Are You Eating Bacteriophages for Dinner?
Bacteriophages – also called phages – are viruses that help bacteria transport genetic instructions to other bacteria long after the bacteria die.
Bacteria often use phages to transmit their legacies on to future generations, along with specific instructions on how to kill off enemies or survive in challenging environments.
They also have been known to pass on specific-specific antibiotic substance production. For this reason, scientists have begun to utilize phages to help kill bacteria in antibiotic resistant scenarios.
The dark side of bacteriophages – and factory farms
However, there is also a dark side of bacteriophages. They can also transmit a bacteria colony’s ability to resist a particular antibiotic or a host of antibiotics.
A new study from researchers from the University of Vienna in conjunction with UK and Australian researchers has determined that up to half of the chicken meat in Australian supermarkets are infected with phages that transmit antibiotic resistance to other bacteria.
The researchers purchased 50 random samples of chicken from supermarkets. From these 50 samples, they isolated 243 bacteriophages. Of the chicken samples tested, 44 percent hosted phages that contained antibacterial resistance.
About a quarter of those phages could transmit antibiotic resistance to E. coli bacteria. The rest of the phages were able to transmit antibacterial resistance to other bacteria.
Some of the more notable antibiotic-resistances found were to kanamycin, chloramphenicol, tetracycline and ampicillin.
A leading researcher of the study, Friederike Hilbert, DVM, had this to say about the study:
“Our work suggests that such transfer could spread antibiotic resistance in environments such as food production units and hospitals and clinics.”
Bacteriophage research has only recently revealed phages as a major source of antibiotic resistance transmission.
“New information from the sequencing of bacterial DNA has shown that transduction must be a driving force in bacterial evolution, and thus, quite common,” added Dr. Hilbert.
Dr. Hilbert is a professor at the University of Veterinary Medicine in Vienna.
This research comes on the heels of another study we reported on that found antibiotic-resistant E. coli was found in a surprising number of chicken sold within the U.S. That research is discussed in this article.
This discussed not only the transmission of antibiotic resistant E. coli, but the leading cause of urinary tract infections. This is more specifically known as an ESBL-positive E. coli. ESBL stands for extended-spectrum beta-lactamases. Beta-lactamases are enzymes that break down various strategies to kill off the bacteria. It makes these types of E. coli infections particularly difficult to shake.
Phage therapy brought into question
For many years, Russia, France and a few other countries have allowed the use of phages to fight antibiotic resistant bacteria infections. The phages are developed in laboratories from colonies of bacteria, and used to transmit a sort of kill switch to other bacteria via the virus.
Phage therapy has been riddled with a low cure rate – of 50 percent or lower. This may be due to many phages specificity with regard to specific strains. This means that a phage produced by particular species of bacteria may only treat that particular strain of bacteria.
As a result, phage treatments typically utilize a cocktail of different phages, from different species and strains of bacteria. This is sorta like throwing 50 darts towards a dartboard and hoping that one hits the bullseye.
Phages sprayed onto U.S. foods?
Increasingly, phages are being sprayed onto many foods and food plant equipment now, including cheese, meat, fruits and vegetables. In September of 2006, the U.S. FDA quietly legalized the spraying of bacteriophages by food producers – meaning agribusinesses. Listex is one of the most popular – a combination of six bacteriophages intended to kill Listeria bacteria.
The problem this brings up is whether these phage cocktails will interfere with our intestinal probiotics.
Do Bacteriophages interfere with our gut probiotics?
Research has determined that practically every bacteria – even probiotics – product phages. These have the effect of controlling populations of bacteria, allowing for a natural diversity within the gut.
So what happens when new bacteriophages are released into the gut? Research has yet to determine precisely what effect additional phages – phage cocktails so to speak – will have upon our gut microbiology. Surely they will affect it somehow.
The moral of the story at least for now is that certain foods – especially those from factory farms that have had a history of overusing antibiotics in animals – are likely to harbor either antibiotic-resistant bacteria or their bacteriophages that pass on antibiotic resistance to other bacteria that were not antibiotic-resistant before.
And the use of bacteriophages as antimicrobial medicines – or food sprays – is potentially playing with fire as we don’t know what the long term effects of this will be.
This reminds us of the pandora’s box that we opened in the first place in the form of antibiotic medicines – which have spawned giga-armies of antibiotic-resistant superbugs: It took a couple of decades for researchers to confirm that antibiotics were creating superbugs. Now it looks like modern science is on its way towards creating super-phages.
Shousha A, Awaiwanont N, Sofka D, Smulders FJ, Paulsen P, Szostak MP, Humphrey T, Hilbert F. Bacteriophages isolated from chicken meat and the horizontal transfer of antimicrobial resistance genes. Appl Environ Microbiol. 2015 May 1. pii: AEM.00872-15.
ASM Society. PHAGE SPREAD ANTIBIOTIC RESISTANCE. May 12, 2015
Ventura M, Sozzi T, Turroni F, Matteuzzi D, van Sinderen D. The impact of bacteriophages on probiotic bacteria and gut microbiota diversity. Genes Nutr. 2011 Aug;6(3):205-7. doi: 10.1007/s12263-010-0188-4.
Nobrega FL, Costa AR, Kluskens LD, Azeredo J. Revisiting phage therapy: new applications for old resources. Trends Microbiol. 2015 Apr;23(4):185-91. doi: 10.1016/j.tim.2015.01.006.