NEW : Romaine lettuce is expanded to Vaughan Foods in Oklahoma . May : Vaughan says it has 100 customers who want the lettuce . NEW : A student sues Freshway Foods , which was involved in earlier recall .
NEW : Romaine lettuce recall expanded to Vaughan Foods in Oklahoma . NEW : Company says it has informed customers who purchased the lettuce . NEW : Sickened student sues Freshway Foods , which was involved in earlier recall .