Candidemia and the susceptibility pattern of Candida isolates in blood

OBJECTIVE: Candida species has become one of the most common blood isolates as well as one of the leading causes of nosocomial bloodstream infections. The purpose of our study was to determine the prevalence of Candida species among our bloodstream infecting organisms and the susceptibility pattern of the Candida isolates to antifungal agents.

METHODS: A prospective study was carried out in the Division of Microbiology, King Khalid National Guard Hospital, Jeddah, Kingdom of Saudi Arabia of all positive blood cultures for Candida species. The study took place from 1st January 1998 to March 2002. Identification and susceptibility pattern of isolates were determined by the Candifast technique to amphotericin B, fluconazole, nystatin, Flucytosine, econazole, ketoconazole and miconazole.

RESULTS: Over a 2-year period, 17,916 blood cultures were performed in our hospital. There were 2,972 positive cultures, of which 83 (2.8%) patients had Candida species isolated from their bloodstream. Of these, 38 (46%) were Candida albicans (C.albicans). The remaining 45 strains were made up of Candida tropicalis 9 (10.8%); Candida parapsilosis 9 (10.8%); Candida species 9 (10.8%); Candida guilliermondi 6 (7.2%); Candida krusei 5 (6%); Candida glabrata 4 (4.8%); Candida pseudotropicalis 2 (2.4%) and Trichosporon species 1 (1.2%). All Candida species were susceptible to amphotericin B. However, only 18 (47%) out of 38 C.albicans were susceptible to fluconazole, while only 8 (17.7%) of 45 non-C.albicans strains were susceptible to this drug.

CONCLUSION: The susceptibility of C.albicans to fluconazole in our hospital using the Candifast method is very low (47%). These results need to be confirmed by carrying out the Etest or the NCCLS M27-A method to confirm the true susceptibilities of Candida strains in our locality.