Note
Outbreak of fungemia caused by Candida parapsilosis in a neonatal intensive care unit: Molecular investigation through microsatellite analysisBrote de fungemia por Candida parapsilosis en una unidad de cuidados intensivos neonetal: genotipificación molecular basada en el estudio de microsatélites

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Abstract

Background

Opportunistic infections are an increasingly common problem in hospitals, and the yeast Candida parapsilosis has emerged as an important nosocomial pathogen, especially in neonatal intensive care units (NICUs) where it has been responsible for outbreak cases. Risk factors for C. parapsilosis infection in neonates include prematurity, very low birth weight, prolonged hospitalization, indwelling central venous catheters, hyperalimentation, intravenous fatty emulsions and broad spectrum antibiotic therapy. Molecular methods are widely used to elucidate these hospital outbreaks, establishing genetic variations among strains of yeast.

Aims

The aim of this study was to detect an outbreak of C. parapsilosis in an NICU at the “Hospital das Clinicas”, Faculty of Medicine of Botucatu, a tertiary hospital located in São Paulo, Brazil, using the molecular genotyping by the microsatellite markers analysis.

Methods

A total of 11 cases of fungemia caused by C. parapsilosis were identified during a period of 43 days in the NICU. To confirm the outbreak all strains were molecularly typed using the technique of microsatellites.

Results

Out of the 11 yeast samples studied, nine showed the same genotypic profile using the technique of microsatellites.

Conclusions

Our study shows that the technique of microsatellites can be useful for these purposes. In conclusion, we detected the presence of an outbreak of C. parapsilosis in the NICU of the hospital analyzed, emphasizing the importance of using molecular tools, for the early detection of hospital outbreaks, and for the introduction of effective preventive measures, especially in NICUs.

Resumen

Antecedentes

Las infecciones oportunistas son un problema cada vez más frecuente en los hospitales, y Candida parapsilosis se está convirtiendo en un importante patógeno nosocomial, sobre todo en las unidades de cuidados intensivos neonatales (UCIN) donde ha sido responsable de brotes de candidiasis invasoras. En recién nacidos, los factores de riesgo de infección por C. parapsilosis incluyen la prematuridad, bajo peso al nacer, la hospitalización prolongada, los catéteres venosos centrales permanentes, alimentación parenteral, las emulsiones grasas por vía intravenosa y la administración de antibióticos de amplio espectro. Para esclarecer el origen y evolución de estos brotes hospitalarios, pueden utilizarse métodos moleculares, que permiten estudiar las variaciones genéticas entre los aislamientos clínicos.

Objetivos

El objetivo del presente estudio fue estudiar un brote de C. parapsilosis en la UCIN del Hospital das Clinicas, Facultad de Medicina de Botucatu, un hospital de asistencia terciaria de São Paulo, Brasil, usando una técnica de genotipificación molecular basada en el estudio de microsatélites.

Métodos

Durante un período de 43 días en la UCIN, se diagnosticaron un total de 11 casos de fungemia por C. parapsilosis. Para confirmar el brote, todas las cepas se sometieron a análisis de tipificación molecular utilizando la técnica de microsatélites.

Resultados

Se observó el mismo genotipo en 9 de las 11 cepas estudiadas, lo que permitió confirmar la presencia de un brote de C. parapsilosis en la UCIN del hospital.

Conclusiones

El presente estudio revela que el análisis de marcadores de microsatélites puede ser de utilidad para los objetivos ya mencionados. Es de destacar la importancia de usar técnicas moleculares para la detección precoz de brotes hospitalarios y la introducción eficaz de medidas preventivas, en especial en las UCIN.

Section snippets

Patients

A total of 11 cases of fungemia by C. parapsilosis (from 11 patients) were identified during a period of 43 days in the NICU at the “Hospital das Clínicas”, Faculty of Medicine of Botucatu, a tertiary hospital with about 467 beds, located in the State of São Paulo, Brazil. The neonatal patients with ages ranging from 7 to 60 days, with 8 males and 3 females, were considered for the study. To check for a possible outbreak in this unit, molecular investigations were initiated. Ethical clearance

Results

As noted in Table 1, with the exception of two samples, all the others showed the same microsatellite genotype. The genotypic profile for the nine isolates was 109–109 bp and 132–132 bp, for the primers used in the study. These results suggest that the isolates from the nine patients were derived from the same strain.

Discussion

Multiple risk factors for acquisition of fungemia by C. parapsilosis in neonatal intensive care units have been identified. These include prematurity, low birth weight, prolonged hospitalization, use of central venous catheters, hyperalimentation, the use of intralipid, parenteral nutrition and the use of broad-spectrum antibiotics, particularly third-generation cephalosporins.16

In our study we demonstrated with the help of molecular biology the presence of an outbreak of C. parapsilosis in the

Conflict of interest

The authors declare that they have no conflict of interest.

Acknowledgments

The authors express their thanks to PhD Marina Korte for her revision of the English text, and to São Paulo Research Foundation (FAPESP) for their financial support.

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