Opportunistic fungal infections are increasingly important cause of morbidity and mortality particularly due to Candida species. Non-Candida albicans such as C. tropicalis, C. glabrata and C.
Krusei are emerging as opportunistic pathogens ad more resistant to antifungal agents. Urinary tract infections in critically ill patients caused by Candida are increasing in recent years, so identification of Candida to the species level and antifungal susceptibility are very important. Urine samples were collected from critically ill patients in Intensive Care Unit [ICU] from 92 patients. Urine samples were cultured on CLED, blood and Sabouraud dextrose agar [SDA] for diagnosis of Candida. After gram staining subculture was done on: morphologic media included Corn meal and Rice agar Tween 80; chromogenic media included CHROM agar [CMA], BIGGY agar [bismuth ammonium citrate, glucose, glycine and yeast extract]. Results of the previous media were compared with those obtained with API 20 C AUX yeast identification kits. The study revealed an overall isolation rate of Candida among urinary tract infections was 23.9% [22/92]. C. albicans was the most frequent species isolated responsible for fungal urinary tract infections 45.5% [10/22]. However, non-albicans species C. glabrata [22.7%], C. tropicalis [18.2%] and C. krusei [13.7%] were also isolated. Rice agar Tween 80 was found effective in discrimination of Candida species as well as Corn meal agar beside it is cheap and available. CMA medium couldn't identify and discriminate C. glabrata while BIGGY agar showed less sensitivity [36.6%] in discrimination of Candida species compared to the result of morphologic media and API 20C AUX. E-test on [SDA] was found to be an accurate method for antifungal susceptibility as it was compared with the reference broth macrodilution method recommended by National Committee for Clinical Laboratory Standards [NCCLs]. For fluconazole the E-test demonstrated 95.5% agreement at +/- 1dilution and 100% at +/- 2 dilutions for all Candida species. For amphotericin B the E-test demonstrated 86.4% agreement at +/- 1dilution and 90.9% at +/- 2 dilutions for all Candida species. E test revealed that 90.9% and 45.5% of all Candida species were susceptible to amphotericin B and fluconazole respectively. In conclusion non-C. albicans species play a great role as causative agent of fungal urinary tract infections especially in critically ill patients, this necessitate accurate isolation and identification of Candida to the species level and selection of proper antifungal therapy. It is recommended to use morphologic media as Corn meal agar or Rice agar Tween 80 for identification of Candida species and use E-test method on SDA media as a fast simple method for determination of MIC of antifungal drugs, an important point that could encourage clinical laboratories to perform antifungal susceptibility routinely
Abeer Ezzat El Sayed ,Mohsen Mohamed El Khayat ,
Pattern of candida urinary tract infections among critically Ill Patients in ICU and antifungal susceptibility trends,
Egypt. J. Med. Microbiol. 2006;
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