<prompt> A 20 years old male patient present to the STD clinic with a genital ulcer. The gram stain of the smear from ulcer shows gram negative coccobacilli. The most appropriate media for culture would be ?Thayer-Main MediumBlood agar with X V factorsChocolate agar with isovitate XTellurite blood agar  <response>: Ans. is c i.e., Chocolate agar with isovitale X . Genital ulcer with smear showing gram negative coccobacilli suggests diagnosis of chancroid caused by H. ducreyi. It is grown best from scraping of the ulcer base on chocolate agar containing 1 IsoVitale X and Vancomycin, 3 mgml and incubated in 10 CO2 at 33degC. - Jawetz 23e p. 281. H.ducreyi . It is Gram negative but often may appear Gram positive and frequently shows bipolar staining. . The bacilli may be arranged in small groups or whorls or in parallel chains giving a school offish or rail road track appearance. . Chocolate agar, enriched with isovitale X and fetal calf serum, and containing Vancomycin acts as a selective media. . It causes chancroid or soft Sore. . Chancroid - Painful, nonindurated irregular ulcer - Ulcers bleed easily - Enalarged, tender inguinal lymph node. . Diagnosis An accurate diagnosis of chancroid relies on cultures of H. ducreyi from the lesion. . Treatment - Single dose of azithromycin -- DOC - Ceftriaxone - Ciprofloxacin Alternatives. - Erythromycin 