文摘
GI-28 genotype represents a novel serotype and is endemic in various geographic locations in China. The novel type may have originated from recombination events and/or the result of accumulation of mutations and selections. The serotype is nephropathogenic, and has a broader tissue tropism (respiratory, digestive, urinary, and reproductive tracts) among chickens. The type is able to cause cystic oviducts which will likely induce the occurrence of false layers.