Klinik örneklerden izole edilen mucorales takımı mantarların tür dağılımı ve antifungal duyarlılıklarının retrospektif olarak belirlenmesi
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Date
2023-10-19
Authors
İkkan, Ayşen
Journal Title
Journal ISSN
Volume Title
Publisher
Bursa Uludağ Üniversitesi
Abstract
Mukormikoz genellikle bağışıklık sistemi baskılanmış hastalarda görülen Mukorales takımı mantarların sebep olduğu bir mantar enfeksiyonudur. Tanısı zor, mortalitesi yüksek ve dünya çapında nadir görülmektedir. İnsidansı tam olarak bilinmemektedir, çünkü popülasyona dayalı az çalışma bulunmaktadır. Bu çalışma ile, Mucorales suşlarının tür tanımlaması morfolojik özellikleri ve MALDI TOF MS ile yapılıp ITS bölgesi ile karşılaştırılmıştır. Bu suşların antifungal duyarlılık profillerine bakılarak ülkemiz için ilk tek merkezli epidemiyolojik veri elde edilmiştir. Bu çalışmada, Bursa Uludağ Üniversitesi Sağlık Uygulama ve Araştırma Merkezi, Merkez Mikrobiyoloji (Mikoloji) Laboratuvarına 2003 ile 2022 tarihleri arasında gelen ve -80oC’da saklanan, ayrı hastalara ait 87 Mucorales suşu kullanıldı. ITS bölgesiyle tanımlama amacıyla sadece referans suşlarla BLAST analiz yapıldı ve oldukça net kurallar kullanıldı. Bu suşlardan 77’si ITS bölgesiyle tanımlandı ve en fazla Rhizopus türleri (%75,3) saptandı. Ancak 10 izolat ITS bölgesi ile tanımlamadı. Tanımlama yetersizliği %5,7 oranında olduğu düşünüldü. Tüm suşlarda cins düzeyinde moleküler tanımlama ile tam uyum sağlanmıştır. MALDI TOF MS ile tanımlamada katı ve sıvı besiyerinden ekstraksiyon arasında tür açısından bir fark olmamakla beraber sıvı ekstraksiyon yöntemi anlamlı bir şekilde daha başarılı bulunmuştur. Tür tanımlanması tam yapılmış 77 suşun, in vitro antifungal duyarlılıkları, CLSI M38 referans yöntem ile belirlendi. Posakonazol direnci saptanmamış ancak amfoterisin B direnci Rhizopus arrhizus suşlarında düşük oranda olsa da görülmüştür. Sonuç olarak bu çalışmada merkezimizde en sık izole edilen türün R. arrhizus olduğu, MALDI TOF MS tanımlamanın sıvı ekstraksiyon yöntemi kullanıldığında oldukça başarılı olduğu ve izolatlarımızda ciddi bir antifungal direncin olmadığı saptandı.
Mucormycosis is a fungal infection caused by fungi of the order Mucorales, usually in immunocompromised patients. It is difficult to diagnose, has a high mortality rate and is rare worldwide. Its incidence is unknown because there are a few population-based studies. In this study, species identification of Mucorales strains was performed by morphological characteristics and MALDI TOF MS and compared with the ITS region. By looking at the antifungal susceptibility profiles of these strains, the first single-center epidemiological data for our country was obtained. In this study, 87 Mucorales strains belonging to different patients, which were received to the Central Microbiology (Mycology) Laboratory of Bursa Uludag University Health Application and Research Center between 2003 and 2022 and stored at -80oC, were used. BLAST analysis was performed only with reference strains for identification by the ITS region and very precise rules were used. Of these strains, 77 were identified by the ITS region, with Rhizopus species being the most common (75.3%). However, 10 isolates were not been abilite identified by the ITS region. Identification failure was considered to be 5.7%. Complete agreement was achieved with molecular identification at the genus level in all isolates. Although there was no difference in terms of species between extraction from solid and liquid media in identification by MALDI TOF MS, the liquid extraction method was significantly more successful. In vitro antifungal susceptibilities of 77 strains with complete species identification were determined by CLSI M38 reference method. No posaconazole resistance was detected, but amphotericin B resistance was observed in Rhizopus arrhizus strains, albeit at a low rate. In conclusion, R. arrhizus was the most frequently isolated species in our center, MALDI TOF MS identification was quite successful when liquid extraction method was used and there was no serious antifungal resistance in our isolates.
Mucormycosis is a fungal infection caused by fungi of the order Mucorales, usually in immunocompromised patients. It is difficult to diagnose, has a high mortality rate and is rare worldwide. Its incidence is unknown because there are a few population-based studies. In this study, species identification of Mucorales strains was performed by morphological characteristics and MALDI TOF MS and compared with the ITS region. By looking at the antifungal susceptibility profiles of these strains, the first single-center epidemiological data for our country was obtained. In this study, 87 Mucorales strains belonging to different patients, which were received to the Central Microbiology (Mycology) Laboratory of Bursa Uludag University Health Application and Research Center between 2003 and 2022 and stored at -80oC, were used. BLAST analysis was performed only with reference strains for identification by the ITS region and very precise rules were used. Of these strains, 77 were identified by the ITS region, with Rhizopus species being the most common (75.3%). However, 10 isolates were not been abilite identified by the ITS region. Identification failure was considered to be 5.7%. Complete agreement was achieved with molecular identification at the genus level in all isolates. Although there was no difference in terms of species between extraction from solid and liquid media in identification by MALDI TOF MS, the liquid extraction method was significantly more successful. In vitro antifungal susceptibilities of 77 strains with complete species identification were determined by CLSI M38 reference method. No posaconazole resistance was detected, but amphotericin B resistance was observed in Rhizopus arrhizus strains, albeit at a low rate. In conclusion, R. arrhizus was the most frequently isolated species in our center, MALDI TOF MS identification was quite successful when liquid extraction method was used and there was no serious antifungal resistance in our isolates.
Description
Keywords
Mucorales, Mukormikoz, Epidemiyolojik veri, MALDI TOF MS, Antifungal duyarlılık, Mucorales, Mucormycosis, Epidemiological data, MALDI-TOF-MS, Antifungal susceptibility testing
Citation
İkkan, A. (2023). Klinik örneklerden izole edilen mucorales takımı mantarların tür dağılımı ve antifungal duyarlılıklarının retrospektif olarak belirlenmesi. Yayınlanmamış yüksek lisans tezi. Bursa Uludağ Üniversitesi Sağlık Bilimleri Enstitüsü.