Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/628
Title: Molecular Characterization of Candida Species in Kuwait
Authors: Mohammad Asadullah Asadzadeh 
Supervisor: Prof. Ziauddin Khan
Keywords: molecular
Issue Date: 2017
Publisher:  Kuwait university - college of graduate studies
Abstract: Candida species are major cause of healthcare-associated infections. Rapid identification and characterization of Candida species are needed for effective preventive and management strategies. This study had three main objectives: (i) to develop molecular methods for rapid detection of several Candida spp. (C. albicans and C. dubliniensis, C. parapsilosis-complex and C. glabrata-complex) by multiplex PCR assays, (ii) to determine genotypic heterogeneity/relatedness among clinical isolates of C. albicans-complex, C. parapsilosis-complex and C. glabrata-complex to study the origin of nosocomial Candida infections and to develop new strategies for treatment, control and prevention of candidemia cases in Kuwait and (iii) to perform antifungal susceptibility testing and to determine clade specificity and molecular basis of drug resistance among Candida spp. isolates. Major findings included: (i) two duplex PCR and two multiplex PCR assays were developed for rapid identification and differentiation of individual species among several Candida species complexes, (ii) fingerprinting of C. albicans isolates from candidemia patients by MLST and AFLP analyses coupled with epidemiological data revealed that individual patients were infected with unique strains, thus ruling out intrahospital transmission of infection, (iii) fingerprinting of C. dubliniensis isolates revealed five ITS haplotypes and only 16 MLST-based DSTs whereby all isolates resistant to 5-FC belonged to ITSH4/DST14 and contained S29L mutation in CdFCA1, (iv) increasing trend in resistance to fluconazole among C. parapsilosis isolates and detection of endemic genotypes in neonatal ICUs during fingerprinting by MLMT, (v) fingerprinting of clinical C. orthopsilosis isolates identified 3 ITS haplotypes and 7 AFLP genotypes including one genotype that has persisted over several years, and (vi) fingerprinting of C. glabrata strains showed that fingerprinting by only two loci had the same discriminatory power as the combined data from 8 loci. In conclusion, several duplex/multiplex PCR assays have been developed for detection of different members of various Candida species complexes. Our data showed that related strains of C. albicans exist and fingerprinting by MLST alone may complicate hospital infection control measures during outbreak investigations. All 5-FC-resistant C. dubliniensis isolates belonged to a single genotype. Fingerprinting of C. parapsilosis isolates showed presence of endemic genotypes in some neonatal ICUs and suggested their transmission to other patients hospitalized in the same unit. We also developed a highly discriminatory fingerprinting method based on only 2 loci for strain differentiation of C. glabrata isolates. The study contributes to our understanding of the molecular epidemiology of Candida infections in Kuwait.
URI: http://hdl.handle.net/123456789/628
Appears in Programs:0520 Microbiology (Ph.D.)

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