Characterization of an Enterococcus faecium strain in a murine mastitis model.

AIM: The aim of the study was to characterize phenotypically and genotypically Enterococcus faecium strains collected from bovine mastitis milk and to evaluate one of them for its virulence in a murine mastitis model. METHODS AND RESULTS: A total of five E. faecium isolates were collected from cows with subclinical mastitis. EF-7A showed resistance to antibiotics tested, it presented alpha haemolysin and did not present gelatinase activity. It yielded cyA, efafm and gelE1 genes and it could be characterized as a moderate biofilm producer. It was able to internalize in MAC-T cells and 1×108 colony forming unit ml-1 was able to establish an intramammary infection in mice. The strain could be recovered from liver, kidney and blood samples. RAPD profiles showed different bands with respect to the inoculated strain. Histopathology analyses showed different grades of polymorphonuclear neutrophils infiltration in mammary glands. CONCLUSION: This is the first report that studied E. faecium strain in a lactating mouse model of mastitis and showed that the experimental inoculation was able to stimulate an inflammatory response resulting in mastitis. Results contribute to a better understanding of intramammary infections caused by E. faecium. SIGNIFICANCE AND IMPACT OF THE STUDY: This investigation shows that mice represent a valuable model for the study of the mastitis pathogenesis caused by E. faecium considering the high costs of using cows for mastitis research.

Phenolic acid protects of renal damage induced by ochratoxin A in a 28-days-oral treatment in rats.

The present study aimed to characterize the chlorogenic acid (ChlA) capacity to reverse the toxic effects induced by ochratoxin A (OTA) in a subacute toxicity test in rats. Male Wistar rats were fed orally by gavage for 28 days with OTA (0.4mg/kg bw/day), ChlA (5mg/kg bw/day) or the combination OTA (0.4mg/kg bw/day)+ChlA (5mg/kg bw/day). No deaths, no decrease in feed intake or body weight in any experimental group were recorded. The negative control group and the animals treated with ChlA alone showed no changes in any parameters evaluated. In OTA-treated group significant changes such as decrease in urine volume, proteinuria, occult blood, increase in serum creatinine values; decrease in absolute and relative kidney weight and characteristics histopathological lesions that indicated kidney damage were observed. However, limited effect on oxidative stress parameters were detected in kidneys of OTA-treated group. Animals treated with the combination OTA+ChlA were showed as negative control group in the evaluation of several parameters of toxicity. In conclusion, ChlA, at given concentration, improved biochemical parameters altered in urine and serum and pathological damages in kidneys induced by OTA exposure, showing a good protective activity, but not by an apparent antioxidant mechanism.

In Vitro and In Vivo Cytogenotoxic Effects of Hot Aqueous Extract of Achyrocline satureioides (Lam.) DC.

In this work we extend the toxicological studies of hot aqueous extract of A. satureioides (As-HAE) evaluating cytotoxic and apoptotic effects on human peripheral blood mononuclear cells (PBMCs). We also determine genotoxic action of this extract in vivo. In addition, the extract was chemically characterized. Finally, we established a comparison with previous data of cold aqueous extract. The As-HAE induced cytotoxicity on PBMCs determined by trypan blue dye exclusion (CC50 = 653 µg/mL) and MTT (CC50 = 588 µg/mL) assays being more toxic than cold extract. However, As-HAE as well as cold extract did not induce apoptosis measured by Hoechst 33258 staining, TUNEL assay, and DNA fragmentation analysis. The in vivo micronucleus test showed that As-HAE exerted cytogenotoxic effects on bone marrow of mice, contrary to what was observed with cold extract. The chemical study of As-HAE allowed identifying the flavonoids found in cold extract: luteolin, quercetin, and 3-O-methylquercetin, but at higher concentrations. We suggest that toxic effects induced by As-HAE could be due to high concentrations of these flavonoids. Given that As-HAE is the most used in folkloric medicine, its administration should be controlled in order to prevent potential cell damage.

Polyphenols as possible bioprotectors against cytotoxicity and DNA damage induced by ochratoxin A.

The present study aimed to investigate the protective effects of luteolin (L), chlorogenic acid (ChlA) and caffeic acid (CafA) against cyto-genotoxic effects caused by OTA. Vero cells and rat lymphocytes were used and viability was measured by neutral red uptake, MTT and trypan blue dye exclusion method. L (50 and 100µg/mL), ChlA (100 and 200µg/mL) and CafA (10-50µg/mL) reduced the damage induced by OTA (10µg/mL) on both cells type shown a good protective effect. The comet and micronucleus tests in Balb/c mice were performed. ChlA (10mg/kg bw) reduced OTA (0.85mg/kg bw)-induced DNA damage on blood and bone marrow cells, CafA (10mg/kg bw) showed protective effect only in blood cells and luteolin (2.5mg/kg bw) failed to protect DNA integrity on cells. In conclusion, polyphenols tested reduced the toxicity caused by OTA on different target cells with good protective effect, being ChlA the compound that showed the best effects.

Evaluation of the cytotoxicity, genotoxicity and apoptotic induction of an aqueous extract of Achyrocline satureioides (Lam.) DC.

Achyrocline satureioides is widely consumed as infusion or aperitif and shows important therapeutic properties. Previously, we reported absence of genotoxicity of cold aqueous extract (CAE) of A. satureioides by Allium test. However, one test cannot predict the genotoxic effects of a substance. Thus, the aim of this work was to investigate cytotoxicity, genotoxicity and apoptotic ability of CAE of A. satureioides. In addition, CAE was chemically characterized. The cytotoxicity was evaluated by Trypan blue and MTT assays. The apoptotic capacity was evaluated by Hoechst staining and DNA fragmentation-analysis. The genotoxicity was studied by comet assay (CA) and micronucleus test. The identification and quantification of flavonoids were performed by HPLC-ESI-MS/MS. The cytotoxicity studies indicated low toxicity of CAE. In addition, CAE did not induce apoptotic effects on human PBMCs. CAE did not show genotoxicity in vitro against Vero cells, at 10-50 µg/mL. CAE did not induce in vivo genotoxic effects, but it showed at high concentrations cytotoxicity by micronucleus assay. CAE presented flavonoids such as quercetin, 3-O-methylquercetin and luteolin. In conclusion, A. satureioides at popularly concentrations used, in aperitif or infusion, can be consumed safely because did not show any cytotoxic or genotoxic effects.

Modificaciones de parámetros clínicos, celulares y moleculares al cabo de un año de inmunoterapia alérgeno específica / Parameters modified of allergy after immunotherapy

Antecedentes. En general, los pacientes alérgicos, después de un año de inmunoterapia (IT), muestran mejoría en la frecuencia e intensidad de los síntomas. Objetivo. Demostrar que la IT tiene efectos moduladores sobre parámetros clínicos, celulares y moleculares de alergia de acuerdo con las edades. Metodología. Se incluyeron 81 pacientes alérgicos asmáticos: 28 infantes, 36 niños, 17 adultos y 27 controles. En los niños y jóvenes se evaluó el pico flujo espiratorio (PEF), reactividad cutánea, se registró eosinofilia sanguínea y de exudado de mucosa nasal, liberación de enzima ß-hexosaminidase (ß-H) de basófilos, proliferación de PBMC estimuladas con alérgeno específico o PHA; se cuantificaron las concentraciones de IgE, IL-13 y sCD23 en sueros y de IFN-γ en sobrenadantes de cultivos de PBMC. Resultados. Niños y adultos sin IT empeoraron sus reducidos valores de PEF. Niños y adultos después de IT mostraron incremento en los volúmenes de PEF (p<0,0001). Todos los grupos con IT redujeron la reactividad cutánea (p<0,0001, p<0,0001 y p<0,02) y la liberación de B-H de basófilos desafiados con el alérgeno específico (p<0,0001, p<0,0001 y p<0,003). Niños y adultos con IT observaron disminución en los niveles de IgE, ambos p<0,05, y redujeron los niveles de células eosinófilos nasales (p<0,0001 y p<0,01). Solamente los niños tratados con IT redujeron los niveles de células eosinófilas sanguíneas (p<0,0001). Las PBMC de infantes y niños con IT disminuyeron los índices de proliferación desafiadas con el alérgeno específico, ambos p<0,05. Los pacientes alérgicos observaron menores niveles de IFN-γ (p<0,02) y más altos niveles de IL-13 (p<0,05) y sCD23 (p<0,001) que los hallados en controles. Conclusiones. La IT demostró efectividad terapéutica en pacientes asmáticos y cambios en parámetros clínicos celulares y moleculares. Algunos de esos parámetros fueron indicadores de la evolución de la enfermedad y ellos fueron diferentes de acuerdo con las edades(AU)

Background: Most allergic patients, after a year of specific immunotherapy (SIT), show improvement in the frequency and intensity of the symptoms. Objective. The objective was to demonstrate that specific immunotherapy has modulating effects on clinical, cellular and molecular parameters, of allergy. Methods. The study included 81 asthmatic allergic patients and 27 healthy controls from 2 to 50 years of age. Peak expiratory flow, skin reactivity, blood and nasal smear eosinophilia was conducted. ß- hexosaminidase enzyme (B-H) release assays and Peripheral Blood Mononuclear Cells cultures stimulated with specific allergens, were realized. Total IgE, sCD23 and IL-13 were measured in serum and IFN- γ, in culture supernatants. Results. In all the cases a reduction in the frequency and intensity of the asthma attacks and a decrease in medical consultations and antiallergic drugs consumption were observed. The patients without SIT diminished low PEF values. Children and adult people with SIT increased the volumes of peak expiratory flow, (p<0.0001). Skin reactivity was reduced in all the SIT groups'. Skin reactivity were p < 0.0001, p<0.0001 y p<0.02) respectively, and B-H released were p<0.0001, p<0.0001 y p<0.003) to each group. The infants without SIT increased IgE levels. Nasal smear eosinophilia fell from children and adults, p < 0.0001. In Infants and children with SIT, the cellular expansion by the allergen was reduced (p<0.05). In allergic patients IFN-γ values were lower than controls, (p < 0.02). IFN -γ synthesis did not vary after a year of allergen -specific immunotherapy. Allergic patients observed higher serum levels of IL-13 (p<0.05) and sCD23 (p<0.001) than controls. Conclusions. SIT after a year demonstrated therapeutic effectiveness in asthmatic patients with changes in multiple parameters: clinical, cellular and molecular. (AU)

Achyrocline satureioides (LAM.) DC (Marcela): antimicrobial activity on Staphylococcus spp. and immunomodulating effects on human lymphocytes.

Achyrocline satureioides (LAM.) DC (Compositae) is a sub-bush original from America and distributed in Europe and Africa. It is mainly used in infusions, as digestive, sedative among others and has antimicrobial and antiviral properties. A research was made into the anti-microbial activity of the A. satureioides decoction on the Staphylococcus spp strains. They were isolated from 18 patients with acne lesions and from 7 patients infected with Staphylococcus spp. (5 strains were taken from catheters and 2 from wounds). The strains were classified through biochemical tests and then were seeded in triptein-soy agar with or without decoction to observe the antibacterial activity. On the other hand, cultures of lymphocytes were made from those patients who displayed infections caused by Staphylococcus spp. and from 12 control non-infected individuals. The lymphocytes were stimulated with decoction or PHA-M. Among the expanded, CD8+ T cells, with anti-human CD8 monoclonal antibody were the outstanding ones by indirect IF. The A. satureiodes decoction inhibited 95% of the isolated Staphylococcus spp. strains and stimulated the lymphocyte expansion, of which 40% were CD8+ T cells. The A. satureiodes decoction showed anti-microbial activity and resulted to be an immunostimulating agent on CD8+ T cells, with lesser mitogenic effects than PHA-M.

Immunomodulating properties of Minthostachys verticillata on human lymphocytes and basophils.

BACKGROUND: Minthostachys verticillata (Griseb.) Epling is a South American traditional medicinal herb used as digestive, anti-spasmodic, anti-inflammatory and bronchial dilator agent among other uses. Its anti-microbial activity against staphylococcal strains and its anti-viral properties against HVS-1 and strain RC/79 of PrV have been demonstrated. OBJECTIVE: To determine the immunomodulating ability of M. verticillata decoction and essential oil. As a complementary study, the main constituents of the essential oil were identified. MATERIALS AND METHODS: Lymphocyte-proliferating activity of both vegetal derivatives was tested and compared with cellular expansion induced by PHA, Pokeweed, CGB in cytomorphological study. A non-stimulate culture was used as control reference. The score of lymphocyte clusters and colonies was performed using the method described by Lange. Among proliferated cells, LT CD8+ subpopulation was characterized by direct immunofluorescence. The in vitro degranulant ability of the vegetal fractions was tested on basophils from allergic and non-allergic individuals sensitized to environmental fungi. Essential oil components of M. verticillata were identified by gas chromatography technique. RESULTS: M. verticillata derivatives reached higher proliferation levels compared to non-stimulated cultures, showed mitogenic activity and induced cluster and colony formation similar to PHA, Pokeweed and CGB. Cells that proliferated after stimulation with derivatives showed 40% of LT CD8+. Tested concentrations of decoction and essential oil did not reach minimum degranulation indexes over basophils, from both allergic and non-allergic individuals. Gas chromatography analysis revealed the presence of pulegone and menthone as the main constituents. CONCLUSIONS: M. verticillata derivatives were mitogenic over LT, inducing significant cluster and colony formation. There was no evidence of degranulating ability over basophils at the concentrations tested. We assume that the derivatives from M. verticillata would induce Th1 deviation in cellular cultures from allergic patients, which would diminish hypersensitivity reactions. Some of the compounds of the essential oil revealed by gas chromatography analysis may be responsible of the biological activity of these products.

Propiedades inmunológicas y mitogénicas de productos derivados de Minthostachys verticillata sobre linfocitos de niños alérgicos con infección viral / Immunological and mitogenis properties of Minthostachys verticillata derivates products on lymphocytes from allergic children with viral infection

Antecedentes. La decocción y el aceite esencial de Minthostachys verticillata han demostrado efectos antimicrobianos sobre el género Staphylococcus y propiedad antiherpéticas. Objetivos. Determinar la capacidad inmunogénica de la decocción vegetal en inmunizaciones experimentales. Investigar la capacidad proliferativa de linfocitos estimulados con derivados de M. verticillata. Evaluar los efectos de la dococción sobre el mitógeno pokeweed (PWM). Detectar y cuantificar LT CD8+ y LB en células proliferadas provenientes de niños alérgicos con infección VHS-1. Materiales y métodos. Se inmunizaron 2 conejos con la decocción. Se evaluaron los anticuerpos por precipitación y hemaglutinación pasiva. Se estudió la proliferación de linfocitos de 25 pacientes de 2 a 14 años, 15 alérgicos con lesiones de Herpes Simplex Tipo 1 (VHS-1) y 10 controles. Las células fueron estimuladas con a) decocción, b) aceite esencial, c) PWM, d) decocción + PWM, e) control. Se caracterizaron y cuantificaron LT CD8+ y LB por IFD. Resultados. La decocción indujo la síntesis de anticuerpos no precipitantes y hemaglutinantes de glóbulos rojos de carnero. Los linfocitos de los pacientes con VHS-1 mostraron niveles linfoproliferativos más elevados(p<0,01). La decocción y el aceite mostraron efectos mitogénicos similares a PWM. El agregado simultáneo de decocción y PWM redujo la proliferación alcamzada por cada uno (p<0,001) tanto en infectados como en controles. Entre células proliferadas se caracterizaron LT CD8+ y LB. Conclusión. La decocción fue inmunogénica, los anticuerpos tuvieron características de coprecipitantes. Los derivados de M. verticillata mostraron propiedades mitogénicas similares a PWM. La decocción inhibió los efectos de PWM

Propiedades inmunológicas y mitogénicas de productos derivados de Minthostachys verticillata sobre linfocitos de niños alérgicos con infección viral / Immunological and mitogenis properties of Minthostachys verticillata derivates products on lymphocytes from allergic children with viral infection

Antecedentes. La decocción y el aceite esencial de Minthostachys verticillata han demostrado efectos antimicrobianos sobre el género Staphylococcus y propiedad antiherpéticas. Objetivos. Determinar la capacidad inmunogénica de la decocción vegetal en inmunizaciones experimentales. Investigar la capacidad proliferativa de linfocitos estimulados con derivados de M. verticillata. Evaluar los efectos de la dococción sobre el mitógeno pokeweed (PWM). Detectar y cuantificar LT CD8+ y LB en células proliferadas provenientes de niños alérgicos con infección VHS-1. Materiales y métodos. Se inmunizaron 2 conejos con la decocción. Se evaluaron los anticuerpos por precipitación y hemaglutinación pasiva. Se estudió la proliferación de linfocitos de 25 pacientes de 2 a 14 años, 15 alérgicos con lesiones de Herpes Simplex Tipo 1 (VHS-1) y 10 controles. Las células fueron estimuladas con a) decocción, b) aceite esencial, c) PWM, d) decocción + PWM, e) control. Se caracterizaron y cuantificaron LT CD8+ y LB por IFD. Resultados. La decocción indujo la síntesis de anticuerpos no precipitantes y hemaglutinantes de glóbulos rojos de carnero. Los linfocitos de los pacientes con VHS-1 mostraron niveles linfoproliferativos más elevados(p<0,01). La decocción y el aceite mostraron efectos mitogénicos similares a PWM. El agregado simultáneo de decocción y PWM redujo la proliferación alcamzada por cada uno (p<0,001) tanto en infectados como en controles. Entre células proliferadas se caracterizaron LT CD8+ y LB. Conclusión. La decocción fue inmunogénica, los anticuerpos tuvieron características de coprecipitantes. Los derivados de M. verticillata mostraron propiedades mitogénicas similares a PWM. La decocción inhibió los efectos de PWM (AU)