Prevalencia de candidiasis vaginal en embarazadas: Identificación de levaduras y sensibilidad a los antifúngicos / Prevalence of vaginal candidiasis in pregnant women: Identification of yeasts and susceptibility to antifungal agents

La mujer embarazada es más susceptible tanto a la colonización como a la infección vaginal por levaduras. El objetivo de este trabajo fue determinar la prevalencia de levaduras aisladas de exudados vaginales de mujeres embarazadas y evaluar la sensibilidad a los antifúngicos de uso frecuente. Se estudiaron 493 pacientes en el período comprendido desde diciembre de 1998 hasta febrero de 2000. La prevalencia de Candida spp. fue 28% (Candida albicans 90,4%, Candida glabrata 6,3%, Candida parapsilosis 1,1%, Candida kefyr 1,1%, especies no identificadas 1,1%). Se determinó la sensibilidad a fluconazol, ketoconazol, itraconazol y nistatina por el método de difusión en agar Shadomy. Todos los aislamientos de C. albicans, C. kefyr y C. parapsilosis fueron sensibles in vitro a los antifúngicos probados, mientras que 1 de 6 aislamientos de C. glabrata presentó resistencia extendida a todos los azoles, pero sensibilidad a nistatina. En mujeres embarazadas C. albicans fue la levadura más frecuentemente aislada de exudados vaginales y continúa siendo ampliamente sensible a los antifúngicos; sólo en C. glabrata se observó resistencia a los azoles. Se recomienda la identificación de la levadura a nivel de especie particularmente en el caso de falla terapéutica y en infecciones recidivantes o crónicas.

Pregnant women are more susceptible to both vaginal colonization and infection by yeast. Our objectives were to determine the prevalence in pregnant women of yeasts isolated from vaginal exudates and their susceptibility to current antifungal drugs. A total of 493 patients was studied between December 1998 and February 2000. The prevalence of Candida spp. was 28% (Candida albicans 90.4%; Candida glabrata 6.3%; Candida parapsilosis 1.1%, Candida kefyr 1.1%; unidentified species 1.1%). The diffusion test in Shadomy agar was employed to determine the susceptibility to fluconazole, ketoconazole, itraconazole and nistatine. All C. albicans, C. kefyr and C. parapsilosis isolates were susceptible in vitro to the antifungal agents tested, while 1 in 6 C. glabrata isolates showed resistance to azole drugs; all strains were susceptible to nistatine. In pregnant women, C. albicans was the yeast most frequently isolated from vaginal exudates; it continues to be highly susceptible to antifungal drugs. Azole resistance was detected only among C. glabrata isolates. Identification to the species level is recommended, specially in cases of treatment failure and recurrent or chronic infection.

Detección de la actividad de desoxiribonucleasa (DNasa) en cepas de Clostridium chauvoei / [Deoxyribonuclease activity detection in Clostridium chauvoei strains]

Beta toxin of C. chauvoei has desoxiribonuclease (DNase) activity which is regarded as one of its virulence factors. The production of DNase was detected in strains isolated from bovines, using as controls C. chauvoei ATCC 10092, and C. perfringens Type A and C. septicum, both laboratory isolates. The enzyme activity was made evident on a DNA substrate observing the macroscopic degradation. A simple methodology was developed using a commercial medium for DNase test, with the incorporation of sterile horse serum. Each strain was streaked on the surface of the medium, incubated in anaerobic atmosphere at 37 degrees C for 48 hours. The plates were revealed with HCI 1 N. The appearance of a clear and transparent zone around and under the microbial growing was considered a positive reaction. Enzyme activity was detected in 10 of 12 strains and also in the controls. The serum addition to the commercial basal medium allows the optimum development of the microorganism showing the enzymatic digestion zone.

Ensayos de citotoxicidad y actividad antiviral de extractos crudos y semipurificados de hojas verdes de Melia azedarach L / [Assays of cytotoxicity and antiviral activity of crude and semipurified extracts of green leaves of Melia azedarach L.]

Crude extracts from fresh green leaves of Melia azedarach L contain an antiviral factor (FAV) able to inhibit the replication of several animal viruses, e.g. Polio, VSV, HSV, FMDV, Sindbis, Junín, Pichinde and Tacaribe in Vero or BHK-21 cells. Crude preparations were subjected to different steps of purification like chromatography on Sephadex G-100 and DEAE-Sephadex. The antiviral activity of G-100 and DEAE fractions was fully conserved, whereas contaminating proteins were lost. Two types of cytotoxicity tests were performed with the different fractions. Two-fold serial dilutions of each of them were added to preformed monolayers of Vero or BHK-21 cells and cellular viability was tested. While crude extracts were toxic at low dilutions (less than or equal to 1:10), G-100 and DEAE fractions were not. The other cytotoxicity assay consisted in seeding the cells in the presence of different concentrations of each fraction. G-100 fraction affected cell growth at low dilutions (less than or equal to 1:5), while DEAE fraction did not. It should be remarked that the purification procedure rendered a partial purified DEAE fraction with an increased specific activity (antiviral activity/mg of protein). It is concluded that an antiviral factor devoid of toxicity exists in M. azedarach L extracts, which exhibited a broad spectrum of antiviral activity.