Conservação genética da orquídea Cattleya granulosa Lindley

Cattleya granulosa Lind is a large and endemic orchid in Atlantic Forest fragments in Northeast Brazil. The facility of collecting, uniqueness of their flowers, which have varying colors between green and reddish brown, and distribution in coastal areas of economic interest make their populations a constant target of predation, which also suffer from environmental degradation. Due to the impact on their populations, the species is threatened. In this study, we evaluate the levels of spatial aggregation in a preserved population, analyze the phylogenetic relationships of C. granulosa Lindl. with four other Laeliinae species (Brassavola tuberculata, C. bicolor, C. labiata and C. schofieldiana) and also to evaluate the genetic diversity of 12 remaining populations of C. granulosa Lindl. through ISSR. There was specificity of epiphytic C. granula Lindl. with a single host tree, species of Eugenia sp. C. granulosa Lindl. own spatial pattern, with the highest density of neighbors within up to 5 m. Regarding the phylogenetic relationships and genetic patterns with other species of the genus, C. bicolor exhibited the greatest genetic diversity (HE = 0.219), while C. labiata exhibited the lowest level (HE = 0.132). The percentage of genetic variation among species (AMOVA) was 23.26%. The principal component analysis (PCA) of ISSR data showed that unifoliate and bifoliolate species are genetically divergent. PCA indicated a close relationship between C. granulosa Lindl. and C. schofieldiana, a species considered to be a variety of C. granulosa Lindl. by many researchers. Population genetic analysis using ISSR showed all polymorphic loci. The high genetic differentiation between populations (ФST = 0.391, P < 0.0001) determined the structure into nine groups according to log-likelihood of Bayesian analysis, with a similar pattern in the dendrogram (UPGMA) and PCA. A positive and significant correlation between geographic and genetic distances between populations was identified (r = 0.794, P = 0.017), indicating isolation by distance. Patterns of allelic diversity suggest the occurrence of population bottlenecks in most populations of C. granulosa Lindl. (n = 8). Genetic data indicate that enable the maintenance of genetic diversity of the species is complex and is directly related to the conservation of different units or groups that are spatially distant.

Capacidade de adesão e formação de biofilme de Candida ssp. isoladas da cavidade oral de pacientes transplantados renais na presença do extrato de Eugenia uniflora

Candidiasis is a major oral manifestation in kidney transplant patients. Candida spp. possess essential virulence factors which contribute for the infectious process, including the ability to adhere to epithelial cells and biofilm formation. The extract obtained from the leaves of Eugenia uniflora [acetone: water (7:3, v/v)] has demonstrated antifungal activity against Candida spp. This study evaluated the influence of the extract of E. uniflora in adhesion to human buccal epithelial cells (HBEC) and biofilm formation of 42 strains of Candida spp. isolated from the oral cavity of kidney transplant patients. Candida spp. strains belonging to a culture collection were reactivated and phenotypically re-identified by classical and molecular methods (genotyping ABC and RAPD), when necessary, to complete the identification to the species level. For the virulence tests evaluated in vitro, yeasts were grown in the presence and absence of 1000 g/mL of the extract. A ratio of 10: 1 (Candida spp. cells x HBECs) was incubated for 1 hour at 37 ° C, 200 rpm, fixed with 10% formalin and the number of Candida cells adhered to 150 HBEC determined by optical microscope. Biofilms were formed on polystyrene microplates in the presence or absence of the extract. The quantification was performed with crystal violet staining at 570 nm. All isolates were viable and exhibited phenotypic characteristics suggestive of each species identified. Two strains presumptively identified as Candida dubliniensis belonged to this species as determined with genotyping ABC, while strains identified as belonging to the Candida parapsilosis species complex were differentiated by RAPD genotyping. Candida albicans was found to be the most adherent species to the buccal epithelia, while C. tropicalis showed remarkable biofilm formation.We could detect that the extract of E. uniflora was able to reduce adhesion to HBEC for both Candida albicans and non-Candida albicans Candida species. On the other hand, only 16 Candida spp. strains (36 %) showed reduced biofilm formation. However, two highly biofilm producer strains of C. tropicalis had an expressive reduction in biofilm formation. This study reinforces the idea that besides growth inhibition, E. uniflora may interfere with the expression of some virulence factors of Candida spp., and may be possibly applied in the future as a novel antifungal agent.

Ecologia parasitária de isópodos e biologia reprodutiva em tibiro, Oligoplites spp (OSTEICHTHYES: CARANGIDAE) das águas costeiras de Natal, Rio Grande do norte

Oligoplites palometa (Cuvier) and Oligoplites saurus (Bloch & Schneider) (Osteichthyes: Carangidae) are coastal pelagic fish species. The objective of this study was to investigate the effect of parasitism by isopods and the reproductive biology of the leather jack, Oligoplites spp. A total of 113 individuals of Oligoplites spp (35 of O. saurus and 78 of O. palometa) were captured during the period between January, 2005 and July, 2007 from the coastal waters of Natal, RN. The morphometric and meristic characters were registered; macroscopic analyses were done to collect the isopod parasites and the gonads were observed to verify the reproductive aspects. The crustacean isopod parasite, Cymothoa spinipalpa (Isopoda: Cymothidae) was encountered on the tongue in the oral cavity in both fish hosts. The parasitic indices of C. spinipalpa showed high values of prevalance of 51,4% for O. saurus and 64,1% for O. palometa. The host presented significant correlations between body mass and body length of O. palometa and the number of parasites. Body lengths of female C. spinipalpa were small due to the limited space available in the oral cavity of the host. There was a significant difference in the sex ratio of O. palometa, males outnumbered the females. The isopod parasites showed specificity to the oral cavity of hosts. Macroscopic analyses of gonads showed four stages of gonadal development for both sex of O. palometa: immature, maturing, mature and spent

Identificação e fatores de virulência de Candida spp isoladas da cavidade bucal de transplantados renais do hospital universitário Onofre Lopes em Natal-RN

Despite Candida species are often human commensals isolated from various oral sites such as: tongue, cheek and palatal mucosa plus subgingival region, there are some properties linked to the organism commonly known as virulence factors which confer them the ability to produce disease. Oral candidiasis is one of the main oral manifestations reported in literature related to kidney transplant patients. The objectives of the present study were to identify and investigate virulence factors of yeasts isolated from the oral cavity of kidney transplant recipients admitted at the Hospital Universitário Onofre Lopes, in Natal RN. Seventy Candida species isolated from 111 kidney transplant recipients were investigated in this study. Identification of the isolates was performed by using the evidence of germ tube formation, hypertonic broth, tolerance to grow at 42°C, micromorphology and biochemical profiles. We observed a high rate of isolation of yeasts from the oral cavity of kidney transplant recipients (63.1%) being C. albicans was the most prevalent species. Oral candidiasis was diagnosed in 14.4% of transplant recipients. We evaluated virulence properties of the isolates regarding to: biofilm formation on polystyrene microplates as well as XTT reduction, adherence to acrylic resin and human buccal epithelial cells and proteinase activity. Most isolates were able to form biofilm by the method of adhesion to polystyrene. All isolates of Candida spp. remained viable during biofilm formation when analyzed by the method of XTT reduction. The number of CFU attached to the acrylic resin suggested high adherence for C. parapsilosis. C. albicans isolates showed higher median adherence to human buccal epithelial cells than non-C. albicans Candida isolates. Nevertheless, this difference was not statistically significant. C. dubliniensis showed low ability to adhere to plastic and epithelial cells and biofilm formation. Proteolytic activity was observed for all the isolates investigated, including the unique isolate of C. dubliniensis. There was a statistically significant association between proteinase production and the presence of oral candidiasis. Studies related to oral candidiasis in renal transplant recipients are limited to clinical and epidemiological data, but investigations concerning Candida spp. virulence factor for this group of individuals are still scarce. We emphasize the importance of studies related to virulence factors of yeasts isolated from this population to contribute to the knowledge of microbiological aspects of oral candidiasis

Características genotípicas e fenotípicas de Candida Albicans isoladas da cavidade bucal de pacientes transplantados renais com ênfase na ação do extrato bruto de Eugenia uniflora em fatores de virulência

Candida albicans is a diploid yeast that in some circumstances may cause oral or oropharyngeal infections. The investigation of natural products is mandatory for the discovery of new targets for antifungal drugs development. This study aimed to determine the genotypes of 48 clinical isolates of C. albicans obtained from the oral cavity of kidney transplant patients from two distinct geographic regions of Brazil. In addition, we investigated three virulence factors in vitro: phospholipase activity, morphogenesis and the ability to evade from polymorphonuclear neutrophils. The expression of these virulence factors in vitro was also investigated in the presence of the crude extract of Eugenia uniflora. The genotype A was the most prevalent (30 isolates; 62.5%), followed by genotype C (15 isolates; 31.5%) and genotype B (3 isolates; 6.25%). When microsatellite technique with primer M13 was applied, 80% of the isolates from the South were placed within the same cluster. All Genotype C strains were grouped together within two different clusters. Genotype C was considered more resistant to PMNs attack than genotypes A and B. Strains isolated from the South of Brazil showed higher ability to combat PMNs phagocytosis. We found a high rate of genotype C strains isolated from the oral cavity of this group of patients. The crude extract of E. uniflora inhibited proper hypha formation and phagocytosis by PMNs, but had no significant effect on phospholipase activity. This study characterized oral C. albicans strains isolated from kidney transplant recipients and will contribute for the better understanding of the pathogenesis and alternative therapeutics for oral candidiasis