Bacteriophage cocktail significantly reduces or eliminates Listeria monocytogenes contamination on lettuce, apples, cheese, smoked salmon and frozen foods

Moon

et al. 2017

Sci Rep

134

115

Discovery of clustered, regularly interspaced, short palindromic repeats and the Cas9 RNA-guided nuclease (CRISPR/Cas9) system provides a new opportunity to create programmable gene-specific antimicrobials that are far less likely to drive resistance than conventional antibiotics. However, the practical therapeutic use of CRISPR/Cas9 is still questionable due to current shortcomings in phage-based delivery systems such as inefficient delivery, narrow host range, and potential transfer of virulence genes by generalized transduction. In this study, we demonstrate genetic engineering strategies to overcome these shortcomings by integrating CRISPR/Cas9 system into a temperate phage genome, removing major virulence genes from the host chromosome, and expanding host specificity of the phage by complementing tail fiber protein. This significantly improved the efficacy and safety of CRISPR/Cas9 antimicrobials to therapeutic levels in both in vitro and in vivo assays. The genetic engineering tools and resources established in this study are expected to provide an efficacious and safe CRISPR/Cas9 antimicrobial, broadly applicable to Staphylococcus aureus.

Section: Discussionmentioning

confidence: 99%

Genetic engineering of a temperate phage-based delivery system for CRISPR/Cas9 antimicrobials against Staphylococcus aureus

Moon

et al. 2017

Sci Rep

134

115

“…This life cycle makes them ideal genetic engineering candidates to selectively eliminate strains or transfer specific genes in microbial populations. Indeed, natural phages have been used to limit growth of undesirable or pathogenic bacteria in humans [41], agriculture [42], food processing [43], and aquaculture [44]. Phages have been further genetically engineered to deliver specific DNA payloads or to alter host specificity.…”

Section: Contemporary Methods For In Situ Microbiome Engineeringmentioning

confidence: 99%

Manipulating Bacterial Communities by in situ Microbiome Engineering

et al. 2016

Microbial communities inhabit our entire planet and play a crucial role in biogeochemical processes, agriculture, biotechnology, and human health. Here, we argue that “in situ microbiome engineering” represents a new paradigm of community-scale genetic and microbial engineering. We discuss contemporary applications of this approach to directly add, remove, or modify specific sets of functions and alter community-level properties in terrestrial, aquatic, and host-associated microbial communities. Specifically, we highlight emerging in situ genome engineering approaches as tractable techniques to manipulate microbial communities with high specificity and efficacy. Finally, we describe opportunities for technological innovation and ways to bridge existing knowledge gaps to accelerate the development of in situ approaches for microbiome manipulations.

“…Phages were not inactivated before enumeration; previous studies have shown that there are no significant differences among results with and without phage inactivation. 26,27 Statistical analysis…”

Section: Salmonella Challenges On Turkeymentioning

confidence: 99%

Bacteriophages safely reduceSalmonellacontamination in pet food and raw pet food ingredients

et al. 2016

Self Cite

Contamination of pet food with Salmonella is a serious public health concern, and several disease outbreaks have recently occurred due to human exposure to Salmonella tainted pet food. The problem is especially challenging for raw pet foods (which include raw meats, seafood, fruits, and vegetables). These foods are becoming increasingly popular because of their nutritional qualities, but they are also more difficult to maintain Salmonella-free because they lack heat-treatment. Among various methods examined to improve the safety of pet foods (including raw pet food), one intriguing approach is to use bacteriophages to specifically kill Salmonella serotypes. At least 2 phage preparations (SalmoFresh Ò and Salmonelex TM ) targeting Salmonella are already FDA cleared for commercial applications to improve the safety of human foods. However, similar preparations are not yet available for pet food applications. Here, we report the results of evaluating one such preparation (SalmoLyse Ò ) in reducing Salmonella levels in various raw pet food ingredients (chicken, tuna, turkey, cantaloupe, and lettuce). Application of SalmoLyse Ò in low (ca. 2-4£10 6 PFU/g) and standard (ca. 9£10 6 PFU/g) concentrations significantly (P < 0.01) reduced (by 60-92%) Salmonella contamination in all raw foods examined compared to control treatments. When SalmoLyse Ò -treated (ca. 2£10 7 PFU/g) dry pet food was fed to cats and dogs, it did not trigger any deleterious side effects in the pets. Our data suggest that the bacteriophage cocktail lytic for Salmonella can significantly and safely reduce Salmonella contamination in various raw pet food ingredients.