Objective: To determine anti-fungal susceptibility of Cryptococcus neoformans andCryptococcus gattii from environmental and clinical sources in Nairobi, Kenya.Design: Prospective study.Setting: Kenya Medical Research Institute, Mycology laboratory, Nairobi, Kenya.Subjects: A total of 123 isolates were tested for their susceptibility to fluconazole(FLC), amphotericin B(AMP) and fluorocytosine (5FC). Clinical isolates were 70(66Cryptococcus neoformans and 4 Cryptococcus gattii) while environmental isolates were53(41 C. neoformans and 12 C. gattii). The isolates were characterised using variousphenotypic tests including microscopic morphology, physiological and biochemicaltests (API 20 Caux), pigmentation on bird seed agar and reaction on canavanineglycine-bromthymolblue agar. European Committee on Anti-microbial SusceptibilityStandards (EUCAST) was used as the reference method for susceptibility testing.Results: Most C. neoformans isolates; clinical (61/66; 92.4%) and environmental (38/41;92.7%) were susceptible to FLC. The number of C. neoformans isolates inhibited atsusceptible dose dependent (SDD) range (16-32μg/ml) by FLC were clinical (4/66; 6.1%)and environmental (2/41; 4.9%). One C. neoformans isolate each; clinical (1/66; 1.5%)and environmental (1/41; 2.4%) was resistant to FLC. All C. gatti isolates from clinicaland environmental were fully susceptible to FLC. The percentage of C. neoformansisolates that were susceptible (S) (MIC ≤ 1.0 μg/ml) to AMP were; clinical(52/66; 90.2%)and environmental (37/41; 78.8%) while the rest were susceptible dose dependent(SDD) with MIC (2-8μg/ml). Reduced susceptibilities to 5FC was displayed in allclinical and environmental C. neoformans and C. gatii isolates; for instance resistanceto 5FC was reported in C. neoformans; clinical (8/66; 12.1%) and environmental (1/41;2.4 %). Among the C. gattii isolates there was also decreased susceptibility to 5FCwith Minimum Inhibition Concentration (MIC) range of between 0.5-32 μg/ml. Therewere no significant differences in susceptibility ranges among all the clinical andenvironmental isolates.Conclusion: This study demonstrated reduced susceptibilities among C. neoformansand C. gattii isolates to commonly used anti-fungal drugs
