id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-306976-p2521bl4	Gao, Mengying	Serotype, antigenicity, and pathogenicity of a naturally recombinant TW I genotype infectious bronchitis coronavirus in China	2016-08-15		.txt	text/plain	5087	232	57	Furthermore, neither the vaccine strains nor the attenuated viruses could provide complete respiratory protection of chickens against a challenge with the ck/CH/LDL/140520 strain, indicating that it is necessary to develop new live vaccines or to evaluate the use of established vaccines in combination to control naturally recombinant TW I-type IBV strains in the future. Our results showed that strain ck/CH/LDL/140520 is very pathogenic, and that it is able to cause cystic oviducts in a high percentage of birds, as well as mortality due to nephritis and respiratory distress with complete tracheal ciliostasis, especially in chickens infected at 1 day of age. In contrast, respiratory signs (sneezing, nasal discharge, and tracheal rales) developed at 3-4 dpc and lasted until 10 dpc in some of the chickens in the groups that were vaccinated with the H120, 4/91, and Conn vaccines, and the attenuated LSD/120720 and LGX/ 100508 viruses when challenged with the nrTW I IBV strain at 20 days of age.	./cache/cord-306976-p2521bl4.txt	./txt/cord-306976-p2521bl4.txt