title: Multilocus sequence analyses reveal extensive diversity and multiple origins of fluconazole resistance in Candida tropicalis from tropical China.
abstract: Candida tropicalis is among the most prevalent human pathogenic yeast species, second only to C. albicans in certain geographic regions such as East Asia and Brazil. However, compared to C. albicans, relatively little is known about the patterns of genetic variation in C. tropicalis. This study analyzed the genetic diversity and relationships among isolates of C. tropicalis from the southern Chinese island of Hainan. A total of 116 isolates were obtained from seven geographic regions located across the Island. For each isolate, a total of 2677 bp from six gene loci were sequenced and 79 (2.96%) polymorphic nucleotide sites were found in our sample. Comparisons with strains reported from other parts of the world identified significant novel diversities in Hainan, including an average of six novel sequences (with a range 1 to 14) per locus and 80 novel diploid sequence types. Most of the genetic variation was found within individual strains and there was abundant evidence for gene flow among the seven geographic locations within Hainan. Interestingly, our analyses identified no significant correlation between the diploid sequence types at the six loci and fluconazole susceptibility, consistent with multiple origins of fluconazole resistance in the Hainan population of C. tropicalis.
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan, China.|Public Research Laboratory, Hainan Medical University, Haikou, Hainan, China.
authors.forename: Jin-Yan
authors.initials: JY
authors.lastname: Wu
authors.affiliation: Public Research Laboratory, Hainan Medical University, Haikou, Hainan, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Guo
authors.affiliation: Public Research Laboratory, Hainan Medical University, Haikou, Hainan, China.
authors.forename: Hua-Min
authors.initials: HM
authors.lastname: Wang
authors.affiliation: Public Research Laboratory, Hainan Medical University, Haikou, Hainan, China.
authors.forename: Guo-Hui
authors.initials: GH
authors.lastname: Yi
authors.affiliation: Public Research Laboratory, Hainan Medical University, Haikou, Hainan, China.
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Zhou
authors.affiliation: Public Research Laboratory, Hainan Medical University, Haikou, Hainan, China.
authors.forename: Xiao-Wen
authors.initials: XW
authors.lastname: He
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, Yunnan, China.|Public Research Laboratory, Hainan Medical University, Haikou, Hainan, China.|Department of Biology, McMaster University, Hamilton, Ontario, L8S 4K1, Canada.
authors.forename: Jianping
authors.initials: J
authors.lastname: Xu
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D041022:Candida tropicalis / Q000145:classification / Q000187:drug effects* / Q000235:genetics*; D002177:Candidiasis / Q000382:microbiology*; D002681:China; D016000:Cluster Analysis; D025141:Drug Resistance, Fungal; D019143:Evolution, Molecular; D015725:Fluconazole / Q000494:pharmacology*; D051456:Gene Flow; D005800:Genes, Fungal; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D014329:Tropical Climate
chemical_list: D000935:Antifungal Agents; D015725:Fluconazole