Conventional Morphology Versus PCR Sequencing, rep-PCR, and MALDI-TOF-MS for Identification of Clinical Aspergillus Isolates Collected Over a 2-Year Period in a University Hospital at Kayseri, Turkey

• Published in: Journal of clinical laboratory analysis 2016-09, Vol.30 (5), p.745-750
• Main Authors: Atalay, Altay, Koc, Ayse Nedret, Suel, Ahmet, Sav, Hafize, Demir, Gonca, Elmali, Ferhan, Cakir, Nuri, Seyedmousavi, Seyedmojtaba
• Format: Article
• Language: English
• Subjects: Aspergillus; Aspergillus - cytology; Aspergillus - isolation & purification; Aspergillus flavus; Fungal infections; Hospitals, University; Humans; MALDI-TOF-MS; Mass spectrometry; Microbiology; Morphology; Polymerase chain reaction; Polymerase Chain Reaction - methods; rep-PCR; Sequence Analysis, DNA - methods; sequencing; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - methods; Turkey
• ISSN: 0887-8013; 1098-2825
• DOI: 10.1002/jcla.21932

Background Aspergillus species cause a wide range of diseases in humans, including allergies, localized infections, or fatal disseminated diseases. Rapid detection and identification of Aspergillus spp. facilitate effective patient management. In the current study we compared conventional morphological methods with PCR sequencing, rep‐PCR, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) for the identification of Aspergillus strains. Materials and Methods A total of 24 consecutive clinical isolates of Aspergillus were collected during 2012–2014. Conventional morphology and rep‐PCR were performed in our Mycology Laboratory. The identification, evaluation, and reporting of strains using MALDI‐TOF‐MS were performed by BioMérieux Diagnostic, Inc. in Istanbul. DNA sequence analysis of the clinical isolates was performed by the BMLabosis laboratory in Ankara. Results Samples consisted of 18 (75%) lower respiratory tract specimens, 3 otomycosis (12.5%) ear tissues, 1 sample from keratitis, and 1 sample from a cutaneous wound. According to DNA sequence analysis, 12 (50%) specimens were identified as A. fumigatus, 8 (33.3%) as A. flavus, 3 (12.5%) as A. niger, and 1 (4.2%) as A. terreus. Statistically, there was good agreement between the conventional morphology and rep‐PCR and MALDI‐TOF methods; kappa values were κ = 0.869, 0.871, and 0.916, respectively (P < 0.001). Conclusion The good level of agreement between the methods included in the present study and sequence method could be due to the identification of Aspergillus strains that were commonly encountered. Therefore, it was concluded that studies conducted with a higher number of isolates, which include other Aspergillus strains, are required.