Federal food authorities said they’re investigating a growing E. Coli outbreak this month tied to Raw Farm, a dairy farm in Fresno commonly described as the country’s largest raw dairy producer. But the company is fighting the claims, saying officials have provided no proof that their products are to blame. The U.S. Food and Drug Administration said last week the California farm’s raw cheddar cheese has now given the digestive bacteria to nine people across three states — seven of whom are in