(CBS) Lemon wedges at bars and restaurants may be packing more than just a zesty citrus punch; they could be putting unwanted bacteria into your drink.

Add lemon to your drink and you could be adding more than just flavor — bacteria that could make you sick, like E-coli.

It's exactly what microbiologist Anne LaGrange Loving found when she decided to test lemon wedges.

"I don't need a schmear of feces with my food, I would characterize that as pretty disgusting,” she said.

In her recently published study, Loving tested 76 lemon slices from 21 different restaurants. Nearly 70 percent of those lemons had bacteria.

Loving found not just fecal organisms, but a virtual bath of bacteria, including organisms from skin and saliva.

"I was frankly very surprised because lemon is known to be antibacterial,” Loving said.

So how does all that bacteria get there in the first place? Servers’ dirty fingers or dirty cutting boards are possible sources.

"I've been studying [germs] for 40 years,” said Dr. Philip Tierno, a renowned germ expert at New York University Medical Center.

He said unless you have a compromised immune system, this bacteria probably won't hurt you.

So people should still order lemon in their drinks and feel OK about it?

"Well, I don't know if they're going to feel OK about it after this study, but certainly it's a very low risk of getting an infection,” Dr. Tierno said. “[But] the possibility is there.”

And that has some saying hold the lemon, please.

You should refuse a drink if you see someone use their bare hands to grab your lemon slice. Servers should be wearing gloves or use tongs.

This study tested lemons that came with water and soda.

If you are wondering about alcoholic drinks, a germ expert says the alcohol in beer, wine and mixed drinks won't kill off the germs. But something like vodka on the rocks might do it.