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O’Brien CE, Oliveira-Pacheco J, Ó Cinnéide E, Haase MAB, Hittinger CT, Rogers TR, Zaragoza O, Bond U, Butler G. Population genomics of the pathogenic yeast Candida tropicalis identifies hybrid isolates in environmental samples. PLoS Pathog 2021; 17:e1009138. [PMID: 33788904 PMCID: PMC8041210 DOI: 10.1371/journal.ppat.1009138] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 04/12/2021] [Accepted: 03/15/2021] [Indexed: 01/02/2023] Open
Abstract
Candida tropicalis is a human pathogen that primarily infects the immunocompromised. Whereas the genome of one isolate, C. tropicalis MYA-3404, was originally sequenced in 2009, there have been no large-scale, multi-isolate studies of the genetic and phenotypic diversity of this species. Here, we used whole genome sequencing and phenotyping to characterize 77 isolates of C. tropicalis from clinical and environmental sources from a variety of locations. We show that most C. tropicalis isolates are diploids with approximately 2-6 heterozygous variants per kilobase. The genomes are relatively stable, with few aneuploidies. However, we identified one highly homozygous isolate and six isolates of C. tropicalis with much higher heterozygosity levels ranging from 36-49 heterozygous variants per kilobase. Our analyses show that the heterozygous isolates represent two different hybrid lineages, where the hybrids share one parent (A) with most other C. tropicalis isolates, but the second parent (B or C) differs by at least 4% at the genome level. Four of the sequenced isolates descend from an AB hybridization, and two from an AC hybridization. The hybrids are MTLa/α heterozygotes. Hybridization, or mating, between different parents is therefore common in the evolutionary history of C. tropicalis. The new hybrids were predominantly found in environmental niches, including from soil. Hybridization is therefore unlikely to be associated with virulence. In addition, we used genotype-phenotype correlation and CRISPR-Cas9 editing to identify a genome variant that results in the inability of one isolate to utilize certain branched-chain amino acids as a sole nitrogen source.
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Affiliation(s)
- Caoimhe E. O’Brien
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - João Oliveira-Pacheco
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Eoin Ó Cinnéide
- School of Medicine, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
| | - Max A. B. Haase
- Laboratory of Genetics, Center for Genomic Science Innovation, Wisconsin Energy Institute, DOE Great Lakes Bioenergy Research Center, J.F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Chris Todd Hittinger
- Laboratory of Genetics, Center for Genomic Science Innovation, Wisconsin Energy Institute, DOE Great Lakes Bioenergy Research Center, J.F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Thomas R. Rogers
- Department of Clinical Microbiology, Trinity College Dublin, Dublin, Ireland; Department of Microbiology, St James’s Hospital, Dublin, Ireland
| | - Oscar Zaragoza
- Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Carretera Majadahonda-Pozuelo, Km2, Majadahonda, Madrid, Spain
| | - Ursula Bond
- Department of Microbiology, School of Genetics and Microbiology, Trinity College Dublin, Ireland
| | - Geraldine Butler
- School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
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Effect of Carbon Sources, Nitrogen Sources and Prebiotics on Growth of Saccharomyces Boulardii. ACTA UNIVERSITATIS CIBINIENSIS. SERIES E: FOOD TECHNOLOGY 2019. [DOI: 10.2478/aucft-2019-0013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Abstract
Saccharomyces boulardii (S. boulardii) has been used as a probiotic for the prevention or treatment of various human gastrointestinal diseases for many years. Thus, S. boulardii has a wide range of application prospects in medicine and food industry. The experiments were investigated with effecting of carbon sources (galactose, sucrose, fructose, maltose, lactose, glucose, and soluble starch), nitrogen sources (tryptone, casein, yeast extract, peptone, soy peptone, beef extract and malted milk; ammonium sulfate, urea, diammonium hydrogen citrate, triammonium citrate, ammonium nitrate, ammonium chloride and potassium nitrate), prebiotics (xylo-oligosaccharide, isomaltooligosaccharide, fructo-oligosaccharide, galacto-oligosaccharide, stachyose, raffinose and inulin) on the number of viable cells and dry cell weight of S. boulardii. The optimum concentration of 5 % glucose or sucrose, 2 % peptone or yeast extract, 0.4 % urea, 0.2 % fructo-oligosaccharide and 0.6 % galacto-oligosaccharide for S. boulardii grew better in medium.
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A new, rapid multiplex PCR method identifies frequent probiotic origin among clinical Saccharomyces isolates. Microbiol Res 2019; 227:126298. [DOI: 10.1016/j.micres.2019.126298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/20/2019] [Accepted: 07/12/2019] [Indexed: 12/28/2022]
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Whole Genome Analysis of 132 Clinical Saccharomyces cerevisiae Strains Reveals Extensive Ploidy Variation. G3-GENES GENOMES GENETICS 2016; 6:2421-34. [PMID: 27317778 PMCID: PMC4978896 DOI: 10.1534/g3.116.029397] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Budding yeast has undergone several independent transitions from commercial to clinical lifestyles. The frequency of such transitions suggests that clinical yeast strains are derived from environmentally available yeast populations, including commercial sources. However, despite their important role in adaptive evolution, the prevalence of polyploidy and aneuploidy has not been extensively analyzed in clinical strains. In this study, we have looked for patterns governing the transition to clinical invasion in the largest screen of clinical yeast isolates to date. In particular, we have focused on the hypothesis that ploidy changes have influenced adaptive processes. We sequenced 144 yeast strains, 132 of which are clinical isolates. We found pervasive large-scale genomic variation in both overall ploidy (34% of strains identified as 3n/4n) and individual chromosomal copy numbers (36% of strains identified as aneuploid). We also found evidence for the highly dynamic nature of yeast genomes, with 35 strains showing partial chromosomal copy number changes and eight strains showing multiple independent chromosomal events. Intriguingly, a lineage identified to be baker's/commercial derived with a unique damaging mutation in NDC80 was particularly prone to polyploidy, with 83% of its members being triploid or tetraploid. Polyploidy was in turn associated with a >2× increase in aneuploidy rates as compared to other lineages. This dataset provides a rich source of information on the genomics of clinical yeast strains and highlights the potential importance of large-scale genomic copy variation in yeast adaptation.
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Elkhihal B, Elhalimi M, Ghfir B, Mostachi A, Lyagoubi M, Aoufi S. [Urinary infection by Saccharomyces cerevisiae: Emerging yeast?]. J Mycol Med 2015; 25:303-5. [PMID: 26522963 DOI: 10.1016/j.mycmed.2015.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 09/13/2015] [Accepted: 09/14/2015] [Indexed: 10/22/2022]
Abstract
Saccharomyces cerevisiae is a commensal yeast of the digestive, respiratory and genito-urinary tract. It is widely used as a probiotic for the treatment of post-antibiotic diarrhea. It most often occurs in immunocompromised patients frequently causing fungemia. We report the case of an adult diabetic patient who had a urinary tract infection due to S. cerevisiae. The disease started with urination associated with urinary frequency burns without fever. The diagnosis was established by the presence of yeasts on direct examination and positivity of culture on Sabouraud-chloramphenicol three times. The auxanogramme gallery (Auxacolor BioRad(®)) allowed the identification of S. cerevisiae. The patient was put on fluconazole with good outcome. This observation points out that this is an opportunistic yeast in immunocompromised patients.
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Affiliation(s)
- B Elkhihal
- Laboratoire central parasitologie-mycologie, hôpital Ibn Sina, rue Lemfadel-Cherkaoui, BP 6527, Rabat-Souissi, Rabat, Maroc; Faculté de médecine et de pharmacie, université Mohamed V, Rabat, Maroc.
| | - M Elhalimi
- Laboratoire central parasitologie-mycologie, hôpital Ibn Sina, rue Lemfadel-Cherkaoui, BP 6527, Rabat-Souissi, Rabat, Maroc; Faculté de médecine et de pharmacie, université Mohamed V, Rabat, Maroc
| | - B Ghfir
- Laboratoire central parasitologie-mycologie, hôpital Ibn Sina, rue Lemfadel-Cherkaoui, BP 6527, Rabat-Souissi, Rabat, Maroc
| | - A Mostachi
- Laboratoire central parasitologie-mycologie, hôpital Ibn Sina, rue Lemfadel-Cherkaoui, BP 6527, Rabat-Souissi, Rabat, Maroc
| | - M Lyagoubi
- Laboratoire central parasitologie-mycologie, hôpital Ibn Sina, rue Lemfadel-Cherkaoui, BP 6527, Rabat-Souissi, Rabat, Maroc; Faculté de médecine et de pharmacie, université Mohamed V, Rabat, Maroc
| | - S Aoufi
- Laboratoire central parasitologie-mycologie, hôpital Ibn Sina, rue Lemfadel-Cherkaoui, BP 6527, Rabat-Souissi, Rabat, Maroc; Faculté de médecine et de pharmacie, université Mohamed V, Rabat, Maroc
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Rajkowska K, Kunicka-Styczyńska A. Phenotypic and Genotypic Characterization of Probiotic Yeasts. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.1080/13102818.2009.10818511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Martins FS, Vieira AT, Elian SDA, Arantes RME, Tiago FCP, Sousa LP, Araújo HRC, Pimenta PF, Bonjardim CA, Nicoli JR, Teixeira MM. Inhibition of tissue inflammation and bacterial translocation as one of the protective mechanisms of Saccharomyces boulardii against Salmonella infection in mice. Microbes Infect 2013; 15:270-9. [PMID: 23376166 DOI: 10.1016/j.micinf.2012.12.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 11/27/2012] [Accepted: 12/03/2012] [Indexed: 01/23/2023]
Abstract
Growing evidences suggest that Saccharomyces boulardii (SB) is efficacious against bacterial infections and inflammatory bowel diseases. This study investigated the effects of treatment with SB provided in a murine model of typhoid fever. Mice were divided into two groups: (1) control animals challenged with Salmonella Typhimurium (ST), and (2) animals receiving SB, and then challenged with ST. At days 0, 1, 5, 10 and 15 post-challenge, animals were euthanized and tissues collected to analyze bacterial translocation, cytokines, signaling pathways and histological analysis. Survival rate and animal weight were also evaluated. Treatment with SB increased survival rate and inhibited translocation of bacteria after ST challenge. Histological data showed that SB also protected mice against liver damage induced by ST. SB decreased levels of inflammatory cytokines and activation of mitogen-activated protein kinases (p38, JNK and ERK1/2), phospho-IκB, p65-RelA, phospho-jun and c-fos in the colon, signal pathways involved in the activation of inflammation induced by ST. Further experiments revealed that probiotic effects were due, at least in part, to the binding of ST to the yeast. Such binding diminishes ST translocation, resulting in decreased activation of signaling pathways which lead to intestinal inflammation in a murine model of typhoid fever.
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Affiliation(s)
- Flaviano S Martins
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
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Muller LAH, Lucas JE, Georgianna DR, McCusker JH. Genome-wide association analysis of clinical vs. nonclinical origin provides insights into Saccharomyces cerevisiae pathogenesis. Mol Ecol 2011; 20:4085-97. [PMID: 21880084 DOI: 10.1111/j.1365-294x.2011.05225.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Because domesticated Saccharomyces cerevisiae strains have been used to produce fermented food and beverages for centuries without apparent health implications, S. cerevisiae has always been considered a Generally Recognized As Safe (GRAS) microorganism. However, the number of reported mucosal and systemic S. cerevisiae infections in the human population has increased and fatal infections have occurred even in relatively healthy individuals. In order to gain insight into the pathogenesis of S. cerevisiae and improve our understanding of the emergence of fungal pathogens, we performed a population-based genome-wide environmental association analysis of clinical vs. nonclinical origin in S. cerevisiae. Using tiling array-based, high-density genotypes of 44 clinical and 44 nonclinical S. cerevisiae strains from diverse geographical origins and source substrates, we identified several genetic loci associated with clinical background in S. cerevisiae. Associated polymorphisms within the coding sequences of VRP1, KIC1, SBE22 and PDR5, and the 5' upstream region of YGR146C indicate the importance of pseudohyphal formation, robust cell wall maintenance and cellular detoxification for S. cerevisiae pathogenesis, and constitute good candidates for follow-up verification of virulence and virulence-related factors underlying the pathogenicity of S. cerevisiae.
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Affiliation(s)
- L A H Muller
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
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Oda Y, Mikumo D, Leo F, Urashima T. Discrimination of Saccharomyces cerevisiae and Saccharomyces paradoxus strains by the SUC2 gene sequences. J GEN APPL MICROBIOL 2010; 56:355-8. [PMID: 20953100 DOI: 10.2323/jgam.56.355] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Yuji Oda
- Department of Food Science, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
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Vanhee L, Goemé F, Nelis H, Coenye T. Quality control of fifteen probiotic products containing Saccharomyces boulardii. J Appl Microbiol 2010; 109:1745-52. [DOI: 10.1111/j.1365-2672.2010.04805.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Zupan J, Raspor P. Invasive growth of Saccharomyces cerevisiae depends on environmental triggers: a quantitative model. Yeast 2010; 27:217-28. [PMID: 20052657 DOI: 10.1002/yea.1746] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In this contribution, the influence of various physicochemical factors on Saccharomyces cerevisiae invasive growth is examined quantitatively. Agar-invasion assays are generally applied for in vitro studies on S. cerevisiae invasiveness, the phenomenon observed as a putative virulence trait in this clinically more and more concerning yeast. However, qualitative agar-invasion assays, used until now, strongly limit the feasibility and interpretation of analyses and therefore needed to be improved. Besides, knowledge in this field concerning the physiology of invasive growth, influenced by stress conditions related to the human alimentary tract and food, is poor and should be expanded. For this purpose, a quantitative agar-invasion assay, presented in our previous work, was applied in this contribution to clarify the significance of the stress factors controlling the adhesion and invasion of the yeast in greater detail. Ten virulent and non-virulent S. cerevisiae strains were assayed at various temperatures, pH values, nutrient starvation, modified atmosphere, and different concentrations of NaCl, CaCl2 and preservatives. With the use of specific parameters, like a relative invasion, eight invasive growth models were hypothesized, which enabled intelligible interpretation of the results. A strong preference for invasive growth (meaning high relative invasion) was observed when the strains were grown on nitrogen- and glucose-depleted media. A significant increase in the invasion of the strains was also determined at temperatures typical for human fever (37-39 degrees C). On the other hand, a strong repressive effect on invasion was found in the presence of salts, anoxia and some preservatives.
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Affiliation(s)
- Jure Zupan
- Biotechnology, Microbiology and Food Safety, Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
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12
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McFarland LV. Systematic review and meta-analysis of Saccharomyces boulardii in adult patients. World J Gastroenterol 2010; 16:2202-22. [PMID: 20458757 PMCID: PMC2868213 DOI: 10.3748/wjg.v16.i18.2202] [Citation(s) in RCA: 300] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 02/13/2010] [Accepted: 02/20/2010] [Indexed: 02/06/2023] Open
Abstract
This article reviews the evidence for efficacy and safety of Saccharomyces boulardii (S. boulardii) for various disease indications in adults based on the peer-reviewed, randomized clinical trials and pre-clinical studies from the published medical literature (Medline, Clinical Trial websites and meeting abstracts) between 1976 and 2009. For meta-analysis, only randomized, blinded controlled trials unrestricted by language were included. Pre-clinical studies, volunteer studies and uncontrolled studies were excluded from the review of efficacy and meta-analysis, but included in the systematic review. Of 31 randomized, placebo-controlled treatment arms in 27 trials (encompassing 5029 study patients), S. boulardii was found to be significantly efficacious and safe in 84% of those treatment arms. A meta-analysis found a significant therapeutic efficacy for S. boulardii in the prevention of antibiotic-associated diarrhea (AAD) (RR = 0.47, 95% CI: 0.35-0.63, P < 0.001). In adults, S. boulardii can be strongly recommended for the prevention of AAD and the traveler's diarrhea. Randomized trials also support the use of this yeast probiotic for prevention of enteral nutrition-related diarrhea and reduction of Helicobacter pylori treatment-related symptoms. S. boulardii shows promise for the prevention of C. difficile disease recurrences; treatment of irritable bowel syndrome, acute adult diarrhea, Crohn's disease, giardiasis, human immunodeficiency virus-related diarrhea; but more supporting evidence is recommended for these indications. The use of S. boulardii as a therapeutic probiotic is evidence-based for both efficacy and safety for several types of diarrhea.
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Zupan J, Mavri J, Raspor P. Quantitative cell wall protein profiling of invasive and non-invasive Saccharomyces cerevisiae strains. J Microbiol Methods 2009; 79:260-5. [DOI: 10.1016/j.mimet.2009.09.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 08/28/2009] [Accepted: 09/03/2009] [Indexed: 11/25/2022]
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Muller LAH, McCusker JH. Microsatellite analysis of genetic diversity among clinical and nonclinical Saccharomyces cerevisiae isolates suggests heterozygote advantage in clinical environments. Mol Ecol 2009; 18:2779-86. [PMID: 19457175 DOI: 10.1111/j.1365-294x.2009.04234.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The genetic structure of a global sample of 170 clinical and nonclinical Saccharomyces cerevisiae isolates was analysed using 12 microsatellite markers. High levels of genetic diversity were revealed both among the clinical and among the nonclinical S. cerevisiae isolates without significant differentiation between these two groups of isolates, rendering a single origin of pathogenic isolates unlikely. This suggests that S. cerevisiae is a true opportunistic pathogen, with a diversity of unrelated genetic backgrounds able to cause infections in humans, and that the ability of S. cerevisiae isolates to cause infections is likely due to a combination of their phenotypic plasticity and the immune system status of the exposed individuals. As was previously reported for bread, beer and wine strains and for environmental S. cerevisiae isolates, the microsatellite genotypes indicated ploidy level variation, from possibly haploid up to tetraploid, among clinical S. cerevisiae isolates. However, rather than haploid, sporulation proficiency and spore viability data indicated that most S. cerevisiae isolates that were mono-allelic at all examined microsatellite loci were likely homothallic and self-diploidized. Interestingly, the proportion of heterozygous clinical isolates was found to be significantly higher than the proportion of heterozygous nonclinical isolates, suggesting a selective advantage of heterozygous S. cerevisiae yeasts in clinical environments.
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Affiliation(s)
- Ludo A H Muller
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
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Buts JP. Twenty-five years of research on Saccharomyces boulardii trophic effects: updates and perspectives. Dig Dis Sci 2009; 54:15-8. [PMID: 18528758 DOI: 10.1007/s10620-008-0322-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Accepted: 05/06/2008] [Indexed: 12/13/2022]
Affiliation(s)
- Jean-Paul Buts
- Laboratory of Pediatric Gastroenterology and Nutrition, Faculty of Medicine, Université Catholique de Louvain, Tour Pasteur +3, 53, Avenue Mounier, 1200, Brussels, Belgium.
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Richard GF, Kerrest A, Dujon B. Comparative genomics and molecular dynamics of DNA repeats in eukaryotes. Microbiol Mol Biol Rev 2008; 72:686-727. [PMID: 19052325 PMCID: PMC2593564 DOI: 10.1128/mmbr.00011-08] [Citation(s) in RCA: 323] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Repeated elements can be widely abundant in eukaryotic genomes, composing more than 50% of the human genome, for example. It is possible to classify repeated sequences into two large families, "tandem repeats" and "dispersed repeats." Each of these two families can be itself divided into subfamilies. Dispersed repeats contain transposons, tRNA genes, and gene paralogues, whereas tandem repeats contain gene tandems, ribosomal DNA repeat arrays, and satellite DNA, itself subdivided into satellites, minisatellites, and microsatellites. Remarkably, the molecular mechanisms that create and propagate dispersed and tandem repeats are specific to each class and usually do not overlap. In the present review, we have chosen in the first section to describe the nature and distribution of dispersed and tandem repeats in eukaryotic genomes in the light of complete (or nearly complete) available genome sequences. In the second part, we focus on the molecular mechanisms responsible for the fast evolution of two specific classes of tandem repeats: minisatellites and microsatellites. Given that a growing number of human neurological disorders involve the expansion of a particular class of microsatellites, called trinucleotide repeats, a large part of the recent experimental work on microsatellites has focused on these particular repeats, and thus we also review the current knowledge in this area. Finally, we propose a unified definition for mini- and microsatellites that takes into account their biological properties and try to point out new directions that should be explored in a near future on our road to understanding the genetics of repeated sequences.
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Affiliation(s)
- Guy-Franck Richard
- Institut Pasteur, Unité de Génétique Moléculaire des Levures, CNRS, URA2171, Université Pierre et Marie Curie, UFR927, 25 rue du Dr. Roux, F-75015, Paris, France.
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17
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Zupan J, Raspor P. Quantitative agar-invasion assay. J Microbiol Methods 2008; 73:100-4. [PMID: 18358550 DOI: 10.1016/j.mimet.2008.02.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 01/18/2008] [Accepted: 02/15/2008] [Indexed: 11/27/2022]
Abstract
A new method for quantification of yeast invasion into the agar medium was developed. Classical agar-invasion assays have been the methods of choice for determination of yeast invasion, but their main disadvantage is the lack of quantification. Our new Quantitative yeast agar-invasion test allows for quantitative measurements and enables sorting strains by their degree of invasiveness. The invasion abilities were measured for 10 clinical and non-clinical Saccharomyces cerevisiae strains and a strain of Candida albicans. Finally, the correlation between the degrees of strains invasiveness and their reported virulence was observed, proposing our assay as a method for quick determination of yeast virulence potential.
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Affiliation(s)
- Jure Zupan
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
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18
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Jubany S, Tomasco I, Ponce de León I, Medina K, Carrau F, Arrambide N, Naya H, Gaggero C. Toward a global database for the molecular typing of Saccharomyces cerevisiae strains. FEMS Yeast Res 2008; 8:472-84. [DOI: 10.1111/j.1567-1364.2008.00361.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Discrimination of Saccharomyces cerevisiae wine strains using microsatellite multiplex PCR and band pattern analysis. Food Microbiol 2008; 25:56-64. [DOI: 10.1016/j.fm.2007.08.001] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2006] [Revised: 08/07/2007] [Accepted: 08/16/2007] [Indexed: 11/22/2022]
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20
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Chang HW, Nam YD, Sung Y, Kim KH, Roh SW, Yoon JH, An KG, Bae JW. Quantitative real time PCR assays for the enumeration of Saccharomyces cerevisiae and the Saccharomyces sensu stricto complex in human feces. J Microbiol Methods 2007; 71:191-201. [PMID: 17900724 DOI: 10.1016/j.mimet.2007.08.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 08/09/2007] [Accepted: 08/29/2007] [Indexed: 11/27/2022]
Abstract
There have been an increasing number of reports of yeast systemic infection involving Saccharomyces cerevisiae strains. The development of a rapid and reliable diagnostic tool is therefore warranted in order to explore the distribution of S. cerevisiae as an opportunistic pathogen in humans. In this study, we designed and validated five primer sets targeting the 26S rRNA gene of S. cerevisiae and the S. sensu stricto complex using 26 yeast strains. Among them, two sets of primers specifically amplified the 26S rRNA gene and the ITS region of S. cerevisiae strains, and three sets were specific for amplifying the same genes in the S. sensu stricto complex. After determining the optimal conditions of two primer pairs for quantitative real time PCR, human fecal samples were analyzed to examine the distribution of S. cerevisiae and the S. sensu stricto complex. It was possible to detect a single cell of S. cerevisiae in environmental sample. Qualitative PCR revealed that out of eleven fecal samples tested, one sample contained S. cerevisiae and four samples contained the S. sensu stricto complex. Quantitative real time PCR revealed that the target gene copy numbers of S. cerevisiae and the S. sensu stricto complex were 0.84 and 2.44 respectively, in 1 ng of DNA from the bulk fecal community.
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Affiliation(s)
- Ho-Won Chang
- Biological Resources Center, KRIBB, Daejeon 305-806, Republic of Korea
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Lopes M, Silva D, Freitas G, Tenreiro R. Simultaneous identification and typing of Candida species by MSP-PCR and AFLP: Study of clinical isolates from a Portuguese pediatric hospital. J Mycol Med 2007. [DOI: 10.1016/j.mycmed.2007.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Landry CR, Townsend JP, Hartl DL, Cavalieri D. Ecological and evolutionary genomics of Saccharomyces cerevisiae. Mol Ecol 2006; 15:575-91. [PMID: 16499686 DOI: 10.1111/j.1365-294x.2006.02778.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Saccharomyces cerevisiae, the budding yeast, is the most thoroughly studied eukaryote at the cellular, molecular, and genetic levels. Yet, until recently, we knew very little about its ecology or population and evolutionary genetics. In recent years, it has been recognized that S. cerevisiae occupies numerous habitats and that populations harbour important genetic variation. There is therefore an increasing interest in understanding the evolutionary forces acting on the yeast genome. Several researchers have used the tools of functional genomics to study natural isolates of this unicellular fungus. Here, we review some of these studies, and show not only that budding yeast is a prime model system to address fundamental molecular and cellular biology questions, but also that it is becoming a powerful model species for ecological and evolutionary genomics studies as well.
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Affiliation(s)
- Christian R Landry
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA.
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Buts JP, Bernasconi P. Saccharomyces boulardii: basic science and clinical applications in gastroenterology. Gastroenterol Clin North Am 2005; 34:515-32, x. [PMID: 16084311 DOI: 10.1016/j.gtc.2005.05.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- Jean-Paul Buts
- Department of Pediatrics, Cliniques Universitaires St-Luc, Catholic University of Louvain, 10 Avenue Hippocrate, B-1200 Brussels, Belgium.
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Current awareness on yeast. Yeast 2005; 22:919-26. [PMID: 16201058 DOI: 10.1002/yea.1167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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