The viruses in question are bacteriophages. These are viruses that infect and replicate within a bacterium. They function like molecular factories, churning out copies of themselves. Phages are the most common viruses found on the planet. A new study has found that a high level of phages have been found in chicken products.
Phages work by transferring and replicating genetic information. One thing they also do is transfer genes from one bacterium to another. The sample of phages from chicken showed that one quarter of the isolated viruses were able to transfer one or more antibiotic resistant genes between bacteria. This means that bacteria that were not ordinarily resistant to antibiotics could become so (something called ‘acquired resistance.’) This discovery has come about through recent advances in molecular microbiological methods. The most commonly isolated phage was called coliphage and the bacterium where it was found to confer resistance most often was Escherichia coli. E. coli has been the cause of many food poisoning outbreaks.
Some phages were found to contain genes that were resistant to a number of common antibiotics, and these can be transferred into host bacteria. These included tetracycline, ampicillin, kanamycin, and chloramphenicol. Researchers are concerned that this represents a mechanism for the spread of antibiotic resistance that has not received sufficient attention. Hitherto, many scientists did not think that phages were a major source of conferring antibiotic resistance to bacteria. The finding suggests that alternative control measures are needed.
In terms of general control measures, a rethink may be needed in terms of controlling contamination for meat processing areas. Many phages, for instant, are resistant to disinfectants of the sort used to clean down food factories.
It should be stressed that the presence of phages do not present a risk to human health. However, with the presence of bacteria in chicken it remains that chicken products should always be correctly heated. With the phages, the key issue is with the finding of a new mechanism that explains the rise of antibiotic resistant bacteria within the community.
The findings have been published in the journal Applied and Environmental Microbiology. The research paper is headed “Bacteriophages isolated from chicken meat and the horizontal transfer of antimicrobial resistance genes.”
