[Antifungal drug resistance: mechanisms of resistance, freqeuncy, prevention and control of resistance].

Fungi are important causes of human infections, especially systemic mycoses. Pathogenic fungi have many complex mechanisms of resistance to antifungal drugs. In this article, information about the cellular, genetic and clinical factors contributing to antifungal-drug resistance, and their diagnostic and epidemiologic characteristics are reviewed. Understanding the mechanisms of resistance should assist in developing better detection and preventive strategies. The emergence of acquired antifungal resistance, especially in immunocompromised hosts, has necessitated routine antifungal susceptibility testing. Initial antifungal screening of clinical isolates by the disk-diffusion method would be followed by confirmation of resistant strains by the broth dilution method. Also, strategies to avoid and suppress the antifungal resistance are discussed. There are several strategies to overcome antifungal resistance, including increased antifungal-dose intensity, immunomodulation, combined antifungal therapy and new antifungals.

Diagnosis of Trichomonas vaginalis infection: The sensitivities and specificities of microscopy, culture and PCR assay.

OBJECTIVES: The aim of this study was to compare wet mount-, Giemsa stain-, acridine orange fluorescent stain-, cultivation- and polymerase chain reaction (PCR)-based approaches to establish which method or combination of methods was most effective in the laboratory diagnosis of trichomoniasis. STUDY DESIGN: Out of 200 investigated patients with various gynecological complaints, Trichomonas vaginalis infection was detected in 27 (13.5%) by any of methods investigated. Among women with trichomonads, a typical clinical finding was presented in only nine. For analysis of sensitivity and specificity of the methods used, the receiver operating characteristic (ROC) curve concept with culture as a gold standard was applied. RESULTS: Infection was diagnosed by wet mount in 14 (7.0%) women, by Giemsa stain in 11 (5.5%) and by acridine orange stain in 16 (8.0%) women. In 21 (10.5%) women, it was diagnosed by culture in Diamond's medium, and in 22 (11.0%) by PCR. For the initial diagnosis of trichomoniasis, wet preparation is the test that is widely available in most STD clinics, but its sensitivity is poor (66.67%). Giemsa stain shows a low sensitivity of 52.38%. Acridine orange shows reasonable sensitivity and specificity of 71.43% and 99.44%, respectively. The sensitivity and specificity of PCR (80.95% and 97.21%) did not exceed that of culture. CONCLUSION: With regard to the fact that trichomoniasis can have an atypical or even asymptomatic course, in order to accurately diagnose this disease, microbiological investigation is necessary. Comparison of different methods showed that at least two techniques, such as culture and acridine orange staining, have the potential for better diagnosis of T. vaginalis infection. PCR detection of infection has been demonstrated to be highly specific and sensitive, but its availability and cost effectiveness are in question. PCR could provide an alternative for laboratory diagnosis of trichomoniasis by culture.