This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Reactive ahritis is caused by: 
Select and explain. 
A. Staphylococcus, B. H. influenzae, C. N. gonorrhoe, D. C. trachomatis
D: C. trachomatis
Answer: D: C. trachomatis 
Explanation: Ans. (d) C. trachomatis Ref CMDT 2014, p 825 Reactive ahritis (formerly called Reiter syndrome) is the clinical tetrad of uretheritis, conjunctivitis (or uveitis), mucocutaneous lesions and aseptic ahritis. Most cases develop within days weeks after either a dysenteric infection or urogential infection. GI Urogenital Shigella Chlamydia trachomatus Salmonella Ureoplasma urealyticum Yersina Compylobacter Associated infection: Ahritis is most commonly assymetric, and frequently involves the large joints (most commonly ankle and knee); Sacroiliatis and ankylosing spondylitis is observed in atleast 20% of patients; especially after frequent recurrences.