Identification of Differentially Expressed Genes in Nocardia brasiliensis Induced by Progesterone and Dihydrotestosterone Using Differential Display PCR.

Sex steroid hormones have an important physiological role in humans. They can also affect the gene expression of many organisms, including bacteria. In Mexico, Nocardia brasiliensis is the main causative agent of actinomycetoma, a granulomatous disease more frequent in men than women, which is thought to be related to a higher occupational risk in men. Therefore, it has been suggested that differences in clinical presentation could be related to sex steroid hormone levels. Attempting to explain the differences in actinomycetoma prevalence between men and women, in this work, the effect of progesterone and dihydrotestosterone on the genetic expression of N. brasiliensis was investigated using a differential display polymerase chain reaction assay. The results showed that both hormones affected the expression of genes encoding proteins related to central metabolism and hypothetical proteins with unknown functions. This study also demonstrated the utility of differential display in this modern era and provided a first approach to the effect of sex hormones on N. brasiliensis gene expression.

Antifúngicos poliénicos. Mecanismo de acción y aplicaciones / Polyenic Antifungals. Action Mechanisms and their Applications

Resumen: Los primeros compuestos con actividad antifúngica específica fueron identificados a mediados del siglo pasado como un producto del metabolismo secundario de bacterias del orden Actinomycetales, y su uso en la clínica redujo de manera importante la morbilidad y la mortalidad relacionadas con infecciones severas por hongos de varios géneros. Muchos de estos compuestos biosintéticos se caracterizan por tener una estructura química de tipo poliénico, con un número variable de dobles enlaces carbono-carbono. Actualmente, además de los fármacos poliénicos, existe otro tipo de compuestos con actividad antimicótica, como los azoles, que se utilizan con mayor frecuencia y que presentan menor toxicidad en los pacientes; sin embargo, se han documentado casos de falla terapéutica con tales compuestos, por lo que el uso de los poliénicos se ha mantenido como la mejor alternativa en esos casos. El presente trabajo brinda información acerca de las propiedades y las aplicaciones de los antifúngicos poliénicos teniendo como modelo a la anfotericina B.

Abstract The first compounds with specific antifungal activity were identified in the middle of the last century as a product of the secondary metabolism of bacteria of the order Actinomycetales, and their clinical use significantly diminished the morbidity and mortality associated with severe fungal infections. Many of such biosynthetic compounds are characterized by a chemical polygenic structure, with a variable number of carbon-carbon double bonds. Currently, besides polygenic antimycotics, there are other antifungal agents, such as the azole compounds, that have less toxicity in patients; however, cases of therapeutic failure with such compounds have been documented, therefore, the use of polygenics is still the best alternative in such cases. This review presents data about the properties and applications of antifungal-polygenic compounds using amphotericin B as a model.

Esophageal candidiasis in patients from a specialty hospital / Candidiasis esofágica en pacientes de un hospital de especialidades

Background: Esophageal candidiasis (EC) is the most common cause of infectious esophagitis. So far, its main risk factor has been HIV infection; in recent years, EC has been favoured by the increasing of diabetes mellitus, wide-spread use of acid-lowering agents, broad-spectrum antibiotics, and inhaled steroids. In Mexico EC has been poorly studied. Objectives: To determine the clinical and epidemiological characteristics of EC, and to identify its etiological agents as well as its antifungal susceptibility. Methods: Patients who revealed the presence of scattered white spots through an upper gastrointestinal system endoscopy, in a period of one year, in a tertiary care hospital, were included. Samples from patches were collected for microscopic examination, culture, and susceptibility tests. Results: Out of 1763 patients studied, 23 had scattered white spots, and most of them presented Kodsi grade I; 13 were men; half of the patients were between the ages 20 to 40; main comorbidity was liver cirrhosis; use of omeprazole was significant. 22 isolates were obtained from 17 patients. The most frequent species were C. albicans (14) and C. parapsilosis (3). In five cases we found a two-species association v. g. Candida famata with Trichosporon mucoides. Half of the isolates showed resistance to one or several antifungal drugs. Conclusions: EC frequency in this study was similar to other studies' results. Obtained isolates showed high resistance to azolic compounds and to caspofungin, which is relevant information to take a therapeutic decision.

Introducción: la candidiasis esofágica (CE) es la causa más común de esofagitis infecciosa. Su principal factor de riesgo ha sido la infección por VIH. En México ha sido poco estudiada. Objetivos: determinar las características clínico-epidemiológicas de la CE e identificar sus agentes etiológicos y su sensibilidad a antifúngicos. Métodos: se incluyeron pacientes a quienes se les detectaron placas blanquecinas durante una endoscopía esofágica, en un periodo de un año, en un hospital de tercer nivel de atención. Se tomó muestra de las placas para examen microscópico, cultivo, y estudios de sensibilidad. Resultados: de 1763 pacientes estudiados, 23 presentaron placas blanquecinas; 13 fueron hombres; la mitad tenía de 20 a 40 años de edad; la principal comorbilidad fue cirrosis hepática; el uso de omeprazol fue significativo. Se obtuvieron 22 aislados de 17 pacientes; predominaron Candida albicans (14) y Candida parapsilosis (3). En cinco casos se encontró asociación de dos especies v. g. Candida famata con Trichosporon mucoides. La mitad de los aislados mostró resistencia a antimicóticos. Conclusiones: la frecuencia de CE fue similar a la de otras casuísticas. Los aislados obtenidos mostraron resistencia elevada a compuestos azólicos y a caspofungina, información relevante para tomar una decisión terapéutica.

First report of infectious endocarditis due to Histoplasma capsulatum in Mexico / Primer reporte de endocarditis infecciosa por Histoplasma capsulatum en México

Background: Infectious endocarditis of fungal origin is rare but of high mortality. The agents involved are mainly opportunists of the genus Candida and Aspergillus; however other fungi can also cause this disease. Clinical case: The case of a woman who suffered unknown origin intermittent fever for several months; and in who, by blood culture (after lysis-centrifugation) and molecular biology techniques, Histoplasma capsulatum was identified as etiological agent. The histological study showed abundant intracellular yeasts and hyphae in intracardiac vegetations. Conclusion: This first report of infectious endocarditis by H. capsulatum in Mexico highlights the importance of using in addition to manual blood culture (lysis-centrifugation) and histological study, faster and more sensitive diagnostic methods, such as serology and molecular biology, to confirm or rule out an invasive fungal infection and identify the agents.

Introducción: la endocarditis infecciosa de etiología micótica es una patología poco frecuente, pero con elevada mortalidad. Los agentes implicados generalmente son oportunistas de los géneros Candida y Aspergillus; sin embargo, otros hongos también pueden ocasionar la enfermedad. Caso clínico: se presenta el caso de una mujer quien cursó con fiebre intermitente de causa desconocida por varios meses y en la que, por medio de estudios de imagen, hemocultivo manual (después de lisis-centrifugación) y técnicas de biología molecular, se identificó Histoplasma capsulatum. El estudio histológico de las vegetaciones intracardiacas mostró abundantes levaduras e hifas. Conclusión: este primer reporte de endocarditis infecciosa por H. capsulatum en México pone en evidencia la importancia de utilizar, además del hemocultivo manual (lisis-centrifugación) y el estudio histológico, métodos de diagnóstico más rápidos y sensibles, como la serología y la biología molecular, para confirmar o descartar una infección fúngica invasiva e identificar los agentes.

First case of chromoblastomycosis due to Phoma insulana.

Chromoblastomycosis is a chronic infection, caused by pigmented fungi affecting skin and subcutaneous tissues characterized by verrucous nodules or plaques. Fonsecaea pedrosoi and Cladophialophora carrionii are the prevalent agents in the endemic areas. Phoma is an uncommon agent of human infection and involved mainly with phaeohyphomycosis cases. The case of a patient with a history of laceration in foot followed by verrucous aspect and scaly lesions, which had evolved for 27 years is presented. On physical examination disease was clinically compatible with chromoblastomycosis and the microscopic examination of scales showed fumagoid cells. On culture a dematiaceous fungus was grown. The agent was confirmed to be Phoma insulana based on its morphology and PCR-sequencing. This fungal agent has not been previously reported in association with this pathology.

Molecular detection of candida species from hospitalized patient's specimens. / Detección molecular de especies de Candida en especímenes de pacientes hospitalizados.

Objective: To identify the most frequent Candida species in specimens from patients hospitalized in different medical centers of Mexico City, with suspected fungal infection. Methods: Specimens were grown on Sabouraud dextrose agar at 28°C for 72 h. In addition, DNA was extracted. Isolates were grown on CHROMagar Candida™, at 37°C for 48 h. The molecular identification was performed by polymerase chain reaction (PCR) using primers specific for four species. Results: Eighty one specimens were processed and included: bronchial lavage, pleural, cerebrospinal, peritoneal, ascites and bile fluids; blood, sputum, bone marrow, oro-tracheal cannula and ganglion. By culture, 30 samples (37%) were positive, and by PCR, 41 (50.6%). By PCR, the frequency of species was: Candida albicans 82.9%, Candida tropicalis 31.7%, Candida glabrata 24.4%, and Candida parapsilosis 4.9%. In 34.1% of specimens a species mixture was detected suggesting a co-infection: Two species in five specimens (C. albicans-C tropicalis and C. albicans-C glabrata), and three species in three specimens (C. albicans-C. glabrata-C. tropicalis). Conclusions: The PCR is an useful tool for detection the most common Candida species causing infection in hospitalized patients, it avoids the requirement of culture weather we start from clinical specimen and it favors the early diagnosis of invasive candidiasis.

[Frequency of invasive fungal infections in a Mexican High-Specialty Hospital. Experience of 21 years]. / Frecuencia de micosis invasivas en un hospital mexicano de alta especialidad. Experiencia de 21 años.

BACKGROUND: Factors such as cancer, HIV infection, use of corticosteroids and antibiotics, favors the increase in the number of invasive fungal infections (IFI) worldwide. METHODS: To determine the frequency and epidemiological aspects of IFI at a mexican, a review of the proven cases diagnosed over the past 21 years (1993-2013) in the Laboratory of Medical Mycology was performed. RESULTS: A total of 472 cases were identified as: 261 candidiasis, 82 mucormycosis, 60 cryptococcosis, 43 aspergillosis and 16 histoplasmosis. A decrease in the frequency of candidiasis was observed, with 74 cases in the first 6 years and 48 in the last five. C. albicans was the most common agent and pulmonary infection the most prevalent. Cryptococcosis also declined from 24 to 10 cases, mainly caused by C. neoformans; two cases of C. laurentii and C. terreus and C unigutulatus were isolated once. Mucormycosis remained steady, but aspergillosis increased significantly, and from 2 cases found in the first studied period, it rose to 23 in the last one. CONCLUSIONS: It is important that High Specialty Hospitals have well-equipped laboratories of Medical Mycology. We suggest the creation of a National Reference Center for Mycoses to collect all the data of these infections, in order to help to the development of strategies for health education, prevention, diagnosis and treatment of them.

Introducción: Factores como el cáncer, la infección por VIH, así como el uso de esteroides y antibióticos, incrementan el número de micosis invasivas (MI). Métodos: Para conocer la frecuencia y algunos aspectos epidemiológicos de las MI en un hospital del IMSS, se revisaron los casos probados diagnosticados en los últimos 21 años (1993-2013) en el Laboratorio de Micología Médica. Resultados: Se identificaron 472 casos, distribuidos en: 261 candidosis, 82 mucormicosis, 60 criptococosis, 43 aspergilosis y 16 histoplasmosis. La candidosis disminuyó de 74 casos en los primeros 6 años, a 48 en los cinco últimos. La localización principal fue pulmonar y el principal agente fue C. albicans. La criptococosis también disminuyó de 24 a 10 casos, principalmente fue causada por C. neoformans, aunque hubo dos casos de C. laurentii, uno de C. terreus y uno de C. unigutulatus. La mucormicosis se mantuvo constante, pero la aspergilosis se incrementó pasando de 2 casos en el primer periodo a 23 en el último. Conclusiones: Es importante que los hospitales de alta especialidad, cuenten con laboratorios de micología médica para realizar el diagnóstico de MI. Se sugiere crear un Centro Nacional de Referencia de Micosis donde se concentren los datos de estas infecciones y contribuya en la elaboración de planes de educación para la salud, prevención, diagnóstico y tratamiento de las mismas.

Endophthalmitis of probable endogenous origin caused by Scedosporium boydii: A case report.

BACKGROUND: Mycotic ocular infections caused by the Scedosporium apiospermum species complex are challenging to treat because of the delayed diagnoses and poor responses to antifungal drugs and surgical treatment. CASE REPORT: A case of a 69-year-old male patient with a history of diabetes mellitus type 2 and prior surgery on the right femur is described. In the 10 days prior to the ophthalmic consultation he started with ocular pain, adding to a previous and progressive loss of visual acuity in his right eye. The diagnosis of endophthalmitis of probable endogenous origin was established. Despite medical treatment, the patient's condition worsened and, due to the imminent risks, an enucleation was performed. Smears of the enucleation tissue revealed fungal cells, and the cultures yielded a fungus belonging to the S. apiospermum species complex, which was identified as Scedosporium boydii by morphological characteristics and sequencing of a PCR amplicon. CONCLUSIONS: A diagnosis of endophthalmitis of probable endogenous origin in the right eye was based on a previous right femur surgery. Potential risk to the patient led to enucleation.

[Onychomycosis frequency in psoriatic patients in a tertiary care hospital]. / Frecuencia de onicomicosis en pacientes con psoriasis en un hospital de especialidades.

BACKGROUND: The changes in psoriatic nails can closely resemble an onychomycosis. Therefore, the fungal infection may be underdiagnosed. It was investigated the frequency of mycosis in fingernails and toenails in 150 patients with psoriasis in a dermatology department. METHODS: The clinical data suggestive of onychomycosis were investigated. Nail scales were obtained and cultured on Sabouraud dextrose agar with and without antibiotic. A direct examination with KOH was also performed. RESULTS: Out of 150 patients, 67 (45 %) had healthy nails; 42 (28 %) presented onychomycosis and 41 (27 %) showed nail changes without infection. Fingernail changes were more associated with psoriatic onychopathy (82.5 %), unlike toenail changes that were more frequently caused by fungal infection (26.4 % vs. 9.45 % in psoriasis). Out of 20 positive cultures, 22 fungi were isolated, of which 11 belonged to Candida spp. (50 %). As risk factor to develope an onychomycosis, only the psoriasis evolution time showed a significant difference (p = 0.033). CONCLUSIONS: In patients with psoriasis, fingernail disorders are mainly due to the own disease, while toenail disorders changes can be associated with onychomycosis. The main etiological agents were yeasts from the genus Candida. The only factor associated with a higher incidence of onychomycosis in these patients was a long lasting psoriasis.

Introducción: los cambios ungueales en los pacientes con psoriasis pueden ser muy parecidos a la onicomicosis y, por lo tanto, las infecciones fúngicas pueden ser subdiagnosticadas. Se investigó la frecuencia de onicomicosis en manos y pies de 150 pacientes con psoriasis de un servicio de dermatología. Métodos: se obtuvieron los datos clínicos de la psoriasis. Se cultivaron escamas de las uñas en agar dextrosa Sabouraud con y sin antibióticos y se hizo un examen directo con KOH. Resultados: de los 150 pacientes, 67 (45 %) presentaron uñas sanas; 42 (28 %) tuvieron onicomicosis, y 41 (27 %) onicopatía sin infección. Las alteraciones ungueales en las manos estuvieron más asociadas con onicopatía psoriásica (82.5 %); los cambios de las uñas de los pies se asociaron más frecuentemente a infección fúngica (26.4 frente a 9.45 % en psoriasis). De 20 cultivos positivos, se aislaron 22 agentes: 11 Candida spp. (50 %). Como factor de riesgo para desarrollar onicomicosis, el tiempo de evolución de la psoriasis mostró una diferencia significativa (p = 0.03). Conclusión: en los pacientes con psoriasis, las alteraciones ungueales de manos se deben principalmente a psoriasis, mientras que los cambios ungueales en los pies se asocian a onicomicosis. Esta fue causada principalmente por Candida sp. El único factor de riesgo asociado para onicomicosis fue la larga evolución de la psoriasis.

Paracoccidioidomycosis in Mexico: clinical and epidemiological data from 93 new cases (1972-2012).

Paracoccidioidomycosis (PCM) is an endemic systemic infection in several countries of Latin America. The few registered cases in Mexico most likely do not reflect the real frequency. Disseminate the epidemiological and clinical data of unreported cases of PCM in Mexico from 1972 until 2012 is the aim of this work. Epidemiological and clinical information of non-published cases of PCM was requested from the principal mycological diagnosis centres in Mexico. A total of 93 cases were received. The infection was found predominantly in men (95.7%), peasants (88.5%) and individual between 31 and 60 years of age. Most of the cases were found in tropical areas of the Gulf of Mexico (54.84%) and the Pacific littoral (20.3%). The main sites of dissemination were the oral mucosa (39.38%) and skin (34.05%). The most effective treatments were itraconazole alone and the combination of itraconazole with sulfamethoxazole-trimethoprim. PCM is a subdiagnosed pathology in Mexico. Therefore, adequate training is necessary to determine the current status of this mycosis.

[Update on the epidemiology of mycetoma in Mexico. A review of 3933 cases]. / Actualización de la epidemiología del micetoma en México. Revisión de 3,933 casos.

UNLABELLED: Mycetoma is one of the most frequent chronic subcutaneous infections in many tropical and subtropical regions. OBJECTIVE: To update the epidemiological data of mycetoma cases in Mexico. METHOD: A survey in the main mycological diagnosis centers in this country was performed. Each mycologist was requested for number of diagnosed mycetoma cases, age, sex, occupation, geographic origin, type of mycetoma, and etiological agents. RESULTS: Until 2012, we have registered 3,933 cases in the last 54 years. Sex distribution corresponds to 75.6% for men and 24.4% for women. In 75.72% is present in adults between 16-50 years old. The predominant work group of patients is farmers (58.41%) followed by housewives (21.79%). Most of patients come from Jalisco, Morelos, Nuevo Leon, Guerrero, Veracruz and Michoacan states. The most affected body areas are limbs (60.29%) and trunk (19.76%). Actinomycetoma has a frequency of 96.52%, and the commonest etiological agent is Nocardia brasiliensis (65.58%). Eumycetoma (3.48%) is mainly caused by Madurella grisea (28.47%) and M. mycetomatis (26.28%). CONCLUSIONS: Mycetoma is an under-diagnosed pathology representing a health problem in rural regions and must be attended with more interest by the health institutions.

[Invasive mycosis, immunocompromise and fever of unknown origin]. / Micosis invasivas en pacientes inmunodeprimidos con fiebre de origen desconocido.

BACKGROUND: fungal invasive infections are frequent in patients with immunosuppression. A common clinical feature is the presence of fever of unknown origin (FUO) in any of its several presentations. The aim of this study was to know the frequency of FUO associated to invasive mycosis in hospitalized patients. METHODS: samples from 34 patients were studied by immunological and microbiological procedures in order to investigate candidiasis, cryptococcosis, aspergillosis and Pneumocystis infection. RESULTS: fungal infection diagnosis was established in 12 (35 %) from 34 patients who full criterion. The fungal species isolated were Candida albicans (six), Aspergillus fumigates (four) and Cryptococcus sp. (two). All candidiasis cases were diagnosed only by microbiological studies, aspergillosis by immunological and microbiological studies, and cryptococcosis only by immunological studies. CONCLUSIONS: we concluded that is important the searching of mycosis in immunocompromised patients with fever of unknown origin by microbiological and immunological procedures.

[Onychomycosis-causing yeasts in four Mexican dermatology centers and their antifungal susceptibility to azolic compounds]. / Levaduras causantes de onicomicosis en cuatro centros dermatológicos mexicanos y su sensibilidad antifúngica a compuestos azólicos.

BACKGROUND: Yeasts represent the second cause of nail fungal infection in the world, and Candida albicans and Candida parapsilosis are the two most common species. OBJECTIVES: To determine the yeast species frequency and their in vitro antifungal susceptibility, obtained from patients with clinical features suggestive of onychomycosis. METHODS: A prospective study was carried out in four dermatological care centers in Mexico from 2004 to 2007. Clinical diagnosis was corroborated by direct examination and culture. The yeast species was determined by morphological and biochemical tests. An antifungal susceptibility test to ketoconazole, itraconazole and fluconazole by the broth microdilution method was performed on each isolate (document M27-A2). RESULTS: One hundred sixty-six yeast isolates were obtained; the most frequently found species were C. parapsilosis (31.9%), C. albicans (22.4%) and Candida guilliermondii (12.7%). Of all isolates, 51 showed resistance to one or several of the azole compounds: 33 to itraconazole, 12 to ketoconazole and 6 to fluconazole. It was remarkable that the four Candida glabrata isolates were resistant to the three azole compounds; C. guilliermondii and Candida famata were resistant to itraconazole in 42.9% and 54.5%, respectively. CONCLUSION: The results obtained show the importance of identifying the aetiological agent and antifungal susceptibility testing in order to avoid therapeutic failures in onychomycosis.

[Mycotic keratitis in an eye care hospital in Mexico City]. / Queratomicosis en un centro de atención oftalmológica en la Ciudad de México.

BACKGROUND: Some of the most common precipitating events for keratomycoses (fungal keratitis), include surgical trauma (after cornea transplantation), the use of contaminated contact lenses or alterations in lacrimal secretions. Diagnosis and treatment (to avoid loss of vision) for these type of infections are challenging. OBJECTIVE: Retrospective review of the diagnosis, epidemiology, etiology and response to treatment in 219 patients with fungal keratitis in Mexico. METHODS: We have studied the diagnosis, epidemiology, etiology and response to treatment in 219 patients from different states in the Mexican Republic in the Cornea Department at an Ophthalmology Hospital in Mexico D.F. RESULTS: Trauma was the precipitating event in 77 patients (36%), of which 12 (5.4%) were due to surgical trauma; 152 patients (64.8%) did not report any prior trauma. There were 165 male (75.3%) and 54 female (24.6%) patients, with an average age of 46 years old. For clinical and visual treatment patients were treated with topical and oral antifungals and surgery. One or more surgeries were performed on a total of 81 patients (36.9%). A total of 62 patients (28.3%) received a corneal transplant, and 19 patients (8.7%) were subjected to conjunctival flap or scleral-conjunctival surgery. CONCLUSIONS: In Mexico, keratomycoses affect mostly male patients in a 4:1 ratio over females. Fusarium solani was the most frequent agent of fungal keratitis in our study (37.2%), and the highest number of corneal ulcers and eviscerations (26%) was present in patients infected by Aspergillus. The best therapeutic responses were with combination of topical antifungals against dematiaceous fungi.

[Antifungal resistance: an emerging problem in Mexico]. / La resistencia a los antifúngicos: un problema emergente en México.

BACKGROUND: An increase in mycosis associated with therapeutic failure has been observed worldwide. The dearth of data in Mexico led us to study antifungal resistance. MATERIAL AND METHODS: Seventy six isolates of patients from the Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social were included: 36 with dermatophytoses and 40 with candidiasis. Dermatophytes were assesed using the E-test method and Candida spp. using the broth microdilution method. Antifungal drugs included itraconazole, ketoconazole and fluconazole for dermatophytes; in addition, voriconazole and amphotericin B were used to treat yeasts. RESULTS: From the 36 dermatophytes, seven isolates (19.4%) showed resistance to one or more antifungal drugs: three to Trichophyton rubrum, three to T. mentagrophytes and one to T. tonsurans. One T. rubrum isolate was resistant to the three azoles; the other six isolates were resistant to fluconazole only. From the 40 Candida isolates, 11 (27.5%) showed resistance: seven to ketoconazole and itraconazole; three only to itraconazole and one to ketoconazole. One C. glabrata isolate showed resistance to the four azoles. None of the yeasts showed resistance to amphotericin B. CONCLUSION: Therapeutic failure could be caused by drug resistance. In our study we found an antifungal resistance of 20% and 27.5% in dermatophytes and in yeasts respectively.

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.

[Effect of Mexican propolis extracts from Apis mellifera on Candida albicans in vitro growth]. / Efecto de extractos de propóleos mexicanos de Apis mellifera sobre el crecimiento in vitro de Candida albicans.

Propolis is a resinous substance collected by bees (Apis mellifera) from different trees and bushes. Due to its antifungal, antibacterial, antiviral and antiparasitic properties, it has continued to be very popular throughout the time showing variable activity depending on its geographical origin. In Mexico, information about this product is very limited. The aim of this work was to evaluate the antifungal activity of four propolis ethanolic extracts from three different Mexican states, and four commercial extracts on Candida albicans growth. A reference strain (ATCC 10231) and 36 clinical isolates of C. albicans were used. The Minimal Inhibitory Concentration (MIC) was determined by the dilution on agar method. Growth curves on Sabouraud Dextrose broth with and without different propolis ethanolic extracts concentrations were performed. In addition, whether the effect was fungistatic or fungicide was determined. The propolis ethanolic extract obtained from Cuautitlán Izcalli, State of Mexico, showed the best biological activity, inhibiting 94.4% from the clinical isolates at 0.8 mg/ml; the reference strain was inhibited at 0.6 mg/ml. The propolis effect was fungistatic in low concentrations and fungicide in concentrations higher to MIC. The Mexican propolis ethanolic extract could be further investigated for its alternative use for the treatment of some C. albicans infections.

La resistencia a los antifúngicos: un problema emergente en México / Antifungal resistance: an emerging problem in Mexico

Antecedentes: Mundialmente se ha observado incremento en los casos de micosis asociada a falla terapéutica. Ante el desconocimiento real de este fenómeno en México, se decidió estudiar la resistencia a antifúngicos. Material y métodos: Se evaluaron 76 aislamientos de pacientes del Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social: 36 con dermatofitosis y 40 con candidiasis. Para dermatófitos se utilizó el método E-test® y para Candida spp. el método de microdilución en caldo. Los antimicóticos fueron itraconazol, ketoconazol y fluconazol para dermatófitos; además, voriconazol y anfotericina B para levaduras. Resultados: De los 36 dermatófitos, siete (19.4%) fueron resistentes a uno o más antifúngicos: tres Trichophyton rubrum, tres T. mentagrophytes y un T. tonsurans. Un T. rubrum mostró resistencia a los tres azoles; los seis aislamientos restantes fueron resistentes sólo a fluconazol. De los 40 aislamientos de Candida, 11 (27.5 %) mostraron resistencia: siete a ketoconazol e itraconazol; tres sólo a itraconazol y uno a ketoconazol. Un aislamiento de C. glabrata fue resistente a los cuatro azoles. Ninguna de las levaduras mostró resistencia a anfotericina B. Conclusiones: La falla terapéutica podría deberse a fenómenos de resistencia. En este trabajo se encontró una resistencia a antifúngicos de 20 y 27.5% en dermatófitos y levaduras, respectivamente.

BACKGROUND: An increase in mycosis associated with therapeutic failure has been observed worldwide. The dearth of data in Mexico led us to study antifungal resistance. MATERIAL AND METHODS: Seventy six isolates of patients from the Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social were included: 36 with dermatophytoses and 40 with candidiasis. Dermatophytes were assesed using the E-test method and Candida spp. using the broth microdilution method. Antifungal drugs included itraconazole, ketoconazole and fluconazole for dermatophytes; in addition, voriconazole and amphotericin B were used to treat yeasts. RESULTS: From the 36 dermatophytes, seven isolates (19.4%) showed resistance to one or more antifungal drugs: three to Trichophyton rubrum, three to T. mentagrophytes and one to T. tonsurans. One T. rubrum isolate was resistant to the three azoles; the other six isolates were resistant to fluconazole only. From the 40 Candida isolates, 11 (27.5%) showed resistance: seven to ketoconazole and itraconazole; three only to itraconazole and one to ketoconazole. One C. glabrata isolate showed resistance to the four azoles. None of the yeasts showed resistance to amphotericin B. CONCLUSION: Therapeutic failure could be caused by drug resistance. In our study we found an antifungal resistance of 20% and 27.5% in dermatophytes and in yeasts respectively.