Palabras clave: Candida lusitaniae, PCR-RFLP, candidosis profunda, infección de tracto respiratorio inferior, ITS, DNA ribosómico. Key words: Candida lusitaniae, PCR-RFLP, lower respiratory tract infection, ITS, ribosomic DNA. RESUMENCandida lusitaniae es una levadura que ha sido descrita como un patógeno nosocomial emergente de baja frecuencia en infecciones profundas. La identificación oportuna de C. lusitaniae es importante porque puede desarrollar resistencia in vivo a la amfotericina B durante la terapia. Reportamos el aislamiento de C. lusitaniae como agente etiológico de infección de tracto respiratorio inferior en un paciente masculino. Los cultivos de orina y esputo fueron negativos para bacterias y positivos para esta levadura. Los aislamientos fueron identificados por méto-dos fenotípicos de rutina y confirmados por secuenciación y polimorfismos de longitud de fragmentos de restricción y PCR de la región espaciadora interna del DNA ribosómico. ABSTRACTThe yeast Candida lusitaniae has been described as an emerging low frequency nosocomial pathogen in deep infections. Early identification of C. lusitaniae is important because it can readily develop in vivo resistance to amphotericin B during treatment. We report the isolation of C. lusitaniae as etiologic agent of a lower respiratory tract infection in a male patient. Urine and sputum cultures were negative for bacteria and positive for yeast. Isolates were identified by routine phenotypic methods and confirmed by ribosomal DNA internal spacer region restriction fragment length polymorphism PCR and sequencing.

Candidiasis is the most common opportunistic fungal infection in HIV patients, and its presence is ascribed mainly to the persistence of the original infecting strain. The latter might acquire genetic variations during interaction with the host, reflecting the adaptation of the strain. Here, we report the case of a 32-year-old man complaining of asthenia, irregular hyperpyrexia, and dry cough, who was admitted to the emergency unit. Laboratory examination showed positivity for HIV. Dark violet macular lesions and ulcerated lesions with verrucous erosion were observed at the tip of the nose, whereas an ulcer without exudates was noted in the pubic region. Candida albicans was recovered from the skin by scraping these lesions. Cultures from the bronchoalveolar lavage (BAL) were negative for bacteria and opportunistic fungi but were positive for Candida albicans. The isolates from the skin and BAL were typed by PCR-RFLP and Candida albicans was identified. Analysis by microsatellite length polymorphisms, established that the pubic isolate was a genetic variant of the isolate from the nose and mouth. This suggested a microevolutionary event. Despite clinical support, the patient died of multiple organ failure.

Candida lusitaniae is a yeast that has emerged as a low frequency nosocomial pathogen in deep infections. Although it usually shows in vitro susceptibility to all antifungal agents, in vivo resistance to amphotericin B has been observed in several clinical cases. Therefore, its early identification in the course of therapy is important. We report the isolation of C. lusitaniae as an etiologic agent of a lower respiratory tract infection in a male patient. Urine and sputum cultures were negative for bacteria and positive for this yeast. Isolates were identified by routine phenotypic methods and confirmed by sequencing and restriction fragment length polymorphism analysis of PCR internal spacer of ribosomal DNA.