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MacNeil D, Strobeck C. EVOLUTIONARY RELATIONSHIPS AMONG COLONIES OF COLUMBIAN GROUND SQUIRRELS AS SHOWN BY MITOCHONDRIAL DNA. Evolution 2017; 41:873-881. [DOI: 10.1111/j.1558-5646.1987.tb05860.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/1986] [Accepted: 11/26/1986] [Indexed: 11/27/2022]
Affiliation(s)
- Donna MacNeil
- Department of Zoology; University of Alberta; Edmonton AB T6G 2E9 Canada
| | - Curtis Strobeck
- Department of Zoology; University of Alberta; Edmonton AB T6G 2E9 Canada
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2
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Abstract
Although plasmids containing rRNA genes (rDNA) are commonly found in fungi, they have not been reported in Candida. We discovered that the yeast opportunistic pathogen Candida albicans contains two types of rDNA plasmids which differ in their structure and number of rDNA repeats. A large circular plasmid of unknown size consists of multiple rDNA repeats, each of which includes an associated autonomously replicating sequence (ARS). In contrast, a linear plasmid, which is represented by a series of molecules with a spread of sizes ranging from 50-150 kbp, carries a limited number of rDNA units and associated ARSs, as well as telomeres. The number of linear plasmids per cell is growth cycle-dependent, accumulating in abundance in actively growing cells. We suggest that the total copy number of rDNA is better controlled when a portion of copies are on a linear extrachromosomal plasmid, thus allowing a rapid shift in the number of corresponding genes and, as a result, better adaptation to the environment. This is the first report of a linear rDNA plasmid in yeast, as well as of the coexistence of circular and linear plasmids. In addition, this is a first report of naturally occurring plasmids in C. albicans.
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MESH Headings
- Blotting, Southern
- Candida albicans/chemistry
- Candida albicans/genetics
- Candida albicans/growth & development
- Chromosomes, Fungal/chemistry
- Chromosomes, Fungal/genetics
- DNA Probes/chemistry
- DNA, Circular/genetics
- DNA, Fungal/chemistry
- DNA, Fungal/genetics
- DNA, Fungal/isolation & purification
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- DNA, Ribosomal/isolation & purification
- Electrophoresis, Gel, Pulsed-Field
- Plasmids/chemistry
- Plasmids/genetics
- Plasmids/isolation & purification
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Affiliation(s)
- D Huber
- Department of Biochemistry and Biophysics, University of Rochester Medical School, Rochester, NY 14642, USA
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3
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Abstract
DNA fingerprinting methods have evolved as major tools in fungal epidemiology. However, no single method has emerged as the method of choice, and some methods perform better than others at different levels of resolution. In this review, requirements for an effective DNA fingerprinting method are proposed and procedures are described for testing the efficacy of a method. In light of the proposed requirements, the most common methods now being used to DNA fingerprint the infectious fungi are described and assessed. These methods include restriction fragment length polymorphisms (RFLP), RFLP with hybridization probes, randomly amplified polymorphic DNA and other PCR-based methods, electrophoretic karyotyping, and sequencing-based methods. Procedures for computing similarity coefficients, generating phylogenetic trees, and testing the stability of clusters are then described. To facilitate the analysis of DNA fingerprinting data, computer-assisted methods are described. Finally, the problems inherent in the collection of test and control isolates are considered, and DNA fingerprinting studies of strain maintenance during persistent or recurrent infections, microevolution in infecting strains, and the origin of nosocomial infections are assessed in light of the preceding discussion of the ins and outs of DNA fingerprinting. The intent of this review is to generate an awareness of the need to verify the efficacy of each DNA fingerprinting method for the level of genetic relatedness necessary to answer the epidemiological question posed, to use quantitative methods to analyze DNA fingerprint data, to use computer-assisted DNA fingerprint analysis systems to analyze data, and to file data in a form that can be used in the future for retrospective and comparative studies.
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4
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Abstract
DNA fingerprinting methods have evolved as major tools in fungal epidemiology. However, no single method has emerged as the method of choice, and some methods perform better than others at different levels of resolution. In this review, requirements for an effective DNA fingerprinting method are proposed and procedures are described for testing the efficacy of a method. In light of the proposed requirements, the most common methods now being used to DNA fingerprint the infectious fungi are described and assessed. These methods include restriction fragment length polymorphisms (RFLP), RFLP with hybridization probes, randomly amplified polymorphic DNA and other PCR-based methods, electrophoretic karyotyping, and sequencing-based methods. Procedures for computing similarity coefficients, generating phylogenetic trees, and testing the stability of clusters are then described. To facilitate the analysis of DNA fingerprinting data, computer-assisted methods are described. Finally, the problems inherent in the collection of test and control isolates are considered, and DNA fingerprinting studies of strain maintenance during persistent or recurrent infections, microevolution in infecting strains, and the origin of nosocomial infections are assessed in light of the preceding discussion of the ins and outs of DNA fingerprinting. The intent of this review is to generate an awareness of the need to verify the efficacy of each DNA fingerprinting method for the level of genetic relatedness necessary to answer the epidemiological question posed, to use quantitative methods to analyze DNA fingerprint data, to use computer-assisted DNA fingerprint analysis systems to analyze data, and to file data in a form that can be used in the future for retrospective and comparative studies.
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Affiliation(s)
- D R Soll
- Department of Biological Sciences, University of Iowa, Iowa City, IA 52242, USA.
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5
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Mercure S, Montplaisir S, Lemay G. Correlation between the presence of a self-splicing intron in the 25S rDNA of C.albicans and strains susceptibility to 5-fluorocytosine. Nucleic Acids Res 1993; 21:6020-7. [PMID: 7904747 PMCID: PMC310489 DOI: 10.1093/nar/21.25.6020] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Candida albicans presents a well characterized EcoRI RFLP pattern of intensely staining bands. One of these bands, the dimorphic 3.7/4.2 kbp fragment shown to originate from the ribosomal RNA-encoding regions (rDNA), has been used by several investigators to subdivide C. albicans strains in two distinct subtypes. In the present manuscript, we report that an epidemiological study of 120 C.albicans strains revealed a significant correlation between these subtypes and susceptibility to 5-fluorocytosine, an antifungal agent extensively used for biotyping C.albicans. The 4.2 kbp strains being generally more susceptible than their counterparts to this agent and one of its metabolic by-product, 5-fluorouracil. A 379 nucleotides insertion in the 25S rRNA-encoding gene of 4.2 kbp type strains was shown to be responsible for the 3.7/4.2 size difference. This intervening sequence is typical of a group I intron by its site of insertion, its predicted secondary structure, and its self-splicing capability. Assuming there is a genuine causal relationship between presence of the intron and resistance to 5-fluorocytosine, one possible mechanism suggests that inhibition of self-splicing by the insertion of 5-fluorouracil residues in the 25S rRNA precursor might be responsible for the higher susceptibility of 4.2 kbp type strains.
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Affiliation(s)
- S Mercure
- Département de Microbiologie et Immunologie, Faculté de Médecine, Université de Montréal, Québec, Canada
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6
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Bart-Delabesse E, Boiron P, Carlotti A, Dupont B. Candida albicans genotyping in studies with patients with AIDS developing resistance to fluconazole. J Clin Microbiol 1993; 31:2933-7. [PMID: 7903316 PMCID: PMC266158 DOI: 10.1128/jcm.31.11.2933-2937.1993] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We characterized Candida albicans strains responsible for recurrent oropharyngeal candidosis (OPC) in four patients with AIDS who developed clinical and mycological resistance to fluconazole (FCZ). Karyotype and restriction fragment length polymorphism analyses were performed on the clonal populations to differentiate relapse from reinfection, and the results were assessed with those of serotype and FCZ MICs. Despite the polymorphism in chromosomal bands larger than 2.2 Mbp related to an intraclonal variation, karyotype analysis showed a single strain type attributable to each patient. On the other hand, EcoRI and HinfI restriction fragments revealed a polymorphism for one patient between the first sample and the subsequent ones, relevant to the acquisition of a new strain causing the following episodes of OPC. This result coincided with switching of the serotype and with the acquisition of a resistance to FCZ. For the other three patients, the similarity of the DNA electrophoretic patterns and the serotype of the samples suggested that recurrence can be due to the initial strain that generates FCZ resistance. Although useful for epidemiological studies, molecular typing methods seem to be inadequate to detect the acquisition of FCZ resistance.
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7
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Reiss E, Morrison CJ. Nonculture methods for diagnosis of disseminated candidiasis. Clin Microbiol Rev 1993; 6:311-23. [PMID: 8269389 PMCID: PMC358291 DOI: 10.1128/cmr.6.4.311] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Two of the nonculture approaches to the diagnosis of DC, enzymatic-fluorometric determination of serum D-arabinitol and detection of marker antigens in antigenemia (enolase and CWMP), have been commercialized and have shown promise in limited clinical trials. These approaches are not new but are the culmination of efforts made over 10 or more years. Clearly, further fine-tuning of both metabolite and antigen detection is needed to simplify the methods and to improve their sensitivity and specificity so that they will be valuable in guiding clinical treatment decisions. An alternative approach, detection of DC by DNA amplification methods such as PCR, is a special case of a compelling technology and one that is capable of standardization across microbial genera. The availability of simplified PCR diagnostic methods for DC remains a tantalizing prospect. Nevertheless, the development of methods to release DNA from very small numbers of Candida organisms in the blood in a form that is sufficiently free of inhibitors of PCR will require further intensive effort. The maturation of these converging laboratory approaches to nonculture diagnosis of DC leads to more optimism about the eventual use of these methods in clinical laboratories.
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Affiliation(s)
- E Reiss
- Molecular Mycology Section, Centers for Disease Control and Prevention, Atlanta, Georgia 30333
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8
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Cooper CR, Breslin BJ, Dixon DM, Salkin IF. DNA typing of isolates associated with the 1988 sporotrichosis epidemic. J Clin Microbiol 1992; 30:1631-5. [PMID: 1352783 PMCID: PMC265355 DOI: 10.1128/jcm.30.7.1631-1635.1992] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
DNA typing techniques were used to examine selected clinical and environmental isolates of Sporothorix spp. recovered from the 1988 sporotrichosis epidemic in multiple states of the United States. Previous studies indicated that isolates in one of the six morphologically or physiologically distinct groups (group I) obtained from environmental sources were Sporothrix schenckii and were the possible etiologic agents responsible for the epidemic. To assess this hypothesis at the genetic level, whole-cell DNA was extracted from selected clinical isolates and representative members of each of the six environmental groups subjected to endonuclease digestion and then analyzed by gel electrophresis. DNA types were assigned on the basis of restriction fragment length polymorphism patterns. One DNA type was common to clinical and group I isolates but was dissimilar from the DNA types exhibited by groups II to VI. In contrast, a variety of DNA types were associated with isolates in groups II to VI. The latter groups appeared to make up a heterogeneous collection of fungi, with some members of the same group having different DNA types but with others from different groups possessing identical DNA types. Thus, DNA typing studies confirmed that group I environmental isolates are indistinguishable from clinical isolates and that group II to VI isolates represent a complex of related fungi with similar Sporothrix anamorphs.
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Affiliation(s)
- C R Cooper
- Laboratories for Mycology, Wadsworth Center for Laboratories and Research, New York State Department of Health, Albany 12201-0509
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9
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Lasker BA, Page LS, Lott TJ, Kobayashi GS. Isolation, characterization, and sequencing of Candida albicans repetitive element 2. Gene X 1992; 116:51-7. [PMID: 1628844 DOI: 10.1016/0378-1119(92)90628-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A 1059-bp Sau3A fragment, designated Candida albicans repetitive element 2 (CARE-2), was isolated from the genome of the pathogenic yeast, C. albicans. CARE-2 DNA was detected on several C. albicans chromosomes separated by transverse alternating-field electrophoresis. A high degree of interstrain variation in the pattern of hybridizing bands were observed by Southern blot analysis, with a minimum of 10-14 copies of CARE-2 per strain. A low frequency of new CARE-2 polymorphisms was observed over time for three strains grown at 25 degrees C or 37 degrees C. No new CARE-2 polymorphisms were observed from two naturally occurring switch phenotypes. To localize repeated DNA, oligodeoxyribonucleotide probes, each representing a different region of CARE-2, were hybridized to genomic blots. A lower number of copies were observed 5' and 3' to a 600-bp region of CARE-2. Nucleotide (nt) sequence analysis of CARE-2 DNA shows the element is characterized by six perfect direct repeats 6 bp in length and shows no significant DNA similarity with any known nt sequence.
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Affiliation(s)
- B A Lasker
- Division of Bacterial and Mycotic Diseases, Centers for Disease Control, Atlanta, GA 30333
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10
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Miyakawa Y, Mabuchi T, Kagaya K, Fukazawa Y. Isolation and characterization of a species-specific DNA fragment for detection of Candida albicans by polymerase chain reaction. J Clin Microbiol 1992; 30:894-900. [PMID: 1572976 PMCID: PMC265181 DOI: 10.1128/jcm.30.4.894-900.1992] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
A 2-kbp DNA fragment, EO3, that was present in multiple copies in the Candida albicans genome was isolated for use in developing a detection method for C. albicans by polymerase chain reaction (PCR). Dot blot hybridization revealed that EO3 was specific for the 40 isolates of C. albicans serotypes A and B used. Using a set of primers (20-mer each) derived from the nucleotide sequence of EO3, we performed specific amplification of a 1.8-kbp DNA fragment within EO3 by PCR. All 40 isolates belonging to C. albicans serotypes A and B contained amplifiable 1.8-bkp fragments, although the DNA of the amplified products exhibited small variations in size, yielding three different fragment groups. Southern blot hybridization probed with EO3 showed that these 1.8-kbp fragments were derived from the EO3 region. Conversely, the 1.8-kbp fragment was not amplified from 38 isolates belonging to seven other medically important Candida species or from isolates of Cryptococcus neoformans, Saccharomyces cerevisiae, various bacteria, and a human cell line. The detection limit of the PCR assay for C. albicans with the EO3 fragment was shown to be approximately 2 to 10 cells and 100 cells in saline and human urine, respectively, by ethidium bromide staining and 2 and 10 cells, respectively, by Southern blot analysis. In addition, EO3 was assumed to originate from mitochondrial DNA on the basis of the results of its characterizations. These results indicate that the PCR system using the 1.8-kbp fragment as a target is a reliable method for identifying C. albicans isolates, thereby suggesting its potentials for specific and sensitive detection of C. albicans in samples from patients with candidiasis.
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Affiliation(s)
- Y Miyakawa
- Department of Microbiology, Yamanashi Medical College, Japan
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11
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Soll DR. Molecular biology of Candida pathogenesis. MOLECULAR AND CELL BIOLOGY OF HUMAN DISEASES SERIES 1992; 1:131-72. [PMID: 1341641 DOI: 10.1007/978-94-011-2384-6_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- D R Soll
- Department of Biology, University of Iowa, Iowa City 52242
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12
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13
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Takeda Y, Kawasaki M, Ishizaki H. Phylogeny and molecular epidemiology of Sporothrix schenckii in Japan. Mycopathologia 1991; 116:9-14. [PMID: 1766461 DOI: 10.1007/bf00436084] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Mitochondrial DNA(mtDNA) diversity was investigated in 257 clinical isolants of Sporothrix schenckii obtained from 4 districts in Japan. S. schenckii was classified into 10 types based on Hae III restriction profiles. Phylogeny of types constructed by the method of Fitch and Margoliash [1] on the estimated sequence divergence within mtDNA using the methods of Nei and Li [2], showed that S. schenckii are grouped into 2 clusters, one group consisting of types 1, 2 and 3, and the other group consisting of the other seven types. In addition, types 1, 2, and 5 were correlated with their geographic origin, whereas type 4 was present throughout Japan.
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Affiliation(s)
- Y Takeda
- Department of Dermatology, Kanazawa Medical University, Ishikawa, Japan
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14
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Pearce MA, Howell SA. Restriction fragment length polymorphism analysis of azole-resistant and azole-susceptible Candida albicans strains. J Clin Microbiol 1991; 29:1364-7. [PMID: 1679438 PMCID: PMC270118 DOI: 10.1128/jcm.29.7.1364-1367.1991] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Restriction fragment length polymorphism analysis was performed with the endonucleases EcoRI, BglII, and HinfI on a collection of Candida albicans strains comprising eight strains randomly selected from clinical microbiology laboratory specimens, three reported azole-resistant strains from treatment failures, and several subcultures of the azole-resistant strain NCPF 3310 (also known as the Darlington strain) received from different laboratories. The results demonstrated a diversity of the restriction fragment length polymorphism patterns that were obtained and revealed that two of the proposed Darlington subcultures had patterns distinct from each other and from those of the other Darlington isolates; both were also found to have lost their azole resistance.
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Affiliation(s)
- M A Pearce
- Institute of Dermatology, St. Thomas' Hospital, London, United Kingdom
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15
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Lasker BA, Page LS, Lott TJ, Kobayashi GS, Medoff G. Characterization of CARE-1: Candida albicans repetitive element-1. Gene 1991; 102:45-50. [PMID: 1864508 DOI: 10.1016/0378-1119(91)90536-k] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A middle repetitive DNA element, Candida albicans repetitive element-1 (CARE-1) has been isolated from the pathogenic yeast C. albicans. CARE-1 appears to be species-specific and constitutes approx. 0.045% of total C. albicans DNA, or a reiteration frequency of about two to twelve copies per haploid genome. The CARE-1 element has been detected on several C. albicans chromosomes separated by field-inversion gel electrophoresis, suggesting that the element is dispersed. Interstrain variation was observed in the number and distribution of hybridizing bands. The element is well conserved, since no nucleotide (nt) heterogeneity was observed when the sequences of two CARE-1 family members isolated from two different chromosomes (A and B) of C. albicans were compared. CARE-1 possesses 467 bp and is characterized by several stretches of A's and T's, short direct repeats and shows no significant homology to any known nt sequence.
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Affiliation(s)
- B A Lasker
- Division of Bacterial and Mycotic Diseases, Centers for Disease Control, Atlanta 30333
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16
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Carruba G, Pontieri E, De Bernardis F, Martino P, Cassone A. DNA fingerprinting and electrophoretic karyotype of environmental and clinical isolates of Candida parapsilosis. J Clin Microbiol 1991; 29:916-22. [PMID: 2056059 PMCID: PMC269908 DOI: 10.1128/jcm.29.5.916-922.1991] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The endonuclease restriction pattern (DNA fingerprinting) and the electrophoretic karyotype of 16 Candida parapsilosis isolates from environmental and clinical sources were investigated. DNA from both whole cells and separated mitochondria was digested with enzymes, including EcoRI, BamHI, KpnI, BglII, HpaII, PvuII, and HindIII. Regardless of their source and pathogenic properties, all isolates showed a uniform, reproducible, and overlapping whole-cell DNA fingerprinting with each endonuclease digest. Mitochondrial DNA fragments were, in all cases, major contributors to the total cellular DNA restriction pattern. In contrast, the electrophoretic karyotype generated by rotating field gel electrophoresis (RFGE) or contour clamped homogeneous field electrophoresis (CHEF) showed a remarkable polymorphism among the isolates. This polymorphism concerned the smaller molecular size section of the karyotype (range, 1.8 to 0.7 Mb), where at least two to five chromosomal bands could be consistently detected by both RFGE and CHEF. Larger (greater than or equal to 3.0 to 1.9 Mb) chromosome-sized DNA bands (four in CHEF and three in RFGE) were quite distinct and common to all isolates. Thus, seven karyotype classes could be defined, on the basis of both the number and size of putative chromosomes. The three categories of isolates (soil, vaginal, and hematological) were not randomly distributed among the seven classes. In particular, the four hematological isolates had a karyotype pattern which was clearly distinct from that shown by the three environmental isolates, and of the nine vaginal isolates only one shared a class with isolates from another source (soil). Although tentative, the classification was totally consistent with the independent and reproducible results obtained by the two pulse-field electrophoretic techniques employed. It is suggested that the electrophoretic analysis of the karyotype might be particularly useful for epidemiological and pathogenicity studies on biotypes of C. parapsilosis.
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Affiliation(s)
- G Carruba
- Department of Experimental Medicine, University of L'Aquila, Italy
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17
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Vazquez JA, Beckley A, Sobel JD, Zervos MJ. Comparison of restriction enzyme analysis and pulsed-field gradient gel electrophoresis as typing systems for Candida albicans. J Clin Microbiol 1991; 29:962-7. [PMID: 1647409 PMCID: PMC269916 DOI: 10.1128/jcm.29.5.962-967.1991] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Candida species are an important cause of infection in immunocompromised hosts and the leading cause of nosocomial fungal infections. Study of the epidemiology of Candida infection has been difficult because of lack of a reliable typing system. We describe a typing system utilizing contour-clamped homogeneous electric fields (CHEF), which is a modified version of pulsed-field gradient gel electrophoresis, and compared it with restriction enzyme analysis (REA) of genomic DNA. The study was done with 35 Candida albicans clinical isolates from separate patients. CHEF and REA were performed on each isolate, and the patterns were compared. The REA procedure revealed 17 strain types while the CHEF procedure was able to distinguish 23 strain types of C. albicans. The CHEF technique yields unique patterns of chromosomal bands that can be used to distinguish clinical isolates and demonstrates greater sensitivity than REA.
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Affiliation(s)
- J A Vazquez
- Department of Internal Medicine, Wayne State University School of Medicine, Detroit, Michigan 48201
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18
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Ho NW, Petros D, Deng XX. Genetic transformation of xylose-fermenting yeast Pichia stipitis. Scientific note. Appl Biochem Biotechnol 1991; 28-29:369-75. [PMID: 1929374 DOI: 10.1007/bf02922616] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A plasmid-mediated transformation system has been developed for the xylose-fermenting yeast Pichia stipitis. We found that plasmid vectors containing the Saccharomyces cerevisiae 2 mu replicon and the kanamycin resistance gene (KmR) could be introduced into the Pichia cells and maintained as extrachromosomal elements. Pichia transformants containing such vectors will be resistant to the antibiotic geneticin that can be inactivated by the protein product of KmR. Plasmids identical to those used for transformation can be recovered from the Pichia transformants. Protocols for transformation of P. stipitis by the CaCl2-polyethylene glycol-protoplast process or by direct electroporation of intact Pichia cells have both been developed.
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Affiliation(s)
- N W Ho
- Laboratory of Renewable Resources Engineering, Purdue University, West Lafayette, IN 47907
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19
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Perlin MH, Bej AK, Will OH, Jacob RJ. Introduction and maintenance of prokaryotic DNA in Ustilago violacea. ACTA ACUST UNITED AC 1991; 5:355-63. [PMID: 1366759 DOI: 10.1007/bf01578094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
A strain of the basidiomycete, Ustilago violacea, was transformed with a prokaryotic plasmid, pMP4-1, which confers resistance to neomycin. U. violacea transformants were selected at a frequency of 5 per microgram pMP4-1 DNA. Such transformants were at least 8-fold more resistant to neomycin than was the untransformed recipient U. violacea. Enzyme activity associated with the neomycin resistance gene was also found in the transformants. Southern DNA-DNA hybridization detected pMP4-1-derived sequences in both nuclear and mitochondrially-associated DNAs from transformants. The patterns of hybridization suggested integration of pMP4-1 sequences into the respective genomes. DNA from the nuclear fraction of U. violacea transformants failed to produce E. coli transformants resistant to neomycin or to carbenicillin. In contrast, DNA from the mitochondrially-associated fraction in U. violacea transformants produced E. coli transformants resistant to neomycin. The E. coli transformants contained a pMP4-1-derivative, pWP8, which was subsequently shown by Southern blot analysis to harbor U. violacea mitochondrial DNA. Thus, a prokaryotic plasmid can be used to transform the eukaryote U. violacea and acquire endogenous sequences from this organism.
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Affiliation(s)
- M H Perlin
- Department of Biology, University of Louisville, KY 40292
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20
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Abstract
Plasmid pUCH1 is a 5.2-kb pUC18 construct bearing the hygB gene fused to a promoter from Cochliobolus heterostrophus. Haploid cells of the basidiomycete, Ustilago violacea, were transformed with this plasmid. In addition to multiple integrations of plasmid sequences into U. violacea nuclear DNA, vector sequences independent of the nuclear genome were indicated by Southern-blot analysis using all or part of pUCH1 as a probe. Hybridization also revealed intact pUCH1 and several larger derivatives in satellite bands from CsCl-bis-benzamide gradients of whole cellular DNA and in DNA from purified mitochondria [mitochondrial (mt) DNA preparations] of transformed U. violacea; circular DNAs consistent with the sizes of DNAs in these satellite bands were seen in electron microscope analyses of the same mt DNA preparations as well. The plasmids could be detected in mt DNA preparations even after 30 generations of transformant growth under selective pressure. Transformation of Escherichia coli by these mt DNA preparations produced bacterial transformants bearing intact pUCH1, as well as several pUCH1 derivatives, including pUCH2, an approx. 8.0-kb plasmid. A 2.5-kb EcoRI fragment from pUCH2 showed only weak hybridization with pUCH1. This unique fragment did hybridize strongly with mt DNA from untransformed U. violacea. This derivative thus appears to have acquired mt sequences from U. violacea.
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Affiliation(s)
- A K Bej
- Department of Biology, University of Louisville, KY 40292
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21
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Telomeric and dispersed repeat sequences in Candida yeasts and their use in strain identification. J Bacteriol 1991; 173:842-50. [PMID: 1987167 PMCID: PMC207079 DOI: 10.1128/jb.173.2.842-850.1991] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Several different repetitive DNA sequences have been isolated from the pathogenic yeast Candida albicans. These include two families of large dispersed repeat sequences (Ca3, Ca24) and a short (23-bp) tandemly repeated element (Ca7) associated with C. albicans telomeres. In addition, a large subtelomeric repeat (WOL17) has been cloned. DNA fragments containing the telomeric repeats are highly variable among different C. albicans strains. We have shown that the Ca3 repeat is relatively more stable and is suitable for use as a species-specific and strain-specific probe for C. albicans.
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22
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Abstract
Candida albicans is among the most common fungal pathogens. Infections caused by C. albicans and other Candida species can be life threatening in individuals with impaired immune function. Genetic analysis of C. albicans pathogenesis is complicated by the diploid nature of the species and the absence of a known sexual cycle. Through a combination of parasexual techniques and molecular approaches, an effective genetic system has been developed. The close relationship of C. albicans to the more extensively studied Saccharomyces cerevisiae has been of great utility in the isolation of Candida genes and development of the C. albicans DNA transformation system. Molecular methods have been used for clarification of taxonomic relationships and more precise epidemiologic investigations. Analysis of the physical and genetic maps of C. albicans and the closely related Candida stellatoidea has provided much information on the highly fluid nature of the Candida genome. The genetic system is seeing increased application to biological questions such as drug resistance, virulence determinants, and the phenomenon of phenotypic variation. Although most molecular analysis to data has been with C. albicans, the same methodologies are proving highly effective with other Candida species.
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Affiliation(s)
- S Scherer
- Department of Microbiology, University of Minnesota School of Medicine, Minneapolis 55455
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Ashman RB, Papadimitriou JM, Ott AK, Warmington JR. Antigens and immune responses in Candida albicans infection. Immunol Cell Biol 1990; 68 ( Pt 1):1-13. [PMID: 2180814 DOI: 10.1038/icb.1990.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- R B Ashman
- Department of Pathology, University of Western Australia, Nedlands
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Mochizuki T, Takada K, Watanabe S, Kawasaki M, Ishizaki H. Taxonomy of Trichophyton interdigitale (Trichophyton mentagrophytes var. interdigitale) by restriction enzyme analysis of mitochondrial DNA. JOURNAL OF MEDICAL AND VETERINARY MYCOLOGY : BI-MONTHLY PUBLICATION OF THE INTERNATIONAL SOCIETY FOR HUMAN AND ANIMAL MYCOLOGY 1990; 28:191-6. [PMID: 1698960 DOI: 10.1080/02681219080000251] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The relationship between Trichophyton interdigitale (Trichophyton mentagrophytes var. interdigitale) and the other members of the T. mentagrophytes complex was studied by restriction enzyme analysis of mitochondrial DNA (mtDNA). The mtDNA of 22 isolates of T. interdigitale from Japanese patients with dermatophytosis was extracted, digested with the restriction enzymes Hae III, Msp I, or Hind III, and the restriction profiles obtained compared with those of Arthroderma simii, Arthroderma benhamiae and Arthroderma vanbreuseghemii. The restriction profiles obtained for T. interdigitale were identical to those of A. vanbreuseghemii. Thus, these two species are considered to be closely related.
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Affiliation(s)
- T Mochizuki
- Department of Dermatology, Shiga University of Medical Science, Japan
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Matthews R, Burnie J. Cloning of a DNA sequence encoding a major fragment of the 47 kilodalton stress protein homologue ofCandida albicans. FEMS Microbiol Lett 1989. [DOI: 10.1111/j.1574-6968.1989.tb03413.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Keath EJ, Painter AA, Kobayashi GS, Medoff G. Variable expression of a yeast-phase-specific gene in Histoplasma capsulatum strains differing in thermotolerance and virulence. Infect Immun 1989; 57:1384-90. [PMID: 2565289 PMCID: PMC313287 DOI: 10.1128/iai.57.5.1384-1390.1989] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
By means of differential hybridization techniques, several yeast-phase-specific DNA sequences were identified in the dimorphic pathogenic fungus Histoplasma capsulatum. A 1.85-kilobase (kb) HindIII fragment from one genomic clone, yps-3, hybridized to at least three distinct yeast poly(A)+ RNAs of 1.3, 1.05, and 0.95 kb from the virulent strain G217B. These mRNAs were not detected in mycelia. When mycelia from G217B were induced to become yeast by transfer from 25 to 37 degrees C, a process requiring approximately 9 days, expression of yps-3 was detected within 24 h, although not in the initial 2 h following the temperature shift. In contrast, a low-virulence strain (Downs) which completes the transition in approximately 2 weeks failed to express the yps-3 gene during phase transitions. A third isolate, G186B, intermediate in its virulence properties and in the time required for the transition (11 days), expressed a single 1.25-kb mRNA but only at low levels in the yeast phase and only after 3 days following the 25-to-37 degrees C temperature shift. Although yps-3 expression does not appear to be essential for the transformation to the yeast phase, it may facilitate the early adaptive processes which permit the mycelium-to-yeast transition and survival of the yeast phase of H. capsulatum at elevated host temperatures. The phase-specific yps-3 nuclear gene is carried on highly polymorphic restriction fragments in all three strains, suggesting that this probe may provide a sensitive diagnostic tool for the classification of H. capsulatum isolates.
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Affiliation(s)
- E J Keath
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
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Suzuki K, Kawasaki M, Ishizaki H. Analysis of restriction profiles of mitochondrial DNA from Sporothrix schenckii and related fungi. Mycopathologia 1988; 103:147-51. [PMID: 3264052 DOI: 10.1007/bf00436813] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Restriction profiles by HaeIII of mitochondrial DNA were studied for classification and distinction of Sporothrix schenckii (100 strains), S. schenckii var. luriei (1), S. curviconia (1), S. inflata (7), Ceratocystis stenoceras (17) and C. minor (7). These 6 species showed unique restriction profiles which could be discriminated from each other S. schenckii was further separable into 11 types, S. inflata into 4 types, C. stenoceras into 4 types and C. minor into 7 types based on restriction profile heterogeneity.
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Affiliation(s)
- K Suzuki
- Department of Dermatology, Kanazawa Medical University, Ishikawa, Japan
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28
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The use of gene probes in the rapid analysis of natural microbial communities. ACTA ACUST UNITED AC 1988. [DOI: 10.1007/bf01569528] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Scherer S, Stevens DA. A Candida albicans dispersed, repeated gene family and its epidemiologic applications. Proc Natl Acad Sci U S A 1988; 85:1452-6. [PMID: 3278313 PMCID: PMC279789 DOI: 10.1073/pnas.85.5.1452] [Citation(s) in RCA: 209] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Candida albicans causes a wide variety of infections but can readily be isolated from the skin and mucosa of healthy individuals. To enable high-resolution epidemiologic studies on this common pathogen, a species-specific DNA probe has been isolated from its genome. There are approximately equal to 10 copies of the sequence dispersed among the chromosome-sized DNA molecules resolved by pulsed-field electrophoresis. New DNA polymorphisms in this gene family arise at high rates. As a consequence, this probe will readily distinguish strains from different patients in the same hospital and from various sites in individual patients. The DNA polymorphisms detected by using this probe are largely due to internal changes in members of the family rather than movement to new genomic locations. This suggests recombination or gene conversion rather than transposition as the mechanism producing the observed variation.
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Affiliation(s)
- S Scherer
- Department of Microbiology, University of Minnesota School of Medicine, Minneapolis 55455
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Lott TJ, Boiron P, Reiss E. An electrophoretic karyotype for Candida albicans reveals large chromosomes in multiples. MOLECULAR & GENERAL GENETICS : MGG 1987; 209:170-4. [PMID: 3312954 DOI: 10.1007/bf00329854] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Using field-inversion gel electrophoresis we defined an electrophoretic karyotype for the yeast, Candida albicans. The karyotype is distinct from other species of Candida and is species specific. A total of five distinct chromosomal mobility groups were observed, at least four of which are composed of a minimum of two fragments each. From the apparent sizes of these fragments relative to the large chromosomes of the morphologically related yeast Saccharomyces cerevisiae, together with the known genome size of this organism, we conclude that the karyotype is the result of the migration of intact chromosomes.
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Affiliation(s)
- T J Lott
- Division of Mycotic Diseases, Centers for Disease Control, Atlanta, GA 30333
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Scherer S, Stevens DA. Application of DNA typing methods to epidemiology and taxonomy of Candida species. J Clin Microbiol 1987; 25:675-9. [PMID: 3033016 PMCID: PMC266058 DOI: 10.1128/jcm.25.4.675-679.1987] [Citation(s) in RCA: 302] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Methods are described for extraction of DNA from the yeast form of Candida spp., followed by digestion and electrophoresis of DNA fragments. The resulting gel patterns (greater than 100 bands) were used to type Candida isolates. Four intense bands identified, three of which are present in each isolate (6 to 7, 3.7 or 4.2, and 2.5 to 3 kilobases), appear to be DNA encoding the rRNA. The methods proved to be both simple and reproducible. The patterns were shown to be stable through several hundred doublings from multiple single colonies. A survey of isolates showed that, on the basis of similarity of gel patterns, several Candida species could be sorted into mutually exclusive groups, and subgroups could be created. Analyses of this survey suggested the possible epidemiologic and taxonomic applications of these methods. DNA typing methods appear to offer important potential advantages over phenotyping methods. The methods provide a base for further epidemiologic studies and for further development of techniques, such as the use of cloned probes for studies of DNA homology.
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Mason MM, Lasker BA, Riggsby WS. Molecular probe for identification of medically important Candida species and Torulopsis glabrata. J Clin Microbiol 1987; 25:563-6. [PMID: 3033014 PMCID: PMC265992 DOI: 10.1128/jcm.25.3.563-566.1987] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
A cloned DNA fragment from Candida albicans containing the gene for the protein actin was used to probe the molecular structure of the actin gene of several medically important yeasts (C. albicans, Candida stellatoidea, Candida tropicalis, Candida pseudotropicalis, Candida krusei, Candida parapsilosis, Candida guilliermondii, and Torulopsis glabrata). Whole-cell DNA from each species was digested with restriction endonucleases, electrophoresed on agarose gels, and transferred to nitrocellulose. Radioactively labeled C. albicans actin gene was hybridized to the DNA fragments on the nitrocellulose. The C. albicans probe produced a strong signal with all of the Candida DNAs tested, indicating considerable conservation of this gene. In addition, the actin genes of all of the species tested were found to have no internal EcoRI or SalI restriction sites. With the exception of C. guilliermondii, all of the species tested had a single internal HindIII recognition site. However, the location of flanking restriction sites was found to be species specific. For all of the enzymes tested, the locations of the flanking restriction sites in C. albicans and C. stellatoidea were identical; all of the other strains yielded fragments clearly distinct from one another. These differences provide a molecular tool for the differentiation of medically important Candida species.
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Costa AL, Valenti A, Ruggeri P. Effects of two stains on blastoconidia of Candida albicans: scanning electron microscope studies. MYKOSEN 1987; 30:69-73. [PMID: 2437448 DOI: 10.1111/j.1439-0507.1987.tb04390.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Abstract
The present review is concerned with recent progress in basic genetic investigations with a variety of fungi which are pathogenic for man and animals. The principles and strategies involved in undertaking genetic investigations of sexual species and of asexual species are discussed. Progress in genetic analysis of Cryptococcus neoformans made possible by the discovery of its sexual phase is described in detail, as is progress in development of parasexual methods of analysis in Candida albicans. The genetic bases of virulence and drug resistance are discussed for those few species in which these phenotypes have been investigated. Suggestions for future research, including the application of recent advances in molecular biology to the study of pathogenic fungi, are presented.
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Wills JW, Troutman WB, Riggsby WS. Circular mitochondrial genome of Candida albicans contains a large inverted duplication. J Bacteriol 1985; 164:7-13. [PMID: 3900049 PMCID: PMC214203 DOI: 10.1128/jb.164.1.7-13.1985] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The mitochondrial DNA (mtDNA) of the dimorphic fungus Candida albicans has a molecular size of 41 kilobase pairs as judged by summation of the fragment sizes produced by digestion with restriction endonucleases EcoRI, PvuII, and a combination of both enzymes. Five of the six EcoRI fragments comprising the mitochondrial genome have been cloned into the plasmid vector, pBR322. Restriction mapping revealed a circular map as predicted by previous observations with the electron microscope. The use of nick-translated, purified mtDNA to probe digests of mtDNA from other strains of C. albicans revealed a common restriction pattern. Use of nick-translated, cloned EcoRI fragments to probe digests of mtDNA revealed a large (at least 5 kilobase pairs), inverted duplication as well as a smaller (less than 0.4 kilobase pairs) region of related sequences.
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