<prompt> Reactive arthritis is usually caused by -Shigella flexneriShigella boydiiShigela shigaShigela dysentriae  <response>: Ans. is a i.e.. Shigella Flexneri o Organisms that have been associated with Reiter Arthritis include the follow ing:C trachomatis L2b serotypeUreaplasma urealyticumNeisseria gonorrhoeaeShigella flexneriSalmonella enterica serovars TyphimuriumMycoplasma pneumoniaeMycobacterium tuberculosisYersinia enterocolitica and pseudotuberculosisCampylobacter jejuniClostridium difficileBeta-hemolytic example, group A and viridans streptococci 