BBC reported that it found the bacteria in three of 10 Starbucks iced drink samples it tested for a TV program that will air Wednesday in Britain.
Three of 10 Caffe Nero drinks also had the bacteria, as well as seven of 10 Costa Coffee drinks tested.
Starbucks told BBC it would conduct its own investigation into the claim.
Clint Davis covers entertainment and trending news topics for the Scripps National Desk. Follow him on Twitter @MrClintDavis. Keep up to date with the latest news by following @ScrippsNational on Twitter.