Cariotipos electroforéticos y análisis de los fragmentos de restricción de ADN genómico: su utilidad como herramientas en estudios epidemiológicos de Candida parapsilosis / [Electrophoretic karyotypes and genomic DNA restriction fragment analysis: their usefulness as tools in the epidemiological study of Candid parapsilosis]

During the past decades, several studies have reported an increase in the incidence of nosocomial candidosis. In a prospective study, performed at the Departamento de Micología, INEI, ANLIS Dr. C. G. Malbrán and the Servicio de Neonatología and Microbiología, Hospital de Niños Sor María Ludovica, from October 1995 to December 1996, 167 patients with candidosis were detected. Candida species isolated were C. albicans (53.1

). The aim of this work was to characterize the clinical C. parapsilosis isolates from pediatric patients hospitalized in two neonatal intensive care units from the same hospital and to evaluate the usefulness of electrophoretic karyotype (EK) and restriction endonuclease analysis of genomic DNA (REAG) using a low frequency digestion enzyme. EK of all isolates disclosed 12 banding patterns and REAG with endonuclease Sfi I showed only 5 groups. However, isolates from the control group could not be separated from the clinical isolates. The isolates within each dendogram group for EK or REAG were apparently unrelated. Our results show that EK yields better results than REAG, but that it falls short of the desired discrimination, which suggests that these techniques do not seem to be useful for studying nosocomial C. parapsilosis outbreaks.

) and C. tropicalis (14.8

Distribución de los serotipos de Cryptococcus neoformans asociados a infecciones humanas en Argentina / [Distribution of Cryptococcus neoformans serotypes associated with human infections in Argentina]

C. neoformans (Cn) causes severe meningitis in immunocompromised patients, particularly those with AIDS. Little is known about Cn serotypes associated with human infections in Argentina due to the lack of antisera availability. The aim of this study was to produce these antisera, to serotype the Argentinean clinical isolates of Cn received at our laboratory from 1984 to 2001 and to evaluate the agreement of these results with the variety differentiation obtained with Canavanine-Glycine-Bromothymol Blue agar (CGB) medium. We studied 123 isolates recovered from first episodes of cryptococcosis from HIV-infected patients (85), non HIV-infected patients (6) and from other non specified patients (32). Of the isolates, 89

(5/123) corresponded to serotype D, 3

(3/129) were serotype AD, 3 isolates were untypable and 2 corresponded to serotype B. All the serotyped isolates agreed with the variety determined by CGB medium. These results indicate that, in our country, most cryptococcal infections in patients with AIDS are associated with serotype A (77/85), which agrees with international studies. In patients with other immunosuppressions, this serotype may be also predominant, although a low number of isolates were tested (4/6). Recovery of Cn serotype B in these clinical isolates suggests that studying the variety and their serotypes might be important to detect a probable epidemiological alteration.

Caracterización molecular de aislamientos clínicos autóctonos de Histoplasma capsulatum var. capsulatum mediante RAPD-PCR. / [Molecular characterization of autochthonous clinical isolates of Histoplasma capsulatum var. capsulatum using RAPD-PCR]

The aim of our work was to determine the genotypic relatedness among H. capsulatum isolates from Argentinian patients with or without AIDS and isolates from other sources and geographic origins. We analyzed band patterns of 16 isolates obtained by RAPD-PCR, 11 Argentinian clinical isolates (8 from patients with AIDS and 3 from patients without AIDS), 2 strains from the CDC, 2 isolates from Mexico and one isolate from Uruguay. With the band patterns obtained, we built a dendrogram, which showed 3 major groups. Group I contained 2 isolates from Mexico, group II 1 strain from CDC and group III included 13 isolates, and was divided into 4 subgroups. Subgroup IIIa contained 2 isolates from patients with and without AIDS. Subgroup IIIb included isolates from patients without AIDS from Chaco. Subgroup IIIc contained 7 isolates from Argentina (from Buenos Aires province) and the Uruguayan isolate (6 isolates from patients with AIDS). Subgroup IIId included only one strain from CDC. All the Argentinian and the Uruguayan isolates went into group III, subgroups IIIa, IIIb and IIIc. This is a preliminary study; however, a relatedness of the RAPD-PCR band patterns and the geographic origin was observed. Although there might be a probable association between immunocompromised patients with AIDS and infective capability of some H. capsulatum isolates, further studies with a larger number of isolates from different sources and geographic origins are necessary to confirm these results.

Cariotipos electroforéticos y análisis de los fragmentos de restricción de ADN genómico: su utilidad como herramientas en estudios epidemiológicos de Candida parapsilosis. / [Electrophoretic karyotypes and genomic DNA restriction fragment analysis: their usefulness as tools in the epidemiological study of Candid parapsilosis]

During the past decades, several studies have reported an increase in the incidence of nosocomial candidosis. In a prospective study, performed at the Departamento de Micología, INEI, ANLIS Dr. C. G. Malbrán and the Servicio de Neonatología and Microbiología, Hospital de Niños Sor María Ludovica, from October 1995 to December 1996, 167 patients with candidosis were detected. Candida species isolated were C. albicans (53.1

), C. parapsilosis (26.5

) and C. tropicalis (14.8

). The aim of this work was to characterize the clinical C. parapsilosis isolates from pediatric patients hospitalized in two neonatal intensive care units from the same hospital and to evaluate the usefulness of electrophoretic karyotype (EK) and restriction endonuclease analysis of genomic DNA (REAG) using a low frequency digestion enzyme. EK of all isolates disclosed 12 banding patterns and REAG with endonuclease Sfi I showed only 5 groups. However, isolates from the control group could not be separated from the clinical isolates. The isolates within each dendogram group for EK or REAG were apparently unrelated. Our results show that EK yields better results than REAG, but that it falls short of the desired discrimination, which suggests that these techniques do not seem to be useful for studying nosocomial C. parapsilosis outbreaks.

Distribución de los serotipos de Cryptococcus neoformans asociados a infecciones humanas en Argentina. / [Distribution of Cryptococcus neoformans serotypes associated with human infections in Argentina]

C. neoformans (Cn) causes severe meningitis in immunocompromised patients, particularly those with AIDS. Little is known about Cn serotypes associated with human infections in Argentina due to the lack of antisera availability. The aim of this study was to produce these antisera, to serotype the Argentinean clinical isolates of Cn received at our laboratory from 1984 to 2001 and to evaluate the agreement of these results with the variety differentiation obtained with Canavanine-Glycine-Bromothymol Blue agar (CGB) medium. We studied 123 isolates recovered from first episodes of cryptococcosis from HIV-infected patients (85), non HIV-infected patients (6) and from other non specified patients (32). Of the isolates, 89

(110/123) were serotype A, 4

(5/123) corresponded to serotype D, 3

(3/129) were serotype AD, 3 isolates were untypable and 2 corresponded to serotype B. All the serotyped isolates agreed with the variety determined by CGB medium. These results indicate that, in our country, most cryptococcal infections in patients with AIDS are associated with serotype A (77/85), which agrees with international studies. In patients with other immunosuppressions, this serotype may be also predominant, although a low number of isolates were tested (4/6). Recovery of Cn serotype B in these clinical isolates suggests that studying the variety and their serotypes might be important to detect a probable epidemiological alteration.

Candida dubliniensis: primer aislamiento en Argentina / Candida dubliniensis: first report in Argentina

Se comunica el primer aislamiento de Candida Dubliniensis en Argentina. La cepa fue aislada a partir de una lesión oral de un paciente de 32 años de edad con SIDA, durante un episodio de una candidiasis orofaríngea recurrente multitratada. Las características fenotípicas y genotípicas fueron coincidentes con las descriptas anteriormente por Sullivan y col. quienes describieron esta nueva especie por primera vez (AU)

Caracterización molecular de aislamientos clínicos autóctonos de Histoplasma capsulatum var. capsulatum mediante RAPD-PCR / Molecular characterization of autochthonous clinical isolates of Histoplasma capsulatum var. capsulatum using RAPD-PCR

The aim of our work was to determine the genotypic relatedness among H. capsulatum isolates from Argentinian patients with or without AIDS and isolates from other sources and geographic origins. We analyzed band patterns of 16 isolates obtained by RAPD-PCR, 11 Argentinian clinical isolates (8 from patients with AIDS and 3 from patients without AIDS), 2 strains from the CDC, 2 isolates from Mexico and one isolate from Uruguay. With the band patterns obtained, we built a dendrogram, which showed 3 major groups. Group I contained 2 isolates from Mexico, group II 1 strain from CDC and group III included 13 isolates, and was divided into 4 subgroups. Subgroup IIIa contained 2 isolates from patients with and without AIDS. Subgroup IIIb included isolates from patients without AIDS from Chaco. Subgroup IIIc contained 7 isolates from Argentina (from Buenos Aires province) and the Uruguayan isolate (6 isolates from patients with AIDS). Subgroup IIId included only one strain from CDC. All the Argentinian and the Uruguayan isolates went into group III, subgroups IIIa, IIIb and IIIc. This is a preliminary study; however, a relatedness of the RAPD-PCR band patterns and the geographic origin was observed. Although there might be a probable association between immunocompromised patients with AIDS and infective capability of some H. capsulatum isolates, further studies with a larger number of isolates from different sources and geographic origins are necessary to confirm these results.(AU)

Sensibilidad in vitro de Paracoccidioides brasiliensis frente a los antifúngicos de uso sistémico / In vitro sensitivity of Paracoccidioides brasiliensis to systemically used antifungal agents

In 1992, the NCCLS proposed a broth macrodilution method for determining the in vitro susceptibility of yeast. However, for dimorphic fungi no standardised method is available. The aim of our study was to evaluate the reference broth macrodilution method with isolates of Paracoccidioides brasiliensis. The in vitro susceptibility of two ATCC strains (32069 and 36324) and nine clinical isolates were determined against serial dilutions of amphotericin B (AMB), ketoconazole (KTZ), and itraconazole (ITZ) from 0.02 to 20 mg/l and fluconazole (FCZ) from 0.1 to 100 mg/l. The inoculum used was 0.5 x 10(4)-2.5 x 10(5) CFU/ml, employing the yeast phase in order to obtain homogeneous growth. The test was incubated with agitation in a rotating shaker at 35 degrees C, and 7 days was the optimal time for MIC final reading. Average MIC50/MIC90 (mg/l) for the eleven isolates tested were the following: AMB: < 0.02/0.16, FCZ: 1.6/6.2, KTZ: 0.08/0.31, ITZ: 0.31/1.3. One clinical isolate showed high MIC for azole drugs (KTZ: 1.3 mg/ml, FCZ: 100 mg/l and ITZ 5 mg/l). Although further studies are necessary to evaluate the usefulness of this methodology for P. brasiliensis, the latter may be clinically useful to predict the development of resistance.(AU)

Sensibilidad in vitro de Paracoccidioides brasiliensis frente a los antifúngicos de uso sistémico. / [In vitro sensitivity of Paracoccidioides brasiliensis to systemically used antifungal agents]

In 1992, the NCCLS proposed a broth macrodilution method for determining the in vitro susceptibility of yeast. However, for dimorphic fungi no standardised method is available. The aim of our study was to evaluate the reference broth macrodilution method with isolates of Paracoccidioides brasiliensis. The in vitro susceptibility of two ATCC strains (32069 and 36324) and nine clinical isolates were determined against serial dilutions of amphotericin B (AMB), ketoconazole (KTZ), and itraconazole (ITZ) from 0.02 to 20 mg/l and fluconazole (FCZ) from 0.1 to 100 mg/l. The inoculum used was 0.5 x 10(4)-2.5 x 10(5) CFU/ml, employing the yeast phase in order to obtain homogeneous growth. The test was incubated with agitation in a rotating shaker at 35 degrees C, and 7 days was the optimal time for MIC final reading. Average MIC50/MIC90 (mg/l) for the eleven isolates tested were the following: AMB: < 0.02/0.16, FCZ: 1.6/6.2, KTZ: 0.08/0.31, ITZ: 0.31/1.3. One clinical isolate showed high MIC for azole drugs (KTZ: 1.3 mg/ml, FCZ: 100 mg/l and ITZ 5 mg/l). Although further studies are necessary to evaluate the usefulness of this methodology for P. brasiliensis, the latter may be clinically useful to predict the development of resistance.

Candidiasis vaginal: etiología y perfil de sensibilidad a agentes antifúngicos de uso clínico / [Vaginal candidiasis: etiology and sensitivity profile to antifungal agents in clinical use]

Candida vaginitis is one of the most frequent infection of the female genital tract with a high incidence. Approximately 75

of sexually active women suffer at least one episode of Candida vaginitis and 10

of them have recurrent episodes. Pregnancy, diabetes mellitus and antibiotic treatment are the most common predisposing factors, C. albicans is the etiologic agent most frequently found. The widespread reports of fluconazole resistance in Candida species and the selection of non Candida albicans prompted the study of species distribution of vulvovaginal candidiasis and their in vitro susceptibility against current antifungal agents. A total of 314 women with vaginal infection were studied. Yeasts were isolated from 104 patients with vulvovaginal candidiasis. The following species were identified: C. albicans 87.5

included C. krusei, C. famata, C. tropicalis and S. cerevisiae. The minimal inhibitory concentration (MIC) was determined for nystatin, isoconazole, fluconazole and ketoconazole, using a broth microdilution method based on NCCLS procedure. Although most of the isolates were C. albicans, the high percentage of C. glabrata recovered suggests the need to identify the yeasts isolated. Fluconazole resistant C. albicans were isolated in 13.46

of the cases. Thus, further studies are required to correlate the possible role of these strains in recurrent vulvovaginal candidiasis.

Candidiasis vaginal: etiología y perfil de sensibilidad a agentes antifúngicos de uso clínico. / [Vaginal candidiasis: etiology and sensitivity profile to antifungal agents in clinical use]

Candida vaginitis is one of the most frequent infection of the female genital tract with a high incidence. Approximately 75

of sexually active women suffer at least one episode of Candida vaginitis and 10

of them have recurrent episodes. Pregnancy, diabetes mellitus and antibiotic treatment are the most common predisposing factors, C. albicans is the etiologic agent most frequently found. The widespread reports of fluconazole resistance in Candida species and the selection of non Candida albicans prompted the study of species distribution of vulvovaginal candidiasis and their in vitro susceptibility against current antifungal agents. A total of 314 women with vaginal infection were studied. Yeasts were isolated from 104 patients with vulvovaginal candidiasis. The following species were identified: C. albicans 87.5

, C. glabrata 8.6

and 3.9

included C. krusei, C. famata, C. tropicalis and S. cerevisiae. The minimal inhibitory concentration (MIC) was determined for nystatin, isoconazole, fluconazole and ketoconazole, using a broth microdilution method based on NCCLS procedure. Although most of the isolates were C. albicans, the high percentage of C. glabrata recovered suggests the need to identify the yeasts isolated. Fluconazole resistant C. albicans were isolated in 13.46

of the cases. Thus, further studies are required to correlate the possible role of these strains in recurrent vulvovaginal candidiasis.

Primer aislamiento ambiental de Cryptococcus neoformans var. gattii en Argentina. / [1st environmental isolation of Cryptococcus neoformans var. gattii in Argentina]

Two strains of C. neoformans var. gattii serotype B were isolated from a park in Buenos Aires city, Argentina. Samples were collected in spring, rubbing with swabs on the inner hollow of Eucalyptus spp. and other trees, which were not identified at the collection moment. Samples were swabbed directly onto cafeic acid with antibiotic agar, then incubated at 28 degrees C and observed daily for a week. Isolates were recovered from cafeic acid medium showing characteristic colonies of the species that allowed differentiation from other microorganisms of the sample. Identification was performed using carbohydrate fermentation, assimilation of nitrogen and carbon sources, and urease and phenoloxidase detection. Strain variety was determined with canavanine-glicine-bromotimol blue agar medium (CGB). Genotypic characterization using AP-PCR with (GACA)4 aleatory primer showed that both band profiles could be differentiated by only one band. These two strains were isolated from tree species different from Eucalyptus spp. These isolates from natural sources demonstrate that C. neoformans var. gattii efosts in Buenos Aires city environment and that it is not necessarily associated with Eucalyptus spp. The presence of C. neoformansvar. gattii in the environment, detected for the first time in Argentina, may explain its sporadic association with human infections in the local population.

Inmunodiagnóstico de micosis endémicas y aspergilosis broncopulmonar: estudio multicéntrico en la República Argentina. / [Immunodiagnosis of endemic mycoses and bronchopulmonary aspergillosis: a multicenter study in Argentina]

In order to contribute to the knowledge of the relative frequency of chronic fungal diseases and assess the performance of diagnostic laboratories in Argentina, a multicenter study was performed with the participation of 25 medical centers located in 12 different provinces and Buenos Aires City. Between 04-01-2000 and 03-30-2001, 965 serum specimens from patients clinically suspected of having histoplasmosis (HP), paracoccidioidomycosis (PCM), coccidioidomycosis (CM) or aspergilosis were analyzed. Agar immunodiffusion tests (IDD) were done locally. All positive and 35

of negative sera were retested in the reference center. Results of laboratories of origin showed 98.8

concordance with those of reference center. Antibodies against any of the etiological agents were detected in 120 specimens from 98 patients. Endemic mycoses (HP, PCM and CM) were diagnosed in 70 patients (71.4

) and aspergilosis in 28 (28.6

). The frequencies of the different mycoses in decreasing order were PCM 47 patients (47.9

), aspergilosis 28 patients (28.6

), HP 13 patients (13.3

) and CM 10 patients (10.2

). The study was carried out on a voluntary basis and some areas of the country were not represented. However, the frequencies were in range with the expected rates in the population under study.

Estudio multicéntrico de fungemias por levaduras en la República Argentina. / [Multicenter study of fungemia due to yeasts in Argentina]

The incidence of candidemia has increased approximately 500

in high-complexity hospitals. A change in the spectrum of Candida infections due to species other than Candida albicans has also been detected. Between April 1999 and April 2000 a multicenter study was performed in order to determine the species distribution associated to candidemias in Argentina and the susceptibility profile of the isolates to the current antifungal drugs. Thirty six institutions have participated. All the 265 yeast strains isolated from blood cultures were identified by morphological, physiological, and biochemical tests. The antifungal susceptibility testing of isolates was performed based on the reference NCCLS procedure. The distribution of species was: Candida albicans (40.75

), Candida parapsilosis (28.67

), Candida tropicalis (15.84

), Candida famata (3.77

), Cryptococcus neoformans (3.77

), Candida glabrata (2.64

), and others (4.53

). Most of the isolates were susceptible to amphotericin B, fluconazole and itraconazole. Mortality associated to the fungemia by yeasts episodes (n=265) was 30

, lower than results previously determined (33-54

). The mortality percentage in patients who received antifungal therapy versus patients without treatment was 26.3

and 47

, respectively.

Pruebas de sensibilidad in vitro para levaduras: evaluación de un micrométodo. / [In vitro sensitivity tests for yeasts: evaluation of a micromethod]

A microdilution antifungal susceptibility test for yeasts was evaluated, based on the macro broth dilution method standardized by the National Committee for Clinical Laboratory Standards (NCCLS) Subcommittee on Antifungal Susceptibility Testing. Both methods were compared using six reference strains with different patterns of susceptibility to the following antifungal drugs: amphotericin B (AMB), flucytosine (5FC), fluconazole (FCZ), itraconazole (ITZ), ketoconazole (KTZ) and miconazole (MCZ). Minimal inhibitory concentration (MIC) results obtained by both methods differed only in 1 or 2 dilutions. Microdilution MICs determined as visual endpoints and as quantitative measurement of 80

inhibition of relative growth showed a significant correlation (p < 0.001) for AMB, 5FC, FCZ, MCZ and ITZ, conversely no correlation (p = 1.00) for KTZ was observed as determined with 47 local isolates of Candida albicans.

Primer aislamiento ambiental de Cryptococcus neoformans var. gattii en Argentina / Firs environmental detection of Cryptococcus neoformans var. gattii in Argentina

Dos cepas de C.neoformans var. gattii serotipo B, fueron aisladas en el Parque de los Patricios de la ciudad de Buenos Aires, Argentina. Las muestras se recogieron en primavera, mediante el hisopado de la superficie interior de huecos y grietas de Eucalyptus spp. y otros árboles que, lamentablemente, no fueron identificados en el momento de la recolección. Los hisopos se inocularon en placas de agar ácido cafeico suplementado con antibióticos que se incubaron a 28ºC durante una semana con observación diaria. Los aislamientos produjeron colonias características de la especie, lo que permitió detectarlos y separarlos de otros microorganismos presentes en la muestra. La identificación se realizó mediante estudios de f

Pruebas de sensibilidad in vitro para levaduras: evaluación de un micrométodo / In vitro susceptibility tests for yeasts: evaluation of a micromethod

Se evaluó un micrométodo para la realización de pruebas de sensibilidad de levaduras frente a antifúngicos, basado en el macrométodo en medio líquido estandarizado por el National Committee for Clinical Laboratory Standards (NCCLS) Subcommittee on Antifungal Susceptibility Testing. En este trabajo se compararon ambos métodos utilizando 6 cepas de referencia de diferente sensibilidad a los siguientes antifúngicos, anfotericina B (AMB), flucitosina (5FC), fluconazol (FCZ), itraconazol (ITZ), ketoconazol (KTZ) y miconazol (MCZ). Se observaron variaciones de sólo 1 ó 2 diluciones entre los resultados de las concentraciones inhibitorias mínimas (CIM) obtenidas con las dos técnicas. Asimismo, se compararon las lecturas visuales de CIM por micrométodo con las mediciones turbidimétricas del crecimiento en distintas concentraciones de antifúngicos frente a 47 aislamientos de Candida albicans. Existió una correlación significativa (p<0.001) entre CIM visual y la inhibición del 80 por ciento de crecimiento determinada por turbidimetría con AMB, 5FC, FCZ, ITZ y MCZ; en cambio no hubo correlación alguna para KTZ (p=1.00) (AU)

Producción de antisueros fúngicos específicos en conejo / Specific fungi antisera production in rabbits

Se probó un método de inoculación en conejos, por vía intradérmica para la producción de antisueros fúngicos contra Aspergillus fumigatus (AF), Histoplasma capsulatum (HC), Paracoccidioides brasiliensis (PB) y Coccidioides immitis (CI), con el fin de ser utilizados como sueros control positivos para pruebas de inmunodifusión en gel de agar (ID). En este trabajo se utilizó como inmunógeno el antígeno en la dilución de uso (DU) para las pruebas de rutina de ID, lo que facilitó su estandarización. Los antígenos de AF, HC, CI se prepararon por los métodos descriptos por el Center for Disease Control (CDC), y el de PB según la técnica descripta por Camargo y col. Todos los conejos produjeron anticuerpos contra los diferentes antígenos específicos (bandas por ID) en el momento en que se alcanzaron los picos de respuesta primaria y luego de cada refuerzo. La respuesta secundaria fue igual o menor que la primaria, aunque se mantuvo la calidad y cantidad de bandas de precipitación específicas detectadas por ID. La inmunización primaria con concentraciones de antígeno mayores o menores a la DU, sólo analizadas en el caso de A. fumigatus, produjo bandas de precipitación menos definidas o en menor número respectivamente, aunque los títulos de anticuerpos fueron similares (AU)

Transmisión nosocomial de Candida albicans en recién nacidos / Nosocomial transmission of Candida albicans in newborn infants

Candida spp. colonization in neonates occurs due to vertical or horizontal transmission. Preliminary studies determined that Candida albicans is the principal agent of these infections. In order to establish nosocomial transmission, 26 Candida albicans strains isolated from patients with candidosis hospitalized during a 18-month period in 2 neonatal intensive care units (NICU) from a pediatric hospital were studied. Fourteen isolates from patients and health care workers, involved in possible outbreaks of an intensive care unit (UCI) and a NICU from another pediatric hospital were also studied. All Candida albicans strains were genotyped by Southern blot hybridization with 27A. Isolates for outbreak confirmation were also hybridized with another specific Candida albicans probe, Ca3. Hybridization patterns demonstrated horizontal transmission in all the units studied. In a NICU, transmission among 4 patients during a 10-month period could be established and in the other NICU, 3 cases of transmission among 2 patients each were demonstrated in periods of 2 to 20 days. The outbreak studies showed the same strain isolated from 2 nurses and from one patient at the NICU and at the ICU identical strains were found in 3 patients. In this study, hybridization with Ca3 in addition to 27A probe did not increase discrimination power among isolates. Genotypic analysis allows, not only, determination of transmission and persistence of strains during prolonged periods or in sporadic outbreaks, but also facilitates necessary epidemiological decisions for optimizing nosocomial fungal infection control measures.(AU)

Estudio multicéntrico de micosis superficiales en Argentina. Grupo EMMS / Multicenter study of superficial mycoses in Argentina. EMMS Group

Dermatomycoses are an important sanitary problem. Our country counts with partial epidemiological data only referred to a few geographical areas. The aim of our work was to perform a multicenter study with the participation of 15 medical centers located at the Capital City and in 11 Provinces of Argentina with different socioeconomical and cultural characteristics. Between October and December 1998, 851 ambulatory patients of both sexes (58 female, 42 male) with lesions compatible with mycoses in skin, nails or scalp were studied. Only 51.6 of the patients had mycoses confirmed by direct microscopic examination and/ or culture. Dermatophytes caused 69.3 of the diagnosticated infections, yeast 12.2 and Malassezia furfur 13.3. Agents of dermatomycoses most frequently isolated were T. rubrum (52.7), T. mentagrophytes (19.2) and M. canis (14.2). C. albicans was the predominant causative agent of yeast infections (44.4). In children below 11 years old, the most frequent infections were tinea capitis 55.4 (M. canis 60, T. tonsurans and M. gypseum 8.3) and tinea corporis 20 (M. canis 46, T. mentagrophytes 30). The most frequent localizations in adult were toenail and feet (63) (T. rubrum 47.3 and 45.7, T. mentagrophytes 9.5 and 23.4, respectively), fingernail 15.6 (C. albicans 25 and T. rubrum 8.3) and trunk and extremities 12.2 (M. furfur 57.5 and T. mentagrophytes 14.9). Direct examination allowed the diagnosis of 94.66 of all positive samples and 91.74 of the cases with positive isolation.(AU)