<prompt> Reactive ahritis is usually caused byShigella flexneriShigella boydiiShigela shigaShigela dysentriae  <response>: Ans. is a i.e., Shigella Flexneri Organisms that have been associated with ReiterAhritis include the following: C trachomatis L2b serotype Ureaplasma urealyticum Neisseria gonorrhoeae Shigella flexneri Salmonella enterica serovars Typhimurium Mycoplasma pneumoniae Mycobacterium tuberculosis Yersinia enterocolitica and pseudotuberculosis Campylobacter jejuni Clostridium difficile Beta-hemolytic example, group A and viridans streptococci 