The origins of antibiotic resistance in humans may be far more complicated than the massive quantities of antibiotics used to stimulate the growth of farm animals or even an overreliance on old school drugs, not to mention pretty disgusting too.

Common house flies and cockroaches exposed to the feces of pigs treated with antibiotics to stimulate growth may also be responsible for spreading antibiotic resistance far beyond their farms. The proof can be found by comparing the gut bacteria of these insects and pigs.

After comparing both, researchers from Kansas State and North Carolina State Universities made a discovery that linked the same kinds of bacteria in pigs and insects with a greater prevalence of antibiotic resistance. Each harbored different members of digestive bacteria from the Enterococcus species. Two specific strains -- Enterococcus faecalis and Enterococcus faecium -- were resistant, not only to common antibiotics like streptomycin and tetracycline but to combinations of these drugs.

The huge worry isn't that humans will be exposed to drug-resistant bacteria from properly cooked sausage or bacon, says North Carolina State University's Dr. Coby Schal. What has experts concerned: The creation of superbugs that are increasingly difficult to fight with existing drugs.

BMC Microbiology January 26, 2011 Free Full PDF Study

Wired/Superbug January 28, 2011

The Daily Mail Online January 26, 2011

North Carolina State University Newsroom January 28, 2011

Physorg.com January 26, 2011