Which of the following are difficult to isolate from culture:

Ans. (d) Malassezia furfur Ref. Harrison 17/e, p 1263, 18/e, p 1669 Malassezia furfur (causative agent of Tinea versicolor) were not usually cultured in the clinical laboratory. Cryptococcus, candida, dermatophytes and Coccidiodes are culturable. Note: Now most epecies can be cultured by adding exogenous lipid in the medium. Other impoant feature of Malassezia: Pa of normal flora of human skin. Lipophilic yeast and require lipid in the medium for growth. Causative agent of Tinea versicolor and catheter associated sepsis (paicularly in infants receiving IV lipid). Diagnosis is confirmed by direct microscopic examination of scrappings of infected cells treated with 10-12% KOH with calcoflour white: sho unbranced hyphae and spherical cells are observed. On inspection with woodlight lesion either do not fluoroscence or appear yellow green.