Total Parenteral Nutrition (TPN)-related Candida guilliermondii infections in Turkey
October 13 2017
Candida guilliermondii (AKA Meyerozyma guilliermondii; teleomorph Pichia guilliermondii) is an emerging opportunistic pathogen with a high mortality rate. Over the past 20 years, it has been responsible for ~2% of invasive candidemias but the incidence is increasing and outbreaks may occur.
Between 2006 and 2015, scientists at Farabi Hospital (Trabzon, Turkey) collected 141 isolates from 122 patients (primarily from blood samples), predominantly recruited from hemato-oncology and adult/neonatal intensive care departments. Isolates were identified as C. guilliermondii by culture on Sabouraud Dextrose Agar and by carbohydrate assimilation reactions. Identification was then confirmed by AluI fingerprinting of the IGS region and by sequencing of the entire ITS region. Only one isolate was found to be the closely-related cryptic species Candida membranifaciens.
Over the decade, the proportion of candidemias caused by C. guilliermondii leapt from 4.8% (2006) to 29.4% (2012), then fell back down to 2.6% (2015). The authors suggest that the outbreak was caused by contamination of total parenteral nutrition (TPN) solutions during manual preparation, and the hospital has since changed to automated TPN preparation. Indeed, 13 isolates were taken from TPN solution.
C. guilliermondii is thought to be constitutionally less susceptible to polyenes and echinocandins. In this study, authors report that one patient died despite receiving caspofungin, and a neonate tested positive despite having received liposomal amphotericin B. 46 of the isolates were also assayed for resistance to azole antifungals: three had an elevated MIC against fluconazole, while one showed cross-resistance for fluconazole, voriconazole, itraconazole and flucytosine.
Figure: C. guilliermondii grown on blood agar (top left), Sabouraud (top right) and CHROMagar (bottom).