Evidence for a general-purpose genotype in Candida albicans, highly prevalent in multiple geographical regions, patient types and types of infection.
Epidemiological studies, using the probe Ca3, have shown that in a given patient population a single cluster of genetically related Candida albicans isolates usually predominates. The authors have investigated whether these local clusters are part of a single group, geographically widespread and highly prevalent as an aetiological agent of various types of candidiasis. An unrooted neighbour-joining tree of 266 infection-causing C. albicans isolates (each from a different individual) from 12 geographical regions in 6 countries was created, based on genetic distances generated by Ca3 fingerprinting. Thirty-seven per cent of all isolates formed a single genetically homogeneous cluster (cluster A). The remainder of isolates were genetically diverse. Using the maximum branch length within cluster A as a cut-off, they could be divided into 37 groups, whose prevalence ranged between 0.3% and 9%. Strains from cluster A were highly prevalent in all but one geographical region, with a mean prevalence across all regions of 41%. When isolates were separated into groups based on patient characteristics or type of infection, strains from cluster A had a prevalence exceeding 27% in each group, and their mean prevalence was 43% across all patient characteristics. These data provide evidence that cluster A constitutes a general-purpose genotype, which is geographically widespread and acts as a predominant aetiological agent of all forms of candidiasis in all categories of patients surveyed.
Schmid
Jan
J
Institute of Molecular BioSciences, Massey University, Palmerston North, New Zealand1.
Herd
Scott
S
Institute of Molecular BioSciences, Massey University, Palmerston North, New Zealand1.
Hunter
Paul R
PR
Public Health Laboratory, Countess of Chester Health Park, Chester , UK2.
Cannon
Richard D
RD
Department of Oral Sciences and Orthodontics, University of Otago , New Zealand3.
Yasin
M Salleh M
MSM
Faculty of Allied Health Sciences, Universiti Kebangsaan Malaysia , Malaysia4.
Samad
Shamin
S
Faculty of Allied Health Sciences, Universiti Kebangsaan Malaysia , Malaysia4.
Carr
Mary
M
Microbiology Division, Wellington Hospital, Wellington, New Zealand5.
Parr
Dinah
D
Microbiology Department, Auckland Hospital, Auckland, New Zealand6.
McKinney
Wendy
W
Microbiology Department, Auckland Hospital, Auckland, New Zealand6.
Schousboe
Mona
M
Microbiology Unit, Canterbury Health Laboratories, Christchurch , New Zealand7.
Harris
Ben
B
Microbiology Unit, Canterbury Health Laboratories, Christchurch , New Zealand7.
Ikram
Rosemary
R
Medlab South Ltd, Christchurch, New Zealand8.
Harris
Mike
M
Medlab South Ltd, Christchurch, New Zealand8.
Restrepo
Angela
A
Corporacion para Investigaciones Biologicas, Medellin, Colombia 9.
Hoyos
Guillermo
G
Corporacion para Investigaciones Biologicas, Medellin, Colombia 9.
Singh
Kumar P
KP
Department of Pathology, CWM Hospital, Suva, Fiji 10.
D002176:Candida albicans / Q000145:classification* / Q000235:genetics*; D002177:Candidiasis / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D016172:DNA Fingerprinting; D004271:DNA, Fungal / Q000032:analysis / Q000235:genetics; D005838:Genotype; D006801:Humans; D015995:Prevalence
D004271:DNA, Fungal