[1] Vanderbilt Univ, Sch Med, Div Gastroenterol, Dept Med, Nashville, TN 37232 USA
[2] Vanderbilt Univ, Sch Med, Dept Med, Div Infect Dis, Nashville, TN 37232 USA
[3] Dept Vet Affairs Med Ctr, Med Serv, Nashville, TN 37212 USA
[4] Cleveland Clin Fdn, Dept Gastroenterol, Cleveland, OH 44195 USA
[5] Cleveland Clin Fdn, Dept Pathol, Cleveland, OH 44195 USA