In vitro antibacterial effects of Zanthoxylum tingoassuiba root bark extracts and two of its alkaloids against multiresistant Staphylococcus aureus

ABSTRACT The emergence of multiresistant strains of bacteria reinforces the need to search for new compounds able to combat resistant organisms. Medicinal plants are a great resource of bioactive substances, providing the possibility of obtaining molecules with potential antimicrobial activity. The aim of the present study is the evaluation of the antibacterial activity of extracts and alkaloids isolated from the root bark of Zanthoxylum tingoassuiba A. St.-Hil., Rutaceae, against four resistant clinical isolates and Staphylococcus aureus ATCC 25923. The dichloromethane and methanol extracts were fractionated by chromatography on silica gel, leading to the isolation of dihydrocheleryhtrine and N-methylcanadine, identified by Nuclear Magnetic Resonance spectroscopy. The antibacterial activity of the extracts and isolated compounds was evaluated by the disc diffusion method and the minimum inhibitory concentration was determined. The dichloromethane extract was the most active against all the tested strains and the two pure alkaloids were more active than the extracts. The anti-MRSA activity of the two benzophenanthridine alkaloids is demonstrated for the first time in this study. These compounds appear as potential leads for the development of new anti-MRSA compounds and could be responsible for the antibacterial activity, justifying the ethnobotanical use of Z. tingoassuiba and other species for the treatment of various infectious diseases.

Nasopharyngeal and Oropharyngeal Colonization by Staphylococcus aureus and Streptococcus pneumoniae and Prognostic Markers in Children with Sickle Cell Disease from the Northeast of Brazil.

We investigated the nasopharynx and oropharynx microbiota in sickle cell disease (SCD) to identify the microorganisms, antibiotic sensitivity, prevalent serotypes, and association of with laboratorial markers. Oropharynx/nasopharynx secretions were investigated in 143 SCD children aging 6 months to 17 years. Pathogens were isolated using standard procedures, and laboratorial markers were performed by automated methods. Staphylococcus aureus (S. aureus) was isolated from nasopharynx and oropharynx of 64 and of 17 SCD children respectively. Streptococcus pneumoniae (S. pneumoniae) was isolated from the nasopharynx and oropharynx of eight SCD patients. Serotypes of S. pneumoniae were 19F, 23F, and 14. All isolates were susceptible to penicillin, and patients whose nasopharynx and oropharynx were colonized by S. pneumoniae had high concentrations of aspartate transaminase, alanine transaminase, and ferritin. S. pneumoniae isolated were not penicillin-resistant serotypes suggesting that the use of penicillin for prophylaxis and/or treatment of infections is safe. Our finding of colonization and laboratory evaluation in SCD patients suggests that microorganisms are involved in the modulation of chronic inflammatory. The association of colonized microorganisms and laboratorial markers suggest a new approach to these patients follow-up, and additional studies of microorganism colonization and their association with SCD patients' clinical outcome will improve control and prevention strategies.

Avaliação da atividade antimicrobiana de duas espécies de Rutaceae do Nordeste Brasileiro / Evaluation of the antimicrobial activity of two Rutaceae species from the Brazilian Northeast

Com o aumento da resistência bacteriana aos antibióticos disponíveis, tornou-se imprescindível a busca por novos fármacos ou protótipos. Os metabólitos secundários produzidos por alguns vegetais como cumarinas, alcaloides e terpenoides podem apresentar várias atividades biológicas, dentre elas, atividade antibiótiotica. O objetivo deste trabalho foi avaliar a atividade antimicrobiana in vitro, pelo método de difusão em disco, das diferentes partes de duas espécies pertencentes à família Rutaceae coletadas na Chapada Diamantina, Bahia, Brasil: Spiranthera odoratissima A. St.-Hil. e Zanthoxylum stelligerum Turcz., bem como do alcaloide diidroqueleritrina, isolado do extrato metanólico de Z. stelligerum frente a cepas padrão de microrganismos e isolados clínicos. Os resultados apresentados indicam que o extrato da raiz da espécie Z. stelligerum e o alcaloide extraído desta apresentaram propriedades antimicrobianas contra as cepas Gram positivas e leveduras. A E. coli foi a única cepa Gram negativa que se mostrou sensível ao extrato e ao alcaloide.

With the increase in bacterial resistance to available antibiotics, it became imperative to search for new drugs or prototypes. The secondary metabolites produced by some plants as coumarins, alkaloids and terpenoids have several biological activities, among them, antibiotic activity. The objective of this study was to evaluate the antimicrobial activity in vitro by the disk diffusion method, from different parts of two species belonging to the family Rutaceae, collected in the Chapada Diamantina, Bahia, Brazil: Spiranthera odoratissima A. St Hil. and Zanthoxylum stelligerum Turcz., and the alkaloid dihydrochelerythrine, isolated from the methanolic extract of Z. stelligerum front of standard strains of microorganisms and clinical isolates. The results indicate that the extract from the roots of Z. stelligerum and the alkaloid had antimicrobial properties against Gram positive and yeast strains. The E. coli was the only Gram negative strain that was sensitive to extract and the alkaloid.

Uso de produtos naturais como coadjuvante no tratamento da doença periodontal. [revisão] / Use of natural products as adjuvant in the treatment of periodontal disease. [review]

A doença periodontal (DP) é descrita como um conjunto de processos inflamatórios e infecciosos que acomete os tecidos periodontais, de etiologia multifatorial, localização sítiodependente e considerada pela Organização Mundial de Saúde como uma das duas principais enfermidades de risco para a saúde bucal. Desencadeada e perpetuada por bactérias anaeróbias Gram-negativas, cuja resistência a antibioticoterapia convencional e a antissépticos bucais exigem a busca por novos métodos coadjuvantes ao tratamento clínico (raspagem e alisamento radicular) da DP. Neste enfoque, o uso de produtos naturais poderia ser muito promissor. O objetivo do trabalho foi realizar uma revisão bibliográfica sobre o tema: utilização de produtos naturais no controle químico do crescimento do biofilme dental subgengival. O trabalho mostrou que este novo conceito de tratamento a base de produtos naturais, merece uma atenção especial, desde que o Brasil é detentor de uma rica biodiversidade e já que diversos trabalhos científicos indicam uma atividade antimicrobiana in vitro em ensaios laboratoriais utilizando produtos naturais. Assim, métodos de tratamento da doença periodontal eficazes e acessíveis à população poderiam modificar o quadro atual em que se encontra a saúde bucal dos brasileiros no cenário internacional.

The periodontal disease (PD) is described as a set of inflammatory and infectious process that attacks periodontal tissue of multifactorial etiology, localized and considered by the World Health Organization (WHO) as one of the two main disease in odontology. Unchained and perpetuated for Gram negative anaerobic bacteria, whose anti-septic and antibiotic resistance demand new methods for clinical treatment (scaling and root planing). In this approach, the use of natural products could be promising. The aim of this work was a literature review about the use of natural products in the chemical control of the growth of subgingival dental biofilm. The work showed that antimicrobial natural agents can be useful as adjunct to mechanical therapy and deserve a special attention, since Brazil hold a rich biodiversity and because scientific works indicate an antimicrobial activity in vitro in assays using natural products. Thus, methods of treatment of periodontal diseases, efficient and accessible to Brazilian population could change the actual scenery of odontology in Brazil.

Avaliação da atividade antibacteriana dos extratos de Avicennia schaueriana Stapf & Leechm. ex Moldenke, Verbenaceae / Evaluation of the antibacterial activity of extracts of Avicennia schaueriana Stapf & Leechm. ex Moldenke, Verbenaceae

A flora tem sido uma fonte valiosa de constituintes bioativos para manutenção da saúde humana. Tal fato tem reforçado a crescente investigação do potencial terapêutico das plantas medicinais. Neste contexto, o presente trabalho teve como objetivo avaliar o potencial antibacteriano dos extratos hidro-alcoólicos da casca, folha, e raiz de Avicennia schaueriana Stapf & Leechm. ex Moldenke, Verbenaceae. As partes vegetais foram coletadas no povoado pesqueiro de Siribinha, Bahia e os extratos vegetais foram preparados pelo método de maceração. Todos os testes de sensibilidade dos extratos vegetais foram avaliados por meio de testes não-paramétricos. O extrato da raiz de A. schaueriana apresentou uma atividade inibitória do crescimento superior aos extratos da folha e casca, com halos de inibição que variaram entre 7 a 18 mm de acordo com as concentrações e as cepas bacterianas testadas. Já a concentração inibitória mínima dos extratos hidro-alcoólicos de A. schaueriana apresentaram uma média de valores entre 0,62 a 10,00 mg/mL para as bactérias analisadas. Os resultados estatísticos confirmaram a diferença de sensibilidade dos microrganismos estudados frente aos extratos de A. schaueriana.

Natural products have been a valuable bioactives constituent source for maintenance of the health human being. Such fact has strengthened the increasing inquiry of the therapeutical potential of medicinal plants. This work had as objective evaluate the antibacterial potential from leaf, root and bark hydro-alcoholics extracts of Avicennia schaueriana Stapf & Leechm. ex Moldenke, Verbenaceae. The plant parts had been collected in the fishing town of Siribinha, Bahia and the plant extracts had been prepared by the method of maceration. All the tests of sensitivity of plant extracts had been evaluated by means of notparametric tests. The results of the test of diffusion in disk showed that the extract of the root of the A. schaueriana had been higher to extracts of the leaf and bark, with inhibition rings from growth varying of 7 to 18 mm; in accordance with the tested concentrations. Already the minimum inhibitory concentration of hydro-alcoholic extracts of A. schaueriana had presented an average of values between 0,62 to 10,00 mg/mL for the analyzed bacteria. The statistical results had confirmed the difference of sensitivity of the studied microorganisms front to extracts of the A. schaueriana.

Microbiological and immunological features of oral candidiasis.

Candida albicans(C. albicans) is the major infectious agent of oral candidiasis, and both innate immunity and cell-mediated immune response participate in the control of the fungal infections. The aim of this study was to correlate the clinical forms of oral candidiasis with the number of colony forming units (CFU) of C. albicans in saliva and to characterize T cell response in patients with oral candidiasis. Participants included 75 subjects: 36 with lesions of candidiasis and 39 without lesions of oral candidiasis. A 2-ml sample of saliva was collected from all subjects for microbiological analysis. Cytokine levels were determined by ELISA in supernatants of peripheral blood mononuclear cells of 25 patients with oral candidiasis, after in vitro stimulation with C. albicans antigens. In 48% of patients, no association was observed with denture use. C. albicans was detected in the saliva of 91.7% of patients with oral candidiasis, and there was an association between the number of CFU and the presence of oral lesions. A type Th1 immune response was observed in supernatants of peripheral blood mononuclear cells stimulated with C. albicans antigens. In contrast, IL-5 and IL-10 levels were very low or undetectable. Together, this study shows an association between clinical forms of oral candidiasis and the number of colonies of C. albicans in saliva, and that a systemic immune response characterized by the production of TNF-alpha and IFN-gamma is observed in patients with oral candidiasis.

Identification of transcription elements in the 5' intergenic region shared by LON and MDJ1 heat shock genes from the human pathogen Paracoccidioides brasiliensis. Evaluation of gene expression.

The MDJ1/LON locus is conserved among pathogenic dimorphic fungi. We have mapped using DNase I footprinting and mobility shift assays three putative heat shock elements and one AP-1 binding domain (ARE) in the 5' intergenic region shared by PbMDJ1and PbLON (ML) from Paracoccidioides brasiliensis. The region bearing an ARE-like towards PbLON also has an opposite skn-1-like element. We studied genetically and pathogenically distinct isolates Pb18 and Pb3, where ML is polymorphic and the number of elements detected was higher. The functionality of the elements was suggested by the stimulatory response of both genes to heat shock and oxidative stress. Co-regulation occurred upon heat shock from 36 to 42 degrees C and, only in Pb3, also during mycelium to yeast transformation (26-36 degrees C). In Pb18, PbMDJ1 seemed to be preferentially expressed in yeast. Our study might help understand regulation of genes involved in fungal adaptation to the host.

The PbMDJ1 gene belongs to a conserved MDJ1/LON locus in thermodimorphic pathogenic fungi and encodes a heat shock protein that localizes to both the mitochondria and cell wall of Paracoccidioides brasiliensis.

J-domain (DnaJ) proteins, of the Hsp40 family, are essential cofactors of their cognate Hsp70 chaperones, besides acting as independent chaperones. In the present study, we have demonstrated the presence of Mdj1, a mitochondrial DnaJ member, not only in the mitochondria, where it is apparently sorted, but also in the cell wall of Paracoccidioides brasiliensis, a thermodimorphic pathogenic fungus. The molecule (PbMdj1) was localized to fungal yeast cells using both confocal and electron microscopy and also flow cytometry. The anti-recombinant PbMdj1 antibodies used in the reactions specifically recognized a single 55-kDa mitochondrial and cell wall (alkaline beta-mercaptoethanol extract) component, compatible with the predicted size of the protein devoid of its matrix peptide-targeting signal. Labeling was abundant throughout the cell wall and especially in the budding regions; however, anti-PbMdj1 did not affect fungal growth in the concentrations tested in vitro, possibly due to the poor access of the antibodies to their target in growing cells. Labeled mitochondria stood preferentially close to the plasma membrane, and gold particles were detected in the thin space between them, toward the cell surface. We show that Mdj1 and the mitochondrial proteinase Lon homologues are heat shock proteins in P. brasiliensis and that their gene organizations are conserved among thermodimorphic fungi and Aspergillus, where the genes are adjacent and have a common 5' region. This is the first time a DnaJ member has been observed on the cell surface, where its function is speculative.

Chromosomal polymorphism, syntenic relationships, and ploidy in the pathogenic fungus Paracoccidioides brasiliensis.

Pulsed field gel electrophoresis (PFGE) and DNA hybridization were used to establish and compare the electrophoretic karyotypes of 12 clinical and environmental Paracoccidioides brasiliensis isolates from different geographic areas. Gene mapping allowed the identification of synteny groups and the use of isolated whole chromosomal bands to probe chromoblots indicated the existence of repetitive sequences, contributing to a better understanding of the structure and organization of the fungus genome. This represents the first comparative mapping study among different isolates. The results are indicative of the existence of genetic differences among natural isolates. DNA content of DAPI-stained nuclei of each isolate was estimated by confocal microscopy. Comparison of the genome sizes estimated by PFGE with those calculated by microfluorometry indicated the possible existence of haploid and diploid (or aneuploid) isolates of the fungus.