Avaliação da citotoxicidade in vitro e genotoxicidade ex-vivo em compostos da Pavonia glazioviana Gürke (Malvaceae / Evaluation of in vitro cytotoxicity and ex-vivo genotoxicity in compounds from Pavonia glazioviana Gürke(Malvaceae)

Introdução: as terapias alternativas que utilizam plantas medicinais e fitoterápicos são bastante comuns no Brasil. Dentre várias espécies vegetais brasileiras utilizadas em terapias destacam-se as espécies da família Malvaceae. Objetivos: o presente estudo teve como objetivo avaliar a citotoxicidade in vitro e a genotoxicidade ex-vivo em compostos da Pavonia glazioviana Gürke espécie brasileira pertencente à família Malvaceae. Metodologia: métodos in vitro foram utilizados para verificar o potencial citotóxico por meio de ensaios hemolíticos e anti-hemolíticos e da análise genotóxica ex-vivo. O Extrato Etanólico Bruto (EEB) e Fração Clorofórmico (FC) foram obtidos na amostra vegetal utilizada neste estudo. Resultados: os produtos EEB-Pg e FC-Pg apresentaram baixo efeito citotóxico apenas nas concentrações de 50 e 100 µg / mL. As amostras expostas às concentrações de 500 e 1000 µg / mL apresentaram índice hemolítico alto a moderado com lise superior a 60%. Foi descrito efeito anti-hemolítico moderado em todas as amostras tratadas com 500 e 1000 µg / mL, com hemólise < 60%. Além disso, os compostos mostraram baixo efeito genotóxico ex-vivo, com um índice geral de células normais superior a 84% em todas as concentrações. Conclusões: os resultados sugerem um baixo perfil tóxico dos compostos obtidos da espécie Pavonia glazioviana, indicando limites seguros para o uso desses produtos naturais.

Introduction: alternative therapies using medicinal plants and herbal medicines are quite common in Brazil. Among several Brazilian plant species used in therapies, the species of the Malvaceae family stand out. Objetctives: the present study aimed to evaluate the in vitro cytotoxicity and ex-vivo genotoxicity in compounds of the Brazilian Pavonia glazioviana Gürke belonging to the Malvaceae family. Methodology: in vitro methods were used to verify the cytotoxic potential through hemolytic and antihemolytic assays and the ex-vivo genotoxic analysis. The Crude Etanolic Extract (CEE) and Cloroformic Fraction (CF) was obtained in vegetal sample used on this study. Results: the CEE-Pg and CF-Pg products only showed a low cytotoxic effect at the concentrations of 50 and 100 µg/mL. The exposure to the concentrations of 500 and 1000 µg/mL showed a high to moderate hemolytic index with lysis higher than 60%. A moderate anti-hemolytic effect was described in all samples treated with 500 and 1000 µg/mL, with hemolysis <60%. In addition, the compounds showed low ex-vivo genotoxic effect with a general index of normal cells greater than 84% at all concentrations. Conclusion: the results suggest a low toxic profile of the compounds obtained from the Pavonia glazioviana Gürke species belonging to the Malvaceae family, indicating safe limits for the use of these natural products.

Antibacterial and hemolytic activity of extracts and compounds obtained from epicarps and seeds of Garcinia madruno(Kunth) Hammel / Actividad antimicrobiana y hemolítica de extractos y compuestos obtenidos del epicarpio y las semillas de Garcinia madruno (Kunth) Hammel

This paper describes the evaluation of the antimicrobial and hemolytic activity of the hexane, dichloromethane, ethyl acetate and methanol extracts from seeds and epicarps of Garcinia madruno; as well garcinol, morelloflavone and volkensiflavone isolated from the same species. In the preliminary test of bacterial susceptibility, hexane extracts from seeds and epicarps and the three compounds tested only displayed inhibitory growth effect against Gram-positive bacteria. The minimum inhibitory concentrations of extract and compounds ranging from 86.6 to 1253.4 µg/mL. The hemolytic activity was assessed; however, except for the methanol extract from seeds, none of the samples studied induced hemolysis. Thus, our results suggest that extracts and compounds from G. madruno have the potential to be used in the control of pathologies associated to Gram-positive bacteria. This is the first report of the antimicrobial and hemolytic activity of extracts of different polarity obtained from seeds and epicarps of this edible species.

El presente artículo describe la evaluación de la actividad antimicrobiana y hemolítica de los extractos de hexano, diclorometano, acetato de etilo y metanol, obtenidos de la semilla y el epicarpio de Garcinia madruno; así como de garcinol, morelloflavona y volkensiflavona; aislados de la misma especie. En el ensayo de susceptibilidad bacteriana, tanto el extracto de hexano obtenido a partir de la semilla y el epicarpio, y los tres compuestos aislados, únicamente mostraron actividad inhibitoria del crecimiento contra bacterias Gram-positivas. La concentración mínima inhibitoria presentó valores entre 86.6 y 1253.4 µg/mL. También se estableció la actividad hemolítica; sin embargo, con excepción del extracto metanólico obtenido a partir de las semillas, ninguna de las muestras evaluadas indujo hemólisis. Por lo tanto, los resultados sugieren que los extractos y compuestos de G. madruno tienen el potencial de ser usados en el control de bacterias Gram-positivas asociadas a diversas patologías. Este es el primer reporte de actividad antimicrobiana y hemolítica de extractos de diferente polaridad obtenidos de las semillas y epicarpios de esta especie comestible.

Hemolytic, anticancer and antigiardial activity of Palythoa caribaeorum venom

Cnidarian venoms and extracts have shown a broad variety of biological activities including cytotoxic, antibacterial and antitumoral effects. Most of these studied extracts were obtained from sea anemones or jellyfish. The present study aimed to determine the toxic activity and assess the antitumor and antiparasitic potential of Palythoa caribaeorum venom by evaluating its in vitro toxicity on several models including human tumor cell lines and against the parasite Giardia intestinalis. Methods: The presence of cytolysins and vasoconstrictor activity of P. caribaeorum venom were determined by hemolysis, PLA2 and isolated rat aortic ring assays, respectively. The cytotoxic effect was tested on HCT-15 (human colorectal adenocarcinoma), MCF-7 (human mammary adenocarcinoma), K562 (human chronic myelogenous leukemia), U251 (human glyoblastoma), PC-3 (human prostatic adenocarcinoma) and SKLU-1 (human lung adenocarcinoma). An in vivo toxicity assay was performed with crickets and the antiparasitic assay was performed against G. intestinalis at 24 h of incubation. Results: P. caribaeorum venom produced hemolytic and PLA2 activity and showed specific cytotoxicity against U251 and SKLU-1 cell lines, with approximately 50% growing inhibition. The venom was toxic to insects and showed activity against G. intestinalis in a dose-dependent manner by possibly altering its membrane osmotic equilibrium. Conclusion: These results suggest that P. caribaeorum venom contains compounds with potential therapeutic value against microorganisms and cancer.(AU)

Enzyme inhibitory, antifungal, antibacterial and hemolytic potential of various fractions of Colebrookia oppositifolia

The purpose of the present investigation was to assess the enzyme inhibition, antifungal, antibacterial and hemolytic activities of various fractions of Colebrookia oppositifolia Smith. The MeOH extract of plant was dissolved in dist. water and partitioned with n-hexane, CHCl[3], EtOAc and n-BuOH sequentially. Enzyme inhibition studies were done against four enzymes i.e. alpha-glucosidase, butyrylcholinesterase, acetyl cholinesterase and lipoxygenase. Ethyl acetate fraction possessed very good activity against alpha-glucosidase [IC[50] 57.38 +/- 1.23 micro g/mL]. CHCl3 fraction displayed good activity against alpha-glucosidase and lipoxygenase while moderate activity against butyryl cholinesterase. EtOAc fraction displayed good activity against lipoxygenase. Antifungal activity was studied against four fungi i.e. Aspergillus niger, Aspergillus flavus, Ganoderma lucidum and Alternaria alternata by the disc diffusion method using fluconazole, a standard antifungal drug, as positive control. Aqueous fraction displayed good activity against G. lucidum and A. flavus. Antibacterial activity was checked against Staphylococcus aureus, Bacillus subtilis, Pasturella multocida and Escherichia coli by the disc diffusion method using streptomycin sulphate, a standard antibiotic, as positive control. Chloroform, ethyl acetate and aqueous fraction showed good activity against E. coli. Chloroform fraction showed good activity against B. subtilis. Ethyl acetate fraction showed good activity against the P. multocida. All the studied fractions showed very less toxicity i.e. < 7%

Detecção dos genes codificantes da toxina CDT, e pesquisa de fatores que influenciam na produção de hemolisinas em amostras de Campylobacter jejuni de origem avícola / Detection of the genes encoding the toxin CDT, and research factors which influence the production of hemolysin in Campylobacter jejuni from poultry products

Membros termofílicos do gênero Campylobacter são reconhecidos como importantes enteropatógenos para o ser humano e animais. A grande diversidade ecológica destes micro-organismos em diferentes habitats tais como água, animais e alimentos predispõem ao aparecimento de novos fatores de virulência. Este trabalho teve por objetivo detectar os genes codificantes da Toxina Distensiva Citoletal (CDT) por meio da técnica de PCR, pesquisar a atividade de hemolisinas e a influência de soluções quelantes e de íons nesta atividade. Foram utilizadas 45 amostras de Campylobacter jejuni de origem avícola para pesquisa de atividade hemolítica, cultivadas em Caldo Triptona de Soja (TSB). Após o crescimento bacteriano, as amostras foram semeadas em Ágar tríptico de soja (TSA) contendo 5% de sangue de ovino. Para verificar a influência de agentes quelantes e solução de íons na atividade hemolítica, as amostras de C. jejuni foram cultivadas em TSB contendo separadamente os quelantes EDTA, ácido acético, soluções de íons CaCl2, MgCl2 e FeCl3, em atmosfera de microaerofilia. Quanto à atividade de hemolisina de C. jejuni em placas de TSA - sangue ovino foi possível observar que houve hemólise em 40% das amostras analisadas apenas com caldo TSB. Somente o ácido acético apresentou ação quelante sobre a atividade de hemolisinas em amostras de C. jejuni semeadas em placas de TSA - sangue ovino. Para detecção dos genes cdtA, cdtB e cdtC através da técnica da Reação em Cadeia da Polimerase (PCR) foram utilizadas 119 amostras de C. jejuni de origem avícola. Foi possível observar que 37,8% possuíam o perfil de genes cdtABC. Os resultados demonstraram em amostras avícolas a presença de cepas de C. jejuni com potencial virulento, devido à presença dos genes da toxina CDT e potencial hemolítico, que apresentou ação reduzida in vitro com ácido acético...

Thermophilic members of the Campylobacter genus are recognized as important enteropathogenics for humans and animals. The great variety of ecological habitats, such as water, food and milk, may promote new virulence factors. To detect the encoding genes distending cytolethal toxin (CDT) by PCR and study the hemolytic activity with influence of chelation solutions and ions, 45 Campylobacter jejuni samples from poultry production origin were used to perform the hemolytic research. To check the influence of chelation agents and solution of ions in the hemolytic activity, samples of C. jejuni strains were grown in tryptone soy broth TSB containing chelation agents separately EDTA, acetic acid, CaCl2, MgCl2 and FeCl3 ions solutions in microaerophilic atmosphere and then streaked on 5% sheep blood tryptic soy agar (TSA). To perform the detection of cdtA, cdtB and cdtC genes the technique of Polymerase Chain Reaction (PCR) was used in 119 samples of C. jejuni from poultry production origin. We found 40% of samples showing hemolysis after growing with TSB. Only the acetic acid showed reduction in hemolysis. The prevalent gene profile was cdtABC in 37.8 % of the samples. It was observed that the results showed the presence of C. jejuni strains with virulent potential, due to presence of the CDT toxin genes and the hemolytic activity, which showed in vitro reduced when acetic acid was added...

Prevalence of the american college of rheumatology hematological classification criteria and associations with serological and clinical variables in 460 systemic lupus erythematosus patients

Objective: To study systemic lupus erythematosus in a Brazilian population using the American College of Rheumatology hematological classification criteria and report associations of the disease with serological and clinical profiles. Methods: This is a retrospective study of 460 systemic lupus erythematosus patients followed in a single rheumatologic center during the last 10 years. Hematological manifestations considered for this study were hemolysis, leukopenia, lymphocytopenia and thrombocytopenia. Results: The cumulative prevalences of leukopenia, thrombocytopenia, lymphocytopenia and hemolytic anemia were 29.8%, 21.08%, 17.7% and 8.4%, respectively. A higher percentage of patients with hemolysis had anticardiolipin IgM (p-value = 0.002). Those with leukopenia had more lymphopenia (p-value = 0.02), psychosis (p-value = 0.01), thrombocy- topenia (p-value <0.0001) and anti-double stranded DNA antibodies (p-value = 0.03). Patients with lymphopenia had more leukopenia (OR = 1.8; 95% CI = 1.01-3.29) and lupus anticoagulant antibodies (OR = 2.2; 95% CI = 1.16-4.39) and those with thrombocytopenia had more leukopenia (OR = 3.1; 95% CI = 1.82-5.44) and antiphospholipid syndrome (OR = 3.1; 95% CI = 1.28-7.87). Conclusion: The most common hematological finding was leukopenia and the least common was hemolysis. Associations of low platelet count and hemolysis were found with antiphospholipid syndrome and anticardiolipin IgM positivity, respectively. Leukopenia and lymphocytopenia are correlated and leukopenia is more common in systemic lupus erythe- matosus patients with psychosis, thrombocytopenia and anti-double stranded DNA.

Study on hemolytic mechanism of polyphyllin II / 中国中药杂志

To study the hemolytic effect of polyphyllin II (PP II) mediated by anion channel protein and glucose transporter 1 (GLUT1), in order to initially reveal its hemolytic mechanism in vitro. In the experiment, the spectrophotometric method was adopted to detect the hemolysis of PP II in vitro and the effect of anion channel-related solution and blocker, glucose channel-related inhibitor and multi-target drugs dehydroepiandrosterone (DHEA) and diazepam on the hemolysis of PP II. The scanning electron microscope and transmission electron microscope were used to observe the effect of PP II on erythrocyte (RBC) morphology. The results showed that PP II -processed blood cells were severely deformed into spherocytes, acanthocyturia and vesicae. According to the results of the PP II hemolysis experiment in vitro, the anion hypertonic solution LiCl, NaHCO3, Na2SO4 and PBS significantly inhibited the hemolysis induced by PP II (P < 0.05), while blockers NPPB and DIDS remarkably promoted it (P < 0.01). Hyperosmotic sodium chloride, fructose and glucose at specific concentrations notably antagonized the hemolysis induced by PP II (P < 0.05). The glucose channel inhibitor Cytochalasin B and verapamil remarkably antagonized the hemolysis induced by PP II (P < 0.01). The hemolysis induced by PP II could also be antagonized by 1 gmol x L(1) diazepam and 100 μmol x L(-1) DHEA pretreated for 1 min (P < 0.01). In conclusion, the hemolytic mechanism of PP II in vitro may be related to the increase in intracellular osmotic pressure and rupture of erythrocytes by changing the anion channel transport activity, with GLUT1 as the major competitive interaction site.

Pesquisa de genes de virulência em cepas de Listeria monocytogenes e Listeria innocua originárias de carne suína e ambiente de abatedouros e açougues / Research of virulence genes in strains of Listeria monocytogenes and Listeria innocua originated from pork and slaughterhouse and meat market environment

Introdução - A bactéria Listeria monocytogenes é um agente zoonótico transmitido, principalmente, por alimentos. Dentre as fontes de contaminação, destacam-se os produtos de origem láctea, carnes e embutidos, além dos ambientes da indústria de processamento alimentício. Na última década, foram detectadas cepas de L. monocytogenes e L. innocua, em ambiente de frigoríficos e alimento. Estas apresentavam variação na intensidade da virulência para células eucarióticas decorrente de mutações nos genes de virulência. Esta alteração em ambas as espécies, e o relato de um caso fatal de listeriose humana ocasionada por L. innocua atípica demandam atenção, pois apresentam maior risco à saúde da população exposta a estes ambientes e alimentos tornando-se, portanto, uma importante questão de saúde pública. Objetivo - Pesquisar genes de virulência em cepas de L. monocytogenes e L. innocua, isoladas em pontos da linha de abate suíno e do comércio de carne no Estado de São Paulo. Material e Métodos Foram estudadas 40 cepas, dentre estas, isolados de L. monocytogenes e L. innocua com atividade hemolítica atípica. Foram realizados testes de atividade hemolítica e produção de fosfolipase A para caracterização dos isolados. A detecção dos genes de virulência foi realizada através da reação em cadeia pela polimerase (PCR). Para confirmação das sequências amplificadas e a análise das mesmas, os fragmentos obtidos foram sequenciados. A identificação molecular das espécies foi realizada por análise filogenética dos genes prs e 16S rRNA. Resultados Dos 40 isolados, cinco de L. monocytogenes e sete de L. innocua apresentaram atividade hemolítica atípica, sendo que nestes últimos também foi observado halo atípico no meio ALOA. As cepas de L. monocytogenes foram positivas para a detecção de todos os genes de virulência estudados. Dois dos isolados atípicos de L. innocua também foram positivos para todos os genes e os outros cinco foram positivos para hly, plcA e inlC. Foram detectadas mutações nas proteínas InlC, InlB, InlA, PI-PLC, PC-PLC e PrfA, nas cepas atípicas, que resultaram em alterações nas suas estruturas secundárias que podem explicar o fenótipo desses isolados. A confirmação de espécie apenas foi alcançada com a análise filogenética do 16S rRNA. Conclusões A partir desses resultados, foi proposta a utilização dos genes prfA, plcB e inlB, como forma de triagem, para diferenciar as espécies L. monocytogenes e L. innocua, de modo a complementar os testes fenotípicos.

[Evaluating the antibacterial, hemolytic and cytotoxic activities of the Iranian Rana ridibunda skin extract as a new source of antimicrobial compound]

Amphibian skins possess various antibacterial compounds that are effective against some microbial pathogens and are mostly released in response to environmental stress. In fact, the skin of Rana ridibunda, a large green frog, is a rich source of antimicrobial compounds that can be developed for therapeutic use. In the present study, the skin extract of Iranian Rana ridibunda was evaluated for its antimicrobial, hemolytic and cytototoxic activities. The frog specimens were collected from Minoodasht located in Golesten province in Iran, during 2009. Subsequently, their skins were removed and the intended compounds were extracted. The crude extract was partially purified by gel filtration chromatography. The antimicrobial effects of skin extract were assessed against various microorganisms such as Escherchia coli, methicillin-resistant and-sensitive Staphyloccus aureus, vancomycin-resistant and-susceptible Enteroccus fecalis, Pseudomonas aeroginosa and Candida albicans. In addition, its minimum inhibition concentration, cytotoxic and hemolytic activities were determined. The crude extract of Rana ridibunda skin had valuable antimicrobial effects against methicillin-resistant and-susceptible S. aureus in comparison with E.coli and vancomycin-resistant and-susceptible E. fecalis. Besides, no antimicrobial activities were seen against P. aeroginosa or C. albicans. Moreover, the hemolytic and cytotoxic activities of the skin extract were minimal. The antimicrobial activity of Iranian Rana ridibunda was comparable to those isolated from other Rana species. In conclusion, the skin extract of Rana ridibunda had the potential for a new therapeutic agent against the emerging drug-resistant bacteria, particularly methicillin-resistant and-sensitive S. aureus

Phytochemical constituents and preliminary toxicity evaluation of leaves from Rourea induta Planch. (Connaraceae) / Constituintes fitoquímicos e avaliação preliminar de toxicidade folhas de Rourea Induta Planch. (Connaraceae)

Most active plants are toxic at high doses and it is therefore important to investigate the preliminary toxicity of plant extracts. The Rourea induta species is a potential drug with no phytochemical or biological studies registered in the literature. Thus, a phytochemical study and a toxicity analysis of the ethanolic extract obtained from the leaves of Rourea induta Planch., Connaraceae, was run. A long chain hydrocarbon, n-tetracosane, and four flavonoids were identified: quercetin, and three glycosylated derivates, quercetin-3-O-α-arabinofuranoside, quercetin-3-O-β-xyloside and quercetin-3-O-β-galactoside. This is the first time these have been isolated in this species. The structures were elucidated by 13C NMR, ¹H NMR, UV and IR spectroscopy. The toxicity evaluation of extracts was performed by the brine shrimp method and determination of hemolytic activity. The samples demonstrated no toxic potential by the analyzed methods.

A maioria das plantas ativas é tóxica em doses elevadas, portanto, é importante a investigação da toxicidade preliminar dos extratos das plantas. A espécie Rourea induta é uma droga potencial que não apresenta estudo fitoquímico ou biológico descrito na literatura. Assim, um estudo fitoquímico e análises toxicológicas foram realizados com o extrato etanólico obtido das folhas de Rourea induta Planch., Connaraceae. Foram obtidos um hidrocarboneto de cadeia longa, n-tetracosano, e quatro flavonóides, quercetina e três derivados glicosilados, quercetina-3-O-α-arabinofuranosideo, quercetina-3-O-β-xilosideo e quercetina-3-O-β-galactosideo. Esta é a primeira vez que estes compostos são isolados nesta espécie. As estruturas foram elucidadas por espectroscopia de RMN-13C, RMN-¹H, ultravioleta e infravermelho. A avaliação da toxicidade dos extratos foi analisada pelo método da Artemia salina e atividade hemolítica. Nenhuma das amostras testadas apresentou um potencial tóxico pelos métodos analisados.

Isolation of a cytolytic component from Naja nigricollis nigricollis [spitting cobra] venom

A cytolytic compound [Vlb] was isolated by fractionation of crude venom from Egyptian Cobra Snake, Naja nigricollis nigricollis using Sephadex G-75, followed by CM- Sephadex. The isolated protein has a cytolytic effect on red cells, stable at different temperatures [25 °C-100°C] and at different pH ranges [5-9]. It is partially pure as indicated by SDS-PAGE, with molecular weight approximately 10 kDa. It has no protease or phospholipase activity. It is a glycoprotein, with maximum absorbance at 280nm. It is non antigenic, with LD50 1.83 mg/ kg body weight. DNA extraction from mouse liver tissue and from hepatocellular carcinoma cell line [HEPG2] gave a single intact band after invitro incubation with Vlb, indicating that apoptosis is not involved in the cytotoxic mechanism. Small doses of Vlb induced lysis in breast, colon and hepatocellular carcinomas cell lines in tissue culture plates

Congenital myopathies: a clinicopathological study of 25 cases.

OBJECTIVE: Congenital myopathies are rare. Through this article, the authors want to present a clinicopathological analysis of 25 new cases. MATERIALS AND METHODS: The clinical data of patients who were diagnosed with congenital myopathy between 2001 and 2006 was retrieved. Muscle biopsies were processed for H&E staining, enzyme histochemistry, and immunohistochemistry. Biopsies were also processed for ultrastructural analysis. RESULTS: During a period of 6 years, 1.12% of the muscle biopsies were diagnosed as congenital myopathies. The most common congenital myopathy was central core disease followed by nemaline rod myopathy and multi-mini core disease. Clinically, they have variable features. The final diagnosis was made with the help of enzyme histochemistry and ultrastructural features. CONCLUSION: This study emphasizes the importance of enzyme histochemistry and electron microscopic examination in the diagnosis of congenital myopathies especially in the absence of genetic studies.

Emulsan analysis produced by locally isolated bacteria and Acinetobacter calcoaceticus RAG-1

Growth of previously isolated bacteria from Iranian oil reservoirs on different carbon and energy sources and under varying conditions have been used to produce a class of extracellular microbial protein-associated lipopolysaccharides named emulsan.Several Bacteria were previously isolated from Iranian oil reservoirs and designated as; Ilam-1 and Paydar-4. In present study, the isolated strains were compared with standard sample of Acinetobacter calcoaceticus RAG-1 from Persian Type Culture Collection [PTCC 1641], IROST. Among the isolated strains, two strains were found to produce an extracellular, emulsifying agent when grown in Mineral Salt Medium containing soya oil, ethanol or local crude oil. The isolated bacteria were cultured and further analysed using protein estimation, reducing sugar analysis, hemolytic activity, surface tension and emulsification activity tests. The crude emulsifier of RAG-1, PAYDAR-4 and ILAM-1 were concentrated from the cell-free culture fluid by ammonium sulfate precipitation to yield 1.89g, 1.78g and 1.69g of bioemulsan respectively. Emulsifying activity was observed over the entire production process. These investigations showed that emulsan produced by isolated Iranian crude oil reservoir were comparable with Acinetobacter calcoaceticus RAG-1 which is made of carbohydrate backbone as its hydrophilic part [N-acetyl-D-galactoseamine, N-acetylgalactoseamine uronic acid, diamino-6-deoxy-D-glucose] and fatty acid chain as its hydrophobic portion

Structure-antimicrobial activity relationship between pleurocidin and its enantiomer

To develop novel antibiotic peptides useful as therapeutic drugs, the enantiomeric analogue of pleurocidin (Ple), which is a well known 25-mer antimicrobial peptide, was designed for proteolytic resistance by D-amino acids substitution. The proteolytic resistance was confirmed by using HPLC after the digestion with various proteases. To investigate the antibiotic effect of L- and D-Ple, the antibacterial activity and hemolytic effect were tested against human erythrocytes. The D-Ple showed a decreased antibacterial activity and a dramatically decreased hemolytic activity compared with L-Ple. The hemolytic effect of analogue was further confirmed by using calcein leakage measurement with liposome. To elucidate these results, the secondary structure of the peptides was investigated by using circular dichroism spectroscopy. The results revealed that D-Ple, as well as L-Ple, had typical ?-helical structures which were mirror images, with a different helicity. These results suggested that the discrepancy of the structure between the two peptides made their antibacterial activity distinct.

Colonización de Streptococcus beta hemolítico del grupo B en gestantes en trabajo de parto y sus neonatos / Colonization of hemolítico Streptococcus beta of group B in gestantes in work of childbirth and its neoborn ones

El objetivo de esta investigación fue establecer en pacientes atendidos en la Maternidad “Dr. Armando Castillo Plaza”, Maracaibo, Venezuela, la relación de la colonización del Streptococcus beta hemolítico del grupo B (SGB) en la vagina y recto de las gestantes a término en trabajo de parto y la colonización de sus neonatos, entre los meses Mayo a Diciembre del 2004. Se estudiaron 100 gestantes con embarazos simples a término en trabajo de parto, independientemente de su edad cronológica y paridad, excluyéndose aquellas embarazadas con ruptura prematura de membrana mayor de 18 horas, con antibioticoterapia en el momento del parto, con fiebre intraparto, coriamnionitis o con antecedente de parto anterior con infección del recién nacido por el SGB. A cada paciente se le tomó hisopado vaginal rectal y secreción nasal a sus neonatos al momento del parto, los cuales se colocaron en un medio de Cary & Blair y se transportaron al laboratorio de bacteriología donde las muestras de vagina y de secreción nasal se cultivaron en agar sangre de carnero con Kanamicina; las muestras rectales se inocularon en agar sangre de carnero con Kanamicina y en caldo cerebro corazón con Ácido Nalidixico y Gentamicina. El SGB fue identificado mediante pruebas convencionales y una vez identificadas se les realizó las pruebas de susceptibilidad siguiendo la metodología descrita por el CLSI 2007 (Bauer & Kirby). La frecuencia de aislamiento del SGB fue de 18% en las pacientes estudiadas y del 10% en sus recién nacidos. La transmisión vertical en el momento del parto fue 55,5%. Los aislamientos de SGB fueron sensibles a todos los antibióticos probados. La frecuencia de colonización en las parturientas y en los neonatos es comparable con las reportadas en otros países. Es necesario establecer pautas para detectar la colonización materna por SGB y así prevenir la sepsis neonatal por este microorganismo.

The objective of this investigation was to establish in patients taken care of in the Maternity “ Dr. Armando Castillo Plaza”, Maracaibo, Venezuela, the relation of the colonization of the hemolítico Streptococcus beta of the B group (SGB) in the vagina and rectum of the gestantes upon maturity in work of childbirth and the colonization of its neoborn ones, between the months May to December of the 2004. 100 gestantes with simple pregnancies in work of childbirth studied upon maturity, independently of its chronological age and parity, excluding themselves those pregnant women with greater membrane premature rupture of 18 hours, with antibioticoterapia at the moment of the childbirth, with fever intrachildbirth, coriamniotitis or with antecedent of previous childbirth with infection of new born by the SGB. To each patient hisopado was taken her vaginal rectal and nasal secretion to its neoborn ones at the time of the childbirth, which was placed in means of Cary & Blair and they were transported to the bacteriology laboratory where the nasal secretion and vagina samples were cultivated in agar blood of sheep with kanamicina; the rectal samples inoculated in agar blood of sheep with kanamicina and in broth brain heart with nalidixico acid and gentamicina. The SGB was identified by means of conventional tests and once identified the methodology described by CLSI 2007 was made the susceptibility tests to them following (Bauer & Kirby). The frequency of isolation of the SGB was of 18% in the studied patients and 10% in new born her. Vertical transmission in the moment of the childbirth was 55.5%. The isolations of SGB were sensible to all proven antibiotics. The frequency of colonization in parturientas and the neoborn ones is comparable with the reported ones in other countries. It is necessary to establish guidelines to detect the maternal colonization by SGB and thus to prevent the neonative sepsis by this microorganism.

Phenotypic characters of urinary isolates of Pseudomonas aeruginosa & their association with mouse renal colonization.

BACKGROUND & OBJECTIVE: Very few studies regarding production of virulence factors in different predominant serotypes of uropathogenic Pseudomonas aeruginosa are available and they have not been correlated to in vivo pathogenicity in the urinary tract. This study was carriedout with the objective to analyze the phenotypic characters of uroisolates of P. aeruginosa in vitro and to study the association of these virulence traits with their ability to cause nephropathogenicity in mouse model of ascending urinary tract infection (UTI). METHODS: Protease, elastase, alginate, haemolysin, pyochelin, pyoverdin and phopholipase C were measured using standard protocols in 18 uroisolates of P. aeruginosa isolated from patients suffering from complicated UTIs. An ascending model of pyelonephritis was established in Swiss Webster (LACA) female mice with these isolates. Quantitative bacterial count and histopathological evaluation of mouse renal tissue was done which were then assessed for a possible association with elaboration of virulence factors. RESULTS: All isolates of P. aeruginosa were able to colonize renal tissue of mice. However, renal counts varied amongst different isolates producing different virulence factors. Isolates producing high levels of haemolysin along with other virulence factors were able to colonize and multiply more in mouse renal tissue as compared to those producing low levels of haemolysin. INTERPRETATION & CONCLUSION: The findings of this study indicated an association between haemolysin production and renal colonization. High level of haemolysin production in vitro could be used as surrogate information for assessing pyelonephritic potential of P. aeruginosa.

Sindrome uremico hemolitico: ubicación nosologica actual / Hemolytic uremic syndrome (HUS): an up-dated nosological classification

An up-date of the causes and pathogenesis of the HUS is reported. After more than 40 years of research we are able to define the infectious agents and the toxin involved. The mechanisms and the molecules involved in the non-diarrheal (atypical) entities producing HUS have also been characterized. This new situation allows us to develop a diagnostic algorithm that enables us to better define preventive and therapeutic measures, based on more rational evidence.

Activité antibactérienne des extraits de Mitracarpus Scaber sur la croissance in vitro des streptocoques hemolytiques

Nous avons teste l'action des extraits (extrait total aqueux; extrait ethanolique 70; residu insoluble dans l'ethanol 70; extrait ethanolique 100et extrait butanolique) de Mitracarpus scaber (Rubiaceae) sur la croissance in vitro des streptocoques ? hemolytiques en milieu liquide et sur milieu solide de Milieu-Hinton. Cette plante codifiee MISCA dans notre etude; a toujours ete utilisee dans la pharmacopee ivoirienne contre les infections cutanees. Les resultats de notre etude montrent que les souches des treptocoques ? hemolytiques sont sensibles a tous les extraits testes. Cependant; seul l'extrait butanolique a une meilleure activite bactericide sur la croissance in vitro de ces souches. Les parametres antibacteriens obtenus sont les suivants : CMI = 3;13 mg/ml; CMB = 0;39 mg/ml et CI50 = 0;02 mg/ml

Estreptococos beta - hemolíticos aislados de pacientes con infecciones estomatológicas / Streptococcus beta - hemolytic isolated from patients with dental infections

La boca normal tiene microorganismos que se adhieren a la superficie mucosa y que al multiplicarse son diseminados con la saliva. Colonizan la nariz, boca, faringe y los dientes. Las bacterias responsables faringitis son principalmente los estreptococos que luego pueden ser diseminados por el organismo causando otras patologías. Objetivos: Aislar los estreptococos beta hemolíticos y sus asociaciones. Materiales y métodos: se estudiaron 66 especímenes purulentos de pacientes masculinos y femeninos de 5 a 55 años de todos los servicios del hospital de clínicas, Facultad de Ciencias Médicas de la Universidad Nacional de Asunción, y procesados en el Departamento de Microbiología. Estudiados desde el 01 de diciembre de 1999 al 31 de marzo del 2001. Resultados: se obtuvo crecimiento microbiano flemones periamigdalinos (31,8%) de faringomigdalitis (47,7%) de senos maxilares (13,6%) y de lesiones cutáneas (6,8%). Se aislaron 72,5% de cocos grampositivos, 23,5% de bacilos gramenegativos y 3,9% de hongos. En la tipificación se obtuvo 35,3% de estreptococos del grupo A, 17,6 del Grupo B, 17,6 del grupo C, 23,5% del grupo F y 5,9% no tipificables. Discusión y Conclusión: comparando con trabajos nacionales (25,86%) y trabajos españoles (30,5%) los estreptococos betahemolíticos hallados de procesos infeccioso (23,5%) son similares en porcentaje; siendo de los grupo A, B y C identificados en 70,6% de los casos.