Novel Polymorphic Multilocus Microsatellite Markers to Distinguish Candida tropicalis Isolates.
Candida tropicalis is an important pathogen. Here we developed and evaluated a polymorphic multilocus microsatellite scheme employing novel genetic markers for genotyping of C. tropicalis. Using 10 isolates from 10 unique (separate) patients to screen over 4000 tandem repeats from the C. tropicalis genome (strain MYA-3404), six new candidate microsatellite loci (ctm1, ctm3, ctm8, ctm18, ctm24 and ctm26) were selected according to amplification success, observed polymorphisms and stability of flanking regions by preliminary testing. Two known microsatellite loci CT14 and URA3 were also studied. The 6-locus scheme was then tested against a set of 82 different isolates from 32 patients. Microsatellite genotypes of isolates from the same patient (two to five isolates per patient) were identical. The six loci produced eight to 17 allele types and identified 11 to 24 genotypes amongst 32 patients' isolates, achieving a discriminatory power (DP) of 0.76 to 0.97 (versus 0.78 for both CT14 and URA3 loci, respectively). Testing of a combination of only three loci, ctm1, ctm3 and ctm24, also achieved maximum typing efficiency (DP = 0.99, 29 genotypes). The microsatellite typing scheme had good correlation compared with pulsed-field gel electrophoresis, although was slightly less discriminatory. The new six-locus microsatellite typing scheme is a potentially valuable tool for genotyping and investigating microevolution of C. tropicalis.
Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.|Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
Xin
X
Fan
Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Meng
M
Xiao
Department of Clinical Laboratory, Tianjin First Centre Hospital, Tianjin, China.
Ping
P
Liu
Centre for Infectious Diseases and Microbiology Laboratory Services, Westmead Hospital, Darcy Road, Westmead, New South Wales, Australia.
Sharon
S
Chen
Centre for Infectious Diseases and Microbiology Laboratory Services, Westmead Hospital, Darcy Road, Westmead, New South Wales, Australia.
Fanrong
F
Kong
Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
He
H
Wang
Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Li
L
Zhang
Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.|Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
Xin
X
Hou
Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Ying-Chun
YC
Xu
D000483:Alleles; D041022:Candida tropicalis / Q000145:classification* / Q000235:genetics*; D002177:Candidiasis / Q000382:microbiology; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D005819:Genetic Markers / Q000235:genetics*; D005838:Genotype; D006801:Humans; D018895:Microsatellite Repeats / Q000235:genetics*; D025202:Molecular Diagnostic Techniques / Q000379:methods; D016533:Mycological Typing Techniques / Q000379:methods; D011110:Polymorphism, Genetic / Q000235:genetics
D005819:Genetic Markers