A report, in BMC Microbiology, shows that antibiotic-resistant bacteria that are capable of producing life-threatening diseases could be originating from animal farms. Antibiotics are commonly used farms to promote the growth of animals. “The insects in the animal farms, including flies and cockroaches, are the major culprits," says Ludek Zurek, PhD, an associate professor of microbial ecology at Kansas State University, the lead researcher.
Pigs have been found to have a number of superbugs in their gut, and once they move from the farms, they may be spreading the bacteria to people, according to researchers. Thus, the insects are more than just a nuisance in the farms, as they are capable of spreading the bacteria from the pig manure to other places and people. These insects may move to the surrounding residential areas. “For example, some of the workers may accidentally carry the cockroaches to their house that can contaminate the foods and drinks because it has the resistant bacteria," says Zurek.
In this study, the researchers collected insects and pig fecal matter from a number of swine farms in North Carolina and Kansas. Back in the lab, they isolated the bacterial strains present in the fecal matter and compared them to the bacterial content in the gut of the insects. They observed that the bacterial matter in gut of the insects was a good match to the ones in the fecal matter. They analyzed almost 119 samples from pigs, 83 from cockroaches and 162 from flies. Out of the total samples researchers particularly studied two species, Enterococcus faecalis and Enterococcus faecium.
About 90% of the samples from the pigs, 94% of the samples from cockroaches and 98% of the samples from flies contained enterococci. These bacterial samples were then tested for antibiotic resistance against eight antibiotics used in human beings and animals. The antibiotic profile was also common between the pig samples and insects. The different samples were resistant to tetracycline, erythromycin, streptomycin and kanamycin.
The study does not prove that there is a direct link between bacteria found in the insects on the swine farms and human health. But Zurek feels that the potential risk is in the animal farms and hence the operators of the swine farms should try to reduce the entomological population in the farms.
According to Abigail Salyers, PhD, professor of microbiology at the University of Illinois-Urbana, the findings of the study echoes some of the earlier reports. Scientists are concerned because once the bacteria enter the gut of human beings it becomes a serious health issue. If the person gets an abdominal procedure, like an appendix removal or a colonoscopy, that accidentally makes a perforation in the colon, the presence of these antibiotic-resistant bacteria may make treatment difficult. Abigail explains that this risk is not yet completely proved and is still a theoretical concern.