J Med Microbiol 56 (2007), 190-195; DOI: 10.1099/jmm.0.46838-0
© 2007 Society for General Microbiology
ISSN 1473-5644
Occurrence and genetic variability of Candida parapsilosis sensu lato in Hungary
Sándor Kocsubé1,
Mónika Tóth1,
Csaba Vágvölgyi1,
Ilona Dóczi2,
Miklós Pesti3,
István Pócsi4,
Judit Szabó5 and
János Varga1,6
1 Department of Microbiology, Faculty of Sciences, University of Szeged, PO Box 533, H-6701 Szeged, Hungary
2 Department of Clinical Microbiology, Faculty of Medicine, University of Szeged, PO Box 427, H-6701 Szeged, Hungary
3 Department of General and Environmental Microbiology, University of Pécs, H-7601 Pécs, Hungary
4 Department of Microbiology and Biotechnology, Medical and Health Science Center, University of Debrecen, PO Box 63, H-4010, Debrecen, Hungary
5 Institute of Medical Microbiology, Faculty of Sciences, University of Debrecen, PO Box 63, H-4010, Debrecen, Hungary
6 CBS Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
Correspondence
János Varga
jvarga{at}cbs.knaw.nl
Received 17 July 2006
Accepted 13 October 2006
The occurrence and genetic variability of Candida parapsilosis isolates in two Hungarian hospitals, located in Debrecen and Pécs, were examined. Among the 209 Candida isolates examined, 20 were found to belong to C. parapsilosis sensu lato, based on morphological, physiological and molecular data. The frequency of occurrence of C. parapsilosis isolates (9.6 %) was lower than that observed in Europe but higher than that observed previously in Hungary. The genetic variability of C. parapsilosis sensu lato isolates was also examined using random amplified polymorphic DNA (RAPD) analysis and sequence analysis of the intergenic transcribed spacer (ITS) region of the rRNA gene cluster. The genetic variability of the isolates was relatively high, as revealed by RAPD analysis. Two isolates were found to belong to the recently described Candida metapsilosis species (C. parapsilosis group III), based on ITS sequence data, RAPD analysis and phenotypic data. These two isolates could also be distinguished from C. parapsilosis sensu stricto isolates using a primer pair developed for the detection of C. parapsilosis group I isolates. To the best of the authors' knowledge, this is the first report on the identification of C. metapsilosis from bloodstream infection.
Abbreviations: ITS, intergenic transcribed spacer; RAPD, random amplified polymorphic DNA.
The GenBank/EMBL/DDBJ accession numbers for the ITS sequences of C. metapsilosis 12821 and Bp57 are DQ786952 and DQ786953, respectively.
Neighbour-joining tree-based ITS sequence data of the examined Candida isolates are available as supplementary data with the online version of this paper.
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INTRODUCTION
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Infections caused by Candida species are widespread throughout the world. Although Candida albicans is the most common Candida species encountered as a cause of human infection, other Candida species have been increasingly associated with disseminated disease since the 1990s. Among them, C. parapsilosis has been the second most common yeast species isolated from bloodstream infections in several surveys (Safdar et al., 2002; Messer et al., 2006; Bassetti et al., 2006). This species has emerged as an important nosocomial pathogen, with clinical manifestations that include fungaemia, endocarditis, endophthalmitis, septic arthritis and peritonitis, and infection usually occurs in association with invasive procedures or prosthetic devices (Weems, 1992). In some children's hospitals, C. parapsilosis has become the predominant species causing candidaemia (Levy et al., 1998). This species is more frequent in bloodstream infections of neonates, in transplant recipients and in patients who have received parenteral nutrition or previous antifungal therapy (Almirante et al., 2006). This species is also frequently associated with catheter-associated candidaemia and intravenous hyperalimentation (Kremery & Barnes, 2002).
Previous studies have clarified that C. parapsilosis sensu lato isolates can be divided into three groups that can be distinguished based on several criteria, including randomly amplified polymorphic DNA (RAPD) analysis (Lehmann et al., 1992), isoenzyme electrophoresis (Lin et al., 1995), sequences of the internal transcribed spacer (ITS) region of the rRNA gene cluster (Lin et al., 1995; Pryce et al., 2006), hybridization to a fingerprinting probe (Enger et al., 2001), DNA relatedness (Roy & Meyer, 1998), morphotyping (Cassone et al., 1995), electrophoretic karyotypes (Lott et al., 1993), single nucleotide polymorphisms (Fundyga et al., 2004), mitochondrial DNA sequence differences (Nosek et al., 2002; Kosa et al., 2006) and biofilm-producing abilities (Song et al., 2005). Recently, Tavanti et al. (2005) have recognized C. parapsilosis groups II and III as separate species, Candida orthopsilosis and Candida metapsilosis, respectively, based on multilocus sequence typing studies. Accordingly, C. parapsilosis sensu lato includes C. parapsilosis sensu stricto and the two newly described species. The two latter species are recovered relatively rarely in clinical samples (Tavanti et al., 2005). In addition, C. parapsilosis group IV has also been recognized recently among Brazilian clinical Candida isolates by Iida et al. (2005).
In this study, we examined the occurrence of C. parapsilosis isolates among Candida isolates collected in Hungarian hospitals, and examined the genetic variability of these isolates using sequence analysis of the ITS region and the RAPD technique.
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METHODS
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Clinical samples.
Altogether, 209 Candida isolates from blood samples from two Hungarian hospitals, located in Debrecen and Pécs, were examined. All examined isolates came from different patients. C. parapsilosis isolates were identified by standard morphological and physiological methods within the hospitals (Barnett et al., 2000).
Phenotypying.
The API 20C AUX version 3.0 kit (bioMérieux) was used to type the species. Isolates from stored slants were streaked onto nutrient agar and incubated at 30 °C for 24 and 48 h. Samples were then analysed according to the manufacturer's prescribed methods. The antifungal susceptibilities of isolates were determined by the Etest method (AB Biodisk). The Etest was performed in accordance with the manufacturer's instructions, with the use of Casitone agar plates (AB Biodisk, 2003). A 0.5 McFarland turbidity suspension was used as a standard in the test. The drug concentrations of Etest strips were 0.016–256 mg l–1 for fluconazole, and 0.002–32 mg l–1 for itraconazole, voriconazole and amphotericin B. The incubation time was 24–48 h at 30 °C, depending on the growth characteristics. The MICs for amphotericin B were taken as the drug concentrations causing 100 % inhibition. MICs for azoles were read at the visually selected end point of 80 % inhibition of growth. Interpretative susceptibility criteria for these antifungal agents were used as published by the Clinical and Laboratory Standards Institute (CLSI) and in the literature (National Committee for Clinical Laboratory Standards, 2002; de Hoog et al., 2000).
Genotyping.
Isolates were cultivated in YPD medium (0.5 % Bacto yeast extract, 1 % glucose, 0.5 % Bacto peptone) and centrifuged, and DNA was extracted from the cells using the Masterpure yeast DNA purification kit (Epicentre Biotechnologies) according to the instructions of the manufacturer. For confirmation of the species assignment of the isolates, the species-specific primer pair developed for C. parapsilosis by Luo & Mitchell (2002) was used. For the identification of C. parapsilosis sensu stricto (group I) isolates, the primer pair developed by Pontieri et al. (2001) was applied. The ITS region of the isolates was amplified using primers ITS1 and ITS4 (White et al., 1990). DNA fragments were purified from the excised agarose blocks using Genelute spin columns (Sigma-Aldrich). Direct sequencing of the fragments was performed on an ABI 373A DNA sequencer (Applied Biosystems) using dideoxy terminator reaction chemistry. Sequences were determined from both strands using ITS1 and ITS4 as primers. The GenBank accession numbers for the ITS sequences of C. metapsilosis 12821 and Bp57 are DQ786952 and DQ786953, respectively.
RAPD analysis of the isolates was carried out according to the literature (Williams et al., 1990). Fungal DNA sequences were amplified by using the following decamer primers of the Operon random primer kit (Operon Technology): OPC-02 (5'-GTGAGGCGTC-3'), OPC-05 (5'-GATGACCGCC-3'), OPC-07 (5'-GTCCCGACGA-3'), OPC-09 (5'-CTCACCGTCC-3'), OPC-12 (5'-TGTCATCCCC-3'), OPC-14 (5'-TGCGTGCTTG-3'), OPC-16 (5'-CACACTCCAG-3'), OPC-18 (5'-TGAGTGGGTG-3'), OPC-20 (5'-ACTTCGCCAC-3'), OPD-12 (5'-CACCGTATCC-3'), OPE-17 (5'-CTACTGCCGT-3'), OPG-07 (5'-GAACCTGCGG-3'), OPG-19 (5'-GTCAGGGCAA-3'), OPH-18 (5'-GAATCGGCCA-3'), OPK-04 (5'-CCGCCCAAAC-3'), OPM-18 (5'-CACCATCCGT-3'), OPR-15 (5'-GGACAACGAG-3') and OPW-17 (5'-ACCGGCTTGT-3'), and UBC (University of British Columbia) primers UBC 8 (5'-CCTGGCGGTA-3'), UBC 18 (5'-GGGCCGTTTA-3') and UBC 66 (5'-GAGGGCGTGA-3').
Data analysis.
Sequence alignments were performed by using CLUSTAL_X (Thompson et al., 1997) and improved manually. Evolutionary distances between the sequences were calculated by Kimura's formula (Kimura, 1980) using the program DNADIST. Phylogenetic trees were prepared by the neighbour-joining method (Saitou & Nei, 1987) using the program NEIGHBOR of the PHYLIP package. Bootstrap values were calculated from 1000 replications of the bootstrap procedure using programs SEQBOOT, DNADIST, NEIGHBOR and CONSENSE of the package (Felsenstein, 1995).
RAPD bands were scored visually. Only those bands were taken into account which were amplified in all three separate RAPD reactions. The binary matrices of RAPD data were converted to distance matrices using PhylTools (Buntjer, 1997). RAPD data were analysed by the neighbour-joining method using the program NEIGHBOR of the PHYLIP package (Saitou & Nei, 1987; Felsenstein, 1995).
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RESULTS AND DISCUSSION
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Occurrence of C. parapsilosis in Hungarian hospitals
Altogether, 103 and 106 Candida isolates were collected in two Hungarian hospitals located in Debrecen and Pécs, respectively, during 2004–2005. Among these, 10 and 16 isolates, respectively, were found to belong to C. parapsilosis sensu lato, based on morphological and physiological criteria (Table 1
). The C. parapsilosis species-specific primer pair (Luo & Mitchell, 2002) was successfully used to confirm the identity of eight and 12 isolates as C. parapsilosis sensu lato. API 20C AUX tests also confirmed that these isolates belonged to C. parapsilosis sensu lato. Overall, 9.6 % of the collected isolates were found to belong to C. parapsilosis sensu lato, while the remaining isolates were found to belong to C. albicans, Candida lusitaniae (teleomorph Clavispora lusitaniae; Kurtzman & Fell, 1998) or Candida krusei (teleomorph Issatchenkia orientalis; Kurtzman & Fell, 1998) (Table 1). This observation could have been caused by misidentifications or, more probably, by contamination of some of the cultures during storage of the isolates after morphological identification.
Previously, C. parapsilosis has been found to be responsible for about 19 % of bloodstream Candida infections in Europe (Pfaller et al., 2001). More recent surveys have revealed that C. parapsilosis is responsible for more than 20 % of candidaemias in Italy (Bassetti et al., 2006; Bedini et al., 2006), Spain (Almirante et al., 2006; Rodriguez et al., 2006; San Miguel et al., 2006) and South American countries (Brito et al., 2006; Rodero et al., 2005), while this species is encountered less frequently in Turkey (12.5 %; Yapar et al., 2006) and Norway (6 %; Sandven et al., 2006). In a worldwide survey, Messer et al. (2006) have found C. parapsilosis to be responsible for candidaemias in 16.36 % of the 336 cases examined from Europe. In another survey, Tortorano et al. (2004, 2006) have found that C. parapsilosis is responsible for 6.9–30 % (mean 13.54 %) of candidaemias in different European countries, with the highest incidence found in Spain. In a previous study, Dóczi et al. (2002) found that C. parapsilosis was responsible for 4.9 % of bloodstream infections caused by Candida species in a university hospital in Hungary. These data indicate that the frequency of C. parapsilosis infections varies widely among different institutions and countries (Pfaller et al., 2001). The 9.6 % incidence of this species found in this survey is higher than that observed previously in Hungary, but lower than the mean observed in European countries.
Genetic variability of C. parapsilosis isolates
RAPD analysis of the isolates was carried out by using 21 random decamer primers. The genetic variability observed among the isolates was low: most isolates exhibited very similar or the same RAPD patterns with most primers tested (Fig. 1). Similarly low genetic variability has been observed among C. parapsilosis sensu stricto isolates by Zeng et al. (1996), Lehmann et al. (1992) and Enger et al. (2001). For preparation of the similarity matrix, the presence or absence of 72 DNA bands was taken into account. The dendrogram based on RAPD data indicates that the C. parapsilosis isolates form two main clusters which are supported by high bootstrap values (Fig. 2). One of these includes two isolates, 12821 and Bp57, which could also be distinguished from other C. parapsilosis isolates using the C. parapsilosis group I-specific primer pair developed by Pontieri et al. (2001). This primer pair did not amplify the expected product from isolates 12821 and Bp57 (data not shown).
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Fig. 1. RAPD profiles of the examined C. parapsilosis sensu lato isolates generated by primer OPR-15. Lanes: 1, 100 bp DNA ladder; 2, C. parapsilosis 5312; 3, C. parapsilosis 5308; 4, C. parapsilosis Bp73; 5, C. parapsilosis Bp46; 6, C. parapsilosis 25329; 7, C. parapsilosis Bp42; 8, C. metapsilosis 12821; 9, C. metapsilosis Bp57; 10, C. krusei Bp47; 11, 1 kb DNA ladder.
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Fig. 2. Neighbour-joining tree based on RAPD profiles of C. parapsilosis sensu lato isolates. Numbers above branches are bootstrap values. Only values above 70 % are indicated.
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Sequences of the ITS region of the isolates were also determined. Phylogenetic analysis of sequence data indicated that two of the isolates that belonged to C. parapsilosis sensu lato were members of the C. metapsilosis species (see Supplementary Fig. S1). In other studies, C. metapsilosis has been identified in the USA, Japan, Brazil, Norway and Belgium (Enger et al., 2001; Rycovska et al., 2004; Iida et al., 2005; Tavanti et al., 2005). To the best of our knowledge, the present study is the first report on the occurrence of this species in Central Europe. In addition, in this study, C. metapsilosis was isolated from a bloodstream infection for the first time. The results of the API 20C AUX tests also indicated that these two isolates belonged to the C. metapsilosis species, since in a similar manner to the results of Lin et al. (1995), the two isolates could grow on D-xylitol, in contrast to the C. parapsilosis sensu stricto isolates (data not shown).
Antifungal susceptibility tests
All isolates were susceptible to the antifungal drugs tested, with MICs <1 mg l–1 for amphotericin B and voriconazole, <8 mg l–1 for fluconazole and <0.125 mg l–1 for itraconazole. The lowest MIC values were obtained for itraconazole and voriconazole. According to earlier studies, the amphotericin B, fluconazole, itraconazole and voriconazole susceptibilities of C. parapsilosis isolates range from 0.03 to 2 mg l–1, 0.06 to 16 mg l–1, 0.03 to 2 mg l–1 and 0.02 to 1 mg l–1, respectively (Lin et al., 1995; Rex et al., 1995; Pfaller et al., 2001; Lu et al., 2004; St-Germain et al., 2001; Tortorano et al., 2004, 2006; de Hoog et al., 2000). The MIC values obtained for C. metapsilosis isolates fell within the range of MICs of C. parapsilosis isolates (data not shown). C. metapsilosis isolates exhibited lower mean MIC values for voriconazole and amphotericin B than C. parapsilosis isolates. Similarly, lower MIC values have been observed for amphotericin B in C. metapsilosis than in C. parapsilosis in earlier studies (Lin et al., 1995). However, further isolates should be examined to draw definite conclusions.
In conclusion, 9.6 % of Candida infections were found to be caused by C. parapsilosis sensu lato in our survey of two Hungarian hospitals. Two of these isolates were found to belong to the recently described C. metapsilosis species. This is believed to be the first report on the identification of C. metapsilosis from bloodstream infection. Further studies are in progress to identify the rest of the Candida isolates using molecular and phenotypic data, and to survey other Hungarian hospitals for the presence of C. metapsilosis.
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ACKNOWLEDGEMENTS
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This work was financially supported by grant GVOP-3.1.1-2004-05-0471/3.0. The technical assistance of Judit Deák and Mária Lele is gratefully acknowledged.
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REFERENCES
|
|---|
AB Biodisk (2003). Etest Technical Guide no. 4: Antifungal Susceptibility Testing of Yeasts. Solna, Sweden: AB Biodisk.
Almirante, B., Rodriguez, D., Cuenca-Estrella, M., Almela, M., Sanchez, F., Ayats, J., Alonso-Tarres, C., Rodriguez-Tudela, J. L. & Pahissa, A. (2006). Epidemiology, risk factors, and prognosis of Candida parapsilosis bloodstream infections: case-control population-based surveillance study of patients in Barcelona, Spain, from 2002 to 2003. J Clin Microbiol 44, 1681–1685.[Abstract/Free Full Text]
Barnett, J. A., Payne, R. W. & Yarrow, D. (2000). Yeasts. Characteristics and Identification. Cambridge, UK: Cambridge University Press.
Bassetti, M., Righi, E., Costa, A., Fasce, R., Molinari, M. P., Rosso, R., Pallavicini, F. B. & Viscoli, C. (2006). Epidemiological trends in nosocomial candidemia in intensive care. BMC Infect Dis 6, 21.[CrossRef][Medline]
Bedini, A., Venturelli, C., Mussini, C., Guaraldi, G., Codeluppi, M., Borghi, V., Rumpianesi, F., Barchiesi, F. & Esposito, R. (2006). Epidemiology of candidaemia and antifungal susceptibility patterns in an Italian tertiary-care hospital. Clin Microbiol Infect 12, 75–80.[CrossRef][Medline]
Brito, L. R., Guimaraes, T., Nucci, M., Rosas, R. C., Paula Almeida, L., Da Matta, D. A. & Colombo, A. L. (2006). Clinical and microbiological aspects of candidemia due to Candida parapsilosis in Brazilian tertiary care hospitals. Med Mycol 44, 261–266.[Medline]
Buntjer, J. B. (1997). Phylogenetic Computer Tools (PhylTools). Version 1.32 for Windows. Wageningen, The Netherlands: Laboratory of Plant Breeding, University of Wageningen.
Cassone, A., De Bernardis, F., Pontieri, E., Carruba, G., Girmenia, C., Martino, P., Fernandez-Rodriguez, M., Quindos, G. & Ponton, J. (1995). Biotype diversity of Candida parapsilosis and its relationship to the clinical source and experimental pathogenicity. J Infect Dis 171, 967–975.[Medline]
De Hoog, G. S., Guarro, J., Gene, J. & Figueras, M. J. (2000). Atlas of Clinical Fungi. Utrecht: Centraalbureau voor Schimmelcultures.
Dóczi, I., Dósa, E., Hajdú, E. & Nagy, E. (2002). Aetiology and antifungal susceptibility of yeast bloodstream infections in a Hungarian university hospital between 1996 and 2000. J Med Microbiol 51, 677–681.[Abstract/Free Full Text]
Enger, L., Joly, S., Pujol, C., Simonson, P., Pfaller, M. & Soll, D. R. (2001). Cloning and characterization of a complex DNA fingerprinting probe for Candida parapsilosis. J Clin Microbiol 39, 658–669.[Abstract/Free Full Text]
Felsenstein, J. (1995). PHYLIP (Phylogeny Inference Package). Version 3.57c. Distributed by the author. Seattle: Department of Genetics, University of Washington.
Fundyga, R. E., Kuykendall, R. J., Lee-Yang, W. & Lott, T. J. (2004). Evidence for aneuploidy and recombination in the human commensal yeast Candida parapsilosis. Infect Genet Evol 4, 37–43.[CrossRef][Medline]
Iida, S., Imai, T., Oguri, T., Okuzumi, K., Yamanka, A., Moretti-Branchini, M., Nishimura, K. & Mikami, Y. (2005). Genetic diversity of the internal transcribed spacers (ITS) and 5.8 S rRNA genes among clinical isolates of Candida parapsilosis in Brazil and Japan. Jpn J Med Mycol 46, 133–137.
Kimura, M. (1980). A simple method for estimating evolutionary rate of base substitutions through comparative studies on nucleotide sequences. J Mol Evol 2, 87–90.
Kosa, P., Valach, M., Tomaska, L., Wolfe, K. H. & Nosek, J. (2006). Complete DNA sequences of the mitochondrial genomes of the pathogenic yeasts Candida orthopsilosis and Candida metapsilosis: insight into the evolution of linear DNA genomes from mitochondrial telomere mutants. Nucleic Acids Res 34, 2472–2481.[Abstract/Free Full Text]
Kremery, V. & Barnes, A. J. (2002). Non-albicans Candida spp. causing fungaemia: pathogenicity and antifungal resistance. J Hosp Infect 50, 243–260.[CrossRef][Medline]
Kurtzman, C. P. & Fell, J. W. (1998). The Yeasts, a Taxonomic Study, 4th edn. Amsterdam: Elsevier.
Lehmann, P. F., Lin, D. M. & Lasker, B. A. (1992). Genotypic identification and characterization of species and strains within the genus Candida by using random amplified polymorphic DNA. J Clin Microbiol 30, 3249–3254.[Abstract/Free Full Text]
Levy, I., Rubin, L. G., Vasishtha, S., Tucci, V. & Sood, S. E. (1998). Emergence of Candida parapsilosis as the predominant species causing candidemia in children. Clin Infect Dis 26, 1086–1088.[Medline]
Lin, D., Wu, L. C., Rinaldi, M. G. & Lehmann, P. F. (1995). Three distinct genotypes within Candida parapsilosis from clinical sources. J Clin Microbiol 33, 1815–1821.[Abstract]
Lott, T. J., Kuykendall, R. J., Welbel, S. F., Pramanik, A. & Lasker, B. A. (1993). Genomic heterogeneity in the yeast Candida parapsilosis. Curr Genet 23, 463–467.[CrossRef][Medline]
Lu, J. J., Lee, S. Y. & Chiueh, T. S. (2004). In vitro susceptibility testing of Candida blood isolates and evaluation of the E-test method. J Microbiol Immunol Infect 37, 335–342.[Medline]
Luo, G. & Mitchell, T. G. (2002). Rapid identification of pathogenic fungi directly from cultures by using multiplex PCR. J Clin Microbiol 40, 2860–2875.[Abstract/Free Full Text]
Messer, S. A., Jones, R. N. & Fritsche, T. R. (2006). International surveillance of Candida spp. and Aspergillus spp. Report from the SENTRY Antimicrobial Surveillance Program (2003). J Clin Microbiol 44, 1782–1787.[Abstract/Free Full Text]
National Committee for Clinical Laboratory Standards (2002). Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts. Approved standard M27-A2, 2nd edn. Wayne, PA: National Committee for Clinical Laboratory Standards.
Nosek, J., Tomaska, L., Rycovska, A. & Fukuhara, H. (2002). Mitochondrial telomeres as molecular markers for identification of the opportunistic yeast pathogen Candida parapsilosis. J Clin Microbiol 40, 1283–1289.[Abstract/Free Full Text]
Pfaller, M. A., Diekema, D. J., Jones, R. N., Sader, H. S., Fluit, A. C., Hollis, R. J., Messer, S. A. & SENTRY Participant Group (2001). International surveillance of bloodstream infections due to Candida species: frequency of occurrence and in vitro susceptibilities to fluconazole, ravuconazole, and voriconazole of isolates collected from 1997 through 1999 in the SENTRY antimicrobial surveillance program. J Clin Microbiol 39, 3254–3259.[Abstract/Free Full Text]
Pontieri, E., Caracciolo, C., Bianchini, S., Dantonio, D., Novelli, G., Dallapiccola, B. & Carruba, G. (2001). Single primer pair for PCR identification of Candida parapsilosis group I isolates. J Med Microbiol 50, 441–448.[Abstract/Free Full Text]
Pryce, T. M., Palladino, S., Price, D. M., Gardam, D. J., Campbell, P. B., Christiansen, K. J. & Murray, R. J. (2006). Rapid identification of fungal pathogens in BacT/ALERT, BACTEC, and BBL MGIT media using polymerase chain reaction and DNA sequencing of the internal transcribed spacer regions. Diagn Microbiol Infect Dis 54, 289–297.[CrossRef][Medline]
Rex, J. H., Pfaller, M. A., Barry, A. L., Nelson, P. W. & Webb, C. D. (1995). Antifungal susceptibility testing of isolates from a randomized, multicenter trial of fluconazole versus amphotericin B as treatment of nonneutropenic patients with candidemia. Antimicrob Agents Chemother 39, 40–44.[Abstract]
Rodero, L., Davel, G., Soria, M., Vivot, W., Cordoba, S., Canteros, C. E. & Saporiti, A. (2005). Multicenter study of fungemia due to yeasts in Argentina. Rev Argent Microbiol 37, 189–195 (in Spanish).[Medline]
Rodriguez, D., Almirante, B., Park, B. J., Cuenca-Estrella, M., Planes, A. M., Sanchez, F., Gene, A., Xercavins, M., Fontanals, D. & other authors (2006). Candidemia in neonatal intensive care units: Barcelona, Spain. Pediatr Infect Dis J 25, 224–229.[CrossRef][Medline]
Roy, B. & Meyer, S. A. (1998). Confirmation of the distinct genotype groups within the form species Candida parapsilosis. J Clin Microbiol 36, 216–218.[Abstract/Free Full Text]
Rycovska, A., Valach, M., Tomaska, L., Bolotin-Fukuhara, M. & Nosek, J. (2004). Linear versus circular mitochondrial genomes: intraspecies variability of mitochondrial genome architecture in Candida parapsilosis. Microbiology 150, 1571–1580.[Abstract/Free Full Text]
Safdar, A., Perlin, D. S. & Armstrong, D. (2002). Hematogenous infections due to Candida parapsilosis: changing trends in fungemic patients at a comprehensive cancer center during the last four decades. Diagn Microbiol Infect Dis 44, 11–16.[CrossRef][Medline]
Saitou, N. & Nei, M. (1987). The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4, 406–425.[Abstract]
Sandven, P., Bevanger, L., Digranes, A., Haukland, H. H., Mannsaker, T. & Gaustad, P. (2006). Candidemia in Norway (1991 to 2003): results from a nationwide study. J Clin Microbiol 44, 1977–1981.[Abstract/Free Full Text]
San Miguel, L. G., Cobo, J., Otheo, E., Martos, I., Muriel, A., Fortun, J. & Moreno, S. (2006). Candidemia in pediatric patients with congenital heart disease. Diagn Microbiol Infect Dis 55, 203–207.[CrossRef][Medline]
Song, J. W., Shin, J. H., Shint, D. H., Jung, S. I., Cho, D., Kee, S. J., Shin, M. G., Suh, S. P. & Ryang, D. W. (2005). Differences in biofilm production by three genotypes of Candida parapsilosis from clinical sources. Med Mycol 43, 657–661.[CrossRef][Medline]
St-Germain, G., Laverdiere, M., Pelletier, R., Bourgault, A. M., Libman, M., Lemieux, C. & Noel, G. (2001). Prevalence and antifungal susceptibility of 442 Candida isolates from blood and other normally sterile sites: results of a 2-year (1996 to 1998) multicenter surveillance study in Quebec, Canada. J Clin Microbiol 39, 949–953.[Abstract/Free Full Text]
Tavanti, A., Davidson, A. D., Gow, N. A., Maiden, M. C. & Odds, F. C. (2005). Candida orthopsilosis and Candida metapsilosis spp. nov. to replace Candida parapsilosis groups II and III. J Clin Microbiol 43, 284–292.[Abstract/Free Full Text]
Thompson, J. D., Gibson, T. J., Plewniak, F., Jeanmougin, F. & Higgins, D. G. (1997). The CLUSTAL X windows interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Res 25, 4876–4882.[Abstract/Free Full Text]
Tortorano, A. M., Peman, J., Benrhardt, H., Klingspor, L., Kibbler, C. C., Faure, O., Biraghi, E., Canton, E., Zimmermann, K. & other authors (2004). Epidemiology of candidaemia in Europe: results of 28 month European Confederation of Medical Mycology (ECMM) hospital-based surveillance study. Eur J Clin Microbiol Infect Dis 23, 317–322.[CrossRef][Medline]
Tortorano, A. M., Kibbler, C., Perman, J., Bernhardt, H., Klingspor, L. & Grillot, R. (2006). Candidaemia in Europe: epidemiology and resistance. Int J Antimicrob Agents 27, 359–366.[CrossRef][Medline]
Weems, J. J., Jr (1992). Candida parapsilosis: epidemiology, pathogenicity, clinical manifestations, and antimicrobial susceptibility. Clin Infect Dis 14, 756–766.[Medline]
White, T. J., Bruns, T. D., Lee, S. B. & Taylor, J. W. (1990). Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In PCR Protocols: a Guide to Methods and Applications, pp. 315–322. Edited by M. A. Innis, D. H. Gelfand, J. J. Sninsky & T. J. White. San Diego, CA: Academic Press.
Williams, J. G. K., Kubelik, A. R., Livak, K. J., Rafalski, J. A. & Tingey, S. V. (1990). DNA polymorphisms amplified by arbitrary primers are useful as genetic markers. Nucleic Acids Res 18, 6531–6535.[Abstract/Free Full Text]
Yapar, N., Uysal, U., Yucesoy, M., Cakir, N. & Yuce, A. (2006). Nosocomial bloodstream infections associated with Candida species in a Turkish university hospital. Mycoses 49, 134–138.[CrossRef][Medline]
Zeng, S., Wu, L. C. & Lehmann, P. F. (1996). Random amplified polymorphic DNA analysis of culture collection strains of Candida species. Med Mycol 34, 293–297.
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