title: Multilocus microsatellite markers for molecular typing of Candida tropicalis isolates.
abstract: BACKGROUND
  Candida tropicalis is considered to be the leading pathogen causing nosocomial fungemia and hepatosplenic fungal infections in patients with cancer, particularly those with leukemia. Microsatellite-based typing methods using sets of genetic markers have been developed and reported for population structure analysis of C. albicans, C. glabrata, and C. parapsilosis, but no studies have been published for genetic analysis of C. tropicalis. The objective of this study was to develop new microsatellite loci that have the ability to distinguish among C. tropicalis isolates.
  
  
  RESULTS
  DNA sequences containing over 10 bi- or tri-nucleotide repeats were selected from the C. tropicalis genome database. Thirty PCR primers sets specific for the microsatellite loci were designed and tested using eight clinically independent isolates. According to the amplification efficiency, specificity, and observed polymorphisms, eight markers were selected for further population structure analysis and molecular typing. Sixty-five independent C. tropicalis isolates were genotyped using these 8 markers. Based on these analyses, six microsatellite loci were confirmed, although two loci were found to be with unstable flanking areas. The six polymorphic loci displayed 4-22 alleles and 7-27 genotypes. The discriminatory power of the six loci ranged from 0.70 to 0.95. Genotyping results obtained by microsatellite analysis were compared to PCR-fingerprinting and multi-locus sequence typing (MLST). The comparisons showed that microsatellite analysis and MLST had the similar discriminatory power for C. tropicalis, which were more powerful than PCR-fingerprinting.
  
  
  CONCLUSIONS
  This is the first attempt to develop new microsatellite loci for C. tropicalis. These newly developed markers will be a valuable resource for the differentiation of C. tropicalis isolates. More C. tropicalis isolates will need to be sequenced and analyzed in order to fully show the potential of these newly developed microsatellite markers.
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China. wuyuan@icdc.cn.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wu
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China. zhouhaijian@icdc.cn.
authors.forename: Hai-jian
authors.initials: HJ
authors.lastname: Zhou
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China. chejie@icdc.cn.
authors.forename: Jie
authors.initials: J
authors.lastname: Che
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China. liwenge@icdc.cn.
authors.forename: Wen-ge
authors.initials: WG
authors.lastname: Li
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China. bianfuning@hotmail.com.
authors.forename: Fu-ning
authors.initials: FN
authors.lastname: Bian
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China. yushuanbao@126.com.
authors.forename: Shuan-bao
authors.initials: SB
authors.lastname: Yu
authors.affiliation: Department of Gynecology and Obstetrics, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China. emily97@126.com.
authors.forename: Li-juan
authors.initials: LJ
authors.lastname: Zhang
authors.affiliation: State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China. lujinxing@icdc.cn.
authors.forename: Jinxing
authors.initials: J
authors.lastname: Lu
mesh_terms: D000328:Adult; D000483:Alleles; D041022:Candida tropicalis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D002177:Candidiasis / Q000382:microbiology; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D058889:Molecular Typing / Q000379:methods*; D016533:Mycological Typing Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D004271:DNA, Fungal