be carefully studied and selected for the production of each bacteriophage candidate for animal therapy.

Genomic and Proteomic Characterization of the Broad-Host-Range Salmonella Phage PVP-SE1: Creation of a New Phage Genus

“…The increased resistance of Salmonella to antibiotics and other biocides has encouraged the development of phage therapy as an alternative to chemotherapy (1,2,13,68,70,73). We recently reported the isolation and characterization of a lytic Salmonella phage with a broad lytic spectrum (61,64). This phage, named PVP-SE1 (previously 2/2), was isolated from a German (Regensburg) wastewater plant and was shown to be potentially useful for the biocontrol and diagnosis of Salmonella, since it infects a wide variety of Salmonella serotypes isolated in different countries and from different sources (food, environmental, and clinical).…”

Effect of Bacteriophage in Enterotoxigenic <i>Escherichia coli</i> (ETEC) Infected Pigs

“…The issue of antibiotic resistance has recently come to the fore, and many studies have shown the therapeutic efficacy of bacteriophage as a substitute for antibiotics [1,6,8,13,15]. In addition, in Korea, the addition of antibiotics to animal feed has been prohibited by law since July 2011.…”

Phages as Therapeutic Tools to Control Major Foodborne Pathogens: Campylobacter and Salmonella

“…Since then, Salmonella phages have been isolated from different sources: wastewater plants, sewage, manure, faeces and caecal contents from different animals (e.g. poultry, turkey, pig, humans), zoo ponds, nests from poultry farms and many others (Andreatti Filho et al, 2007;Santos et al, 2010;Sillankorva et al, 2010). The search for different Salmonella phages from different sources may be attributed to the interest prompted by the medical and veterinary significance of their pathogenic host.…”

“…Felix 01 is characterized by its broad lytic spectrum among Salmonella and has been used as a diagnostic tool in the identification of Salmonella. Recently, a phage with a broader host range than Felix 01 has been described which presents great potential not only as a therapeutic agent but also as a diagnostic tool Santos et al, 2011;Sillankorva et al, 2010) (Figure 2). Fig.…”