Actividad bactericida de anticuerpos anti-ABO en colonias aisladas de Escherichia coli

Se ha estudiado la interacción entre antígenos ABO y microorganismos, incluidos los presentes en la microbiota, sobre la posible acción de antígenos y anticuerpos ABO en la susceptibilidad a enfermedades infecciosas. El objetivo de esta investigación fue determinar el título mínimo de la bacteria Escherichia coli capaz de sufrir la acción bactericida in vitro de los anticuerpos humanos anti-ABO. La selección de las muestras de sangre utilizadas se realizó mediante la aplicación de un cuestionario, fenotipado sanguíneo (un voluntario de cada fenotipo ABO) y la titulación de anticuerpos ABO. Se preparó una suspensión bacteriana (inoculo) y se agregó al suero de los voluntarios, seguido de la inoculación en Mueller Hinton Agar, luego de 24 horas, los resultados se leyeron e interpretaron con análisis por duplicado. No hubo diferencia significativa en la Prueba Bactericida entre las pruebas 1 y 2 en los grupos sanguíneos A, B, AB, O y Control Positivo. Hubo una diferencia significativa en el suero humano puro cuando se analizó el Grupo A x Control Positivo; Grupo B x Control Positivo; Grupo AB x Control Positivo y Grupo O x Control Positivo. No hubo diferencia significativa en las otras diluciones. Se concluye que los anticuerpos anti-ABO tienen efecto bactericida cuando existe una alta concentración de bacterias en el ambiente.

The interaction between ABO antigens and microorganisms, including those present in the microbiota, has been studied about the possible action of antigens and ABO antibodies in susceptibility to infectious diseases. This research aimed to determine the minimum titer of the Escherichia coli bacteria capable of undergoing in vitro bactericidal action of human anti-ABO antibodies. The selection of blood samples was performed through a questionnaire, blood phenotyping (one volunteer of each ABO phenotype), and the titration of ABO antibodies. A bacterial suspension (inoculum) was prepared and added to the serum of the volunteers, followed by inoculation in Mueller Hinton Agar. After 24 hours, the results were read and interpreted with duplicate analysis. There was no significant difference in the bactericidal test between tests 1 and 2 in blood groups A, B, AB, O, and Positive Control. There was a significant difference in pure human serum when Group A x Positive Control was analyzed, Group B x Positive Control, Group AB x Positive Control, and Group O x Positive Control. There was no significant difference in the other dilutions. It is concluded that anti-ABO antibodies have a bactericidal effect when there is a high concentration of bacteria in the environment.

Distribution and antifungal susceptibility of Candida species isolated from clinical samples in southern Brazil

Abstract Invasive infections caused by Candida species have been strongly associated with poor prognosis and high resistance rates to some antifungals. This study aimed to identify Candida species isolated from different anatomical sites and to describe their susceptibility profile to antifungals. Ninety-four clinical isolates of Candida were obtained from a Medical Laboratory of Santa Catarina/Brazil. Species identification was performed by MALDI-TOF MS. Susceptibility assays were performed as described by Clinical Laboratory Standard Institute (CLSI) microboth method. Among the analyzed samples, C. albicans was the pathogen most incident (59.9%) followed by C. parapsilosis complex (14.9%), C. glabrata complex (8.5%), and C. tropicalis (6.3%). 37 Candida strains were isolated from vaginal content (39.3%), 21 from the nail (22.4%), 8 from tracheal aspirates (8.5%), and 7 from urine (7.4%). Together, the Candida isolates presented decreased susceptibility to azole drugs, mainly to fluconazole and itraconazole. Amphotericin B showed sensibility in 95.7% of samples analyzed. Previous knowledge about etiology and antifungal susceptibility becomes indispensable to conduct an efficient treatment.

Compatibility and efficiency of preservatives in emulsive cosmetics containing high surfactant content

Abstract The objective of this study was to determine the influence of nonionic surfactants on the effectiveness of preservatives used in emulsions containing high surfactant content. Mixtures of different concentrations were prepared between polyethoxylated (40) hydrogenated castor oil (PHCO) and polyoxyethylene sorbitan monooleate (PSO), with methylparaben, phenoxyethanol, methylparaben, ethylparaben, propylparaben, and isobutylparaben (PMEPBI) blend, phenoxyethanol and benzoic acid (BP) blend, and phenoxyethanol and caprylyl glycol (PC) blend. Subsequently, the compatibility of the formulation ingredients and the effectiveness of the preservatives were evaluated by the challenge test. It was found that PHCO and PSO inactivated the antimicrobial action of methylparaben and PMEPBI. Paraben-free preservatives BP and PC had less influence on surfactants than systems containing parabens. When incorporated into microemulsions and nanoemulsions containing 40% and 20% surfactants, methylparaben and BP 0.2% and 0.5% were only effective against Aspergillus niger. The PMEPBI 0.2% was effective as a preservative in nanoemulsified formulations against A. niger, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The results demonstrate that the efficacy of the preservative system in formulations containing nonionic surfactant excipients depends on the type of excipient, the components of the formulation, the preservative systems composition, the excipient to preservative ratio, and the availability in the formulation.

Taxifolin and gastro-adhesive microparticles containing taxifolin promotes gastric healing in vivo, inhibits Helicobacter pylori in vitro and proton pump reversibly in silico.

Taxifolin (3,5,7,3,4-pentahydroxy flavanone or dihydroquercetin, Tax) was identified as a gastroprotective compound and a gastroadhesive formulation was recently developed to prolong its residence time and release in the stomach. So, the gastric healing effectiveness of Tax and gastro-mucoadhesive microparticles containing Tax (MPTax) against the acetic acid induced-gastric ulcer in rats was investigated in this study. Moreover, the interactions between Tax and H+/K+-ATPase were investigated in silico, and its anti- H. pylori activity was determined in vitro. The oral treatment with MPTax (81.37 mg/kg, containing 12.29% of Tax) twice a day for seven days reduced the ulcer area by 63%, compared to vehicle-treated group (Veh: 91.9 ± 10.3 mm2). Tax (10 mg/kg, p.o) reduced the ulcer by 40% but with a p = 0.07 versus Veh group. Histological analysis confirmed these effects. Tax and MPTax increased the gastric mucin amount, reduced the myeloperoxidase activity, and increased the glutathione reduced content at ulcer site. However, only MPTax decreased the lipoperoxide accumulation at ulcer site. Besides, Tax and MPTax normalize the catalase and glutathione S-transferase activity. Tax showed reversible interaction with H+/K+-ATPase in silico and its anti-H. pylori effects was confirmed (MIC = 625 µg/mL). These results suggest that the antiulcer property of Tax involves the strengthening of the gastric protective factors in parallel to its inhibitory interaction with H+/K+-ATPase and H. pylori. Considering that ulcer healing action displayed by Tax was favored by gastroadhesive microparticles, this approach seems to be promising for its oral delivery to treat acid-peptic diseases.

Eugenia umbelliflora mediated reduction of silver nanoparticles incorporated into O-carboxymethylchitosan/y-Fe2O3: Synthesis, antimicrobial activity and toxicity.

The purpose of this study was to synthesize a new magnetic material with antimicrobial properties, incorporated into a biopolymer and containing silver nanoparticles (Ag NP) prepared extract of Eugenia umbelliflora as a reducing agent. Silver nanoparticles incorporated into magnetic nanocomposite O-carboxymethylchitosan/y-Fe2O3/Ag0 (CMAgE) composite were synthesized using an extract of E. umbelliflora. The antimicrobial activity of the pathogenic microorganism is reported here. The synthesized nanoparticles were also characterized, and quantified by Ag analysis. The minimum inhibitory concentrations (MIC) of CMAgE against Staphylococcus aureus, Escherichia coli, and Candida albicans were 16.5, 1000 and 500 µg/mL, respectively. The results show that these materials have significant synergistic effect on each other. The potential phytotoxic effect of the nanocomposites was evaluated using Cucumis sativus seeds. The positive values for seedling elongation inhibition (SEI) show that CMAgE and methanol extract of Eugenia umbelliflora (Eug) cause growth inhibition at a concentration of 1000 mg/L. The germination index (GI) values of 40% and 80% at 1000 mg/L, for CMAgE and Eug, respectively, showed inhibition of germination. CMAgE and Eug showed cytotoxic effects against Artemia salina nauplii, with LC50 values of 72.5 µL/mL and < 5.0 µL/mL respectively, after 48 h.

Characterization and evaluation of the cytotoxic potential of the essential oil of Chenopodium ambrosioides

Abstract The essential oil of Chenopodium ambrosioides L., Amaranthaceae, was obtained by steam distillation in a Clevenger apparatus and characterization was performed using chromatographic and spectroscopic assays (GC-FID, GC/MS, 1H NMR). Two major compounds were identified: p-cymene (42.32%) and ascaridole (49.77%). The ethanolic extract and hydrolate were fractionated by liquid–liquid partitioning and the compounds were characterized by GC/MS. The essential oil, ethanol extract and fractions by partitioning with dicloromethane, ethyl acetate and butanol were tested in tumor cell lines (K562, NALM6, B15, and RAJI). Significant cytotoxic activity was found for essential oil (IC50 = 1.0 µg/ml) for RAJI cells and fraction dicloromethane (IC50 = 34.0 µg/ml) and ethanol extract (IC50 = 47.0 µg/ml) for K562 cells. The activity of the essential oil of C. ambrosioides is probably related to the large amount of ascaridol, since the other major compound, p-cymene, is recognized as a potent anti-inflammatory and has low cytotoxic activity.

Macrocarpal-like Compounds from Eugenia umbelliflora Fruits and Their Antibacterial Activity.

Certain members of the genus Eugenia are used as foods. One of these species is Eugenia umbelliflora, which is used for its fruits. The aim of the study was to isolate the constituents of the CH2Cl2 fraction obtained from E. umbelliflora O. Berg (Myrtaceae) and also to evaluate its antimicrobial properties. Two new meroterpenoids, eugenial C (3) and eugenial D (4) were isolated from the unripe fruits of E. umbelliflora and their structures established mainly by extensive NMR spectroscopy. In previous studies, the CH2Cl2 extract showed significant antibacterial activity, which can be attributed to meroterpenoids isolated in this study. The compounds eugenials C and D exhibited potent activity against Bacillus subtilis and Staphylococcus aureus and different strains of MRSA and activity similar to those of the antibiotics used in antimicrobial therapies.

Seasonal phytochemical study and antimicrobial potential of Vetiveria zizanioides roots.

This paper describes the seasonal phytochemical variation and the antimicrobial potential of V. zizanioides roots collected in Brazil. Considering the high levels of chemical constituents and their biological activity in dichloromethane fraction, the plants were grown in different seasons and the respective dichloromethane fractions were analyzed by gas chromatography-mass spectrometry. The antimicrobial activity was evaluated against several pathogenic microorganisms by determining the minimum inhibitory concentration (MIC) using the agar dilution method. Yields of dichloromethane fractions from plants collected in the autumn and spring occurred in a higher proportion than in other seasons. Khusimol (2) was isolated by column chromatography and identified by NMR and CG-MS, along with other sesquiterpenes, including ß-vetivenene (1), vetiselinenol (3), isovalencenol (4), vetivenic acid (5), α-vetivone (6) and ß-vetivone (7). Some extracts showed promising antimicrobial effects, with MICs ranging from 31.25 to 500 µg mL-1. Kushimol was slightly active against the tested microorganisms.

Effects of the topical application of an ethyl acetate fraction from Vernonia scorpioides on excisional wounds infected with Staphylococcus aureus in rats

We investigated the healing process on excisional wounds infected with Staphylococcus aureus in rats, treated with 50 µL of ethyl acetate III from Vernonia scorpioides (Lam.) Pers., Asteraceae, rifamycin diethylamide B 25 mg, or saline. The lesions were measured daily and after seven days were surgically removed and histologically processed. The results indicate a favorable action of the EAIII, demonstrated by the increased wound contraction, smaller area of necrotic tissue, good development of granulation tissue, extensive extracellular matrix deposition and epithelial regeneration. This sub-fraction was phytochemically investigated in parallel studies, revealing the presence of sesquiterpene lactones (glaucolides and hirsutinolides) such as diacethylpiptocarphol and related hirsutinolides, flavonoids and cinnamic acid derivatives and also a new polyacetylene, which have been previously published. Results support the effectiveness of V. scorpioides antimicrobial activity in infected wound healing in rats.

Release of tetracycline from O-carboxymethylchitosan films.

O-carboxymethylchitosan films containing tetracycline were prepared by the casting method. The films were hardened by reaction with glutaraldehyde-induced crosslinking and heat treatment at 90°C, 120°C and 150°C. The effect, on the films, of hardening methods, water uptake, moisture, drug release and antimicrobial activity against Staphylococcus aureus was evaluated. The O-carboxymethylchitosan films were soluble in simulated saliva and after treatment, and the water uptake of the films decreased as the temperature or presence of glutaraldehyde increased. The antimicrobial activity of tetracycline was preserved, and efficiency was dependent on the hardening treatment to which the films were submitted.

Chemical composition and antimicrobial activity of Hedyosmum brasiliense Miq., Chloranthaceae, essential oil

Hedyosmum brasiliense Miq., Chloranthaceae, is an endemic species of Brazil, locally known as "cidrão". Although H. brasiliense is popularly used as sedative, chemical constituents of this species remains uncharacterized. This work presents the essential oil composition, obtained by distillation of the fresh leaves and from a stored sample for three months, analysed by GC-FID and GC-MS. The inhibitory effects of essential oil were tested by the agar dilution method against six bacterial species (Bacillus subtilis, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus and S. saprophyticus). In addition, six fungal species (Candida albicans, C. parapsilosis, Microsporum canis, M. gypseum, Trichophyton rubrum and T. mentagrophytes) were included. Among the determined constituents, α-terpineol (10.2 percent), curzerene (8.9 percent), pinocarvone (8.4 percent) and β-thujene (7.1 percent) were found as the main components. The essential oil has only low activity against Gram-negative microorganisms. However, is remarkable active against Gram-positive bacteria and fungi with MIC values ranging from 0.125 to 2.5 percent (v/v).

Óleo essencial de Hedyosmum brasiliense Miq., Chloranthaceae: composição e atividade antimicrobiana. Hedyosmum brasiliense Miq. Chloranthaceae, é uma espécie endêmica no Brasil, conhecida como "cidrão". Embora H. brasiliense seja utilizada como calmante na medicina popular, não foi ainda caracterizada quanto aos constituintes químicos. Este trabalho apresenta a composição do óleo essencial, obtido pela destilação de folhas frescas e de amostra de óleo essencial armazenada por três meses, analisadas por GC-FID e CG-MS. Os efeitos inibitórios do óleo essencial foram testados pelo método da diluição em agar, contra seis espécies de bactérias (Bacillus subtilis, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus e S. saprophyticus). Adicionalmente, seis espécies de fungos (Candida albicans, C. parapsilosis, Microsporum canis, M. gypseum, Trichophyton rubrum e T. mentagrophytes) foram incluídas. Dentre os principais constituintes, α-terpineol (10,2 por cento), curzereno (8,9 por cento), pinocarvona (8,4 por cento) e β-tujeno (7,1 por cento) foram os encontrados em maior quantidade. O σleo essencial apresentou baixa atividade contra microorganismos Gram-negativos. Entretanto, a atividade é extraordinária contra bactérias Gram-positivas e fungos, com valores de MIC entre 0,125 a 2,5 por cento (v/v).

Antifungal activity of Eugenia umbelliflora against dermatophytes.

Antifungal activities of Eugenia umbelliflora Berg. (Myrtaceae) were tested in vitro against a panel of standard and clinical isolates of human fungal pathogens (dermatophytes and opportunistic saprobes). Methanol extracts of leaves and fruits of E. umbelliflora were separately prepared and partitioned, to yield dichloromethane (DCM), ethyl acetate (EtOAc) and aqueous fractions (Aq). Three compounds (1-3) were obtained from the DCM extract using chromatographic procedures. Antifungal assays were performed using agar dilution techniques. Both extracts (fruits and leaves), their DCM and EtOAc fractions, and compound 2 (betulin and betulinic acid) presented selective antifungal activity against dermatophytes (Epidermophyton floccosum, Microsporum canis, Microsporum gypseum, Trichophyton rubrum, Trichophyton mentagrophytes), with MIC values between 200 and 1000 microg/mL, and interestingly, inhibited 4/5 species with MIC values of < or = 500 microg/mL. The aqueous fractions of fruits and leaves, and compounds 1 (alpha, beta amyrin) and 3 (taraxerol) were inactive up to the maximum concentrations tested (1000 microg/mL).

Avaliação do potencial antimicrobiano de Plinia glomerata (Myrtaceae) / Evaluation of the antimicrobial effects of Plinia glomerata (Myrtaceae)

A planta Plinia glomerata (Myrtaceae), popularmente conhecida como cabeludinha ou " jabuticaba-amarela" , ocorre amplamente no sul do Brasil e é cultivada como ornamental e frutífera comestível. O presente trabalho avaliou as propriedades antimicrobianas dos extratos, frações e substâncias puras isoladas da planta contra bactérias e fungos patogênicos. As concentrações inibitórias mínimas (CIM) foram determinadas através do método de diluição em ágar. As frações acetato de etila (AE) e fração aquosa (AQ) demonstraram a melhor atividade contra Staphylococcus aureus. A fração AQ também foi efetiva contra Escherichia coli. As substâncias puras, ácido 3,4,3'-trimetóxi-flavelágico-4'-O-glicosídeo e ácido 3,4,3'-trimetóxi-flavelágico foram inativas até a concentração de 500 µg/mL contra os microrganismos testados. Em relação aos resultados antifúngicos, os extratos metanólico (EM) e acetônico (EA) e a fração aquosa (AQ) mostraram boa atividade somente contra dermatófitos. Os resultados obtidos permitem concluir que a Plinia glomerata possui princípios ativos com ação antimicrobiana, sugerindo que outras substâncias da planta estão agindo contra os microrganismos indicados ou a existência de efeitos sinérgicos.

Plinia glomerata, commonly known as " yellow jaboticaba" or " cabelluda" occurs widely in south of Brazil. This work evaluated the antimicrobial properties of the extracts, fractions and isolated compounds of this plant against pathogenic microorganisms, bacteria and fungi. The minimal inhibitory concentration (MIC) was determined through the method of dilution in agar. The ethyl acetate (EtOAc) and aqueous fractions demonstrated the best activity against Staphylococcus aureus. The aqueous fraction also exhibited good activity against Escherichia coli. The pure substances 3,4,3'-trimethoxy-flavellagic-4'-O-glucose acid and 3,4,3'-trimethoxy-flavellagic acid were inactive up to 500 µg/mL. Regarding results against fungi, EA and EM extracts as well as AQ fraction showed good activity only against dermatophytes. The results suggest that P. glomerata produces active principles with antimicrobial activity, suggesting that other substances from the plant are acting against the microorganisms or the existence of synergic effects.

The influence of the essential oil of Melaleuca alternifolia on the healing of infected dental alveoli: a histological study in rats

The plant Melaleuca alternifolia is native to Australia. The distillation of its leaves produces an essential oil, commonly known as oil of Melaleuca, or Tea tree oil, which present antimicrobial activity. This study investigates the action of this oil on the repair process of infected dental alveoli. 48 rats were used (Rattus novergicus albinus, Wistar). After tooth extraction and posterior infection of the dental alveoli with Staphylococcus aureus, the animals were separated into three groups: Group I: curettage and irrigation with physiologic saline solution; Group II: curettage and irrigation with physiologic saline solution and topical application of rifamycin diethylamide B 25 mg; and Group III: curettage and irrigation with physiologic saline solution and topical application of oil of Melaleuca 20 percent. The animals were sacrificed 24 hours, 7, 14 and 21 days after the treatment with powder and the repair process of the dental alveoli was analyzed using an optical microscope. The results were submitted to qualitative and quantitative analysis and it was concluded that tea tree oil at 20 percent caused a delay in the repair process of infected dental alveoli in rats, as demonstrated by the presence of more necrosis area and less osteogenesis.

A planta Melaleuca alternifolia é nativa da Austrália e a destilação de suas folhas produz um óleo essencial conhecido por óleo de Melaleuca, ou Tea tree oil, usado como antimicrobiano. Nesse estudo, foi verificado a atividade deste óleo no processo de reparo de alvéolos dentais infectados. 48 ratos foram utilizados (Rattus novergicus albinus, Wistar) e após a extração do dente e posterior infecção do alvéolo com Staphylococcus aureus, os animais foram separados em três grupos: Grupo I: curetagem e irrigação do alvéolo com soro fisiológico; Grupo II: curetagem e irrigação com soro fisiológico e tratamento com Rifocina 25 mg; e Grupo III: curetagem e irrigação com soro fisiológico e aplicação tópica de óleo de Melaleuca 20 por cento. Os animais foram sacrificados 24 horas, 7, 14 e 21 dias após o tratamento e o processo de reparo do alvéolo dental foi analisado por microscopia ótica. Os resultados foram submetidos à análise quantitativa e qualitativa e foi possível concluir que o óleo a 20 por cento causou um retardo no processo de reparo dos alvéolos dentais infectados dos ratos, demonstrado por maior área de necrose e menor osteogênese.

Antibacterial activity of extract, fractions and four compounds extracted from Piper solmsianum C. DC. VAR. solmsianum (Piperaceae).

Piper solmsianum C. DC. var. solmsianum (Piperaceae) is a shrub commonly found in areas with wet tropical soils. Other Piper species have been used in folk medicine as antitumoral and antiseptic agents. We studied the crude methanolic extract, some organic fractions and compounds isolated from this plant for possible antimicrobial activity against Gram-positive and Gram-negative bacteria. The bioautographic assays disclosed three inhibition zones. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined showing excellent activity, particularly against the Gram-positive bacteria (Bacillus cereus, Staphylococcus aureus, Staphylococcus saprophyticus and Streptococcus agalactiae). It appears that the antimicrobial activity of Piper solmsianum is related mainly to the presence of conocarpan and eupomatenoid-5 (neolignans). However another, as yet unidentified, active compound could also be extracted from the plant.

Antimicrobial activity of fractions and compounds from Calophyllumbrasiliense (Clusiaceae/Guttiferae).

Calophyllum brasiliense (Clusiaceae/Guttiferae) is a native Brazilian medicinal plant traditionally used against several diseases, including infectious pathologies. Crude methanolic extracts (CME) and two fractions, denoted non-polar (soluble in chloroform) and polar (nonsoluble in chloroform), were prepared from different parts of the plant (roots, stems, leaves, flowers and fruits) and studied. The following compounds were isolated and tested against pathogenic bacteria and yeasts by determination of the minimal inhibitory concentration (MIC): brasiliensic acid (1), gallic acid (2), epicatechin (3), protocatechuic acid (4), friedelin (5) and 1,5-dihydroxyxanthone (6). The results indicated that all the parts of the plant exhibited antimicrobial activity against Gram-positive bacteria, which are selectively inhibited by components of C. brasiliense. No activity was observed against Gram-negative bacteria and yeasts tested. Regarding the isolated compounds, substance 4 showed antimicrobial activity against all the tested microorganisms, whereas compound 6 exhibited antimicrobial activity only against Gram-positive bacteria. The results from the current study confirm and justify the popular use of this plant to treat infectious processes.