11,13,15 Hafez, part 2

11 Mycoplasmas have affected poultry production for many years and effective control of mycoplasma infection has been a fundamental stepping stone to improved performance and productivity. However, infections appear to be making a comeback. Numerous species of mycoplasmas have been isolated from avian sources. Two species are recognised as predominantly pathogenic to chickens and turkeys. Mycoplasma gallisepticum (MG) affects the respiratory system and is referred to as chronic respiratory disease (CRD) in chickens, and infectious sinusitis in turkeys. Mycoplasma synoviae (MS) may cause either respiratory diseases and/or joint diseases. Two additional species are known to be pathogenic to turkeys. Mycoplasma meleagridis (MM) causes airsacculitis, and Mycoplasma iowae (MI) causes decreases in hatchability. Mycoplasmas are the smallest self replicating procaryotic organisms. They have no cell wall but are bounded by a triple layered plasma membrane which is composed mainly of lipids and proteins.