>> we are finding the same or related e. coli in human infections and retail meat sources chicken. >> reporter: top researchers have strong evidence of a link between the disease and chicken super bug. the grocery store meat carrying the same e. coli strain as the resistant strain causing painful and long-lasting bladder infections. same dna fingerprint. a writer for the food and environment reporting net work interviewed researchers as part of a joint investigation with abc news. >> when they looked at the infections and they looked at bacteria in the animals and looked at bacteria on the meat they all matched. >> reporter: and this is no ordinary infection. >> i couldn't function fully for -- for weeks. almost a month. >> reporter: the superbug hangs on longer, resisting antibiotics and comes back repeatedly as it did with atlanta's dory brigs.