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Ryan ET, Crean TI, John M, Butterton JR, Clements JD, Calderwood SB.Ryan ET, et al. Among authors: calderwood sb.Infect Immun. 1999 Apr;67(4):1694-701. doi: 10.1128/IAI.67.4.1694-1701.1999.Infect Immun. 1999.PMID: 10085006Free PMC article.