(UPDATED, July 22, 10:29 a.m.) The Food and Drug Administration finally might have found the clue it’s been looking for.

David Acheson, FDA’s associate commissioner for foods, said July 21 that a jalapeño pepper in a McAllen, Texas, distribution center has tested positive for Salmonella Saintpaul.

Acheson called the sample taken from Agricola Zaragoza Inc. “a significant break” in an outbreak investigation that started May 31.

Acheson said other product samples and environmental samples taken from the Texas facility had tested negative and stressed that the distributor had not been pinpointed as the source of the outbreak. He said the investigation still is ongoing.

Acheson said the jalapeños were sourced from Mexico but did not name a grower or packer.

Agricola Zaragoza is recalling jalapeños shipped since June 30. The FDA said in a news release that the jalapeños were distributed in 35-pound reusable plastic containers and in 50-pound bags with no brand or label.

Public health officials initially linked a multistate outbreak to tomatoes in May, and Robert Tauxe, deputy director of the CDC's Division of Foodborne, Bacterial and Mycotic Diseases, said tomatoes have not been exonerated and still were under investigation.

Acheson, however, said that tomatoes currently in distribution are safe to eat.

He said FDA is advising consumers nationwide not to eat fresh jalapeños or products that include the peppers. The advisory applies to domestic products as well as imports. FDA also is advising consumers in high-risk groups, such as infants, the elderly and people with impaired immune systems, to avoid eating fresh serrano peppers or foods that contain those peppers.

Spokespeople for Publix Super Markets Inc., Lakeland, Fla., and Wegmans Food Markets Inc., Rochester, N.Y., said the retailers had removed jalapeños from their shelves following the FDA advisory.

Meanwhile, Steve Solomon, deputy director of FDA’s office of regional operations, said jalapeños, serrano peppers and avocados recalled July 17 by Hidalgo, Texas-based Grande Produce because of possible salmonella contamination, were not part of the outbreak. Solomon said those products had tested positive for a different strain of salmonella.

Tauxe said the outbreak has resulted in 1,251 reported illnesses in 43 states, Washington, D.C., and Canada. There have been at least 229 hospitalizations. The most recent onset date of a reported illness is July 4.