Molecular characterization and antifungal susceptibility testing of Candida nivariensis from blood samples - an Iranian multicentre study and a review of the literature

PURPOSE: Identification of the emerging yeast species Candida nivariensis among presumptively identified Iranian Candida glabrata isolates. METHODOLOGY: Clinical C. glabrata species complex isolates from blood (n=100; 46.9), vaginal swabs (n=20; 9.4), bronchoalveolar lavage (n=10; 4.7) and sputum (n=12; 5.6) from 68 patients from Iran were investigated. Isolates were characterized by CHROMagar, multiplex PCRs, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), amplified fragment length polymorphism (AFLP) fingerprinting, internal transcribed spacer (ITS)/large subunit (LSU) rDNA and FKS1/FKS2 sequencing, and the European Committee on Antimicrobial Susceptibility Testing broth microdilution method. A comprehensive literature review was conducted and all the relevant clinical and microbiological data were collected. RESULTS: Four C. nivariensis isolates were recovered from blood samples of three subjects and were all consistently identified by nine-plex PCR, Bruker MALDI-TOF MS, and LSU and ITS rDNA sequencing. AFLP genotyping clustered the isolates into two groups. Sequencing of the FKS1 and FKS2 hotspots showed no accountable amino acid substitutions. All isolates were susceptible to amphotericin B, fluconazole, itraconazole, posaconazole, voriconazole, anidulafungin and micafungin. CONCLUSION: In total, 4 out of 213 clinical C. glabrata species complex candidemia isolates were C. nivariensis. Improvement of the BioMerieux Vitek MS database is required to accurately identify C. nivariensis and it is advised to alternatively use CHROMagar and/or PCR-based techniques. As other species within the Nakaseomyces clade may cause infection and showed high MIC values for antifungals, inclusion of their spectra into the MALDI-TOF MS database seems relevant. Due to developing resistance to fluconazole and insufficient efficacy of caspofungin, the combination of catheter removal plus treatment with caspofungin, or voriconazole, or micafungin might be effective for patients

Five-year laboratory-based study of candida albicans versus non-albicans candida species at a tertiary pediatric care hospital in Iran

Objective: To determine the distribution of Candida albicans and non-albicans Candida species in various specimen types of pediatric patients Design: Retrospective cross-sectional study using laboratory database Setting: Children�s Medical Center, Tehran, Iran from 2012 to 2016 Subjects: All specimens from pediatric patients with positive culture for Candida species in microbiological examinations Intervention: None Main outcome measures: Frequency of Candida species in different specimen types for five years Results: During the study period, 2755 out of 2,95,525 (0.93) specimens were positive for Candida growth in culture. Of them, 550 (19.96) were from normally sterile specimens or sites. C. albicans was the predominant species (68.9), significantly isolated from both genders (P=.009), and all age groups (P=.011). However, in 2014 and 2015, almost 50 of isolates from normally sterile specimens or sites were non-albicans Candida species. Urine samples were the greatest source of isolation (n=1314, 47.7), followed by throat swabs (n=472, 17.1) and blood specimens (n=344, 12.5). Children were the prevailing age group for Candida isolation (n=1435, 52.1), followed by infants (n=1012, 36.7) and neonates (n=308, 11.2). Conclusion: C. albicans was the dominant species in Children�s Medical Center. However, the proportion of non-albicans Candida species was higher in some specimen types and the frequency of Candida species was different in various wards. These data could be beneficial in a clinical setting. © 2020, Kuwait Medical Association. All rights reserved

Frequency of Candida species isolated from patients in children’s medical center, Tehran, Iran

Background: Candida species originating from either endogenous or exogenous sources are one of the main causes of opportunistic infections. Colonization is an important independent risk factor for invasive candidiasis, and many patients admitted to neonatal intensive care unit (NICU) and pediatric intensive care unit (PICU) are colonized with Candida species that may result in invasive candidiasis. Awareness among clinicians about various aspects of colonization is critical to optimal management. The aim of this study was to determine the frequency and species distribution of Candida strains isolated from predisposed patients hospitalized at Children’s Medical Center (CMC), Tehran, Iran. Methods: From June 2014 to June 2016, 347 Candida isolates were collected from 341 patients either hospitalized in different wards or referred as outpatients. The yeasts were identified by colony color characteristics using CHROMagar Candidamediumand by amplification of the ITS1-5.8S rDNA-ITS2 region in DNA extracted from each isolate followed by analysis of species specific electrophoretic patterns of PCR products digested with the restriction enzyme MspI. Results: Of the 341 patients, 213 were males and 128 were females. Most samples were obtained from the 1 – 12-month age group, and the majority of samples represented urine (n = 182), throat swabs (n = 57), and stool samples (n = 53), respectively. The samples were mostly from patients in general wards. The most commonly isolated species was C. albicans (77%), followed by C. tropicalis (8.4%), C. parapsilosis (7.5%), C. glabrata (2.3%), C. kefyr (1.7%), C. krusei (1.1%), C. lusitaniae (0.6%), C. guilliermondii (0.3%), C. albicans + C. parapsilosis (1.4%), and C. albicans + C. glabrata (0.3%). Conclusions: C. albicans is the most common species isolated from children in Iran, followed by C. tropicalis and C. parapsilosis, a prevalence pattern that is relatively different from studies in other countries. Neonates and infants 1 - 12 months of age hospitalized in ICU, were more colonized by Candida species than other group

Molecular characterization and antifungal susceptibilitytesting of Candida nivariensis from blood samples – an Iranian multicentre study and a review of the literature

Purpose. Identification of the emerging yeast species Candida nivariensis among presumptively identified Iranian Candida glabrata isolates. Methodology. Clinical C. glabrata species complex isolates from blood (n=100; 46.9%), vaginal swabs (n=20; 9.4%), bronchoalveolar lavage (n=10; 4.7%) and sputum (n=12; 5.6%) from 68 patients from Iran were investigated. Isolates were characterized by CHROMagar, multiplex PCRs, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), amplified fragment length polymorphism (AFLP) fingerprinting, internal transcribed spacer (ITS)/large subunit (LSU) rDNA and FKS1/FKS2 sequencing, and the European Committee on Antimicrobial Susceptibility Testing broth microdilution method. A comprehensive literature review was conducted and all the relevant clinical and microbiological data were collected. Results. Four C. nivariensis isolates were recovered from blood samples of three subjects and were all consistently identified by nine-plex PCR, Bruker MALDI-TOF MS, and LSU and ITS rDNA sequencing. AFLP genotyping clustered the isolates into two groups. Sequencing of the FKS1 and FKS2 hotspots showed no accountable amino acid substitutions. All isolates were susceptible to amphotericin B, fluconazole, itraconazole, posaconazole, voriconazole, anidulafungin and micafungin. Conclusion. In total, 4 out of 213 clinical C. glabrata species complex candidemia isolates were C. nivariensis. Improvement of the BioMerieux Vitek MS database is required to accurately identify C. nivariensis and it is advised to alternatively use CHROMagar and/or PCR-based techniques. As other species within the Nakaseomyces clade may cause infection and showed high MIC values for antifungals, inclusion of their spectra into the MALDI-TOF MS database seems relevant. Due to developing resistance to fluconazole and insufficient efficacy of caspofungin, the combination of catheter removal plus treatment with caspofungin, or voriconazole, or micafungin might be effective for patients

Molecular Identification, Genotypic Diversity, Antifungal Susceptibility, and Clinical Outcomes of Infections Caused by Clinically Underrated Yeasts, Candida orthopsilosis, and Candida metapsilosis: An Iranian Multicenter Study (2014–2019)

Despite the increasing occurrence of Candida orthopsilosis and Candida metapsilosis in clinical settings, little is known about their microbiological and clinical properties. Herein, we conducted a national retrospective study (2014–2019) from multiple centers in Iran. Among the 1,770 Candida isolates collected, we identified 600 Candida parapsilosis species complex isolates. Isolate identification was performed by 9-plex PCR, matrix-assisted laser desorption-time of flight mass spectrometry (MALDI-TOF MS), and rDNA sequencing, and antifungal susceptibility testing (AFST) followed CLSI M27-A3/S4; genotyping was performed by amplified fragment length polymorphism (AFLP) analysis; and clinical information was mined. Thirty-one isolates of C. orthopsilosis from various clinical sources, one mixed sample (blood) concurrently containing C. orthopsilosis and C. parapsilosis and one isolate of C. metapsilosis from a nail sample were identified. Although both 9-plex PCR and MALDI-TOF successfully identified all isolates, only 9-plex PCR could identify the agents in a mixed sample. For the C. orthopsilosis isolates, resistance (non-wild type) was noted only for itraconazole (n = 4; 12.5%). Anidulafungin and fluconazole showed the highest and voriconazole had the lowest geometric mean values. AFLP analysis showed three main and four minor genotypes. Interestingly, 90% of nail isolates clustered with 80% of the blood isolates within two clusters, and four blood isolates recovered from four patients admitted to a hospital clustered into two genotypes and showed a high degree of similarity (>99.2%), which suggests that C. orthopsilosis disseminates horizontally. Supported by our data and published case studies, C. orthopsilosis and C. metapsilosis can be linked to challenging clinical failures, and successful outcomes are not always mirrored by in vitro susceptibility. Accordingly, conducting nationwide studies may provide more comprehensive data, which is required for a better prognosis and clinical management of patients