title: Synergism between avian infectious bronchitis virus and Haemophilus gallinarum.
mesh_terms: D000818:Animals; D006190:Haemophilus / Q000472:pathogenicity*; D011201:Poultry Diseases / Q000473:pathology*; D012141:Respiratory Tract Infections / Q000473:pathology / Q000662:veterinary*; D014713:Viruses, Unclassified / Q000472:pathogenicity*