A 29 year old sexually active male presents with burning micturition. On clinical examination no ulcer is seen in the genitals. Urine examination shows 50 WBCs/HPF, no RBC's, leucocyte esterase positive, gonococcal culture negative. What could be the MOST probable causative organism?
Treponema pallidum Neisseria gonorrhea Chlamydia trachomatis H. ducreyi