title: Multilocus sequence typing for the analysis of clonality among Candida albicans strains from a neonatal intensive care unit.
abstract: Nosocomial Candida albicans infections are a significant problem in neonatal intensive care units (NICUs). We investigated the clonality of C. albicans isolates recovered over an 8-year period from neonates at a NICU. We also validated multilocus sequence typing (MLST) compared with pulsed-field gel electrophoresis (PFGE) for the genotyping of C. albicans strains from the same NICU. A total of 43 clinical isolates (10 blood, 19 urine, and 14 other) were obtained from 43 neonates between 2005 and 2012. Clonal strains were defined as the isolation of two or more strains with identical or similar genotypes as determined with both MLST and PFGE. Using MLST, the 43 isolates yielded 25 diploid sequence types (DSTs) and 10 DSTs were shared by 28 isolates (65.1%). Among the 28 isolates sharing 10 DSTs, isolates from each of seven DSTs had the same or similar PFGE pattern. In addition, two sets of isolates that differed by MLST at only one locus had the same or similar PFGE pattern. Overall, when the MLST and PFGE results were combined, 22 isolates (51.2%) shared eight genotypes, suggesting clonal strains. Strains from each of seven genotypes (total, 19 isolates) were isolated among the 22 clonal strains within a 6-month period, whereas three strains of one genotype were obtained over a 3-year interval. Our findings suggest that horizontal transmission of C. albicans may occur more frequently than vertical transmission among NICU patients and that MLST appears to be a useful method for genotyping C. albicans strains isolated from NICU patients.
authors.affiliation: Department of Paediatrics, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Eun Song
authors.initials: ES
authors.lastname: Song
authors.affiliation: Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea shinjh@chonnam.ac.kr.
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Hee-Chang
authors.initials: HC
authors.lastname: Jang
authors.affiliation: Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Min Ji
authors.initials: MJ
authors.lastname: Choi
authors.affiliation: Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Institut Pasteur, Unité Biologie et Pathogénicité Fongiques INRA USC2019 Laboratoire de Parasitologie-Mycologie, Service de Microbiologie, Hôpital Necker-Enfants Malades, Université Paris Descartes, Faculté de Médecine, Paris, France.
authors.forename: Marie-Elisabeth
authors.initials: ME
authors.lastname: Bougnoux
authors.affiliation: Institut Pasteur, Unité Biologie et Pathogénicité Fongiques INRA USC2019.
authors.forename: Christophe
authors.initials: C
authors.lastname: d'Enfert
authors.affiliation: Department of Paediatrics, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Young Youn
authors.initials: YY
authors.lastname: Choi
mesh_terms: D002176:Candida albicans / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D002177:Candidiasis / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D018562:Disease Transmission, Infectious; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D008297:Male; D017720:Molecular Epidemiology / Q000379:methods; D058885:Multilocus Sequence Typing / Q000379:methods*; D016533:Mycological Typing Techniques / Q000379:methods*
keywords: Candida albicans; genotyping; multilocus sequence typing; neonatal intensive care unit; pulsed-field gel electrophoresis