A Yersinia pestis-specific, lytic phage preparation significantly reduces viable Y. pestis on various hard surfaces experimentally contaminated with the bacterium

Abstract

Five Y. pestis bacteriophages obtained from various sources were characterized to determine their biological properties, including their taxonomic classification, host range and genomic diversity. Four of the phages (YpP-G, Y, R and YpsP-G) belong to the Podoviridae family, and the fifth phage (YpsP-PST) belongs to the Myoviridae family, of the order Caudovirales comprising of double-stranded DNA phages. The genomes of the four Podoviridae phages were fully sequenced and found to be almost identical to each other and to those of two previously characterized Y. pestis phages Yepe2 and φA1122. However, despite their genomic homogeneity, they varied in their ability to lyse Y. pestis and Y. pseudotuberculosis strains. The five phages were combined to yield a “phage cocktail” (tentatively designated “YPP-100”) capable of lysing the 59 Y. pestis strains in our collection. YPP-100 was examined for its ability to decontaminate three different hard surfaces (glass, gypsum board and stainless steel) experimentally contaminated with a mixture of three genetically diverse Y. pestis strains CO92, KIM and 1670G. Five minutes of exposure to YPP-100 preparations containing phage concentrations of ca. 109, 108 and 107 PFU/mL completely eliminated all viable Y. pestis cells from all three surfaces, but a few viable cells were recovered from the stainless steel coupons treated with YPP-100 diluted to contain ca. 106 PFU/mL. However, even that highly diluted preparation significantly (p = < 0.05) reduced Y. pestis levels by ≥ 99.97%. Our data support the idea that Y. pestis phages may be useful for decontaminating various hard surfaces naturally- or intentionally-contaminated with Y. pestis.

Engineering Modular Viral Scaffolds for Targeted Bacterial Population Editing

“…We hypothesized that these differences could be responsible for their divergent host ranges. Indeed, we were unable to detect productive T3 infection of Y. ptb strains IP2666 and YPIII, which are known hosts for phage R (Rashid et al, 2012). Because we did not have access to phage R, we introduced the desired mutations in T3 gene 17 by PCR so that it would encode the same tail fiber as phage R (Figure 4A).…”

Engineering Modular Viral Scaffolds for Targeted Bacterial Population Editing

“…We introduced these three mutations in T3 gene 17 by PCR so that it would encode the same tail fiber as phage R (Figure 4A). While T3 did not plaque on Y. ptb strains IP2666 and YPIII, which are known hosts for phage R (Rashid et al, 2012), synthetic T3 phage with the R tail fiber (T3 R(gp17) ) was able to infect Y. ptb IP2666 and YPIII (Figure 3 and Figure S2). The adsorption efficiencies of T3 WT and T3 R(gp17) against Y. ptb IP2666 were found to be 0.01±0.01% and 90.05±1.1%, respectively.…”

Salmonella Phages and Prophages: Genomics, Taxonomy, and Applied Aspects

“…Recently, using lytic bacteriophages to remove specifi c foodborne and non-foodborne bacterial pathogens from hard surfaces has been gaining increased attention. For example, some studies have focused on determining the efficacy of phages targeting some major foodborne bacterial pathogens, such as Listeria monocytogenes [ 235 , 236 ] and E. coli O157:H7 [ 237 , 238 ], as well as some non-foodborne pathogens of high bioterrorism concern [ 239 ]. Also, a phage-based preparation (ListShield™) was recently granted registration by the U.S. Environmental Protection Agency (EPA) as an antimicrobial for signifi cantly reducing L. monocytogenes contamination of nonfood-contact surfaces in food processing plants and food handling establishments (EPA Registration # 74234-1).…”