A 30 year old woman with a bad obstetric history presents with fever. The blood culture from the patient grows gram-positive small to medium coccobacilli that are pleomorphic, occurring in sho chains. Direct wet from the culture shows tumbling motility. The most likely organism is -

. Ans. is 'a' i.e., Listera monocytogenes . The impoant clues in this question are . Organisms are gram positive coccobacilli . Organisms are pleomorphic and occuring in sho chains. . There is tumbling motility. . All these are the features of Listeria monocytogens. . Corynebacteria are gram positive bacilli (not coccobacilli) and are nonmotile. . Enterococci (group ' d' streptococci) are gram positive cocci (not coccobacilli) and are non motile.