Incidencia de los distintos agentes etiológicos de micosis superficiales / [Incidence of various etiologic agents of superficial mycosis]

In a retrospective review of laboratory records at the Department of Mycology, National Institute of Microbiology [quot ]Dr. Carlos G. Malbrán[quot ], during the period June 1989-July 1991, 1225 putatively immunocompetent cases of superficial mycoses were identified. Ninety five percent of these patients were adults and 5

children. Among the total cases, dermatomycoses were caused, 67.6

by Malassezia furfur. and 0.5

by other fungi, as proven by the isolation of the etiological agents. (Figure 1, Table 2). Among the dermatophytes Trichophyton rubrum and Trichophyton mentagrophytes greatly predominated accounting for 66.6

of the isolates, respectively, whereas Microsporum canis (8.0

) and Microsporum gypseum (0.3

) were found with less frequency (Figure 2). Nails (47

) were the most common source of isolates in adults, followed by feet (28

) and hands (2

) (Table 1). Regarding the relative efficiency of the diagnostic methods, the analyses of laboratory results evidenced that, 98

of the cases with clinical findings compatible with mycoses and 76

of the cases with positive cultures (Table 1) were identified by microscopic observation.

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.(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)

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)

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.

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.