Molecular tracking of Candida albicans in a neonatal intensive care unit: long-term colonizations versus catheter-related infections

Abstract

Nosocomial neonatal candidiasis is a major problem in infants requiring intensive therapy. The subjects of this retrospective study were nine preterm infants admitted to the neonatal intensive care unit of the Hospital Central de Asturias between March 1993 and August 1994. The infants were infected with or colonized by Candida albicans. Five patients developed C. albicans bloodstream infections. A total of 36 isolates (including isolates from catheters and parenteral nutrition) were examined for molecular relatedness by PCR fingerprinting and restriction fragment length polymorphism (RFLP) analysis. The core sequence of phage M13 was used as a single primer in the PCR-based fingerprinting procedure, and RFLP analysis was performed with C. albicans-specific DNA probe 27A. Both techniques were evaluated with a panel of eight C. albicans reference strains, and each technique showed eight different patterns. With the 36 isolates from neonates, each technique enabled us to identify by PCR and RFLP analysis seven and six different patterns, respectively. The combination of these two methods (composite DNA type) identified eight different profiles. A strain with one of these profiles was present in three patients and in their respective catheters. Patients infected with or colonized by this isolate profile were clustered in time. Among the other patients, each patient was infected over time and at multiple anatomic sites with a C. albicans strain with a distinct DNA type. We conclude that C. albicans was most commonly producing long-term colonizations, although horizontal transmission probably due to catheters also occurred.

Phenotypes and randomly amplified polymorphic DNA profiles of Candida albicans isolates from root canal infections in a Finnish population

“…In conclusion, the current phenotyping and genotyping data, hitherto unavailable for root canal isolates of C. albicans, imply a broad spectrum of strain diversity within an unusual human habitat. The broad spectrum of heterogeneity of the strains observed is quite similar to previous reports from other oral and nonoral sources (4,8,10,17). Furthermore, our data imply that unusual strains of C. albicans are not involved in root canal infections.…”

The Ins and Outs of DNA Fingerprinting the Infectious Fungi

“…Several DNA fingerprinting studies have examined the role of catheters (184,310,410), peritoneal dialysis (412), prosthetic valves (51), glycerin suppositories (412), hospital construction (51), and the general hospital environment (38,124,178,203,401). In most of these studies, there was proof or suggestion from the DNA fingerprinting data that either treatment or environment played a role in the transmission of nosocomial infections.…”

Intraspecific comparative genomics of Candida albicans mitochondria reveals non-coding regions under neutral evolution

“…The genome of C. albicans has been extensively studied to identify intraspecific variability and several typing methods were developed to effectively elucidate the epidemiology of C. albicans and to discriminate clinical isolates to help identify the source of contamination (Cliff et al 2008;Fanello et al 2001). DNA fingerprinting methods such as restriction fragment length polymorphism (RFLP), randomly amplified polymorphic DNA (RAPD) and pulsed field gel electrophoresis (PFGE), have been widely used for C. albicans typing (Fanello et al 2001;Heo et al 2011;Noumi et al 2009;Ruiz-Diez et al 1997). However, these techniques are prone to ambiguity and subjective interpretations because of variations in electrophoretic patterns such as band size and intensity.…”