Klinik örneklerden izole edilen germ tüp pozitif maya kökenlerinde candida albicans ve candida dubliniensis ayırımının fenotipik yöntemlerle ve PCR ile belirlenmesi
Discrimination of candida albicans and candida dubliniensis among germ tube positive yeast strains isolated from the clinical samples by means of phenotypic methods and PCR
Yazar: ÖNCÜ AKGÜL
Danışman: DOÇ.DR. NİLGÜN ÇERİKÇİOĞLU
Marmara Üniversitesi / Sağlık Bilimleri Enstitüsü / Mikrobiyoloji ve Klinik Mikrobiyoloji Ana Bilim Dalı
Derece: Yüksek Lisans, 2006
Konu: Biyoloji = Biology

Özet:
1- ÖZETSon yıllarda özellikle HIV ile enfekte ve AIDS'li hastalardan artan sıklıkta izoleedilen Candida dubliniensis fırsatçı bir patojen olup, azol grubu antifungaller iletedavinin tekrarlanması durumunda ilaçlara karşı direnç geliştirebilmektedir ve bunedenle tanımlanması zorunlu hale gelmiştir. Candida dubliniensis germ tüp veklamidospor üretebilen bir tür olarak, geriye dönük çalışmalarda daha önceden C.albicans olarak değerlendirilmiş olan izolatların arasında henüz az oranda da olsasaptanmaktadır.Çalışmamızda, yatan hastalardan 2004- 2005 yılları arasında izole edilen ve C.albicans olarak tanımlanmış olan 300 köken arasında C. dubliniensis oranını saptamayıve bu mayanın tanısında kullanılabilecek PCR dışı en uygun testi belirlemeyi amaçladık.Fenotipik testlere göre olası C. dubliniensis yönünde şüphelendiğimiz kökenler (ısı tolerans testinde 23, mısır unlu Tween 80 agarda 42, kazein agarda 20, metil maviliSabouraud agarda 42, Pal's agarda 9, tütün agarda 4, modifiye tuz tolerans testinde 2köken ) arasında en az bir testte sonuç veren seçilmiş 100 kökenin yalnızca 2 tanesi PCRile de C. dubliniensis olarak doğrulanmıştır.Bu iki köken ( %2 ) API ID 32C asimilasyon kiti ile de aynı sonucu vermiştir.Çalışmamızda C. albicans ve C. dubliniensis'i ayırmada yalnızca modifiye tuztolerans testi PCR ve API ID 32C ile uyumu nedeniyle % 100 başarılı olaraksaptanmıştır. Tütün agar testinde de çok düşük ( % 0.6 ) bir yalancı pozitiflikgözlenmiştir.Sonuçlarımıza dayanarak, PCR ve diğer otomatize sistemlerin bulunmadığıortamlarda; uygulamadaki ve yorumlamadaki kolaylık da göz önüne alınarak, iki türünayırımında bu iki fenotipik testin kullanılabileceğini düşünmekteyiz.Anahtar Kelime: Candida albicans, C. dubliniensis, fenotipik testler, PCR, API2- SUMMARYDiscrimination of Candida albicans and Candida dubliniensis among Germ TubePositive Yeast Strains Isolated from the Clinical Samples by means of PhenotypicMethods and PCRCandida dubliniensis as an opportunistic pathogen has been increasingly isolatedmainly from the HIV infected and AIDS patients in recent years, may develop resistanceagainst repeatedly used azole antifungals; therefore it appears that identification of itbecame necessary. In retrospective studies, as a germ tube and chlamydospore producingspecies, C. dubliniensis has been detected among the strains previously named as C.albicans although in relatively small rates, already.In this study we aimed to detect the proportion of C. dubliniensis among 300strains of C. albicans, isolated from the hospitalized patients between 2004- 2005 and todetermine the most suitable non- PCR test to be used in identification of this yeast.Among the strains which we suspected to be C. dubliniensis ( 23 in heat tolerance,42 in corn meal Tween 80 agar, 20 in casein agar, 42 in methyl blue SA, 9 in Pal's agar, 4in tobacco agar and 2 in modified salt tolerance tests ) 100 were selected due to beingpositive for at least one test, only 2 ( 2 % ) were confirmed as C. dubliniensis both byPCR and API ID 32C assimilation kit.In our study only modified salt tolerance test was 100 % successful as being inaccordance with PCR and API ID 32C. In tobacco agar test, a false positive result as lowas 0.6 % was revealed.Depending on our results, in respect to their simplicity in application andinterpretation, these two phenotypic tests can be used in the absence of PCR and otherautomatized systems.Key Words: Candida albicans, Candida dubliniensis, phenotypic tests, PCR, API

Abstract:
2- SUMMARYDiscrimination of Candida albicans and Candida dubliniensis among Germ TubePositive Yeast Strains Isolated from the Clinical Samples by means of PhenotypicMethods and PCRCandida dubliniensis as an opportunistic pathogen has been increasingly isolatedmainly from the HIV infected and AIDS patients in recent years, may develop resistanceagainst repeatedly used azole antifungals; therefore it appears that identification of itbecame necessary. In retrospective studies, as a germ tube and chlamydospore producingspecies, C. dubliniensis has been detected among the strains previously named as C.albicans although in relatively small rates, already.In this study we aimed to detect the proportion of C. dubliniensis among 300strains of C. albicans, isolated from the hospitalized patients between 2004- 2005 and todetermine the most suitable non- PCR test to be used in identification of this yeast.Among the strains which we suspected to be C. dubliniensis ( 23 in heat tolerance,42 in corn meal Tween 80 agar, 20 in casein agar, 42 in methyl blue SA, 9 in Pal?s agar, 4in tobacco agar and 2 in modified salt tolerance tests ) 100 were selected due to beingpositive for at least one test, only 2 ( 2 % ) were confirmed as C. dubliniensis both byPCR and API ID 32C assimilation kit.In our study only modified salt tolerance test was 100 % successful as being inaccordance with PCR and API ID 32C. In tobacco agar test, a false positive result as lowas 0.6 % was revealed.Depending on our results, in respect to their simplicity in application andinterpretation, these two phenotypic tests can be used in the absence of PCR and otherautomatized systems.Key Words: Candida albicans, Candida dubliniensis, phenotypic tests, PCR, API