State health officials say a Yellowstone County case of the bacterial disease Listeriosis has been linked to a cluster of cases in six other states that is possibly tied to cantaloupes grown in Colorado.

The Department of Public Health and Human Services said Wednesday that further tests are being done to determine if a Gallatin County case is also linked.

Federal health officials issued a warning for cantaloupes grown in the Rocky Ford region of Colorado as a bacterial outbreak was blamed for four deaths in New Mexico and illnesses in that state along with Colorado and four other states.