Selection and Characterization of a Multivalent Salmonella Phage and Its Production in a Nonpathogenic Escherichia coli Strain

Institute for Biotechnology and Bioengineering, Center of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4700-057 Braga, Portugal.
Applied and Environmental Microbiology (Impact Factor: 3.67). 11/2010; 76(21):7338-42. DOI: 10.1128/AEM.00922-10
Source: PubMed


We report the selection and amplification of the broad-host-range Salmonella phage phi PVP-SE1 in an alternative nonpathogenic host. The lytic spectrum and the phage DNA restriction profile were not
modified upon replication in Escherichia coli Bl21, suggesting the possibility of producing this phage in a nonpathogenic host, contributing to the safety and easier approval
of a product based on this Salmonella biocontrol agent.

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Available from: Sanna Sillankorva
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    • "Others showed that the propagation of polyvalent Salmonella phage phi PVP-SE1 on a non-pathogenic Escherichia coli strain did not change the microbiological properties and the DNA restriction profile of that phage. The availability of such non-pathogenic phage-production hosts will facilitate the purification process leading to a safer phage product [13]. "
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    ABSTRACT: Team1 (vB_SauM_Team1) is a polyvalent staphylococcal phage belonging to the Myoviridae family. Phage Team1 was propagated on a Staphylococcus aureus strain and a non-pathogenic Staphylococcus xylosus strain used in industrial meat fermentation. The two Team1 preparations were compared with respect to their microbiological and genomic properties. The burst sizes, latent periods, and host ranges of the two derivatives were identical as were their genome sequences. Phage Team1 has 140,903 bp of double stranded DNA encoding for 217 open reading frames and 4 tRNAs. Comparative genomic analysis revealed similarities to staphylococcal phages ISP (97%) and G1 (97%). The host range of Team1 was compared to the well-known polyvalent staphylococcal phages phi812 and K using a panel of 57 S. aureus strains collected from various sources. These bacterial strains were found to represent 18 sequence types (MLST) and 14 clonal complexes (eBURST). Altogether, the three phages propagated on S. xylosus lysed 52 out of 57 distinct strains of S. aureus. The identification of phage-insensitive strains underlines the importance of designing phage cocktails with broadly varying and overlapping host ranges. Taken altogether, our study suggests that some staphylococcal phages can be propagated on food-grade bacteria for biocontrol and safety purposes.
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    • "After serial passage on the two alternative hosts, the researchers observed a smaller burst size and longer rise period for the phage propagated on the heterologous E. coli host than on the homologous Salmonella host, but the lower cost of producing a safer phage product justified in their opinion these growth disadvantages . Notably, no difference in host range was observed between the phage propagated on the pathogenic Salmonella or non-pathogenic E. coli host (Santos et al., 2010). Propagation on a laboratory strain avoids biosafety production conditions and the risk of transfer of bacterial or prophage-encoded toxins (Canchaya et al., 2003) from the pathogenic host into the phage preparation. "
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    • "transfer of virulence or toxin genes to recipient cells via generalized transduction (Hagens and Loessner, 2010). Furthermore , it would simplify production and increase the safety of phage preparations (Santos et al., 2010). However, the narrow host range of the phages isolated in this study makes them useful for this proof of concept study but unsuitable as ''real world'' biocontrol candidates. "
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