984 resultados para Resistant rootstocks


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In Brazil, garden and cut rose bushes are propagated through cuttings or grafting. The rootstocks used in most of the traditional areas of cultivation are not identified, being known just by the vulgar name. There is not any information in the literature on the morphologic characteristics, nor about the productivity of different cultivars on the rootstocks available in Brazil. The objective of this work was to characterize and determine productivity of nine rootstocks (Rosa multiflora 'Paulista'; R. multiflora 'Japones'; R. multiflora 'Iowa'; R. multiflora 'Kopmans'; R. indica 'Mayor'; R. indica x multiflora; R. sp. 'Natual Brier'; R. manetti and R. canina 'Inermis') grafted with 'Versilia' and 'Tineke' scions. Morphologic studies were undertaken to characterize branches of adult plants to determine shape and dimensions of the leaf; number of prickles/15 cm of stem; vigor of the stems; incidence of Diplocarpon rosae (blackspot) and coloration of the leaf. The productivity (number of commercial flowers/plant/month) was evaluated for 6 months (October, 2000 to March, 2001), in the city of Andradas, Minas Gerais State, located at 1251 meters above sea level. Since there was significant difference in just two months for both rootstocks, 'Tineke' and 'Versilia', no rootstocks could be considered inadequate. Nonetheless, in general, the rootstocks that showed a better performance with 'Tineke' were, R. multiflora 'Kopmans' and R. manetti and with 'Versilia', R. multiflora 'Kopmans' and Rosa sp. 'Natual Brier'.

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Multiresistant Staphylococcus aureus constitutes an important public health problem, especially in view of its possible spread in nosocomial environments. In the present work, we analyzed the susceptibility profile of 80 S. aureus stains from human infections resistant to at least 10 drugs. For this study, the techniques used were the disk method and minimum inhibitory concentration (MIC) of the following drugs: cefuroxime, ciprofloxacin, clindamycin, erythromycin, gentamycin, imipenem, oxacillin, rifampicin, tetracycline and vancomycin, according the criteria of the National Committee for Clinical Laboratory Standards (NCCLS). Methicillin was included in the antibiogram as a marker, which is usually used in drugs selection for the treatment of staphylococcal infections. Results indicated that the most effective drug was vancomycin. For the other 10 drugs, the percentage of resistant strains ranged from 85% to 93.75%. In relation to the MICs, it was observed that vancomycin (MIC 90% = 0.615ug/ml) was the most effective drug; followed by rifampicin (MIC 90% = 2.6ug/ml) and ciprofloxacin (MIC 90% = 26.6ug/ml). The drugs that showed the least effective activity were cefuroxime, clindamycin, erythromycin, gentamycin, and oxacillin. On the other hand, observation of β-lactamase production revealed that most of the methicillin-resistant strains produced β-lactamase (83.7%), potentiating the risks of nosocomial infections. In general, vancomycin still continues to be one of the most effective drugs for staphylococcal infections therapy.

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Th1 cells, in cooperation with activated macrophages, are required to overcome Yersinia enterocolitica infection in mice. The pathway macrophages utilize to metabolize arginine can alter the outcome of inflammation in different ways. The objective of this study was to verify the pattern of macrophages activation in Y. enterocolitica infection of BALB/c (Yersinia-susceptible) and C57BL/6 (Yersinia-resistant) mice. Both strains of mice were infected with Y. enterocolitica O:8 WA 2707. Peritoneal macrophages and spleen cells were obtained on the 1st, 3rd and 5th day post-infection. The iNOS and the arginase activities were assayed in supernatants of macrophage cultures, by measuring their NO/citrulline and ornithine products, respectively. TGFβ-1 production was also assayed. The Th1 and Th2 responses were evaluated in supernatants of lymphocyte cultures, by IFN-γ and IL-4 production. Our results showed that in the early phase of Y. enterocolitica infection (1st and 3rd day), the macrophages from C57BL/6 mice produced higher levels of NO/citrulline and lower levels of ornithine than macrophages from BALB/c mice. The infection with Y. enterocolitica leads to an increase in the TGF-β1 and IL-4 production by BALB/c mice and to an increase in the IFN-γ levels produced by C57BL/6 mice. These results suggest that Y. enterocolitica infection leads to the modulation of M1 macrophages in C57Bl/6 mice, and M2 macrophages in BALB/c mice. The predominant macrophage population (M1 or M2) at the 1st and 3rd day of infection thus seems to be important in determining Y. enterocolitica susceptibility or resistance.

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Multiple resistances to antimicrobial drugs arising in Escherichia coli isolates may complicate therapeutic management of urinary tract infection (UTI) by this organism. In order to assess the multidrug resistance (MDR) among urinary E. coli isolates, we have tested 11 antimicrobial drugs against 67 isolates from outpatients attended in a tertiary-care teaching hospital and of 78 isolates from a municipal health unit, respectively in Ribeirão Preto, State of São Paulo, Brazil. Seventy-six percent and 22% of the isolates from the tertiary-care hospital and the municipal unit, respectively, were resistant to three or more different classes of agents, and were considered to present MDR. Among the isolates from the hospital patients, 73.0%, 65.0%, 58.0%, 58.0% and 31.0% were resistant to tetracycline, ampicillin, cephalothin, trimethoprim-sulfamethoxazole (TMP/SMX) and norfloxacin, respectively; resistance from the municipal unit patients were 31.0%, 37.0%, 8.0%, 29.0% and 12.0% respectively, to the same drugs. The predominant phenotype among the MDR isolates presented is ampicillin, TMP/SMX and tetracycline resistance. The high prevalence of drug resistance among UTI patients calls for continuous surveillance to assure effective control of this infection. © 2007 by The Brazilian Journal of Infectious Diseases and Contexto Publishing. All rights reserved.

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Two tests were performed. In the first, resistance to Didymella bryoniae was determined for the following genotypes: the pumpkins 'Ikky', 'Agroceres', 'Kirameki' and 'Shelper', watermelon progenies 1a, 2a, 3a, 5a, 1b, 2b, 3b and 5b, and 'Gherkin' (C. anguria). The plants were inoculated with the fungus during transplanting. The evaluations of the test were performed every 15 d according to a scoring scale adopted by Dusi et al. (1994). The second test examined compatibility among the rootstocks x grafts, and their effects on production. The rootstocks, 5 pumpkins including 'Ikky', 'Agroceres', 'Kirameki', 'Shelper', six watermelon progenies 1a, 2a, 5a, 1b, 2b and 5b, and one 'Gherkin', were planted one week before planting of the grafted 'Bônus No. 2' melon. The experiments were carried out with 12 treatments, including the control ('Bônus No. 2') with 3 replications with 14 grafted plants per each replication. For the first test, the first three evaluations (at 15, 30 and 45 d after inoculation) did not show characteristic lesions of stem canker, but progeny 3b was found to be susceptible in evaluations performed at 60 and 75 d after inoculation. Progeny 3a demonstrated intermediate susceptibility, while progenies 1a, 2a, 5a, 1b, 2b and 5b, the pumpkins 'Kirameki', 'Shelper', 'Ikky' and 'Agroceres', and 'Gherkin', showed resistance to Didymella bryoniae. In the second test, watermelon progenies 1a, 5a, 1b and 2b, and the pumpkins 'Kirameki', 'Shelper', 'Ikky' and 'Agroceres' showed a level of grafting success of 100%, while results with progenies 2a and 5b, and 'Gherkin' were different in grafting success, respectively 91.67, 98.33 and 43.33%. For other fruit parameters, weight, longitudinal and transverse diameters, pulp thickness and level of total soluble solids, there were no differences among the treatments.

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Most of the interspecific rootstocks (Lycopersicum esculentum × L. hirsutum) used in grafted Spanish tomato crops are resistant to Meloidogyne nematodes, but the 'Mi' resistance gene does not work well at high soil temperatures. Ralstonia solanacearum is a bacterial disease usual in tropical areas, but recently identified with low incidence in several European countries. This disease could be controlled by grafting tomato on Solanum torvum, which is also resistant to Meloidogyne. However, S. torvum and tomato have low grafting affinity, which could be improved using an intermediate rootstock. Some cultivars of eggplant have a relatively good affinity with tomato and complete affinity with S. torvum. In this study we compared two tomato cultivars (one resistant to Verticillium dalihae, Fusarium oxysporum v. lycopersici race 2 and Meloidogyne spp., and one non-resistant) grafted onto 'Beaufort' (Lycopersicum esculentum × L. hirsutum), 'Torvum Vigor' (Solanum torvum) and also with an intermediate grafting of eggplant ('Cristal') between tomato and S. torvum, with nongrafted plants as controls. This arrangement was carried out in two cropping cycles (winter-spring and summer-autumn). In both cycles, plants grafted onto S. torvum, both single or double grafted, yielded less than those grafted onto 'Beaufort' or nongrafted plants. In the spring cycle, no differences were found between single and double-grafted plants using S. torvum rootstocks, but in the autumn cycle double grafted plants had higher yields than the single grafted plants. The severity of nematode infections, in terms of reducing yields, and/or hypothetical infections of Ralstonia, will determine the utility of this technique in tomato production.

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The lychee (Litchi chinensis Sonnerat), of the family Sapindaceae, is a highly valued fruit throughout the world. It is native to southern China, but it is cultivated in many parts of the world. In Brazil, the cultivation of the lychee was initiated in the 1970s in the State of São Paulo and has been increasing in production even though the crop size still averages only 1.4 ha per producer. The low crop size is attributed to the high cost of seedlings and the amount of time required for the plant to bear fruit. These factors discourage planting in large areas. The purpose of this research is to study some aspects of what is vitally important for the production of lychee seedlings on a large scale, with low cost and good genetic quality. Tests were performed using rootstocks from seeds of lychee and longan (Euphoria longan Lam.). Scions for grafting were taken from plants of lychee 'Bengal' in the collection of fruit species from FCAV-UNESP, Campus of Jaboticabal, Brazil. The experiments were started in September 2007 and the grafting process was performed in each month of the year finishing in August 2008. During this period the influence of these criteria were evaluated: 1) time of the year; 2) species of rootstock; 3) percentage of grafting success; 4) stem height at grafting point; 5) stem diameter at grafting point. Therefore, through statistical analysis we obtained significant differences in relation to the rootstock used, the months of the year in which the grafting was performed and the interaction between rootstock and the month in which the grafting was performed.

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In spite of significant results achieved with scion genetic improvement in stone fruits, the peach culture in Brazil still needs studies and new technologies regarding the use of rootstocks. A wide research project has being developed at the Faculdade de Ciências Agrárias e Veterinárias (FCAV/UNESP), Jaboticabal, Brazil, dealing with the use of mume clones (Prunus mume) as rootstocks for peach trees, which has produced promising results. In this research, two mume genotypes propagated by herbaceous cuttings were tested as rootstocks for peach cultivar Aurora-1. Three different tree spacing were used: 6 x 2 m, 6 x 3 m and 6 x 4 m. The experiment was carried out at Vista Alegre do Alto (21°10'14 S, 48°37'45 W, 700 m of altitude), São Paulo State, Brazil. Growing field conditions included Hapludalfs soil with medium sandy texture and using micro sprinkler irrigation. The region has an average chilling accumulation 17.9 hours per year. The evaluations were taken in 2005 and 2006 (2nd and 3rd year after planting, respectively). The trunk diameter was evaluated every three months, from the 24th to the 41st month after planting, totalizing seven evaluations. Plants on 'Rigitano' had higher trunk diameter on the 33rd, 39th and 41st month after planting (May/06, November/06 and February/07, respectively). No significant differences were observed in the other evaluations. The diameter at 5 cm above to the graft point was larger than below, but no incompatibility symptoms were observed between rootstocks and scion. Spacing tested did not influence trunk diameter, phenology and flower bud production in 'Aurora-1' scion. In conclusion, 'Rigitano' and 'Clone 15' are recommended for high density plantings of peach 'Aurora-1' in Brazil, and the 6 x 2 m spacing can be recommended, with productivity advantages for peach under low air relative humidity and mild winter conditions. © ISHS 2012.

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Resistant hypertension (RH) is characterized by blood pressure above 140 × 90 mm Hg, despite the use, in appropriate doses, of three antihypertensive drug classes, including a diuretic, or the need of four classes to control blood pressure. Resistant hypertension patients are under a greater risk of presenting secondary causes of hypertension and may be benefited by therapeutical approach for this diagnosis. However, the RH is currently little studied, and more knowledge of this clinical condition is necessary. In addition, few studies had evaluated this issue in emergent countries. Therefore, we proposed the analysis of specific causes of RH by using a standardized protocol in Brazilian patients diagnosed in a center for the evaluation and treatment of hypertension. The management of these patients was conducted with the application of a preformulated protocol which aimed at the identification of the causes of resistant hypertension in each patient through management standardization. The data obtained suggest that among patients with resistant hypertension there is a higher prevalence of secondary hypertension, than that observed in general hypertensive ones and a higher prevalence of sleep apnea as well. But there are a predominance of obesity, noncompliance with diet, and frequent use of hypertensive drugs. These latter factors are likely approachable at primary level health care, since that detailed anamneses directed to the causes of resistant hypertension are applied. © 2012 Livia Beatriz Santos Limonta et al.

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Disseminated fusariosis has emerged as a significant, usually fatal infection in immunocompromised hosts despite antifungal treatment. We describe here two patients with acute leukemia who developed disseminated amphotericin-resistant fusariosis, and review of six studies of cases series in the literature. Two Fusarium solani strains were isolated from blood and skin cultures of one patient, and one strain from the blood culture of the second patient. Both patients died despite antifungal treatment. Strains were identified by sequencing of ITS1 and ITS4 regions. Random amplified polymorphic DNA analysis of the three F. solani isolates showed a low degree of similarity. Screening for Fusarium spp. contaminants within our facility was negative. Using the CLSI M-38-A2 broth dilution method and E tests®, we found that the MICs were low for voriconazole (0. 12 and 0. 5 mg/L, respectively), unexpectedly high for amphotericin B (≥8 and ≥32 μg/mL, respectively) and itraconazole (≥16 mg/ml). Patients with leukemia or persistent neutropenia should be assessed for disseminated fungal infections, including biopsy and skin cultures. Antifungal susceptibility tests are important due to the possibility of the strains being amphotericin resistant. Treatments must be aggressive, with high doses of antifungals or combined therapy. © 2012 Springer Science+Business Media Dordrecht.

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Two tomato scions (cvs. 'Raf' and 'Gorety') were grafted on three different rootstocks: S. torvum, 'Beaufort' (Lycopersicum esculentum × Lycopersicum hirsutum) and intermediate grafting of eggplant 'Cristal' between tomato and S. torvum (double graft). Plants were grown in Mediterranean greenhouse conditions. The response to grafting was measured through growth parameters, Fv/Fm and leaf macronutrients analysis, and it was compared with non-grafted plants. The scions grafted on S. torvum in simple and double graft showed lower fresh and dry weight of leaves, number of commercial fruits, plant height, Fv/Fm and decreased their capacity to absorb several nutrients resulting in a lower mineral concentration in scions leaves, as a result of a thickened graft union. On the other hand, both scions showed a good response when grafted on the rootstock 'Beaufort', with which growth parameters, yield and photosynthetic capacity were similar to non-grafted plants. © 2013 Copyright Taylor and Francis Group, LLC.

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Photodynamic therapy has been investigated as an alternative method of killing pathogens in response to the multiantibiotic resistance problem. This study evaluated the photodynamic effect of curcumin on methicillin-resistant Staphylococcus aureus (MRSA) compared to susceptible S. aureus (MSSA) and L929 fibroblasts. Suspensions of MSSA and MRSA were treated with different concentrations of curcumin and exposed to light-emitting diode (LED). Serial dilutions were obtained from each sample, and colony counts were quantified. For fibroblasts, the cell viability subsequent to the curcumin-mediated photodynamic therapy was evaluated using the MTT assay and morphological changes were assessed by SEM analysis. Curcumin concentrations ranging from 5.0 to 20.0 μM in combination with any tested LED fluences resulted in photokilling of MSSA. However, only the 20.0 μM concentration in combination with highest fluence resulted in photokilling of MRSA. This combination also promoted an 80% reduction in fibroblast cell metabolism and morphological changes were present, indicating that cell membrane was the main target of this phototherapy. The combination of curcumin with LED light caused photokilling of both S. aureus strains and may represent an alternative treatment for eradicating MRSA, responsible for significantly higher morbidity and mortality and increased healthcare costs in institutions and hospitals. © 2012 Springer-Verlag London Ltd.

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The aim of this work was to determine the resistance level of Haemonchus contortus isolated from the Santa Inês flock of the Embrapa (Brazilian government's Agricultural Research Company), Southeast Livestock Unit (CPPSE), as well as to determine costs of characterizing and maintaining this isolate in host donors. Forty-two male Santa Inês lambs were experimentally infected with 4000 H. contortus infective larvae of the field isolate of CPPSE, called Embrapa2010, and divided into six treatment groups, which received triclorfon, albendazol plus cobalt sulfate, ivermectin, moxidectin, closantel and levamisole phosphate, as well as a negative control group (water). Egg per gram (EPG) counts were performed at 0, 3, 7, 10 and 14. days post treatment when the animals were slaughtered for parasite count. The data were analyzed using the RESO statistical program, considering anthelmintic resistance under 95% of efficacy. EPG and worm count presented a linear and significant relation with 94% determination coefficient. The susceptibility results obtained by RESO through both criteria (EPG and worm count) were equal, except for closantel, showing that the isolate Embrapa2010 is resistant to benzimidazoles, macrocyclic lactones and imidazothiazoles. The need of a control group did not appear to be essential since the result for susceptibility in the analyses with or without this group was the same. Suppression in egg production after treatment did not occur in the ivermectin and moxidectin groups. In the control group, the establishment percentage was just 12.5 because of the low number of third-stage larvae, resistance (innate and infection immunity) of the animals studied plus good nutrition. Drug classes presented similar efficacy between adults and immature stages. The costs for isolate characterization were calculated for 42 animals during 60. days. The total cost based on local market rates was approximately US$ 8000. The precise identification of Brazilian isolates and their establishment in host donors would be useful for laboratorial anthelmintic resistance diagnoses through in vitro tests, which has an annual cost of approximately US$ 2500 for maintenance in host donors. © 2012 Elsevier B.V.

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We studied a nonconcurrent cohort of 582 patients admitted to a medical-surgical intensive care unit. Use of antimicrobials (imipenem and metronidazole) was a risk factor for acquisition of imipenem-resistant Acinetobacter baumannii only for the subcohort of patients admitted in months in which colonization pressure was lower than the median value. © 2013 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

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Methicillin-resistant Staphylococcus aureus (MRSA) poses a threat for patients in burn units. Studies that mix epidemiological designs with molecular typing may contribute to the development of strategies for MRSA control. We conducted a study including: molecular characterization of Staphylococcal Chromosome Cassette mecA (SCCmec), strain typing with pulsed field gel electrophoresis (PFGE) and detection of virulence genes, altogether with a case-case-control study that assessed risk factors for MRSA and for methicillin-susceptible S. aureus (MSSA), using S. aureus negative patients as controls. Strains were collected from clinical and surveillance cultures from October 2006 through March 2009. MRSA was isolated from 96 patients. Most isolates (94.8%) harbored SCCmec type III. SCCmec type IV was identified in isolates from four patients. In only one case it could be epidemiologically characterized as community-associated. PFGE typing identified 36 coexisting MRSA clones. When compared to MSSA (38 isolates), MRSA isolates were more likely to harbor two virulence genes: tst and lukPV. Previous stay in other hospital and admission to Intensive Care Unit were independent risk factors for both MRSA and MSSA, while the number of burn wound excisions was significantly related with the former (OR = 6.80, 95%CI = 3.54-13.07). In conclusion, our study found polyclonal endemicity of MRSA in a burn unit, possibly related to importing of strains from other hospitals. Also, it pointed out to a role of surgical procedures in the dissemination of MRSA strains. © 2013 Elsevier Ltd and ISBI. All rights reserved.