Study of Cryptococcus neoformans var.gattii from Eucalyptus camaldulensis in some northern regions of Iran

Introduction: So far Eucalyptus camaldulensis is the only known environmental source o f Cryptoc oc cus neoformans var.gattii in Australi a. Bas ed upon the hypothesis th at Australian orig in E.camaldulensis trees could be a natural habitat for the C.neoformans var.gatti i in Iran as well, this study was performed on 380 E.camaldulensis. Materials and Methods: Trees grown and loc ated in Garmsar, Gonbad e Natural sources training center and Sadd-e- Ghaboos. Over a period of 23 months samples of stem bark (380), flowe rs (3 00) and fruits(80) were obtaincd. The supernatants of the sample suspensions were inoculated onto sabouraud dextrose agar and niger see d agar, incubated at 30°C for 7 days. The ide ntity of 138 isolates which produced blastoc onidia on cornmeal agar supplemented with twce n-80 based on the results obtained from using a battrey of morphological, biochemical and physiological tests including staining by lactophenol cotton blue and India ink technique, urease production and ass imilation te sts by AP I 20c Aux. Fin ally, canavanin glycine bromo tymol blue (GCB) a nd glycine cyclohexamid phenol re d (GCP) were used to distinguish C. neofo rma nsvarieties. Results: Ove ra ll , 2 of isolate s (one from Ga rrnsar and the other from Sadd-e- Ghabo os Voshmgir) were fo und to be C.neoformans var.gatt ii and 43 of isolates determined C.albidus and 36 of isol a tes de te rmined C.lau re nt ii a nd 57 of isol a te s dete rmined C.sp. Ni ger se ed aga rco ntaining 0. 1% glucose is used fo r rap id mel ani n production, con sequently C. neo fo rmans prod uce d dark-b rown colo nies and most st rain s o f C.laure nt ii turned niger seed agar to green and a few C.SP turned niger seed agar to blue. Al so 3 isolates of Henders onula to ruloidea were recovered from the Gonbade natural sources tra ining center. Conclusion: The results show that australian origin E.camaldulensis trees could be a natural habit at for the C.neoformans var.gatti i and this study also showed that GCB medium serves as an excellent tota l for the sepration of the two varieties of C.neoformans, but it is not use ful in detection of C.neo formans from C.laurentii.