id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-260145-grz0fe9l	Liu, Shengwang	Altered pathogenicity, immunogenicity, tissue tropism and 3′-7 kb region sequence of an avian infectious bronchitis coronavirus strain after serial passage in embryos	2009-07-23		.txt	text/plain	7486	366	51	title: Altered pathogenicity, immunogenicity, tissue tropism and 3′-7 kb region sequence of an avian infectious bronchitis coronavirus strain after serial passage in embryos In this study, we attenuated a Chinese LX4-type nephropathogenic infectious bronchitis virus (IBV) strain, CK/CH/LHLJ/04V, by serial passage in embryonated chicken eggs. At the age of 15 days, groups 1-4 were inoculated intranasally with 0.1 ml per chick containing 10 4.7 -10 4.8 median embryo infectious doses (EID 50 ) at passage level 3 of strains CH/CK/LHLJ/04V, CK/CH/LDL/04II, CK/CH/LXJ/02I and CK/CH/LSHH/03I. The CH/CK/LHLJ/04V strain was serially passaged 110 times by inoculating 9-day-old SPF chicken eggs by the allantoic cavity route as described previously [19] . Virus titrations were performed in 9-day-old embryonated chicken SPF eggs via the allantoic cavity route of inoculation, and titers were expressed as 50% (median) embryo infectious doses (EID 50 ) [9, 37] .	./cache/cord-260145-grz0fe9l.txt	./txt/cord-260145-grz0fe9l.txt