Airway colonisation by Candida and Aspergillus species in Iranian cystic fibrosis patients

Abstract

Cystic fibrosis (CF) is associated with increased rates of morbidity and mortality due to fungal and bacterial colonisation of the airways or respiratory infections. The prevalence of fungi in Iranian CF population has been underestimated. Therefore, the current study was conducted to define the frequency of fungi in respiratory specimens obtained from Iranian CF patients based on conventional and molecular assays.Furthermore, in vitro antifungal susceptibility testing was performed on the obtained isolates according to the guidelines from the Clinical and Laboratory Standards Institute. A cohort of 42 CF patients, including 29 males and 13 females, were categorised according to the referenced diagnostic criteria. Candida albicans (n = 24, 80%), C. dubliniensis (n = 2, 6.6%), C. parapsilosis (n = 2, 6.6%), C. tropicalis (n = 1, 3.3%), C. glabrata (n = 1, 3.3%) and Meyerozyma caribbica (n = 1, 3.3%) were isolated from 73.8% of the CF patients. Aspergillus terreus (n = 3, 42.8%) was identified as the most common Aspergillus species, followed by A. fumigatus (n = 2, 28.5%), A. oryzae (n = 1, 14.2%) and A. flavus (n = 1, 14.2%). Bacterial and fungal co-colonisation was detected in 7 (16.6%) and 22 (52.3%) samples that were positive for Aspergillus and Candida species, respectively. However, Scedosporium species and Exophiala dermatitidis never were detected. In terms of geometric mean (GM) minimum inhibitory concentrations (MICs), posaconazole (0.018 μg/mL) and caspofungin (0.083 μg/mL) exhibited the highest antifungal activities against all Candida species. In addition, posaconazole exhibited the lowest MIC range (0.008-0.063 μg/mL) against all Aspergillus species, followed by caspofungin (0.016-0.125 μg/mL) and voriconazole (0.125-0.25 μg/mL). To conclude, it is essential to adopt a consistent method for the implementation of primary diagnosis and determination of treatment regimen for the CF patients. However, further studies are still needed to better define the epidemiology of fungal organisms in CF patients from the Middle East and the clinical significance of their isolation.

Genotyping, antifungal susceptibility, enzymatic activity, and phenotypic variation in Candida albicans from esophageal candidiasis

“…Candida albicans as a major human fungal pathogen 16 , 17 , 18 , 19 can switch between different morphological phenotypes. Histopathological examination in a murine model demonstrated the presence of pseudohyphae and C .…”

Pulmonary infection secondary to Blastobotrys raffinosifermentans in a cystic fibrosis patient: Review of the literature

“…Fungi are associated with the respiratory deterioration and decline in forced expiratory volume in one second (FEV1) in CF patients, which leads to a lower quality of life and increased mortality . Candida species are frequently isolated from the airways of cystic fibrosis patients, as are Aspergillus , Scedosporium, Exophiala species and members of the Rasamsonia argillacea species complex, either as colonisers or as true causes of infection 17–19 . In addition, Blastobotrys species have been reported to be cultured from respiratory samples in CF patients and chronic bronchitis, and from peritoneal fluid in patients undergoing continuous ambulatory peritoneal dialysis 7–9,11 .…”

“…Candida species are frequently isolated from the airways of cystic fibrosis patients, as are Aspergillus, Scedosporium, Exophiala species and members of the Rasamsonia argillacea species complex, either as colonisers or as true causes of infection. [17][18][19] In addition, Blastobotrys in CF patients and chronic bronchitis, and from peritoneal fluid in patients undergoing continuous ambulatory peritoneal dialysis. [7][8][9]11 However, many clinical microbiology laboratories do not routinely identify yeasts cultured from respiratory specimens.…”

Nocardia farcinica meningitis in a patient with high-grade astrocytoma

“…Genomic DNA was extracted from 7 days old culture and stored at -20 °C prior to use [11]. Briefly, the PCR amplification of 16S rRNA gene was done using the universal primers 16S-Cont-F (5` GATTAGATACCCTGGTAGT CCAC-3`) and 16S-Con t-R (5`-CCCGGGAACGTATTCAC CG-3`) [11,12]. Sequence data were adjusted, using Lasergene SeqMan software (DNAStar, Madison, WI, USA) and compared with the GenBank database.…”