[Tinea capitis: clinical features and therapeutic alternatives]. / Tinea capitis: aspectos clínicos y alternativas terapéuticas.

A descriptive observational and cross-sectional study was carried out. The clinical characteristics, etiologic agents, treatments and outcome of 33 cases of tinea capitis in the Mycology Unit at Francisco J. Muñiz Hospital of Buenos Aires City between January 2015 and December 2019 were analyzed. The median age of the patients was 7 years, 21 of whom were male, 3 were HIV-positive and 22 had pets. The isolated etiologic agents were the following: Microsporum canis in 22 cases, Trichophyton tonsurans in 8, Nannizzia gypsea in 2 and Trichophyton mentagrophytes in one patient. Suppurative tinea capitis (krion Celsi) was detected in 10 cases and the same number of patients presented other skin locations of their dermatophytosis in addition to those in the scalp. Twenty-one cases were orally treated with griseofulvin and 12 with terbinafine. Those patients with suppurative tinea capitis received drops of betamethasone by mouth besides the antifungal drugs. All patients had good clinical and mycological response to the treatments, all lesions disappeared, and mycological studies turned negative by the end of the treatments. We conclude that both drugs were effective for the treatment of tinea capitis; however, lesions in those cases receiving terbinafine involuted more slowly.

Inherited CARD9 Deficiency in a Patient with Both Exophiala spinifera and Aspergillus nomius Severe Infections.

PURPOSE: Caspase-associated recruitment domain-9 (CARD9) deficiency is an inborn error of immunity that typically predisposes otherwise healthy patients to single fungal infections and the occurrence of multiple invasive fungal infections is rare. It has been described as the first known condition that predisposes to extrapulmonary Aspergillus infection with preserved lungs. We present a patient that expands the clinical variability of CARD9 deficiency. MATERIALS AND METHODS: Genetic analysis was performed by Sanger sequencing. Neutrophils and mononuclear phagocyte response to fungal stimulation were evaluated through luminol-enhanced chemiluminescence and whole blood production of the proinflammatory mediator interleukin (IL)-6, respectively. RESULTS: We report a 56-year-old Argentinean woman, whose invasive Exophiala spinifera infection at the age of 32 years was unexplained and reported in year 2004. At the age of 49 years, she presented with chronic pulmonary disease due to Aspergillus nomius. After partial improvement following treatment with caspofungin and posaconazole, right pulmonary bilobectomy was performed. Despite administration of multiple courses of antifungals, sustained clinical remission could not be achieved. We recently found that the patient's blood showed an impaired production of IL-6 when stimulated with zymosan. We also found that she is homozygous for a previously reported CARD9 loss-of-function mutation (Q289*). CONCLUSIONS: This is the first report of a patient with inherited CARD9 deficiency and chronic invasive pulmonary aspergillosis (IPA) due to A. nomius. Inherited CARD9 deficiency should be considered in otherwise healthy children and adults with one or more invasive fungal diseases.

Genomic diversity of the human pathogen Paracoccidioides across the South American continent.

Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis widely reported in the Gran Chaco ecosystem. The disease is caused by different species from the genus Paracoccidioides, which are all endemic to South and Central America. Here, we sequenced and analyzed 31 isolates of Paracoccidioides across South America, with particular focus on isolates from Argentina and Paraguay. The de novo sequenced isolates were compared with publicly available genomes. Phylogenetics and population genomics revealed that PCM in Argentina and Paraguay is caused by three distinct Paracoccidioides genotypes, P. brasiliensis (S1a and S1b) and P. restrepiensis (PS3). P. brasiliensis S1a isolates from Argentina are frequently associated with chronic forms of the disease. Our results suggest the existence of extensive molecular polymorphism among Paracoccidioides species, and provide a framework to begin to dissect the connection between genotypic differences in the pathogen and the clinical outcomes of the disease.

[Disseminated histoplasmosis in patients with AIDS. Buenos Aires, 2009-2014]. / Histoplasmosis diseminada en pacientes HIV/Sida. Buenos Aires, 2009-2014.

A retrospective study was carried out on 171 cases of disseminated histoplasmosis diagnosed in HIV/AIDS patients during the period 2009-2014. Although HIV diagnosis rates remained stable over the study period, a sensible increase in the number of histoplasmosis cases was observed in the last three years. Disseminated histoplasmosis was prevalent in males with an average age of 37.8 years. At diagnosis, only 54/171 (31.6%) were receiving HAART, and CD4+ T-lymphocyte counts ranged from 4 to 264 cells/upsilon. Cutaneous lesions, including ulcerated papules or molluscoid plaques, were present in 110/171 (64.3%), with Histoplasma capsulatum being observed in all skin scraping specimens upon Giemsa staining. Respiratory manifestations were second in frequency with bronchoalveolar lavage showing a high diagnostic performance. Radiological findings included milliary patterns, interstitial infiltrates, and focalized condensations. Out of 141 blood cultures performed, H. capsulatum was isolated in 82 (58.2%). No significant difference in diagnostic performance was found between blood cultures and skin scraping (p = 0.6164). Other opportunistic infections were observed in 70/171 (40.9%) prior to or concomitantly with histoplasmosis. Association with Mycobacterium tuberculosis was recorded in 16/171 (9.4%) and one had a multi-drug resistant isolate. The severity of histoplasmosis determined the monotherapy with amphotericin B deoxycholate in 115 (67.3%), itraconazole in 42 (24.5%), and combined therapies in 14 (8.2%). Mortality was 19.9% (34/171). Finally, we emphasize that the higher prevalence in the last three years of the study should prompt the medical community to consider the diagnosis of histoplasmosis to reduce mortality of AIDS patients.

[Performance evaluation of Rapid™ Yeast Plus (Remel) system from two different culture media]. / Evaluación del rendimiento del sistema Rapid™ Yeast Plus (Remel) a partir de 2 medios de cultivo diferentes.

Within the genus Candida, Candida albicans is the most commonly isolated species from clinical samples. Due to the emergence of other species which can show a higher index of antifungal resistance, a fast identification of these species is necessary. The aim of this work was to evaluate the performance of the RapID Yeast Plus system from two different subculture media formulations: Sabouraud dextrose agar adjusted by Emmons (the medium is indicated in the equipment insert) and Sabouraud glucose agar, which is the most frequently used in Buenos Aires City laboratories. One hundred and sixty-six clinical sample strains coming from different hospitals belonging to the Mycology Network of Buenos Aires City were studied. From the obtained results, we conclude that the conditions and culture medium indicated by the manufacturer should be followed.

[Cryptococcal meningitis in patients with diabetes and AIDS]. / Criptococosis meníngea en pacientes con diabetes y sida.

INTRODUCTION: Cryptococcal meningitis is a severe AIDS-related infectious disease, with a high mortality rate. Diabetes mellitus (DM) is a metabolic disorder very common worldwide. Infectious diseases in diabetic patients are always more severe than in non-diabetic ones. The aim of this study was to compare the outcome of a group of HIV-positive patients with DM and cryptococcal meningitis with a similar group HIV-positive patients with cryptococcal meningitis, but without DM. MATERIAL AND METHODS: A total of 182 clinical records of HIV-positive patients suffering cryptococcal meningitis were reviewed, and 28 of them with similar clinical and epidemiological characteristics, were chosen. They included 14 patients with DM (group A) and the remaining 14 who did not suffer this metabolic disorder (group B). RESULTS: Only 21.4% (3/14 cases) of group A patients had negative CSF cultures after 10 weeks of treatment. In group B patients, 78.5% (11/14 cases) achieved negative CSF cultures before 10 weeks. A higher overall mortality rate was observed in the diabetic patients (85.7%, 12/14 cases) than in the non-diabetic group (21.4%, 3/14 cases). All CSF isolates were identified as Cryptococcus neoformans, and all strains were susceptible in vitro to amphotericin B and fluconazole. CONCLUSIONS: Cryptococcal meningitis in diabetic patients was associated with a poor clinical outcome and a high mortality rate. A longer treatment induction period is suggested in order to improve the outcome of cryptococcal meningitis in diabetic patients.

[Evaluation of Vitek 2 for the identification of Candida yeasts]. / Evaluación del sistema Vitek 2 para la identificación de las principales especies de levaduras del género Candida.

The aim of this investigation was to evaluate the performance of Vitek 2 YST cards (bioMérieux, Inc., Hazelwood, MO, USA) for the identification of yeasts of the genus Candida. A total of 168 isolates were analyzed and the results were compared to those of the API 20 C AUX (24%) o API ID 32 C (76%) kits (bioMérieux, Marcy L'Etoile, France). Each isolate was grown in chromogenic agar and in corn meal agar (Oxoid, UK) to observe its micromorphology. C. albicans and C. dublininesis were identified by additional biochemical and molecular tests. The agreement observed was 98.3%. Only three isolates were incorrectly identified by Vitek 2: one strain of C .tropicalis and one strain of C. krusei were identified as C. parapsilosis by YST while one strain of C. krusei was identified with low discrimination. The average time for obtaining results was 18.25 h. Vitek 2 is a simple, safe and useful system for the identification of significant Candida species.

[Evaluation of the VITEK 2 system (AST-YSO1 cards) for antifungal susceptibility testing against different Candida species]. / Evaluación de las tarjetas AST-YSO1 del sistema Vitek 2 para determinar la sensibilidad a antifúngicos de levaduras del género Candida.

The aim of this investigation was to evaluate the results of antifungal susceptibility for various Candida species using the Vitek 2 semi-automated system (AST-YSO1 cards, bioMérieux), and to compare them with those obtained by the CLSI (Clinical and Laboratory Standards Institute) broth microdilution reference method (Document M27-A3,2008). The essential agreement (EA) was > 90%, except for Candida glabrata against voriconazole (VCZ); and for Candida krusei against fluconazole (FCZ). The overall categorical agreement (CA) was > 90% when FCZ was evaluated and 89.5% at 24h and 80.7% at 48 h for VCZ. The average time for obtaining results was 15.5h. Minor errors were 7.8% at 24h and 6.1% at 48 h for FCZ, and 10.5% at 24h and 19.3% at 48 h for VCZ. There was only one very major error for FCZ against Candida parapsilosis and no major errors were observed. For amphotericin B, only three isolates showed MICs ≥ 2 µg/ml. The Vitek 2 system detected the MIC value for various Candida species and showed excellent agreement with the reference method proposed by the CLSI.

[Invasive aspergillosis: definitions, diagnosis, and treatment]. / Aspergilosis invasiva: definiciones, diagnóstico y tratamiento.

Invasive aspergillosis (IA) is a serious disease with high mortality. There are several risk factors and in-hospital outbreaks related with construction have been described. An entity related to COVID-19 infection, known as COVID-19 associated pulmonary aspergillosis (CAPA), has recently appeared. Early and appropriate treatment is of paramount importance, especially in immunocompromised and critically ill patients. Diagnosis is based on recognition of predisposing factors, clinical signs, imaging, direct examination, culture, histopathology, and biomarkers such as galactomannan. The drug of choice is voriconazole, but alternative therapies must be taken into account given the increasing presence of resistant isolates.

La aspergilosis invasiva (AI) es una enfermedad grave y con alta mortalidad. Existen factores de riesgo y se describen brotes intrahospitalarios relacionados con construcciones. También se describe una entidad relacionada con la infección por COVID-19, conocida como aspergilosis pulmonar asociada a COVID-19 (APAC). Es de vital importancia implementar un tratamiento adecuado y precoz, especialmente en pacientes inmunocomprometidos y críticamente enfermos. El diagnóstico se basa en reconocer los factores predisponentes, la clínica, la obtención de imágenes, exámenes directos, cultivos, histopatología y biomarcadores como el galactomanano. La droga de elección es el voriconazol, pero se deben conocer las alternativas terapéuticas dada la creciente presencia de aislamientos resistentes.

Preemptive Therapy in Cryptococcosis Adjusted for Outcomes.

Cryptococcosis is one of the most serious opportunistic diseases in patients living with HIV. For this reason, early diagnosis and appropriate treatment are important. OBJECTIVES: The aim of the study was to understand the development of patients diagnosed with cryptococcosis by detection of Cryptococcus antigen in serum by lateral flow assay (CrAg LFA) without nervous system involvement and with treatment in accordance with the results. MATERIALS AND METHODS: A retrospective, longitudinal, analytical study was performed. Seventy patients with cryptococcosis initially diagnosed by serum CrAg LFA without meningeal involvement between January 2019 and April 2022 were analyzed for medical records. The treatment regimen was adapted to the results of blood culture, respiratory material, and pulmonary tomography imaging. RESULTS: Seventy patients were included, 13 had probable pulmonary cryptococcosis, 4 had proven pulmonary cryptococcosis, 3 had fungemia, and 50 had preemptive therapy without microbiological or imaging findings compatible with cryptococcosis. Among the 50 patients with preemptive therapy, none had meningeal involvement or cryptococcosis recurrences to date. CONCLUSION: Preemptive therapy avoided progression to meningitis in CrAg LFA-positive patients. Preemptive therapy with dose adjustment of fluconazole in patients with the mentioned characteristics was useful despite the use of lower doses than recommended.

Evaluation of an enzyme immunoassay technique on detecting urinary Histoplasma capsulatum antigen in the diagnosis of disseminated histoplasmosis in Argentina.

INTRODUCTION: Histoplasmosis is a systemic mycosis of universal distribution, highly endemic in the Americas. It is caused by a dimorphic fungus Histoplasma capsulatum var. capsulatum. It affects both immunocompetent and immunocompromised individuals where progressive and disseminated forms are observed. A very important risk factor is HIV infection/AIDS, with a mortality rate of 20-40% in Latin America. The diagnosis of this mycosis is made by conventional and molecular methods or by antigen and antibody detection. METHODS: In this retrospective, longitudinal and analytical study, carried out over a period of 2 years, the sensitivity (S) and specificity (E) of a commercial kit for the detection of Histoplasma antigen by EIA technique (HC-Ag) was evaluated in 50 patients with AIDSassociated histoplasmosis. In addition, its performance was compared with that of other diagnostic techniques routinely used in our laboratory. RESULTS: HC-Ag had a S of 94%, E 96%, positive likelihood coefficient (CVP): 20.68 and negative likelihood coefficient (CVN): 0.06. The delay time of the results was 4 days, similar to that of antibody detection and n-PCR and much less than that of blood cultures. The combination of methods improved S to 100%; with similar values in E. CONCLUSION: The HC-Ag method demonstrated its usefulness in the diagnosis of progressive disseminated histoplasmosis and the combination of methods is a good option to increase sensitivity and decrease the time to reach the diagnosis of certainty. This allows improving the strategy in the management of the disease and decreasing its case-fatality rate.

Introducción: La histoplasmosis es una micosis sistémica de distribución universal, altamente endémica en las Américas. Es causada por un hongo dimórfico: Histoplasma capsulatum var. capsulatum. Afecta tanto a inmunocompetentes como a inmunocomprometidos, se observan formas progresivas y diseminadas. Un factor de riesgo muy importante es la infección por HIV/sida, con una tasa de mortalidad del 20-40% en América Latina. El diagnóstico de esta micosis se realiza por métodos convencionales y moleculares o por detección de antígenos y anticuerpos. Métodos: En este estudio retrospectivo, longitudinal y analítico, realizado en un periodo de 2 años, se evaluó la sensibilidad (S) y especificidad (E) de un kit comercial para la detección de antígeno de Histoplasma por técnica de EIA (HC-Ag) en 50 pacientes con histoplasmosis asociada a sida. Además, se comparó su rendimiento con el de otras técnicas diagnósticas utilizadas habitualmente en nuestro laboratorio. Resultados: HC-Ag tuvo una S del 94%, E del 96%, coeficiente de verosimilitud positiva (CVP) de 20.68 y coeficiente de verosimilitud negativa (CVN) de 0.06. El tiempo de demora de los resultados fue de 4 días, similar al de la detección de anticuerpos y n-PCR y mucho menor que el de los hemocultivos. La combinación de métodos mejoró la S a 100%; con valores similares en E. Conclusión: El método HC-Ag demostró su utilidad en el diagnóstico de histoplasmosis diseminada progresiva y la combinación de métodos es una buena opción para aumentar la sensibilidad y disminuir el tiempo para llegar al diagnóstico de certeza. Esto permite mejorar la estrategia en el manejo de la enfermedad y reducir su tasa de letalidad.

Sporotrichosis in Argentina: clinical and epidemiological analysis / Esporotricosis en Argentina: análisis clínico y epidemiológico

Introduction: Sporotrichosis is an implantation mycosis caused by Sporothrix spp. It is distributed worldwide and can be found in vegetation and soil. The most frequent route of infection is by trauma with elements contaminated with fungal propagules. Since domestic cats are the most affected animals and can transmit this infection to humans, sporotrichosis is considered a zoonosis. Clinical presentations include nodular lymphangitis, fixed cutaneous, pulmonary (rare), and disseminated (exceptional). Objectives: To analyze the epidemiology of sporotrichosis in Argentina during 2010 and 2022. To describe the clinical presentation, diagnostic methods, and treatment of cases diagnosed during this period. To know the circulating genotypes and to observe possible associations with the geographic location where the infection was acquired. Materials and methods: Analytical, retrospective, and observational study. We analyzed the medical records of patients with sporotrichosis from 12 health institutions in Argentina, between 2010 and 2022. Results: We present 54 cases in which the most frequent clinical form was nodular lymphangitis, and the treatment of choice was itraconazole. Conventional diagnosis was made in all cases. Culture of clinical samples was more sensitive than direct examination because it allowed the isolation of Sporothrix spp. in all 54 cases. Molecular identification was performed in 22 cases, with Sporothrix schenkii sensu stricto being the most frequently isolated species. Conclusions: This study allowed to know the epidemiology of this mycosis in Argentina, as well as the availability of diagnostic methods and the treatment of choice.

Introducción: La esporotricosis es una micosis de implantación causada por Sporothrix spp. Este se encuentra distribuido mundialmente y se puede encontrar en la vegetación y en el suelo. La ruta más frecuente de adquisición de la infección es por traumatismos con elementos contaminados con propágulos del hongo. Los gatos domésticos son los animales más afectados y pueden transmitirla a los humanos, por lo que es considerada una zoonosis. Las formas clínicas incluyen: la linfangítica nodular, la cutánea fija, la pulmonar (poco habitual) y la diseminada (excepcional). Objetivo: Analizar la epidemiología de la esporotricosis en Argentina entre los años 2010 y 2022. Describir la presentación clínica, los métodos de diagnóstico y el tratamiento de los casos diagnosticados en este período. Conocer los genotipos circulantes y observar su relación con el lugar geográfico de adquisición de la infección. Materiales y métodos. Se llevó a cabo un estudio analítico, retrospectivo y observacional, en el que se analizaron las historias clínicas de los pacientes con esporotricosis de 12 instituciones de salud de Argentina, entre los años 2010 y 2022. Resultados: Se presentan 54 casos en los que la forma clínica más frecuente fue la linfangítica nodular y el tratamiento de elección fue el itraconazol. En todos los casos se realizó diagnóstico convencional. El cultivo de las muestras clínicas resultó más sensible que el examen directo, ya que permitió el desarrollo de Sporothrix spp. en los 54 casos. En 22 casos se hizo identificación molecular y Sporothrix schenkii sensu stricto fue la especie más frecuentemente aislada. Conclusiones: Este estudio permitió conocer la epidemiología de esta micosis en Argentina, así como la disponibilidad de métodos diagnósticos y el tratamiento de elección.

Standardization and characterization of antigens for the diagnosis of aspergillosis.

The aim of this study was to develop and characterize antigens for the diagnosis of aspergillosis. Nine strains of Aspergillus species Aspergillus fumigatus , Aspergillus flavus , and Aspergillus niger were grown in Sabouraud and Smith broth to produce exoantigens. The antigens were tested by immunodiffusion against sera from patients with aspergillosis and other systemic mycoses. The protein fraction of the antigens was detected by SDS-PAGE; Western blot and representative bands were assessed by mass spectrometry coupled to a nano Acquity UltraPerformance LC and analyzed by the Mascot search engine. Concurrently, all sera were tested with Platelia Aspergillus EIA. The most reactive antigens to sera from patients infected by A. fumigatus were produced by A. fumigatus MG2 Sabouraud and pooled A. fumigatus Sabouraud samples, both with a sensitivity of 93% and specificity of 100% and 97%, respectively. Aspergillus niger and A. flavus antigens were reactive against A. niger and A. flavus sera, each one with a sensitivity and specificity of 100%. Two proteins, probably responsible for antigenic activity, ß-glucosidase in A. fumigatus and α-amylase in A. niger were attained. The commercial kit had a specificity of 22%, sensitivity of 100%, positive predictive value of 48%, and negative predictive value of 100%. The antigens produced showed high sensitivity and specificity and can be exploited for diagnostics of aspergilloma.

[Disseminated infection due to Penicillium marneffei related to HIV infection: first observation in Argentina]. / Infección diseminada por Penicillium marneffei en un paciente HIV-positivo: Primera observación en la República Argentina.

The first case observed in Argentina of AIDS-related human penicillosis is herein presented. The patient was a six- teen year-old young man coming from a rural area of southern China. He was admitted at the F. J. Muñiz Hospital of Buenos Aires city with severe pneumonia and adult respiratory distress. Penicillium marneffei was isolated from bronchoalveolar lavage fuid and was microscopically observed in a skin cytodiagnosis. P. marneffei identification was confirmed by rRNA amplification and its phenotypic characteristics. The patient suffered an advanced HIV infection and also presented several AIDS-related diseases due to CMV, nosocomial bacterial infections and Pneumocystis jirovecii which led to a fatal outcome.

Chronic recurrent vulvovaginitis is not only due to Candida.

BACKGROUND: Recurrent vulvovaginitis is a growing problem that affects millions of women worldwide. In many cases it is treated as vulvovaginal candidiasis, but there is not always microbiological confirmation. AIMS: To determine the etiology of vulvovaginitis in a group of patients. METHODS: This is a cross-sectional study in which the data from the medical records of 316 adult patients who consulted for vulvovaginitis were analyzed. Eighty nine percent of the cases had already suffered previous episodes. RESULTS: The median age was 34 (265 patients were between 16 and 45 years old). Yeasts were isolated in culture from 211 (66.8%) patients, although pseudo-hyphae and yeasts were observed in only 166 samples (52.5%) in the direct microscopic examination. Multiple predisposing factors were found, among which the use of contraceptives or previous antibiotics stand out. Most of the patients (almost 90%) had been treated with antifungals, with or without microbiological confirmation. Candida albicans was isolated in 187 (88.6%) patients, followed by Candida glabrata in 6 (2.8%) patients. Association with bacterial vaginosis was found in 35.1% and with intermediate bacterial microbiota in 33.2% of the cases. A remarkably high proportion of C. albicans isolates resistant to fluconazole (80.1%) and itraconazole (58.8%) was found. CONCLUSIONS: A microbiological analysis is essential to confirm the diagnosis of vulvovaginal candidiasis, whether simple, complicated, or recurrent. Identifying the isolated yeast species and determining its susceptibility to antifungal agents are particularly important.

Tongue lesion due to Cryptococcus neoformans as the first finding in an HIV-positive patient.

BACKGROUND: Cryptococcosis is a severe universally distributed mycosis which mainly affects immunocompromised hosts. This mycosis is caused by yeasts of two species complex of the genus Cryptococcus: Cryptococcus neoformans and Cryptococcus gattii. Meningeal cryptococcosis is the most frequent clinical presentation of this disseminated mycosis. The oral mucosa involvement is extremely unusual. CASE REPORT: We present a case of cryptococcosis with an unusual clinical form. The patient was assisted because she had an ulcerated lesion on the lingual mucosa. Encapsulated yeasts compatible with Cryptococcus were found in microscopic exams of wet preparations from lingual ulcer clinical samples obtained for cytodiagnosis and mycological studies. Cryptococcus neoformans (C. neoformans var. grubii VNI) was isolated in culture. This patient did not know her condition of HIV seropositive before the appearance of the tongue lesion. CONCLUSIONS: The involvement of the oral mucosa is uncommon in this fungal infection, but is important to include it in the differential diagnosis in HIV positive patients.

[Clinical problems in Medical Mycology: problem number 55]. / Problemas clínicos en Micología Médica: problema número 55.

A 31-year-old woman, with signs of HIV infection (oral thrush, weight loss, asthenia) presented to our hospital with dyspnea and fever. A rapid HIV test yielded a positive result, and cryptococcal capsular antigen was detected in serum. In the mycological study of the clinical respiratory samples, yeasts compatible with Cryptococcus were observed under light microscope in a wet mount; structures compatible with Pneumocystis jirovecii were also observed in Giemsa stain. Treatment for both pathologies was prescribed but, unfortunately, the patient died 7 days after. The finding of two etiologic agents in the same clinical picture is rare but not exceptional, and it always must be considered in immunocompromised hosts.

Correlation of Etest and Neo-Sensitabs diffusion assays on Mueller-Hinton-methylene blue agar with broth microdilution reference method (CLSI-M27-A2) for testing susceptibilities of Cryptococcus neoformans to amphotericin B and fluconazole.

Cryptococcus neoformans causes disseminated infection in 7-8% of HIV positive patients admitted to Hospital F. J. Muñiz in Buenos Aires. Meningoencephalitis is the most frequent clinical manifestation and is one of the main causes of death in those patients with AIDS. The standard treatment for this mycosis consists of amphotericin B followed by fluconazole until two successive cultures of CFS are negative. Although resistance to these drugs is infrequent, minimal inhibitory concentrations (MIC) of some antifungals can be high. Since it is important to know the susceptibility levels of this fungus to the antifungal drugs usually employed in our institution, we analyzed the susceptibility test results of C. neoformans with two diffusion methods (Etest and NeoSensitabs tablets) employing Mueller-Hinton agar with 2% glucose and 0.5 microg/ml methylene blue. These results were compared with MICs obtained through the use of the broth microdilution reference method (CLSI). Results showed good agreement with the reference method, with no very major errors and only two major errors for fluconazole using NeoSensitabs tablets. For all the above mentioned, we confirm the usefulness of Mueller-Hinton agar to evaluate C. neoformans susceptibility to amphotericin B and fluconazole with these two agar diffusion methods.

[Presumptive identification of Candida spp. and other clinically important yeasts: usefulness of Brilliance Candida Agar]. / Identificación presuntiva de Candida spp. y de otras levaduras de importancia clínica: utilidad de Brilliance Candida Agar.

Fungal infections caused by yeasts have increased during the last decades and invasive forms represent a serious problem for human health. Candida albicans is the species most frequently isolated from clinical samples. However, other emerging yeast pathogens are increasingly responsible for mycotic infections, and some of them are resistant to some antifungal drugs. Consequently, it is necessary to have methods that can provide a rapid presumptive identification at species level. Numerous chromogenic agar media have been shown to be of value as diagnostic tools. We have compared a chromogenic medium, Brilliance Candida Agar, with CHROMagar Candida, the chromogenic medium most used in our country. A multicentre study was conducted in 16 Hospitals belonging to the Mycology Net of Buenos Aires City Government. A total of 240 yeast isolates were included in this research. The new chromogenic agar showed results very similar to those obtained with CHROMagar Candida.