Abstract 1609 Poster Session II, Sunday, 5/2 (poster 125)

Systemic candidiasis affects approximately 5% of very low birth weight (≤1500g) infants. The Neonatal Candidiasis Study Group was formed to investigate the epidemiology, treatment and prevention of systemic neonatal candidiasis. A specimen archive was created; each participating institution was asked to forward six recent isolates from their intensive care nursery. The archive's purpose is to provide a bank of specimens for susceptibility testing, specifically to allow detection of shifts in susceptibility patterns following any interventions. To date, 89 Candida isolates from 15 institutions have been processed by the Medical Mycology Research Center at the University of Texas Medical Branch. The mean gestational age of the patients is 28 weeks (range, 23-40), birth weight 1200g (range, 426-3806) and age at time of culture 35 days (range, 1-198). The source of these isolates is blood (48), urine (14), skin/soft tissue (8), sputum/tracheal aspirate (6), CSF (4), catheter tips (3) and others (6). For species identification, germ-tube tests are considered confirmation of C. albicans, non-albicans isolates are further identified by inoculation of a Vitek YBC card or AP120C strip and a Dalmau plate. The strains submitted to the archive are C. albicans (50, 56%), C. parapsilosis (30, 34%), C. tropicalis (4, 4.5%), C. guillermondi (2), C. glabrata (2) and C. lusitaniae (1). Eight isolates (9%) from 7 institutions were misidentified by the referring laboratory. Fluconazole MIC's were determined for the isolates in the specimen archive using NCCLS M27 standards. Isolates with MIC values below 8 µg/ml are considered susceptible whereas those with MIC's greater than 64 µg/ml are resistant. Six isolates (6.7%) from 5 patients at 4 institutions had fluconazole MIC's ≥8 µg/ml. (Table) All of the isolates with reduced susceptibility to fluconazole were non-albicans species. The high incidence of species misidentification coupled with the existence of relatively resistant isolates from intensive care nurseries underscores the need for consistent mycologic evaluation of nursery Candida strains. We recommend that isolates be forwarded to a reference laboratory whenever species identification or susceptibility testing is critical in the care of the patient or if valid data is required for studies.

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