Evidence for a general-purpose genotype in Candida albicans , highly prevalent in multiple geographical regions, patient types and types of infection

Schmid, Jan; Herd, Scott; Hunter, Paul; Cannon, Richard D.; Yasin, Mohamed Salleh Mohamed; Samad, Shamin; Carr, M.; Parr, Dinah; McKinney, Wendy; Schousboe, Mona; Harris, Ben G.; Ikram, Rosemary; Harris, Mike; Restrepo, Ángela; Hoyos, Guillermo; Singh, Kumar P.

doi:10.1099/00221287-145-9-2405

Cited by 67 publications

(95 citation statements)

References 22 publications

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“…The results recorded here confirm a tendency, already noted by Schmid et al (1993), in a population of C. albicans strains from vaginal samples using the DNA fingerprints with the moderately repetitive sequence Ca3, observing that the majority of the stocks of C. albicans are in a relatively homogeneous group. A high genetic similarity was also reported, using the same Ca3 probe, in strains isolated from women with vaginal candidiasis, from a same geographical region (Schmid et al 1999).…”

Section: Albicansmentioning

confidence: 85%

First characterization of Candida albicans by random amplified polymorphic DNA method in Nicaragua and comparison of the diagnosis methods for vaginal candidiasis in Nicaraguan women

Bello

González

Barnabé

et al. 2002

Mem. Inst. Oswaldo Cruz

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The genital candidiasis is one of the pathogenic demonstrations of yeast. Candida albicans is the most frequent species; it is usually isolated in 85 to 90% from the vaginal mycoses (Odds et al. 1988).Vaginal candidiasis affects females at least once during their lifetime, at an estimated rate of 70 to 75%, of whom 40 to 50% will experience a recurrence (Sobel 1999).In Nicaragua, we know very little about the prevalence and incidence of vaginal candidiasis and no study of the biology of C. albicans has been carried out. In this country, diagnosis of vaginal candidiasis is mainly based on the clinical presentation. Laboratories of the hospitals and health centres (peripheral laboratories) carry out only the microscopic diagnosis from the vaginal fluid. In the laboratory of the National Centre of Diagnosis and Reference of Nicaragua (CNDR), the yeast identification is based on the observation of the microscopic aspects, culture and biochemical tests.Most of the genetic studies revealed that C. albicans is predominantly clonal (Pujol et al. 1993, Helstein et al. 1993, Lockhart et al. 1995, Xu et al. 1999. Some authors have proposed that clonal propagation with a remaining capacity of recombination, shape the population structure of C. albicans (Caugant & Sandven 1993, Gräser et al. 1996, Tibayrenc 1997 Southern blot hybridization with the moderately repetitive DNA Ca3 probe, not only clustered moderately related isolates in a similar fashion but also afforded similar levels of resolution of microevolution within a clonal population.The goal of this study was to use the RAPD method to examine the patterns of yeast genetic diversity among women with vaginitis from a single geographic area. We were specifically interested to know the frequency of yeast in vulvovaginal secretions. We also compared the conventional methods of yeast diagnosis from vaginal samples used in Nicaragua and yeast culture method. MATERIALS AND METHODSThe vaginal swabs were taken from 106 women exhibiting symptoms of vulvovaginitis, who were attended in the outpatient ward of the CNDR in Managua, Nicaragua, between June and August 1997. Swabs were processed by the method routinely used for the detection of germinated yeast pathogens: microscopic examination of wet mount, with a 10% potassium hydroxide (KOH) preparation, and the Gram's stain. Samples were inoculated into Sabouraud-glucose agar, supplemented with chloramphenicol, and were incubated at 37°C for 48 h. For identification of C. albicans, isolates were placed in foetal calf serum for 4 h to test for the production of germ tubes and were incubated on Rice-Agar-Tween (RAT ® ) BioMérieux Laboratories, France for 48 h to induce chlamydospores. All yeast isolates were preliminary identified to the species level according to the CHROMagar Albicans® Test (Mycoplasme International, Toulon, France). This medium contains a chromogene substrate for immediate identification of C. albicans (green), C. tropicalis (metallic blue), C. glabrata (pink) and C. krusei (pale pink). Yeast species were conf...

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Section: Albicansmentioning

confidence: 85%

First characterization of Candida albicans by random amplified polymorphic DNA method in Nicaragua and comparison of the diagnosis methods for vaginal candidiasis in Nicaraguan women

Bello

González

Barnabé

et al. 2002

Mem. Inst. Oswaldo Cruz

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“…The strains had not been extensively subcultured after their isolation from patients and were revived from glycerol stocks for these experiments. Twenty-three MTL-homozygous clinical isolates used for growth-rate determinations were WO-1 (Slutsky et al 1987;Miller and Johnson 2002);L26, GC75, p37005, 19F, p87, 12C, p60002, p78048, p57072, p94015 (Wu et al 2007); 85/005, AM2005/0377, T101, M97105, 81/139, SCS103353G, SCS103354N, AM2003/018, AM2003/ 0165, AM2002/087, RIHO9, 81/196 (Schmid et al 1999;Odds et al 2007).…”

Section: Analyses Of D N /D Smentioning

confidence: 99%

“…Serial transfers and growth-rate determinations were carried out under two conditions: Either (i) in YPD (1% yeast extract, 2% Bacto-peptone (Bacto TM , Becton Dickinson, Sparks, MD) and 2% glucose (Asia Pacific Specialty Chemical Limited, NSW, Australia)) at 37°or (ii) in a defined medium containing 0.17% yeast nitrogen base without Source: Schmid et al (1999). a Based on Ca3 fingerprinting; GPG, general-purpose genotype, equivalent to major group A, which is subdivided in to subgroups A1 and A2 (Schmid et al 1999) amino acids and ammonium sulfate (Becton and Dickinson), 0.5% ammonium sulfate, 0.08% glucose, 0.2 M NaCl (Goddard et al 2005) at 42°.…”

Section: Analyses Of D N /D Smentioning

confidence: 99%

“…The 10 strains used for mating experiments are listed in Table 1. They were chosen (Holland and Schmid 2005) from a collection of 266 infection-causing isolates from 12 geographical regions in 6 countries (Schmid et al 1999) so that 5 represented the GPG group (equivalent to clade 1; Schmid et al 1999;Tavanti et al 2005a;Odds et al 2007) and 5 the remainder of the species. The strains had not been extensively subcultured after their isolation from patients and were revived from glycerol stocks for these experiments.…”

Section: Analyses Of D N /D Smentioning

confidence: 99%

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Selective Advantages of a Parasexual Cycle for the YeastCandida albicans

Zhang

Magee

et al. 2015

Genetics

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The yeast Candida albicans can mate. However, in the natural environment mating may generate progeny (fusants) fitter than clonal lineages too rarely to render mating biologically significant: C. albicans has never been observed to mate in its natural environment, the human host, and the population structure of the species is largely clonal. It seems incapable of meiosis, and most isolates are diploid and carry both mating-type-like (MTL) locus alleles, preventing mating. Only chromosome loss or localized loss of heterozygosity can generate mating-competent cells, and recombination of parental alleles is limited. To determine if mating is a biologically significant process, we investigated if mating is under selection. The ratio of nonsynonymous to synonymous mutations in mating genes and the frequency of mutations abolishing mating indicated that mating is under selection. The MTL locus is located on chromosome 5, and when we induced chromosome 5 loss in 10 clinical isolates, most of the resulting MTL-homozygotes could mate with each other, producing fusants. In laboratory culture, a novel environment favoring novel genotypes, some fusants grew faster than their parents, in which loss of heterozygosity had reduced growth rates, and also faster than their MTL-heterozygous ancestors-albeit often only after serial propagation. In a small number of experiments in which co-inoculation of an oral colonization model with MTL-homozygotes yielded small numbers of fusants, their numbers declined over time relative to those of the parents. Overall, our results indicate that mating generates genotypes superior to existing MTL-heterozygotes often enough to be under selection.KEYWORDS Candida albicans; mating; parasexual cycle; cryptic sexual cycle S EX is costly and disrupts well-adapted allele combinations. It can also be advantageous by speeding up adaptation or by purging deleterious mutations. It has been difficult to establish how, precisely, these and other benefits outweigh the cost of sex. Indeed, abandoning sex in favor of clonal reproduction can be advantageousasexual species arise frequently. Their life spans are short, however, indicating that sex may be essential for the long-term survival of species (Otto and Lenormand 2002;Rice 2002).Sexual cycles have not been observed for 20% of fungal species (Carlile et al. 2001). Whether these species are truly asexual or merely restrict the frequency of sex-a strategy believed to maximize its benefits (Heitman 2006)-is difficult to determine. Genetic marker distributions in such species often suggest limited recombination (Carlile et al. 2001). However, clonal reproduction will initially copy the genetic marker distributions that were generated by sex, and new mutations and genetic drift will only slowly erase evidence of past recombination (Schmid et al. 2004;Cox et al. 2013). With rare exceptions, fungi without observable sexual cycles are derived from recent sexual ancestors (Carlile et al. 2001;Schmid et al. 2004;Butler 2007). Thus genetic marker distributi...

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“…Cytopathology presents high specificity for the diagnosis of candidiasis (27,34) , still its use for the diagnosis of oral lesions and infections is not very frequent among dental surgeons (41,44) . Whereas oral cytopathology can be performed with material obtained by different methods, the technique that best provides quality material is the scrape, a process of mechanical separation of epithelium that can be made with different instruments (2,4) .…”

Section: Discussionmentioning

confidence: 99%

Comparative analysis of Gram’s method and PAS for the identification ofCandidaspp. samples from the oral mucosa

Padilha¹,

Picciani²,

Santos

et al. 2014

Jornal Brasileiro De Patologia E Medicina Laboratorial

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Evidence for a general-purpose genotype in Candida albicans , highly prevalent in multiple geographical regions, patient types and types of infection

Cited by 67 publications

References 22 publications

First characterization of Candida albicans by random amplified polymorphic DNA method in Nicaragua and comparison of the diagnosis methods for vaginal candidiasis in Nicaraguan women

First characterization of Candida albicans by random amplified polymorphic DNA method in Nicaragua and comparison of the diagnosis methods for vaginal candidiasis in Nicaraguan women

Selective Advantages of a Parasexual Cycle for the YeastCandida albicans

Comparative analysis of Gram’s method and PAS for the identification ofCandidaspp. samples from the oral mucosa

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