<prompt> School of fish appearance is seen in?Bacterial vaginosisHemophilus DucreyiGonococcusChlamydia  <response>: Ans. b Hemophilus DucreyiRef: Harrison 19th ed. 1012 School of fish appearance stained smear from genital lesions in cases of chancroid. Causative agent of chancroid is Hemophilus ducreyi. H. Ducreyi a major cause of genital ulceration in developing countries characterized by painful sores on the genitalia. Another early symptom is dark or light- green shears in excrement. Chancroid starts as an erythematous papular lesion that breaks down into a painful bleeding ulcer with a necrotic base and ragged edge. H. ducreyi can be cultured on chocolate agar 