Genetic diversity of medically important and emerging Candida species causing invasive infection

BMC Infectious Diseases

Research Article

Anderson Messias Rodrigues¹  Karina Bellinghausen Merseguel²  Angela Satie Nishikaku²  Analy Salles de Azevedo Melo²  Arnaldo Lopes Colombo²  Ana Carolina Padovan³  Renata Carmona e Ferreira⁴  Marcelo Ribeiro da Silva Briones⁴ 

[1] Departamento de Microbiologia, Imunologia e Parasitologia, Disciplina de Biologia Celular, Universidade Federal de São Paulo, São Paulo, Brazil;Laboratório Especial de Micologia (LEMI), Disciplina de Infectologia, Departamento de Medicina, Universidade Federal de São Paulo, São Paulo, Rua Pedro de Toledo, 669, quinto andar, Edifício de Pesquisas II, Zipcode 04039-032, São Paulo, SP, Brazil;Laboratório Especial de Micologia (LEMI), Disciplina de Infectologia, Departamento de Medicina, Universidade Federal de São Paulo, São Paulo, Rua Pedro de Toledo, 669, quinto andar, Edifício de Pesquisas II, Zipcode 04039-032, São Paulo, SP, Brazil;Departamento de Microbiologia e Imunologia, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, Alfenas, MG, Brazil;Laboratório de Genômica Evolutiva e Biocomplexidade, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, Brazil;

关键词: Candida;    DNA sequencing;    Internal transcribed spacer region;    Haplotype network;    Nosocomial acquisition of candidemia;   

DOI  :  10.1186/s12879-015-0793-3

 received in 2014-09-29, accepted in 2015-01-30,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundGenetic variation in the ribosomal DNA (rDNA) internal transcribed spacer (ITS) region has been studied among fungi. However, the numbers of ITS sequence polymorphisms in the various Candida species and their associations with sources of invasive fungal infections remain poorly investigated. Here, we characterized the intraspecific and interspecific ITS diversity of Candida spp. strains collected from patients with bloodstream or oroesophageal candidiasis.MethodsWe selected cultures of representative medically important species of Candida as well as some rare and emerging pathogens. Identification was performed by micromorphology and by biochemical testing using an ID32C® system, as well as by the sequencing of rDNA ITS. The presence of intraspecific ITS polymorphisms was characterized based on haplotype networks, and interspecific diversity was characterized based on Bayesian phylogenetic analysis.ResultsAmong 300 Candida strains, we identified 76 C. albicans, 14 C. dubliniensis, 40 C. tropicalis, 47 C. glabrata, 34 C. parapsilosis (sensu stricto), 31 C. orthopsilosis, 3 C. metapsilosis, 21 Meyerozyma guilliermondii (C. guilliermondii), 12 Pichia kudriavzevii (C. krusei), 6 Clavispora lusitaniae (C. lusitaniae), 3 C. intermedia, 6 Wickerhamomyces anomalus (C. pelliculosa), and 2 C. haemulonii strains, and 1 C. duobushaemulonii, 1 Kluyveromyces marxianus (C. kefyr), 1 Meyerozyma caribbica (C. fermentati), 1 Pichia norvegensis (C. norvegensis), and 1 Lodderomyces elongisporus strain. Out of a total of seven isolates with inconsistent ID32C® profiles, ITS sequencing identified one C. lusitaniae strain, three C. intermedia strains, two C. haemulonii strains and one C. duobushaemulonii strain. Analysis of ITS variability revealed a greater number of haplotypes among C. albicans, C. tropicalis, C. glabrata and C. lusitaniae, which are predominantly related to endogenous sources of acquisition. Bayesian analysis confirmed the major phylogenetic relationships among the isolates and the molecular identification of the different Candida spp.ConclusionsMolecular studies based on ITS sequencing are necessary to identify closely related and emerging species. Polymorphism analysis of the ITS rDNA region demonstrated its utility as a genetic marker for species identification and phylogenetic relationships as well as for drawing inferences concerning the natural history of hematogenous infections caused by medically important and emerging Candida species.

【 授权许可】

Unknown   
© Merseguel et al.; licensee BioMed Central. 2015. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.