Phage Therapy in Agriculture and Animal Husbandry
It may surprise many people just how important that the study of Bacteriophages and the implementation of Phage Therapy in the growing of crops, and in looking after animals or even fish, as like all living things they take the same risks as we do, and can infect us, or ev en wipe out civilisations with huge crop failures.The following article deals the following important issues, among many others.
1) Phage to control plant diseases such as bacterial spot on tomatoes and Erwinia infections of fruit trees (fire blight) and root crops (soft rot).
2) Phage to treat animal disease such as E. coli respiratory infections in chickens, furunculosis (Aeromonas salmonicida) in fish, and mastitis in cattle.
3) Phage to control human food-borne pathogens, such as Salmonella in fowl and Escherichia coli O157:H7 in cattle, and Listeria during food processing.
Phage Therapy: new methods for the potential eradication of E. coli O157 in livestock.
Andrew Brabban1, Raul Raya1,
Todd Callaway2, and
Since the advent of antibiotics, both the health care and agriculture sectors have relied heavily on them to control bacterial pathogens. However, increasing levels of antibiotic resistance have reduced the efficacy of many current therapies, prompting legislation that has reduced the use of antibiotics in animals. This has led researchers to seek fresh ideas. Bacteriophage therapy is one “old” idea undergoing a renaissance, with the potential to resolve the antibiotic predicament we find ourselves in today. Lytic bacteriophages are viruses that attach to specific bacterial surface receptors, inject their DNA, and express genes that lead to the synthesis of new phages. The process ends with the programmed lysis (death) of the host and the release of dozens or hundreds of new phages. The use of phages as antimicrobial agents has a number of advantages over other methods. Phages are highly specific allowing for the removal of the targeted microorganisms from a mixed population. Unlike antibiotics that decay over time and distance, phage numbers actually increase working their way deeper into pockets of infestation. Further phage are living entities that adapt and evolve. As phage can also pass from host to host, they have the potential to establish an infectious cure. Interest in agricultural applications is now rapidly expanding in 3 major areas;
1) Phage to control plant diseases such as bacterial spot on tomatoes and Erwinia infections of fruit trees (fire blight) and root crops (soft rot).
2) Phage to treat animal disease such as E. coli respiratory infections in chickens, furunculosis (Aeromonas salmonicida) in fish, and mastitis in cattle.
3) Phage to control human food-borne pathogens, such as Salmonella in fowl and Escherichia coli O157:H7 in cattle, and Listeria during food processing.
Today I will talk about our most recent efforts to control Escherichia coli O157:H7; a pathogen that can produce severe diarrhea, kidney damage and death in humans. In the U.S., >70,000 illnesses and 60 deaths are reported yearly with most cases traced back to livestock contamination - drinking water, milk, produce or ground beef.. Livestock show no signs of illness and the levels are generally low, making contaminated animals hard to identify. We have developed a promising way of reducing O157:H7 concentrations in livestock through bacteriophages CEV1, CEV2 and CEV3. Phage CEV1 was isolated from the feces of sheep resistant to gastrointestinal colonization by O157:H7 strains that had previously been used as standard gut colonizers. Phages CEV1 and CEV2 infect >90% of the O157:H7 strains tested, and a small number other strains. Preliminary trials of CEV1 and CEV2 to evaluate their use as a potential management strategy in vitro and in vivo have been highly successful. In model systems reflecting the cow/sheep gut, CEV1 eliminated the two virulent 0157:H7 strains in 11 days. Initial animal studies have shown the phage have great promise as an orally administered treatment; treated sheep showed a substantial reduction in intestinal levels of O157:H7 in with a single dose of CEV1 within 2 days. Further reduction was seen with a cocktail of CEV1 and CEV2, as well as in those sheep naturally carrying phage CEV2. These results indicate the protective effect of bacteriophages against E. coli O157:H7. We hope this approach will significantly contribute to the important job of creating a safer human food supply for the 21st Century.
Dr. Andrew D. Brabban, Lab I, The Evergreen
Love Me Love My Phages
