PHILADELPHIA (CBS) – Pop the top of your favorite drink: a soda, a beer or an energy drink. Americans consume millions of canned beverages.

But did you know you could be getting a sip of Bacillus? How about some Pseudomonas luteola? Or a splash of Staphylococcus?

An investigation found nearly a dozen germs lurking on the tops of 20 drink cans that were inside grocery stores, gas stations, restaurants and vending machines.

“I really wasn’t expecting these to be as bad as they actually are,” said Karen Deiss, a microbiologist.

She found black furry mold on a can from a corner store, and yeast on an energy drink from a vending machine.

And there was some Pseudomonas aeruginosa growing on a can from a vending machine. That’s a bacteria that can cause skin or ear infections, typically associated with dirty hot tubs.

Testing also showed Enterobacter cloacae, that’s something usually found in toilets.

“Something from the rectum would be the better way to describe it. I mean it’s Coliform, so it’s something that lives in human and animal large intestines,” said Dr. Cedric Spak, an infectious disease specialist.

The investigation found the dirtiest cans came from store and gas station shelves.

“We see bacteria on everything,” said Connie Cutler, director of infection prevention for Main Line Health.

She says the kind of germs found on drink cans is usually only dangerous for people with compromised immune systems.

“Thankfully our bodies have good immune systems, the majority of us, and so we can tolerate a certain amount of bacteria,” said Connie.

It’s not clear when or how the cans became contaminated with the germs. The American Beverage Association says manufacturers’ packaging meets and often exceeds all government health standards.

And it says, “… consumers should take reasonable care to ensure the packaging has not been damaged or soiled once in the marketplace.”

And if you really want to avoid bacteria, wiping off the can will get rid of most germs; to the point where even Connie, the germ police, will drink from a can.

In case you’re wondering, the investigation also found the cleanest cans tested were in 12-packs.