PubMed Health⌕ Search

Biomedical subjects

C R Paula

Publications and source records attributed to C R Paula.

At least 19 recordsLinked to original sources
PubMed2006

Superoxide dismutase in Cryptococcus neoformans varieties gattii, grubi, and neoformans.

Some clear dissimilarities occur among the varieties of Cryptococcus neoformans but there are few studies about the differences among individual yeast antioxidant enzymes. The total superoxide dismutase (SOD) activities and the copper, zinc-depend SOD (Cu,ZnSOD) and manganese-dependent SOD (MnSOD) isoenzymes of five reference C. neoformans strains belonged to A, B, C, AD and D serotypes (Table I) and other nine C. neoformans isolates (Table II) were determined. There were significant differences (p < 0.01 and p < 0.05) in total SOD activity among the varietie gattii (serotype C) and the other varieties. Cu,ZnSOD showed difference (p < 0.05) between A and D serotypes. These results point out a variety and serotype-independent SOD activity in C. neoformans reference strains and the other isolates that were evaluated.

Cryptococcus neoformans↗
PubMed2005

Trichophyton rubrum isolated from aids and human immunodeficiency virus-infected patients in São Paulo, Brazil: antifungal susceptibility and extracellular enzyme production.

BACKGROUND: In order to identify intraspecific variations in Trichophyton rubrum and to correlate them to the immunological status of the host, sixty strains isolated from AIDS, HIV-positive and HIV-negative patients were compared for the production of extracellular enzymes and for their susceptibility to several antifungal drugs. METHODS: The isolates were tested for their ability to secrete keratinases, proteinases, phospholipases, lipases and DNases. Likewise, we investigated their susceptibility to amphotericin B, ketoconazole, ciclopiroxolamine, griseofulvin, miconazole and tolnaftate. RESULTS: Variations in the Minimal Inhibitory Concentration (MIC80)) values were observed for all antifungals tested, but they were similarly distributed among the three clinical groups. Griseofulvin showed the most prominent differences among the three groups of isolates. Regarding enzyme secretion, all samples secreted keratinases and DNases, while none secreted phospholipases. Proteinases and lipases were secreted by some of them. CONCLUSIONS: The differences among isolates of the three groups were not statistically significant and therefore could not be ascribed to a given clinical status. Intraspecific variations similarly occurred in each group, irrespective of the immunological status of the patients.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Phenotypic and genotypic evaluation of fluconazole resistance in vaginal Candida strains isolated from HIV-infected women from Brazil.

We conducted a study to determine the antifungal susceptibility of vaginal Candida isolates from HIV-infected Brazilian women. Among 127 women enrolled, positive cultures for yeast were obtained from 31 of 38 (81%) women with symptomatic vulvovaginitis, and from 41 of 89 (46%) asymptomatic women. Susceptibility testing demonstrated 11 of the 72 isolates had either resistance or dose-dependent susceptibility to azole drugs, including four Candida albicans strains. Expression of the MDR1, CDR1, CDR2 and ERG11 genes was evaluated in all of the C. albicans isolates, and all four of the strains with reduced susceptibility to fluconazole had increased expression of CDR1 as compared to the fluconazole-sensitive strains. No increased expression of the other genes was identified. This large survey of Candida isolates from HIV-infected women from Brazil demonstrates that reduced susceptibility to azoles occurs at a low frequency among vaginal yeast isolates, and when present in C. albicans, azole resistance is associated with increased expression of CDR1.

AIDS-Related Opportunistic Infections↗
PubMed2005

Allergenic extracts from Metarhizium canisopliae: obtainment and characterization.

Metarhizium anisopliae is used as a biopesticide for insects that damage agricultural plantations like sugar cane and forage plants. In a previous study the sensitization to this fungus of asthmatic patients coming from sugar cane areas was showed. The aims of this work were: to compare crude extracts obtained with Tris-HCl and Coca liquid from several growth phases of M. anisopliae concerning the total content of proteins and their electrophoretic analysis profile; to evaluate in vivo allergic sensitization in Balb/c mice and allergic patients from a sugar cane area, and to characterize the allergenic fractions in the sera of patients positive for the prick test by means of Western-blotting. The extract obtained with Coca liquid on the 16th day was the one that presented the greatest number of proteic fractions, including all those present in the other extracts. Twelve fractions were verified in this extract with approximate molecular weights from 94 to 14 kDa. The allergenicity of the extract obtained on the 16th day was proven by the production of IgE antibodies in Balb/c mice, with titres of 200. Prick tests carried out with the extract of the 16th day in 79 atopic individuals (from sugar cane area), 35 atopic individuals (from urban area) and 11 non- atopic individuals showed respective positivity of 29%, 9% and 0%. The allergenic characterization in vitro was performed by means of Western blotting, and the fractions that reacted with the positive individuals' sera were those of approximate molecular weights of 67 kDa (95%); 20 kDa (55%); 94 kDa (36%); 34 and 36 kDa (23%); 43 and 48 kDa (14%); 16 kDa (9%) and 54kDa (5%). It was concluded that the crude allergenic extract, obtained with Coca liquid from the 16th day growth of Metarhizium anisopliae, contains allergenic fractions and can be used in diagnostic screening tests.

Allergens↗
PubMed2004

Cryptococcus neoformans shows a remarkable genotypic diversity in Brazil.

The genotypic diversity of Brazilian Cryptococcus neoformans strains was analyzed. The majority of the samples were alphaA (65%), followed by alphaB (17.5%), alphaD (9%), alphaAaD hybrids (5%), and alphaC (3.5%). A considerable genotypic diversity occurred within C. neoformans var. grubii, and a new amplified fragment length polymorphism genotype, 1B, was recognized.

Animals↗
PubMed2003

Biosynthesis of chondroitinase and hyaluronidase by different strains of Paracoccidioides brasiliensis.

The biosynthesis of chondroitinase and hyaluronidase by different isolates of Paracoccidioides brasiliensis was investigated in 20 strains isolated from patients (17 strains), a penguin (Pygocelis adeliae, one strain), an armadillo (Dasypus novemcinctus, one strain) and the environment (dog food, one strain). All the P. brasiliensis isolates studied had the ability to produce chondroitinase and hyaluronidase, although differences in colony morphology and enzyme production were detected among them. These results suggest that further investigations should be carried out in the clinical field in order to clarify the potential role of P. brasiliensis enzyme production in the pathogenesis of paracoccidioidomycosis.

Animal Feed↗
PubMed2002

Yeasts isolated from blood and catheter in children from a public hospital of São Paulo, Brazil.

The great majority of nosocomial fungal infections, especially fungemias, are caused by yeasts, mostly of the genus Candida. In addition, such infections may be associated with intravascular catheters. In this study, 80 yeast strains were isolated from hospitalized children, being 59 from blood cultures and 21 from vascular catheter cultures. The prevalent species in both blood and catheter was C. parapsilosis (32.2% and 48.9%, respectively), followed by C. albicans (16.9% and 28.6%, respectively). Concerning enzyme production, 78.8% of the 80 isolates presented strong proteolytic activity but 78.8% showed no phospholipase activity. We also detected two prevalent "killer" biotypes: 511 and 888. Additionally, in five patients, it was possible to observe that the yeast species, "killer" biotype and proteolytic and phospholipase activity of blood and catheter were similar. In view of this, we suggest a transmission of nosocomial yeast infection from catheter to blood.

Brazil↗
PubMed2002

Allergenic evaluation of Malassezia furfur crude extracts.

Crude extracts of the lipophilic yeast Malassezia furfur were obtained from 2, 6, 10 and 28 day old cultures. The in vitro cultivation periods corresponded, respectively, to the lag phase, middle of the log phase, end of log phase and the decline phase of the growth curve, which was based on viable cell counts obtained with a fluorescent viability test. Biochemical analyses showed that the protein and carbohydrate contents were greater in day 10 extracts. Seventy patients with different allergic manifestations and 30 healthy volunteers were skin prick tested using the extracts. Of these, thirteen (18.57%) patients gave positive responses. SDS PAGE gradient electrophoretic profiles of the preparations indicated that the 28 day extracts contained the greatest number of protein bands with molecular weights ranging mostly between 30 and 94 kDa. Immunoblots incubated with individual patient sera showed that four IgE binding M. furfur allergens of approximately 88, 61, 52 and 39 kDa were present in the 28 day extracts. The components identified could be used for detecting IgE mediated responses to M. furfur among individuals affected with different allergic conditions.

Allergens↗
PubMed2001

Susceptibility profile of vaginal yeast isolates from Brazil.

Vaginal specimens for culture were obtained from two hundred and five immunocompetent, non-hospitalized patients selected among all women attending the Gynecology and Obstetric Ambulatory Clinic of the University of Espírito Santo, Brazil, during a 2-year period (From 1998 to 1999). Patients were checked for signs and symptoms of vulvovaginitis and previous use of topical and systemic antifungal drugs. Yeast isolates were identified by classical methods and the antifungal susceptibility profile was determined according to NCCLS microbroth assay. The prevalence of vaginal yeast isolates from asymptomatic women was 25% (30/121) and 60% (50/84) among patients with symptoms of vulvovaginitis. Candida albicans was the most frequently isolated species in both groups (46% and 90%, respectively), followed by C. glabrata (13% and 6%, respectively). All isolates were susceptible to amphotericin B. Only ten isolates had dose dependent susceptibility (DDS) or resistance to azoles; and seven of these were non-albicans species. Based on our results we suggest that species identification and antifungal susceptibility testing need not be routinely performed in immunocompetent women, and may be reasonable only for the minority of patients with complicated vulvovaginal candidiasis that fail to respond to therapy.

Antifungal Agents↗
PubMed2001

Phenotypic characterization of Trichophyton rubrum isolates from two geographic locations in Brazil.

To characterize possible Trichophyton rubrum phenotypes, which circulate in two Brazilian localities, we tested 53 isolates of this dermatophyte for their ability to assimilate several carbon sources, for keratinase, proteinase, phospholipase, lipase and desoxiribonuclease (DNase) secretions, and for their susceptibility to the antifungals fluconazole, ketoconazole and itraconazole. For each method, the isolates were submitted to similarity analysis and the methods were evaluated for their discriminatory indexes. None of the isolates were capable of assimilating arabinose, dulcitol, lactose, melibiose, ribose and xylose, while all of the isolates assimilated maltose, sucrose and sorbitol. However, adonitol, cellobiose, dextrin, erythritol, fructose, galactose, inulin, mannitol, mannose, raffinose, rhamnose and trehalose were assimilated by some isolates but not by others. All isolates secreted keratinase and DNase, while none secreted phospholipase. Proteinase and lipase were secreted only by some isolates. All but four isolates were resistant to fluconazole, most of them were sensitive to ketoconazole and all were sensitive to itraconazole. Carbohydrate assimilation was the method that presented the highest discriminatory index, and also the method that displayed the largest number of biotypes. Taken together, these data suggest that significant phenotypic variations exist among T. rubrum isolates. They seem to occur independently from their geographic origins.

Antifungal Agents↗
PubMed2001

Phenotypic characterization of Microsporum canis isolated from cats and dogs.

To characterize strains of Microsporum canis that infect dogs and cats in São Paulo city, 30 isolates of this dermatophyte were tested for their ability to assimilate carbon and nitrogen sources, for proteinase and phospholipase secretion, for susceptibility to yeast killer toxins, and for susceptibility to the antifungals fluconazole, ketoconazole, itraconazole, 5-fluorocytosine and amphotericin B, in E test. All samples assimilated the nitrogen sources asparagine, ammonium sulphate, urea and sodium nitrate, as well as the carbon sources inulin, mannitol, trehalose, meso-erythritol, maltose, mannose, sorbitol, cellobiose, fructose and dextrin. Not all the samples assimilated adonitol, galactose, arabinose, rhamnose, raffinose, melibiose, ribose and sucrose, and none of them was capable of growing with dulcitol, lactose, or xylose as the only carbon source. Proteinase and phospholipase secretion was observed for most isolates. In the test of yeast killer toxin, 10 types could be identified, with four types exclusively observed in isolates from dogs and two types exclusively observed in isolates from cats. In the E test, all isolates were found to be resistant to the fluconazole and 5-fluorocytosine, while they were variably sensitive to amphotericin B, ketoconazole and itraconazole. When the data were submitted to the qualitative analysis in the matrix distance program FITOPAC, the similarity of the isolates could be assessed.

Animals↗
PubMed2001

Production of extracellular enzymes by Microsporum canis and their role in its virulence.

Microsporum canis is the most prevalent dermatophyte of domestic animals. Several enzymes produced by dermatophytes, particularly keratinases, are considered to play a role in the virulence of this fungus. To investigate the possible relationship between the clinical status of M. canis infection and enzymatic activity of isolates, we studied the relationship between keratinase, elastase, lipase and DNase levels produced in vitro by different isolates and virulence as expressed in a guinea pig model. Samples isolated from symptomatic dogs and cats showed a statistically significantly (P < 0.05) higher keratinase activity than samples isolated from asymptomatic animals. Experimental infection of guinea pigs showed that a strain with high in vitro keratinase activity induced acute infection, which resolved clinically and mycologically faster than the infection induced by a strain with low keratinase activity. This suggested a strong correlation between high keratinase activity and the development of symptoms. The same correlation was not observed for other enzymes tested.

Animals↗
PubMed2000

Proteinase, phospholipase, hyaluronidase and chondroitin-sulphatase production by Malassezia pachydermatis.

The production of four functional enzyme categories was investigated in 30 strains of Malassezia pachydermatis isolated from dogs with otitis or dermatitis. The most appropriate reading intervals for these assays were determined with the aid of statistical comparisons. All strains produced proteinase and chondroitin-sulphatase; hyaluronidase and phospholipase were produced by all skin isolates (15/15) and 14 out of 15 ear canal isolates. Strains from ear canals did not differ significantly as a group from skin strains in quantitative production of any of the four enzymes; production of proteinase and chondroitin-sulphatase in particular was markedly uniform.

Animals↗
PubMed2000

Environmental isolation of Cryptococcus neoformans var. gattii and C. neoformans var. neoformans in the city of São Paulo, Brazil.

In order to determine the environmental occurrence of both varieties of Cryptococcus neoformans in the city of São Paulo, pigeon droppings and vegetable material from trees of the genus Eucalyptus were collected at typically crowded places. A total of 38 sites downtown where large heaps of pigeon droppings could be found were selected for sampling. Pigeon droppings from 10 (26.3%) of these sites were positive for C. neoformans var. neoformans in at least one sample. Twelve eucalyptus woods located within four municipal parks were also surveyed; vegetable material from Eucalyptus spp. trees were collected monthly over a 2-year period. C. neoformans var. gattii was recovered from a wood in Ibirapuera Park during the same season on two different occasions (November 1996 and November 1997); this park contained specimens of Eucalyptus camaldulensis, a natural habitat of C. n. var. gattii. C. n. var. neoformans was detected in a wood in Ibirapuera Park and Aclimação Park. The results show that both C. n. var. neoformans and C. n. var. gattii are present in the urban environment of São Paulo city at sites where large numbers of people normally gather.

Animals↗
PubMed1999

Production of proteinase and phospholipase by Paracoccidioides brasiliensis.

We have investigated the production of proteinase and phospholipase by 20 different isolates of Paracoccidioides brasiliensis. Isolates were grown in Bacto-peptone, Dextrose, pH 5.5, agar slants, at 27 degrees C for 30 days, and cultures were transferred onto Petri dishes containing basis medium and bovine serum albumin fraction V and sterile egg yolk as substrates for enzyme production, and incubated at 27 degrees C. After 30 days net enzyme activity was visualized and quantitatively evaluated, measuring a ratio between colony diameter and diameter of the transparent (proteinase) or white (phospholipase) ring zone surrounding it. Results demonstrated that all isolates had the ability to produce proteinase and phospholipase, even though variability in enzyme production was noted among different isolates of P. brasiliensis.

Endopeptidases↗
PubMed1997

Protein profiles of Malassezia pachydermatis isolated from dogs.

The protein fractions of 30 Malassezia pachydermatis isolates from dogs (15 with otitis and 15 with dermatitis) were investigated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The electrophoresis runs resulted in bands ranging from 15.0-145.7 kDa in the ear canal secretion isolates. The values for the skin isolates varied between 16.0-141.1 kDa. The presence of protein bands occurred most frequently within the 30-40 kDa bands (66.7%), 40-50 kDa (70.0%), 50-60 kDa (73.3%) and 80-90 kDa (83.3%). No statistical differences were determined, considering the behavior of M. pachydermatis isolates from ear and skin in each band of molecular weight values, nor in the number of bands obtained.

Animals↗
PubMed1997

Phenotype and genotype of Candida albicans strains isolated from pregnant women with recurrent vaginitis.

Fourteen out of 80 pregnant women receiving prenatal care presented signs and symptoms of recurrent vaginal candidiasis. Candida albicans strains were isolated from 12 patients (85.7%), and these were submitted to morphotyping (morphological characteristics of the colony), antifungal typing (pattern of sensitivity to amphotericin B, 5-fluorcytosine, myconazole, ketoconazole and fluconazole) and genotyping (electrophoretic migration of DNA fragments digested with EcoRI and HinfI). Alteration of morphotype and antifungal type was observed in 50% of the patients, but the genotype of the strains isolated from the same patients at different times was identical in all subjects. The predominant morphotypes presented continuous fringes and the basic changes observed among antifungal types was the emergence of strains resistant to myconazole, which was the drug used for the treatment of the first episode of vaginitis. We conclude that recurrent vaginal candidasis is caused by the persistence of a single yeast genotype that undergoes morphological and behavioral changes in the presence of antifungal agents due to the selective pressure to which it is submitted.

Candida albicans↗