Third strain of salmonella might be linked to outbreak

The state Department of Health has identified a third strain of salmonella bacteria that may be linked to Roma tomatoes served at Sheetz convenience stores that are believed to have sickened more than 400 people.

The health department said yesterday that its investigation suggests a third and rare strain of salmonella -- Salmonella thompson -- has been identified in about a dozen cases.

"This really doesn't change anything for the general public," said health department spokesman Richard McGarvey. "We feel the contaminated source -- tomatoes from Sheetz -- was eliminated very promptly."

No new cases of salmonella have been reported for nearly a month.

Nearly all of the 330 cases identified in Pennsylvania -- and more than 80 cases in other states -- were linked to the Salmonella javiana strain. Four cases were linked to the rare Salmonella anatum, the same strain as found on Roma tomatoes from one Sheetz store.

While interviews are continuing, McGarvey said "all of the indications" show that the dozen cases tied to the third strain are linked to tomatoes at Sheetz.

All of the cases being investigated date to July 10 or earlier, McGarvey said.

The U.S. Food and Drug Administration is trying to find the origin of the contamination, but that is a difficult process, McGarvey said.

"Hopefully, they will be able to identify it. Don't be surprised if they don't," he said.

Sheetz bought all of its sliced Romas from Coronet Foods, a Wheeling, W.Va., distributor that slices and dices produce. Ninety-nine percent of Coronet's sliced Romas went to Sheetz stores.