Candidemia among Hospitalized Pediatric Patients Caused by Several Clonal Lineages of Candida parapsilosis.

Rasmus Krøger Hare,Arezoo Charsizadeh,Amir Arastehfar,Hamid Eshaghi,Maiken Cavling Arendrup,Teun Boekhout,Søren Rosendahl,Ferry Hagen,Farnaz Daneshnia,Hossein Mirhendi

doi:10.3390/jof8020183

Abstract

Candida parapsilosis is the second most common cause of candidemia in some geographical areas and in children in particular. Yet, the proportion among children varies, for example, from 10.4% in Denmark to 24.7% in Tehran, Iran. As this species is also known to cause hospital outbreaks, we explored if the relatively high number of C. parapsilosis pediatric cases in Tehran could in part be explained by undiscovered clonal outbreaks. Among 56 C. parapsilosis complex isolates, 50 C. parapsilosis were genotyped by Amplified Fragment Length Polymorphism (AFLP) fingerprinting and microsatellite typing and analyzed for nucleotide polymorphisms by FKS1 and ERG11 sequencing. AFLP fingerprinting grouped Iranian isolates in two main clusters. Microsatellite typing separated the isolates into five clonal lineages, of which four were shared with Danish isolates, and with no correlation to the AFLP patterns. ERG11 and FKS1 sequencing revealed few polymorphisms in ERG11 leading to amino-acid substitutions (D133Y, Q250K, I302T, and R398I), with no influence on azole-susceptibilities. Collectively, this study demonstrated that there were no clonal outbreaks at the Iranian pediatric ward. Although possible transmission of a diverse C. parapsilosis community within the hospital cannot be ruled out, the study also emphasizes the necessity of applying appropriately discriminatory methods for outbreak investigation.

Highlights

In a recent study of the epidemiology of pediatric candidemia in Tehran, Iran, Candida parapsilosis complex species isolates accounted for 24.7% of the cases [1]
The results of the microsatellite analyses showed that the Iranian outbreak, which was considered as two clones when assayed with Amplified Fragment Length Polymorphism (AFLP) markers, consisted of five clusters
This can be explained by the low resolution of the current format of the AFLP that introduce null-alleles resulting in binary data

Summary

Introduction

In a recent study of the epidemiology of pediatric candidemia in Tehran, Iran, Candida parapsilosis complex species isolates accounted for 24.7% of the cases [1]. Fluconazole-resistant C. parapsilosis isolates have been increasingly reported in several countries, including but not limited to South Africa [7], India [8], South Korea [9], Kuwait [10], Mexico [11], Italy [12], and Finland [13], and has been associated with poor outcome and clinical failure [6,14,15]. Outbreaks involving fluconazole-resistant C. parapsilosis include azole-naïve patients and limit the use of fluconazole as the first-line agent in developing countries [3,15,16]. A recent study from Brazil found isogenic fluconazole-resistant C. parapsilosis isolates from the hands of healthcare workers, inanimate surfaces, and patient bloodstream infections [15]

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