Tomatoes from a produce supplier have tested positive for salmonella, but not the strain responsible for sickening dozens of people who ate at a convenience store chain, state health officials said Monday. The supplier of the Roma tomatoes, Wheeling, W.Va.-based Coronet Foods, said that tests turned up no contamination at its processing plant but it still would suspend purchasing and processing the tomatoes, which represent 1 percent of its line. Pennsylvania officials had believed that tainted tomatoes or lettuce, or both, were to blame, because those who got sick ate those foods and because they ingested a strain of salmonella usually found on produce.