Victor Silva

Onychomycosis caused by Fusarium solani and Fusarium oxysporum in São Paulo, Brazil

Fusarium species are common soil saprophytes and plant pathogens that have been frequently reported as etiologic agents of opportunistic infections in humans. We report eight cases of onychomycosis caused by Fusarium solani (4) and Fusarium oxysporum (4) in São Paulo, Brazil. These species were isolated from toenails in all cases. The infections were initially considered to be caused by dermatophytes. The clinical appearance of the affected toenails was leukonychia or distal subungual hyperkeratosis with yellowish brown coloration. The eight cases reported here suggest that Fusarium spp. should be taken into consideration in the differential diagnosis of tinea unguium.

Invasive fungal infections in Chile: a multicenter study of fungal prevalence and susceptibility during a 1-year period

During the first year of an ongoing surveillance program of invasive fungal infections (IFI) a total of 130 patients (56% male) with fungal strains isolated from blood and other sterile sites were reported from 13 hospitals in Chile. Significant yeast isolates were obtained from 118 patients, and molds affected 12 patients. The main patient groups affected were neonates, children less than 1 year old and adults aged 50-79 years. All fungal bloodstream infections (BSI) were due to yeasts; 79 patients (61%) were affected. The main risk factors recorded were antibiotic therapy (76%), stay in the intensive care unit (ICU) (70%) and presence of a central venous catheter (65%). Nosocomial infections were represented in 83.5% of BSI. Overall, Candida albicans (40.8%), C. parapsilosis (13.1%), C. tropicalis (10%) and Cryptococcus neoformans (10%) were the most common species. Aspergillus fumigatus (3.1%) was the most frequent mold. C. albicans (48.1%) and C. parapsilosis (17.7%), were the most frequent agents recovered from blood. Saccharomyces cerevisiae and Trichosporon mucoides, two emerging pathogens, were also isolated. All yeasts tested were susceptible to amphotericin B with minimal inhibitory concentration (MIC) < or = 1 microg/ml. Resistance to itraconazole (MIC > or = 1 microg/ml) and fluconazole (MIC > or = 64 microg/ml) was observed in 4 and 6% of cases, respectively. C. glabrata was the least susceptible species, with 50% of isolates resistant to itraconazole and 33% resistant to fluconazole, with one strain showing combined resistance. Reduction of BSI requires greater adherence to hand-washing and related infection control guidelines.

Nosocomial candiduria in women undergoing urinary catheterization. Clonal relationship between strains isolated from vaginal tract and urine

We determined the incidence of nosocomial candiduria associated with indwelling urinary catheters in 42 women with and without Candida spp. vaginal colonization being treated in the intensive care unit (ICU). We established a relationship between strains initially isolated from the vaginal tract and those subsequently recovered from urine samples through the use of random amplified polymorphic DNA (RAPD). The overall incidence of nosocomial candiduria in these patients was 21.4%. Vaginal colonization by Candida spp. was detected in 11 patients (26.2%) of whom 6 (54.5%) developed candiduria. In comparison, only 3 (9.7%) cases of candiduria were found in women who were not colonized by the yeast (RR: 4.4, 95% CI 1.61-86.8, P=0.005). The dendrogram obtained by RAPD using 14 primers showed that the strains isolated from vagina and urine samples in five women had high similarity values (SAB >0.9) forming independent clusters. Our study suggests that women vaginally colonized by Candida spp. in an ICU setting have a high risk of acquiring nosocomial candiduria and that strains isolated from both sites in a single patient may be genetically related.

Endocarditis verrucosa secundaria a Saccharomyces cerevisiae: Caso clínico

We report a preterm infant with 30 weeks of gestation, that received broad spectrum antimicrobials during the first days of life. At nine days of life, the infant appeared with abdominal distension and hematochezia. A systolic murmur with changing auscultatory features also appeared. An echocardiography showed an atrial vegetation. A yeast, that was identified as the emergent pathogen Saccharomyces cerevisiae appeared in two blood cultures. Treatment with amphotericin B was started, the dose was adjusted calculating the minimal inhibitory concentration of amphotericin B, and measuring plasma levels of the antimicrobial. Therefore the minimal effective dose was prescribed, avoiding its deleterious effects. After 14 days of antifungal therapy, a new echocardiography showed a reduction in the size of the atrial vegetation. At 35 days, it disappeared and amphotericin B was discontinued. On the outpatient follow up, the infant has shown a normal growth and a normal cardiac auscultation (Rev Med Chile 2002; 130: 1165-9)

Identificación y susceptibilidad antifúngica de Candida spp aisladas de micosis invasora. Influencia del porcentaje de inhibición del crecimiento para la determinación de CIM

BACKGROUND An increase in the frequency of resistant strains to antifungal drugs has been detected in the last decade. AIM To report the minimal inhibitory concentration (MIC) to amphotericin B, fluconazole, ketoconazole and itraconazole. To compare the MIC obtained with 80% and 50% of growth inhibition to the azoles. MATERIAL AND METHODS Fifty yeast strains isolated between 1998 and 1999, from 17 adults and 33 children with invasive mycosis were studied. Susceptibility was determined by broth microdilution method with RPMI 1640 plus glucose 2% according to the National Committee for Clinical Laboratory Standards (1997). RESULTS The most frequently isolated strains were C albicans in 27 cases and C parapsilosis in 12. All isolates were susceptible to amphotericin B. According to the MICs obtained with 80% of inhibition, 12 strains had MICs considered as resistant to azoles. Five strains were resistant both to fluconazole and itraconazole. Considering MICs obtained with 50% of inhibition, only five strains were found resistant to azoles (p < 0.05). Using this criterion, only one C glabrata strain was found to be simultaneously resistant to fluconazole and itraconazole. CONCLUSIONS Similar results in the pattern of susceptibility of Candida spp to azoles, to those reported abroad, are obtained when the MIC is calculated using 50% inhibition.

Antifungal susceptibility of 50 Candida isolates from invasive mycoses in Chile

We determined the antifungal susceptibility of 50 Candida isolates from invasive mycoses in intensive care unit patients in Chile. Candida albicans (27 isolates) and C. parapsilosis (12 isolates) were the most common etiologic species. Candida glabrata (five isolates) was isolated only from children. Our data are consistent with those of recent Brazilian and Argentinean studies but differ from those of some US, Canadian and Norwegian studies, in which the relatively azole-resistant C. glabrata was the predominant non-C. albicans species seen. All isolates in this study were susceptible to amphotericin B. Itraconazole and fluconazole resistance were observed in 6 and 4% of the isolates, respectively.

Dermatomycoses caused by Nattrassia mangiferae in São Paulo, Brazil

Nattrassia mangiferae formerly known as Hendersonula toruloidea,is a phaeoid coelomycete described by Nattrass in 1933. We report five casesof N. mangiferae infections in São Paulo, Brazil. This fungus wasisolated from interdigital lesions on the feet in one patient, toenails in threecases and fingernails in the other one. The infections were initially consideredto be caused by a dermatophyte. Although there are only a few cases describedin the medical literature, the five cases reported suggest that N. mangiferaeshould be taken into consideration in the differential diagnosis of tinea pedisinfections.

Avaliação da sensibilidade de cepas de Malassezia furfur a imidas cíclicas

Malassezia furfur (Pityrosporum orbiculare) is a lipophilic microrganism and it has also been associated with pityriasis versicolor, folliculitis, seborrheic and atopic dermatitis, fungemia and systemic infections. The treatment comprehends antimicotics or imidazol derivatives solutions, specially cetoconazol. With purpose of evaluating new alternatives to the therapeutics of mycosis infections, the antifungical activity of cyclic imides was determinated in the present study. The imides 3,4-cichloro-N-phenylmaleimide (6,3 µg/ml), 3,4dichloro-N-benzyl-maleimide (25 µg/mL) and 3,4dichloro-N-phenyl-propyl-maleimide (25 µg/mL) were the compounds which produced the best activities of inhibition against strains of M. furfur.

¿Es aplicable el sistema de vigilancia epidemiológica de las infecciones intrahospitalarias que recomienda el CDC- americano (sistema NNIS) en un hospital chileno?

Background: The National Nosocomial Infections Surveillance System (NNIS system) is the method for surveying nosocomial infections used by the Centers for Disease Control (CDC). This strategy allows the comparison of different hospitals, using rate adjustments. In Chile, this system is not used. Aim: To report the application of this system in a tertiary reference hospital in Chile. Materials and methods: We performed a six months prospective cohort study. The active surveillance was carried out by using the intensive care unit and surgery components of the NNIS system. Tabulation and analysis of the data were done according to the NNIS system. In a parallel prevalence study, we determined the NNIS system sensitivity to detect nosocomial infections. Results: A total of 492 patients were followed with a global nosocomial infection rate of 14%, for discharged patients. The calculated sensitivity and specificity of the system was 84.2 and 97% respectively. In the intensive care unit, 45 of 169 patients had nosocomial infections, with an adjusted rate of 2.8% for mean hospitalization time and severity of illness. In the cardiovascular and thoracic surgical units, 216 and 107 procedures were surveyed, respectively. The global rates of nosocomial infections were 7.4 and 7.5%, respectively. The adjusted rates according to risk factors were 0.9 and 2.3%, respectively. Conclusions: These data indicate that the surgical units had surgical site infections rates similar to those reported by the CDC. Nosocomial infections rates in Chile can be compared with rates observed in other countries. The epidemiological data collected can be useful to focus intervention or preventive strategies (Rev Med Chile 2001; 129: 1379-86)

Actividad antifúngica y perfil de seguridad del producto natural derivado del aceite de maravilla ozonizado (AMO3) en dermatofitos

In vitro antifungal susceptibility, in vivo antifungal activity and security from a natural product obtained from sunrise oil (AMO 3 ) against dermatophytes This work studied safety and antifungal activity of ozonized sunfl ower oil (AMO 3 ) against dermatophytes. AMO 3 was prepared through a new original process that modifi es the oil before ozonation by alcoholic catalytic esterifi cation. Susceptibility was studied in 41 dermatophytes by agar diffusion and broth microdilution tests. The experimental model to assess the topical safety of the oil included 60 CF1 mice divided in three groups that were treated with vaseline (control), 1% AMO 3 and 50% AMO3 (overdose), respectively. Then, experimental dermatophytosis was induced in CF1 mice. Seventy-fi ve individuals were selected and divided in 5 groups that were treated once a day with placebo, cream with 1%, 2% and 3% AMO 3 plus an untreated control group. This new natural product showed antifungal activity against all strains studied. The MIC ranged between was 0,125 and 1%, while minimum fungicidal concentration (MFC) was 2%. The application of vaseline and AMO 3 1% and 50% did not produce clinical or histopathological lesions. The mice with dermatophytosis that were treated with 1%, 2% and 3% AMO 3 showed 100% clinical cure and 94% average mycological cure, exceeding placebo and control groups (p < 0,05). This product exhibits high antifungal activity and could be a safe alternative for ringworm topical treatment.