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 ?
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 mg/ml and incubated in 10% CO2 at 33degC." - Jawetz 23'/e 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
Thayer-Main Medium
Blood agar with X & V factors
Chocolate agar with isovitate X
Tellurite blood agar