id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-299428-gon6bzat	Mondal, Shankar	Sequence analysis of infectious bronchitis virus isolates from the 1960s in the United States	2012-10-11		.txt	text/plain	3262	152	56	To better understand the molecular epidemiology of infectious bronchitis virus (IBV) in the United States following the introduction of commercial IBV vaccines, we sequenced the S1 and N structural protein genes of thirteen IBV field isolates collected in the 1960s. Analysis of the S1 sequence showed that seven isolates were of the Massachusetts (Mass) genotype, five were SE17, and one was of the Connecticut (Conn) genotype, suggesting that these three IBVs were circulating in commercial poultry raised in different regions in the United States during the 1960s. In addition, the Mass-type isolates had high levels of sequence identity in the S1 gene compared with widely used modified live vaccines (Mass41, Ma5 and H120) and modern field strains from the USA and other countries, suggesting a common ancestor.	./cache/cord-299428-gon6bzat.txt	./txt/cord-299428-gon6bzat.txt