Patricia Manzano-Gayosso

Fungal peritonitis in 15 patients on continuous ambulatory peritoneal dialysis (CAPD)

Peritonitis is a frequent complication in patients with chronic renal failure on continuous ambulatory peritoneal dialysis (CAPD) treatment. The aim of this study was to know the prevalence of fungal peritonitis on patients undergoing CAPD, and to determine the antifungal susceptibility pattern of the identified isolates. Samples of the peritoneal dialysis fluid from 165 patients on CAPD treatment with peritonitis manifestations were submitted to mycological study (direct microscopic examination, culture and antifungal susceptibility test). Ten Candida isolates were identified, being C. albicans and C. parapsilosis the most common species. From isolates obtained, three species (C. albicans, C. parapsilosis, and C. guilliermondii) presented itraconazole resistance while C. glabrata was resistant to both itraconazole and ketoconazole. Aspergillus fumigatus was associated to peritonitis in three cases and Acremonium sp. in two.

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.

Effectiveness of terbinafine in the eradication of Microsporum canis from laboratory cats

Summary. In this study, the coats of 20 cats with no dermatophytosis lesions were sampled for colonization by Microsporum canis, which was isolated in 45% of cases. All cats were treated with oral terbinafine for 3 weeks. The drug was administered orally at a daily dosage 8.25 mg kg−1. Mycologic status was assessed at the end of the treatment; and after follow‐up at 2 days, and 4 and 9 weeks. The final evaluation revealed a complete mycologic cure of all cats by obtaining negative cultures, thereby demonstrating that terbinafine is an effective method of eradication of dermatophyte colonization.

Dermatophytoses in Mexico City.

Summary. We analysed 2350 biological samples from patients with a clinical diagnosis of superficial mycoses who attended outpatient services over a 7‐year period. Samples of scales were processed by direct microscopic examination with 15% KOH and cultured on Sabouraud glucose agar with chloramphenicol and cycloheximide. Laboratory examination confirmed dermatophytosis in 860 (36.6%) cases, of which 80.9% were caused by Trichophyton rubrum. The most frequently observed dermatophytoses were tinea unguium (60%) and tinea pedis (25.6%). In agreement with previous observations, we demonstrate that T. rubrum continues to increase in Mexico.

Resistencia a compuestos azólicos de aislamientos clínicos de Trichophyton spp.

Resumen Ante el aumento de pacientes con dermatofitosis y mala respuesta terapeutica, se estudio la sensibilidad antifungica a itraconazol, ketoconazol y fluconazol por el metodo E-test, en 36 aislamientos clinicos de dermatofitos. Considerando los parametros del Clinical Laboratory Standards Institute, se encontro resistencia a uno o mas antifungicos en siete aislamientos (19,4%): tres de Trichophyton rubrum, tres de Trichophyton mentagrophytes y uno de Trichophyton tonsurans. Un aislamiento de T. rubrum mostro resistencia a los tres azoles y los seis restantes unicamente a fluconazol. Es importante establecer la sensibilidad antifungica como parte del protocolo de estudio de pacientes con dermatofitosis con mala respuesta terapeutica.

Nocardia brasiliensis: in vitro and in vivo growth response to steroid sex hormones

As actinomycetoma is more frequent in males than in females, the possibility that hormones might modify theNocardia brasiliensis growth and the course of experimental actinomycetoma was explored. FiveN. brasiliensis strains were grown on Sabouraud agar containing estradiol, progesterone or testosterone, in 3 different concentrations. Colony diameters were measured weekly for 7 weeks.N. brasiliensis strains were also grown in Sabouraud broth containing hormones. Glucose concentration was measured weekly for 6 weeks. Finally, experimental actinomycetoma was produced in male and female hormone-treated mice. Invasion rate, plantar pad diameter and positive retrocultures were assessed. In vitro experiments showed that progesterone and testosterone inhibitN. brasiliensis growth, manifested by lower colony diameters and greater glucose concentrations. In vivo experiments demonstrated that estradiol limits actinomycetoma development. Progesterone and testosterone induced greater diameters of inoculated plantar pads and greater invasion rates with greater positive culture numbers than estradiol. Results partially explain the resistance of females to actinomycetoma.

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.

Dynamics of dermatophytosis frequency in Mexico: an analysis of 2084 cases.

We analysed 15,101 biological samples from patients presenting with superficial mycoses who attended outpatient services over a 10-year period. Scale samples were processed for direct microscopic examination with 15% KOH and cultured on Sabouraud glucose agar plus chloramphenicol and cycloheximide. Laboratory examination confirmed 4,709 cases of superficial mycosis (31.18%), of which 2,084 (44.26%) were dermatophytoses. The species most frequently encountered was Trichophyton rubrum (71.2%), followed by T. tonsurans (6.9%), T. mentagrophytes (5.5%), Microsporum canis (4.5%) and Epidermophyton floccosum (1.3%). The most frequent clinical form of dermatophytosis was tinea unguium (59.9%), followed by tinea pedis (24.5%). We demonstrate that the number of cases of T. rubrum is increasing in Mexico.

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 Cuautitlan 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.

Cytokine production and lymphocyte proliferation in patients with Nocardia brasiliensis actinomycetoma.

IFN-γ, TNF-α, IL-4, IL10 and IL-12 concentrations in the supernatant of peripheral blood mononuclear cell (PBMC) cultures and the in vitro proliferation of PBMC were studied in 25 patients with actinomycetoma caused by Nocardia brasiliensisand in 10 healthy controls from endemic zones. Cell cultures were stimulated by a N. brasiliensiscrude cytoplasmic antigen (NB) and five semi-purified protein fractions (NB2, NB4, NB6, NB8, and NB10) separated by isoelectric. Phytohemagglutinin (PHA) and purified protein derivative (PPD) of Mycobacterium tuberculosiswere used as control antigens. Skin tests were performed by injecting 0.1 ml of candidin and PPD intradermally (ID). Patients showed a poor response to tuberculin, while their response to candidin was more than two fold greater than that observed in the controls. Cell proliferation showed no statistically significant differences in either group. IFN-γ production was higher in the healthy controls than in the patients, whereas TNF-α secretion was slightly higher in the patients’ cultures. IL-4 was detected in the patients’ cultures but not in the controls. IL-10 and IL-12 were present at low concentrations in both groups. These results suggest that patients with actinomycetoma show normal antigen recognition, but with low IFN-γ production, and higher concentrations of IL-4, IL-10 and TNF-α in the patients’ PBMC cultures, indicating that they probably have a Th2 type of immune response.