Regina Celia Candido

Volatile Retention and Antifungal Properties of Spray-Dried Microparticles of Lippia sidoides Essential Oil

Spray drying microencapsulation of Lippia sidoides essential oil was investigated. Maltodextrin DE10 and gum arabic at different proportions (4:1, 3:2, 2:3, 0:1 m/m) was used as a carrier. The content of essential oil related to the carrier was 20 and 25% in weight and the emulsions were atomized from 30% up to 60% (m/m) of total solid concentration. Spray dryer inlet temperatures varied from 140 to 160°C and the best thermal efficiency and powder recovery were found at 160°C. Product properties and process performance were assessed on the basis of microscopic features of the powder (shape and size of microparticles), moisture content, and powder recovery. Encapsulation efficiency was estimated through determination of the content of essential oil in the microcapsules. The best encapsulation efficiency was related to experimental parameters as follows: solid content of the encapsulating composition of 50% (m/m), maltodextrin:gum arabic ratio of 0:1 (m/m) and carrier:essential oil ratio of 4:1 (m/m). Antifungal activities of microparticles were evaluated, evidencing their potential as important antifungal agents. The positive findings in this study encourage further research and provide perspectives for the development of phytotherapeutic products from essential oil of Lippia sidoides.

Effervescent tablets and ultrasonic devices against Candida and mutans streptococci in denture biofilm.

OBJECTIVE To evaluate the antimicrobial action of effervescent tablets and ultrasound on Candida spp. and mutans streptococci from denture biofilm. BACKGROUND It is not uncommon for edentulous patients to be elderly and find it difficult to brush their dentures. Hence, auxiliary methods are required for cleansing dentures as well as treating oral infections. MATERIALS AND METHODS Seventy-seven complete denture wearers were randomly assigned into four groups: (A) Brushing with water (control); (B) Effervescent tablets; (C) Ultrasonic device (Ultrasonic Cleaner, model 2840 D); (D) Effervescent tablets and ultrasonic device. All groups brushed their dentures with a specific brush and water, three times a day, before applying their treatments. Denture biofilm was collected at baseline and after 21 days. The samples were collected by brushing the dentures with saline and the detached microbial cells were quantified by plating. Counts [log (CFU+1) ml(-1) ] of total aerobes, Candida spp. and mutans streptococci were compared by one-way anova or Kruskal-Wallis test (α = 0.05). RESULTS No significant difference was found among the methods from C. albicans (p = 0.76), C. tropicalis (p = 0.94) and C. glabrata (p = 0.80). Lower counts were found for methods B and D when compared with the other methods against mutans streptococci (p < 0.001). Method B showed lower total aerobic counts than A, whereas C and D showed intermediate results (p = 0.011). CONCLUSION The effervescent tablets significantly reduced mutans streptococci and total aerobes from denture biofilm. However, they was not as effective against C. albicans. Ultrasonic cleansing presented a discrete antimicrobial effect and was less effective than the tablets for complete denture disinfection.

In vitro susceptibility to antifungal agents of environmental Cryptococcus spp. isolated in the city of Ribeirão Preto, São Paulo, Brazil

Infections by Cryptococcus strains other than C. neoformans have been detected in immunocompromised patients. Of these strains, three are considered human pathogens: C. albidus, C. laurenttii, and C. uniguttulatus. This study deals with the in vitro susceptibility of Cryptococcus to drugs such as amphotericin B, itraconazole, fluconazole, and 5-fluorocytosine. Environmental Cryptococcus isolates (50) distributed as follows: C. neoformans var. neoformans (16), C. albidus (17), C. laurentii (14), and C. uniguttulatus (3) were evaluated by the micro and macrodilution techniques, according to EUCAST and NCCLS recommendations, respectively. Considering both methodologies the respective minimal inhibitory concentrations (MIC) were 0.125 and 2 microg/ml for amphotericin B, 0.06 and 8 microg/ml for itraconazole, and 0.5 and more than 64 microg/ml for fluconazole and 5-fluorocytosine. Agreement percentages for the two methodologies were 100% for amphotericin B and fluconazole for all the strains tested. For itraconazole, the agreement percentage was 81.3% in the C. neoformans strain and 100% for all the others. All species had a agreement percentage of 94.1 to 100% when susceptibility to 5-fluorocytosine was tested. It is concluded that environmental isolates of C. neoformans var. neoformans, C. albidus, C. laurentii, and C. uniguttulatus may show high MICs against certain drugs, suggesting in vitro primary resistance to the antifungals tested.

Enzimotipagem de espécies do gênero Candida isoladas da cavidade bucal

The production of phospholipase and proteinase exoenzymes was evaluated in seventy nine samples of Candida isolated from the oral cavity of patients with oral lesions characteristic of candidosis and from individuals presenting a clinically normal mouth, attended at the University of Dentistry of Ribeirao Preto USP. Among the strains of C. albicans isolated from oral lesions, the phospholipase and proteinase were detected in 83.3% and 66.7%, respectively. C. tropicalis and C. parapsilosis produced only proteinase. Regarding the isolated strains from niches without lesions, out of a total of 32 C. albicans, 71.9% presented phospholipase and 68.7% proteinase. C. tropicalis only presented the enzyme proteinase, C. glabrata, C. krusei, C. guilliermondii and Candida spp did not present any of the exoenzymes. Among the samples of C. albicans from both groups, the enzymotype 22 (positive phospholipase and proteinase weakly positive), was prevalent. Different enzymotypes of the same species were detected in samples collected from the same patient.

Ocorrência de dermatófitos em amostras de unhas, pés e mãos coletadas de estudantes universitários

The objective of this paper was to evaluate the occurrence of dermatophytes, specifically in the nails, feet and hands of university students with and without lesions. Two hundred and eighty samples were collected; 31 (11.1%) were positive by direct examination, while only 20 (7.1%) showed dermatophyte growth in culture, as well as direct positive examination. Trichophyton rubrum was the most frequently isolated (80%) dermatophyte followed by T. mentagrophytes (20%). Considering the sites analyzed, dermatophyte occurrence was: 10.4% in toenails, 5% in foot skin, 2.5% in fingernails and 0.4% in hand skin.

Trypanocidal and antifungal activities of p-hydroxyacetophenone derivatives from Calea uniflora (Heliantheae, Asteraceae).

The dichloromethane extract of underground parts of Calea uniflora (Heliantheae, Asteraceae) exhibited trypanocidal and antifungal activities. Four p‐hydroxyacetophenone derivatives were isolated as the main compounds: 2‐senecioyl‐4‐(hydroxyethyl)‐phenol (1), 2‐senecioyl‐4‐(angeloyloxy‐ethyl)‐phenol (2), and two new derivatives, 2‐senecioyl‐4‐(methoxyethyl)‐phenol (3) and 2‐senecioyl‐4‐(pentadecanoyloxyethyl)‐phenol (4). 1 and 4 were active towards Trypanosoma cruzi trypomastigotes, reducing their number by 70 and 71% at 500 μg mL−1, whereas 2 and 3 were inactive. All the compounds tested showed antifungal activity with minimal inhibitory concentration values between 500 and 1000 μg mL−1 against pathogenic Candida spp. and dermatophytes. The isolation, structure elucidation, NMR spectral assignments and bioactivity results of these compounds are reported.

Candida sp in the oral cavity with and without lesions: maximal inhibitory dilution of Propolis and Periogard

Fifty individuals of both sexes aged on average 45.2 years were evaluated at the Semiology Clinic of FORP-USP in order to isolate and identify yeasts from the oral cavity, with and without lesions, and to determine the maximal inhibitory dilution (MID) of the commercial products Propolis (Apis-Flora) and Periogard (Colgate) against the strains isolated. Yeasts of the genus Candida were detected in the saliva of 9/19 (47.4%) individuals with a clinically healthy mouth, 18/22 (81.8%) of individuals with oral lesions, and in 4/9 (44.4%) of patients with deviation from normality, and were detected in 19/22 (86.4%) of the lesions. In the group with oral candidiasis, we isolated in tongue and lesion, respectively for each specie: C.tropicalis (8% and 10.7%), C.glabrata (4% and 3.6%) and C.parapsilosis (2% and 3.6%), in addition to C.albicans (71.4% and 67.8%) as the only species and the prevalent. The total cfu counts/ml saliva showed a higher mean value in the group with oral candidiasis (171.5% x 103) than in the control group (72.6 x 103) or the group with abnormalities (8.3 x 103). Most of the test strains 67/70 (95.71%) were sensitive to the antiseptics, with Propolis presenting a MID of 1:20 for 54/70/77.1%), and Periogard a MID of 1:160 for 42/70 (60%) strains from healthy sites, results similar to those obtained with strains from oral lesions. Different results were mainly observed among different species. The results indicate the possibility of using the antiseptics Propolis and Periogard (chlorhexidine) for the prevention and treatment of oral candidiasis.

in Vitro Activity of Antimycotic Agents Determined by e-Test Method Against Vaginal Shape Candida Species

Vaginal candidiasis continues to be a common cause of vaginal discharge, pruritus and other local complaints in women worldwide. Although numerous antimycotic agents are available for the treatment of yeast vaginitis there is little comparative data on the in vitro activity of these drugs. The objectives of this study were to isolate and identify the Candida species in the vagina and anus of patients treated in a gynaecology clinic, as well as determine the susceptibility to azolic compounds measured by the E-test method. Vaginal and rectal swabs were collected from 80 adult non-pregnant patients, seen at a gynaecological clinic, aged 18–59 years, with sexual activity, with and without vaginitis. The swabs were processed by methods routinely used for the detection of pathogenic yeasts. The susceptibility of the isolates to fluconazole, ketoconazole and itraconazole, was measured by the agar diffusion method (E-test), using RPMI 1640 medium with 2% glucose and phosphate buffer. Candida species (33) strains were isolated from 17 patients at similar proportions from both anatomical sites, and 12 patients harboured 24 strains of C. albicans in the vaginal and rectal tracts. Twenty one percent of the strains of C. albicans were resistant to ketoconazole, 54% were resistant to itraconazole and 0% were resistant to fluconazole. The sensitivity of strains isolated from the two sites were similar, indicating that these are strains of the same phenotype.

Avaliação da produção de melanina por espécies de Cryptococcus em quatro diferentes meios de cultura

The capacity of Cryptococcus spp to produce melanin in media containing phenol compounds is widely used for identifying these species in the laboratory. The aim of the present study was to compare the production of this pigment by Cryptococcus spp. in four culture media. Sixteen strains of Cryptococcus neoformans, 17 of Cryptococcus albidus, 13 of Cryptococcus laurentii and two of Cryptococcus uniguttulatus were tested in the following media: potato-carrot agar, Niger seed agar, sunflower seed agar and L-dopa agar. The melanin production was evaluated on the basis of colony pigmentation. Its production after five days of incubation was demonstrated by 93.8% of the strains of Cryptococcus neoformans in the media of potato-carrot agar, sunflower seed agar and L-dopa agar. From the isolates of Cryptococcus albidus, 29.4% produced the pigment in potato-carrot agar and L-dopa agar, 11.8% in Niger seed agar and 36% in sunflower seed agar. From Cryptococcus laurentii, 53.8% produced the pigment in potato-carrot agar and sunflower seed agar, 61.5% in L-dopa agar and 84.6% in Niger seed agar. Only one strain of Cryptococcus uniguttulatus presented slight production of the pigment, in potato-carrot agar.

Dermatophyte susceptibilities to antifungal azole agents tested in vitro by broth macro and microdilution methods

The in vitro susceptibility of dermatophytes to the azole antifungals itraconazole, fluconazole and ketoconazole was evaluated by broth macro and microdilution methods, according to recommendations of the CLSI, with some adaptations. Twenty nail and skin clinical isolates, four of Trichophyton mentagrophytes and 16 of T. rubrum were selected for the tests. Itraconazole minimal inhibitory concentrations (MIC) varied from < 0.03 to 0.25 microg/mL in the macrodilution and from < 0.03 to 0.5 microg/mL in the microdilution methods; for fluconazole, MICs were in the ranges of 0.5 to 64 microg/mL and 0.125 to 16 microg/mL by the macro and microdilution methods, respectively, and from < 0.03 to 0.5 microg/mL by both methods for ketoconazole. Levels of agreement between the two methods (+/- one dilution) were 70% for itraconazole, 45% for fluconazole and 85% for ketoconazole. It is concluded that the strains selected were inhibited by relatively low concentrations of the antifungals tested and that the two methodologies are in good agreement especially for itraconazole and ketoconazole.