Chicago-based tortilla maker Azteca Foods Inc. last week agreed to federal mediation to resolve a five-month strike by workers represented by Local 1159 of the United Electrical, Radio and Machine Workers of America, say union and company officials. The decision follows calls by U.S. Reps. Luis Gutierrez, D-Chicago, and Janice Schakowsky, D-Evanston, for Azteca to accept mediation. Meeting dates had not been set as of deadline. The plant has continued to operate during the strike.