Browsing by Author "Kaufman, Sara"

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    Candidiasis esofágica: análisis clínico y micológico
    (2005) Olmos, Martín A; Araya, Valentina; Concetti, Hugo; Ramallo, Jennifer; Piskorz, Eduardo; Pérez, Héctor; Cahn, Pedro; Kaufman, Sara; Guelfand, Liliana
    La candidiasis esofágica es una infección epitelial que requiere un defecto adicional inmunitario. Candida albicans es la especie más frecuente, aunque pueden encontrarse otras. Un problema emergente es la resistencia al fluconazol, droga de elección para tratarla. Los objetivos fueron: determinar la frecuencia de candidiasis esofágica en pacientes sometidos a endoscopía, analizar los factores predisponentes, identificar las especies causantes, y estudiar la sensibilidad in vitro al fluconazol. Durante 12 meses se realizaron 1.321 endoscopías donde se detectaron 34 pacientes con candidiasis esofágica. Se hicieron 1.230 endoscopías en pacientes HIV negativos y 91 en HIV positivos. Se diagnosticó candidiasis esofágica en 11 (0.9%) y 23 (25.3%), respectivamente. En HIV negativos, fueron causas predisponentes: antibioticoterapia prolongada, prótesis dentarias sin higiene, uso prolongado de inhibidores de la bomba de protones, secreción ácida, corticoides inhalatorios, malignidad y vasculitis bajo corticoterapia. La histopatología fue positiva en 48.6%. El cultivo se desarrolló en el 91.2%. C. albicans fue la especie más frecuente (93.5%) y en 5 pacientes (16.1%) se la encontró asociada a C. glabrata (3) C. tropicalis (1) y C. parapsilosis (1). En un caso solo se cultivó C. glabrata y en otro C. tropicalis. De las 31 cepas, 25 fueron sensibles al fluconazol, 4 dosis dependientes (1 C. albicans, 3 C. glabrata), y 2 resistentes (1 C. albicans, 1 C. glabrata). En nuestro hospital, la frecuencia de candidiasis esofágica fue baja, excepto en HIV positivos. El principal agente etiológico fue C. albicans, aunque también se cultivaron otras especies. C. albicans y C. glabrata mostraron dosis dependencia y resistencia al fluconazol.
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    Prevalence of cryptococcal infection among advanced HIV patients in Argentina using lateral flow immunoassay
    (2017-06-15) Frola, Claudia; Guelfand, Liliana; Blugerman, Gabriela; Szyld, Edgardo; Kaufman, Sara; Cahn, Pedro; Sued, Omar; Pérez, Héctor
    Background Globally, Latin America ranks third among regions with most cases of AIDS related cryptococcal meningitis. In 2009, a lateral flow immunoassay (LFA) for the detection of cryptococcal antigen (CrAg) was developed as a potential point-of-care test for diagnosis of cryptococcal infection. In 2011 World Health Organizations recommended on CrAg screening for HIV positive persons with CD4 below 100 cells/μL, followed by preemptive fluconazole treatment. However, in Argentina no formal recommendations for CrAg screening have been issued. Methods HIV positive patients > = 18 years with advanced immunosuppression (CD4 counts ≤100 cells/μL within 3 months or WHO stage III/IV), who visited the hospital between April 1, 2014 and January 31, 2015, were included. The LFA was performed according to the manufacturer’s instructions on all serum samples. When CrAg detection was positive, a lumbar puncture was performed to rule out cryptococcal meningitis. Patients without evidence of meningeal involvement were treated with preemptive oral fluconazole in ambulatory care. Results We included 123 patients. Prevalence of CrAg-positivity was 8.1%. Among the 10 CrAg-positive patients, 6 had meningeal involvement detected through the CSF analysis (CSF India-ink testing, CSF CrAg and culture). The remaining 4 patients with positive CrAg received targeted preemptive treatment with oral fluconazole and were free of cryptococcal disease during the follow-up period. None of the 113 patients with a negative CrAg test result developed cryptococcal disease. Conclusions This is the first study in Argentina, to our knowledge, describing the prevalence of cryptococcosis and usefulness of CrAg screening. LFA provided early diagnosis to determine a high prevalence of CrAg in our hospital, and that screening for subclinical infection with preemptive antifungal treatment, prevented a substantial proportion of meningeal disease.
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    Transient Fungemia Caused by an Amphotericin B-Resistant Isolate of Candida haemulonii
    (2002-06-01) Rodero, Laura; Cuenca-Estrella, Manuel; Córdoba, Susana; Cahn, Pedro; Davel, Graciela; Kaufman, Sara; Guelfand, Liliana; Rodríguez-Tudela, Juan L
    A bloodstream infection due to Candida haemulonii afflicting a patient with fever and a medical history of megaloblastic anemia is reported. The clinical isolate was misidentified by the API 20C and VITEK identification systems. The results of susceptibility tests showed that the MIC of amphotericin B for C. haemulonii was 4 μg/ml. Additional susceptibility testing procedures based on the use of antibiotic medium 3 and Iso-Sensitest broth were performed, and killing curves were determined. Two collection strains of C. haemulonii were employed as controls. The three isolates exhibited resistance to amphotericin B in vitro regardless of the antifungal susceptibility testing method employed. In addition, the MICs of fluconazole for the three isolates were high. Further studies are needed in order to ascertain whether this species exhibits innate or acquired resistance to amphotericin B and other antifungal agents. Candida haemulonii (Van Uden & Kolipinski) S. A. Meyer & Yarrow (Yarrow and Meyer 1978) (syn. Torulopsis haemulonii) is a yeast species that has been reported in the scales of animals and in seawater and has been recently associated with an epidemic disease afflicting laboratory animals (Ornithodoros moubata) in the Czech Republic (5, 10, 11). This fungus is also involved in human infections such as onychia, ulcers of the feet or legs, and candidemia (10). Identification of C. haemulonii is difficult because it is phenotypically very similar to Candida famata (teleomorph, Debaryomyces hansenii) and Candida guilliermondii (teleomorph, Pichia guilliermondii), although it can be distinguished by its inability to assimilate cellobiose and its negative or weak assimilation of raffinose (8, 10). In addition, commercial yeast identification systems have failed to identify C. haemulonii isolates (16). Lehmann et al. studied 25 clinical isolates of C. haemulonii and described two genetically distinct groups within the species (group I and group II) on the basis of isoenzyme profiles, DNA reassociations, and physiological characteristics (9, 10, 16). No differences in clinical associations between the groups were described, but it was determined that C. haemulonii constitutes a species complex. The susceptibility pattern of C. haemulonii is unknown, but an anecdotal report has suggested that it could be resistant to amphotericin B (AMB) and other antifungal agents (4). Here, we describe a case of transient fungemia due to a C. haemulonii strain which exhibited resistance to AMB and fluconazole in vitro. Killing curves were determined and additional susceptibility tests were performed to assess the activity of AMB against the isolate.