Patient with leakage of fluid and meconium stained liquor at 34 weeks of gestation is suffering from preterm premature rupture of membrane (PROM). Infections play a major role in the premature rupture of membrane. Most commonly found organisms were trichomonas vaginalis, Chlamydia trachomatis, mycoplasma, group B streptococci and other bacteria. From the options listed in the question only listeria monocytogens is a bacteria, so it is the cause of PROM in this patient. Ref: Harrison's Principles of Internal Medicine, 17th Edition, Page 897; Williams Obstetrics, 23rd Edition, Page 163, 1224; Textbook of Obstetrics By Padubidri, 1st Edition, 2006, Page 126; Avery's Diseases of the Newborn, 8th Edition, Page 556, 557