Assessment of genetic relatedness of vaginal isolates of Candida albicans from different geographical origins

Andrade, M. Pinto De; Schönian, Gabriele; Forche, Anja; Rosado, Laura; Costa, Isabel de Sá Affonso da; Müller, Michaela; Presber, W; Mitchell, Thomas G.; Tietz, Hans‐Jürgen

doi:10.1016/s1438-4221(00)80112-5

Cited by 14 publications

(15 citation statements)

References 24 publications

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“…However, particular genotypes can be overrepresented among pathogenic human isolates (13,14), and thus our human isolates may not be fully representative of the genetic diversity of human isolates in the area. Nevertheless, the reliability of the analysis is supported by the fact that the relationships among human isolates found in this work are consistent with the diversity and phylogenetic structure of human isolates assessed previously (7,8,15).…”

Section: Fig 2 Genetic Relations Ofsupporting

confidence: 84%

Genetic Relationship between Human and Animal Isolates ofCandida albicans

2005

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Analyzing Candida albicans isolates from different human and animal individuals by Ca3 fingerprinting, we obtained no evidence for host-specific genotypes and for the existence of species-specific lineages, even though a certain degree of separation between human and animal isolates was found. Therefore, animals could potentially serve as reservoirs for human Candida infection.Candida albicans can be found in the intestinal tracts and in the oral cavities of healthy individuals, and is also the predominant causative agent of human candidosis (5,12,17). In addition, all domestic animals like cattle, horses, pigs, cats, and dogs as well as birds are susceptible to Candida infections (4). This suggests that animals could be vectors of transmission or reservoirs of strains causing human disease and may present a risk for immunocompromised patients. Although, many case reports of candidiasis in animals are published (6, 9, 11), very little is known about the identity and origins of these infecting strains and the genetic relationship among C. albicans isolates from human and animal sources (1).To investigate whether C. albicans strains from humans are genetically distinct from animal isolates, 27 strains isolated from sputum, lungs, or feces of humans with candidemia (16 from human immunodeficiency virus-positive patients and 11 from other patients) were analyzed by Ca3 fingerprinting (13). In addition, 18 isolates from various animal species recovered from specimens submitted by veterinarians in Saxony (Germany) to the Institute of Bacteriology and Mycology of the Veterinary Faculty were typed as well (see Table 1 for details of isolates). None of the humans were owners of, or in close contact with, the animals sampled. C. albicans strains were grown in YPD medium (1% yeast extract, 2% Bacto peptone, 2% glucose) at 30°C and 250 rpm overnight. For Southern blot analysis, genomic DNA was extracted as described previously (3) and digested with EcoRI. Blots were hybridized with probe Ca3 (13) labeled with digoxigenin using a DIG DNA labeling and detecting kit (Roche). After prehybridization and hybridization performed at 68°C, the membrane was washed twice with 2ϫ SSC (1ϫ SSC is 0.15 M NaCl plus 0.015 M sodium citrate, pH 7.0)-0.1% sodium dodecyl sulfate (SDS) at 25°C for 5 min and twice with 1ϫ SSC-0.1% SDS at 68°C for 15 min. The immunological detection was carried out as recommended by the manufacturer. To quantify strain differences, molecular size and intensity of bands from C. albicans isolates were scored by comparison with the pattern of the reference strain 3153A on the same blot according to Schmid et al. (13). Signals of low intensity Յ2.1 kb and fast-evolving high-molecular-size bands Ն10.3 kb (10) were not included in the comparison. Intensity of hybridization was defined in arbitrary units: 0 U, absence of a band, 1 U, weak, 2 U, medium, and 3 U, strong signal (13). Paup‫ء‬

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Section: Fig 2 Genetic Relations Ofsupporting

confidence: 84%

Genetic Relationship between Human and Animal Isolates ofCandida albicans

2005

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“…Recently, atypical strains of C. albicans from Angola and Madagascar were characterized for genetic relatedness (18,31). They were demonstrated to be un- able to assimilate NAG or GLN and to be slow growing at 37°C.…”

Section: Resultsmentioning

confidence: 99%

Ca3 Fingerprinting of Candida albicans Isolates from Human Immunodeficiency Virus-Positive and Healthy Individuals Reveals a New Clade in South Africa

et al. 2002

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To examine the question of strain specificity in oropharyngeal candidiasis associated with human immunodeficiency virus (HIV) infection, oral samples were collected from 1,196 HIV-positive black South Africans visiting three clinics and 249 Candida albicans isolates were selected for DNA fingerprinting with the complex DNA fingerprinting probe Ca3. A total of 66 C. albicans isolates from healthy black South Africans and 46 from healthy white South Africans were also DNA fingerprinted as controls. Using DENDRON software, a cluster analysis was performed and the identified groups were compared to a test set of isolates from the United States in which three genetic groups (I, II, and III) were previously identified by a variety of genetic fingerprinting methods. All of the characterized South African collections (three from HIV-positive black persons, two from healthy black persons, and one from healthy white persons) included group I, II, and III isolates. In addition, all South African collections included a fourth group (group SA) completely absent in the U.S. collection. The proportion of group SA isolates in HIV-positive and healthy black South Africans was 53% in both cases. The proportion in healthy white South Africans was 33%. In a comparison of HIV-positive patients with and without oropharyngeal symptoms of infection, the same proportions of group I, II, III, and SA isolates were obtained, indicating no shift to a particular group on infection. However, by virtue of its predominance as a commensal and in infections, group SA must be considered the most successful in South Africa. Why group SA isolates represent 53 and 33% of colonizing strains in black and white South Africans and are absent in the U.S. collection represents an interesting epidemiological question.

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“…These data are yet another example of how molecular diagnostic methods with rRNA sequences as the target can replace classic phenotype-based microbiological identification methods. In fact, several atypical C. albicans strains were correctly identified by the C. albicans PNA FISH method (7,15). Also, C. dubliniensis, a recently described Candida species that is almost indistinguishable from C. albicans by standard methods, tested negative by the C. albicans PNA FISH method.…”

Section: Discussionmentioning

confidence: 99%

“…Clinical isolates of C. albicans were from various clinical specimens, including blood, and were chosen to represent different strains, i.e., serotype A, C. albicans bv. stellatoidea, and phenotypically aberrant isolates such as a red-pigmented strain (7) and strains that failed to assimilate glucosamine and N-acetylglucosamine (15). All strains and isolates were identified by D1-D2 26S ribosomal DNA (rDNA) sequence analysis as described previously (8).…”

mentioning

confidence: 99%

Fluorescence In Situ Hybridization with Peptide Nucleic Acid Probes for Rapid Identification of Candida albicans Directly from Blood Culture Bottles

Rigby¹,

et al. 2002

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A new fluorescence in situ hybridization (FISH) method that uses peptide nucleic acid (PNA) probes for identification of Candida albicans directly from positive-blood-culture bottles in which yeast was observed by Gram staining (herein referred to as yeast-positive blood culture bottles) is described. The test (the C. albicans PNA FISH method) is based on a fluorescein-labeled PNA probe that targets C. albicans 26S rRNA. The PNA probe is added to smears made directly from the contents of the blood culture bottle and hybridized for 90 min at 55°C. Unhybridized PNA probe is removed by washing of the mixture (30 min), and the smears are examined by fluorescence microscopy. The specificity of the method was confirmed with 23 reference strains representing phylogenetically related yeast species and 148 clinical isolates covering the clinically most significant yeast species, including C. albicans (n ‫؍‬ 72), C. dubliniensis (n ‫؍‬ 58), C. glabrata (n ‫؍‬ 5), C. krusei (n ‫؍‬ 2), C. parapsilosis (n ‫؍‬ 4), and C. tropicalis (n ‫؍‬ 3). The performance of the C. albicans PNA FISH method as a diagnostic test was evaluated with 33 routine and 25 simulated yeast-positive blood culture bottles and showed 100% sensitivity and 100% specificity. It is concluded that this 2.5-h method for the definitive identification of C. albicans directly from yeast-positive blood culture bottles provides important information for optimal antifungal therapy and patient management.

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Assessment of genetic relatedness of vaginal isolates of Candida albicans from different geographical origins

Cited by 14 publications

References 24 publications

Genetic Relationship between Human and Animal Isolates ofCandida albicans

Genetic Relationship between Human and Animal Isolates ofCandida albicans

Ca3 Fingerprinting of Candida albicans Isolates from Human Immunodeficiency Virus-Positive and Healthy Individuals Reveals a New Clade in South Africa

Fluorescence In Situ Hybridization with Peptide Nucleic Acid Probes for Rapid Identification of Candida albicans Directly from Blood Culture Bottles

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