Genetic analysis of the endemic fungal pathogens Coccidioides posadasii and Coccidioides immitis in Mexico.

Coccidioidomycosis (CM) is a mycotic disease that affects mammals, including humans. Official data relative to CM in Mexico has not been collected since 1995, thus its prevalence remains unknown. The objectives of this study were to identify the predominant Coccidioides species in Mexico, infer their current geographical distribution and explore the correlation between species and clinical presentation. We collected 154 strains, which were cultured, inactivated, and processed for DNA extraction. Nine microsatellite loci, the Ag2/PRA gene and Umeyama Region were amplified from each isolate. To infer the current geographical distribution of Coccidioides spp. and to establish a correlation between genotype and clinical presentation, we evaluated genetic population structure under the following grouping criteria: putative origin and clinical presentation records. Microsatellite analysis showed that 82% of the isolates corresponded to C. posadasii and 18% were C. immitis. The species identification results obtained using Umeyama region, Ag2/PRA, and microsatellites of five of the isolates were inconsistent with the data collected for the remaining isolates. C. posadasii strains were found primarily in the northeastern region and C. immitis in the northwestern region. However, there was no relationship between clinical presentation and Coccidioides species. The molecular markers used in this study proved to have a high power of resolution to identify the Coccidioides species recovered in culture. While we found C. posadasii to be the most abundant species in Mexico, more detailed clinical records are needed in order to obtain more accurate information about the infections in specific geographical locations.

Cellulose-Silica Nanocomposites of High Reinforcing Content with Fungi Decay Resistance by One-Pot Synthesis.

Hybrid bionanocomposites based on cellulose matrix, with silica nanoparticles as reinforcers, were prepared by one-pot synthesis of cellulose surface modified by solvent exchange method to keep the biopolymer net void for hosting inorganic nanoparticles. Neither expensive inorganic-particle precursors nor crosslinker agents or catalysts were used for effective dispersion of reinforcer concentration up to 50 wt %. Scanning electron microscopy of the nanocomposites shows homogeneous dispersion of reinforcers in the surface modified cellulose matrix. The FTIR spectra demonstrated the cellulose features even at 50 weight percent content of silica nanoparticles. Such a high content of silica provides high thermal stability to composites, as seen by TGA-DSC. The fungi decay resistance to Trametes versicolor was measured by standard test showing good resistance even with no addition of antifungal agents. This one-pot synthesis of biobased hybrid materials represents an excellent way for industrial production of high performance materials, with a high content of inorganic nanoparticles, for a wide variety of applications.

[Antifungal and phagocytic immunostimulation treatment of chronic disseminated dermatophytosis]. / Dermatofitosis diseminada crónica asociada a fagocitosis deficiente tratada con antimicóticos e inmunoestimulación fagocitaria.

A 39 years old man with a long-standing disseminated dermatophytosis even with several antifungal treatments is presented. From lesions, Trichophyton rubrum var. typical downy, T. tonsurans and Candida albicans were isolated and showed sensivity to azolic compounds in vitro. The phagocytic activity in vitro compared with normal control was depressed. Treatment with itraconazole and immunomodulation using a bacterial antigen was indicated. During the last two years the patient has been clinical and mycologically healthy, and his phagocytosis activity has become normal. In patients with chronic and relapsing dermatophytosis, the immune response evaluation is recommended, and immunomodulation could be useful as a rational measure in patients with a particular immunodeficiency.

Onychomycosis incidence in type 2 diabetes mellitus patients.

The onychomycosis incidence was determined in 250 type 2 diabetes mellitus (T2DM) patients who were registered at the Internal Medicine Service from a Mexico city General Hospital throughout a year (January-December 2006). Out of the total of studied T2DM patients, 93 (37.2%) showed ungual dystrophy and from these, in 75.3% a fungal etiology was corroborated. Out of 70 patients, 34 were men and 36 women, with an average of 63.5 years. Correlation between T2DM evolution time and onychomycosis was significant (P < 0.01). Distal-lateral subungual and total dystrophic onychomycosis were the most frequent clinical types (55.1% and 33.7%, respectively). Fifty-eight fungal isolates were obtained; 48.6% corresponded to dermatophytes, Trichophyton rubrum being the first species (37.1%). All these strains corresponded to two morphological varieties: "yellow" and typical downy. From the yeast-like isolates, 12 corresponded to Candida spp., firstly C. albicans and C. parapsilosis; three to Cryptococcus spp. (C. albidus, C. uniguttulatus and C. laurentii); two Trichosporon asahii; and only one to Pichia ohmeri. Six non-dermatophytic molds were isolated: two Chrysosporium keratinophylus, two Scopulariopsis brevicaulis, one Aspergillus fumigatus, and one Acremonium sp. The fungal mixture corresponded to T. mentagrophytes with C. guilliermondii; T. mentagrophytes with C. glabrata; T. rubrum with C. glabrata; T. rubrum with P. ohmeri.

[Frequency of mycosis in immunosuppressed patients at a regional hospital of Mexico City]. / Frecuencia de micosis en pacientes inmunosuprimidos de un hospital regional de la Ciudad de México.

OBJECTIVE: To isolate and identify the fungi in specimens collected from immunocompromised patients seen in Mexico City hospital, and to assess their association with mycosis. MATERIAL AND METHODS: A total of 268 specimens from 108 patients were processed for mycological study, including direct examination, smears, cultures, and microcultures in specific media, in addition to biochemical tests. Most of the patients had been diagnosed with pulmonary tuberculosis and Acquired Immunodeficiency Syndrome (AIDS). RESULTS: One hundred and eighty-three yeasts and 66 mycelial fungi were isolated. Forty-five mycoses were diagnosed; the most frequent mycosis was pulmonary candidosis (32 cases). Candida albicans and C parapsilosis were the predominant species associated with mycotic infection. Five Cryptococcus neoformans var. neoformans, one C albidus, three Histoplasma capsulatum and one Geotrichum candidum isolates were associated with mycosis. CONCLUSIONS: Of the studied patients, 41.6% showed a mycotic infection, principally associated with AIDS and pulmonary tuberculosis. The English version of this paper is available at:http://www.insp.mx/salud/index.html.

Dermatofitosis diseminada crónica asociada a fagocitosis deficiente tratada con antimicóticos e inmunoestimulación fagocitaria / Antifungal and phagocytic immunostimulation treatment of chronic disseminated dermatophytosis

Se presenta el caso de un hombre de 39 años de edad con dermatofitosis crónica diseminada. De las lesiones se aislaron Trichophyton rubrum var. vellosa típica, T. tonsurans y Candida albicans, todos sensibles in vitro a compuestos azólicos. La actividad fagocítica in vitro comparada con un control normal mostró deficiencia en la misma. Se indicó tratamiento con itraconazol e inmunoestimulación con antígeno bacteriano. Durante los dos últimos años el paciente se ha mantenido clínica y micológicamente sano y su actividad fagocitaria es normal. En los pacientes con dermatofitosis crónica recidivante es recomendable la valoración de la respuesta inmune y la inmunomodulación puede ser útil como parte del tratamiento.

A 39 years old man with a long-standing disseminated dermatophytosis even with several antifungal treatments is presented. From lesions, Trichophyton rubrum var. typical downy, T. tonsurans and Candida albicans were isolated and showed sensivity to azolic compounds in vitro. The phagocytic activity in vitro compared with normal control was depressed. Treatment with itraconazole and immunomodulation using a bacterial antigen was indicated. During the last two years the patient has been clinical and mycologically healthy, and his phagocytosis activity has become normal. In patients with chronic and relapsing dermatophytosis, the immune response evaluation is recommended, and immunomodulation could be useful as a rational measure in patients with a particular immunodeficiency.

Frecuencia de micosis en pacientes inmunosuprimidos de un hospital regional de la Ciudad de México / Frequency of mycoses in immunosuppressed patients in a regional hospital in Mexico City

OBJETIVO: Aislar e identificar hongos en diferentes especímenes de pacientes inmunocomprometidos, atendidos en un hospital de la Ciudad de México, y determinar su asociación con micosis. MATERIAL Y MÉTODOS: Se realizó un estudio de tipo observacional transversal en pacientes del Hospital Regional General Ignacio Zaragoza, de junio de 1999 a mayo de 2000. De 108 pacientes se procesaron 268 especímenes para estudio micológico que incluyó examen directo, frotis, cultivos y microcultivos en medios específicos además de pruebas bioquímicas. La mayoría de pacientes tenía diagnóstico clínico de tuberculosis pulmonar y de síndrome de inmunodeficiencia adquirida. RESULTADOS: Se obtuvieron 183 aislamientos de levaduras y 66 de hongos filamentosos. Se diagnosticaron 45 micosis que en su mayoría correspondieron a candidosis pulmonar (32 casos). Las especies de Candida más frecuentes asociadas a patología fueron Candida albicans y C parapsilosis. Se obtuvieron cinco aislamientos de Cryptococcus neoformans variedad neoformans, uno de C albidus, tres de Histoplasma capsulatum y uno de Geotrichum candidum, asociados a infección micótica. CONCLUSIONES: El 41.6 por ciento de los pacientes estudiados presentaron una micosis asociada principalmente a síndrome de inmunodeficiencia adquirida y a tuberculosis pulmonar.

OBJECTIVE: To isolate and identify the fungi in specimens collected from immunocompromised patients seen in Mexico City hospital, and to assess their association with mycosis. MATERIAL AND METHODS: A total of 268 specimens from 108 patients were processed for mycological study, including direct examination, smears, cultures, and microcultures in specific media, in addition to biochemical tests. Most of the patients had been diagnosed with pulmonary tuberculosis and Acquired Immunodeficiency Syndrome (AIDS). RESULTS: One hundred and eighty-three yeasts and 66 mycelial fungi were isolated. Forty-five mycoses were diagnosed; the most frequent mycosis was pulmonary candidosis (32 cases). Candida albicans and C parapsilosis were the predominant species associated with mycotic infection. Five Cryptococcus neoformans var. neoformans, one C albidus, three Histoplasma capsulatum and one Geotrichum candidum isolats were associated with mycosis. CONCLUSIONS: Of the studied patients, 41.6 percent showed a mycotic infection, principally associated with AIDS and pulmonary tuberculosis.

Hallazgo de Candida albicans en manos de manejadores de alimentos / Candida albican findings in hands of people handling food

Las levaduras del género Candida frecuentemente son el agente causal de infecciones en sitios corporales expuestos a factores como la humedad y la maceración. En este estudio fueron incluidos 1,059 individuos manipuladores de alimentos de diversos centros comerciales de la ciudad de México y un grupo testigo sano de 139 personas. En todos ellos se tomaron muestras de manos para el aislamiento de hongos potencialmente patógenos. Se encontró que 30.7 por ciento de los trabajadores estudiados son portadores de diversas levaduras; la mayoría de estos aislamientos se obtuvo de los trabajadores del área de panadería. De los 325 aislamientos levaduriformes obtenidos, C. albicans representó 12.4 por ciento y el restante 85.8 por ciento correspondió a Candida no albicans; otras levaduras aisladas fueron Rhodotorula (0.9 por ciento) y Trichosporon (0.9 por ciento). En el grupo testigo solamente se aislaron levaduras de Candida en 11.5 por ciento; de éstas, seis correspondieron a C. albicans (37.5 por ciento) y 10 (62.5 por ciento) a C. no albicans. No se aislaron hongos filamentosos.

Onicomicosis: diagnóstico etiológico y frecuencia en 282 casos / Onichomycosis: diagnosis and incidence

Con la finalidad de conocer la frecuencia de diferentes agentes etiológicos de las onicomicosis, se hizo un estudio en 442 pacientes que presentaban diagnóstico sugestivo de esta micosis en manos o en pies. En todos ellos se practicó examen directo y cultivo de las escamas. En 282 (63.8 por ciento) de estos pacientes se comprobó el diagnóstico micológico por examen microscópico directo y/o por cultivo. El 93.8 por ciento de los pacientes con onicomicosis fueron adultos, con predominio del sexo femenino (55.0 por ciento). T. rubrum fue el hongo más frecuente aislado como causa de onicomicosis, en el 66.8 por ciento. Los dermatofitos afectaron más las uñas de los pies, en tanto que las levaduras del género Candida fueron más comunes en las manos. La mayoría de los 282 casos de onicomicosis se diagnosticaron tanto por examen directo como por cultivo (55.8 por ciento); en 21 casos (7.4 por ciento) el diagnóstico se estableció por cultivo. Se discute la importancia del laboratorio de micología en el diagnóstico preciso de las micosis, señalando la utilidad del cultivo para conocer la taxonomía del hongo causante y para un mejor manejo clínico, epidemiológico y terapéutico del paciente