Culture-dependent and culture-independent characterization of microorganisms associated with Aedes aegypti (Diptera: Culicidae) (L.) and dynamics of bacterial colonization in the midgut

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Antimicrobial activity of 2% chlorhexidine gluconate, 1% sodium hypochlorite and paramonochlorophenol combined with furacin against S. aureus, C. albicans, E. faecalise and P. aureginosa

OBJETIVO: Analisar a ação antimicrobiana da clorexidina a 2%, do hipoclorito de sódio a 1% e do paramonoclorofenol associado ao furacin sobre S aureus, C albicans, E faecalise e P aureginosa. METODOLOGIA: Foram utilizadas 40 placas Petri. Quatro placas foram separadas como controle negativo e em 4 outras, além do meio de cultura, semearam-se os microrganismos, com o círculo de papel, para se obter o controle positivo. em 32 placas seguiu-se a colocação de 4 círculos de filtro de papel esterilizados e impregnados das substâncias testes e controle, depositados em cada quadrante das mesmas. Os grupos foram analisados por 7 dias. Para a verificação dos resultados, usaram-se os halos de inibição de crescimento bacteriano. RESULTADOS: A clorexidina 2% foi significantemente (P<0,05) mais efetiva para todas as cepas microbianas que as demais substâncias. O hipoclorito de sódio a 1% apresentou resultados intermediários. O paramonoclorofenol associado ao furacin (PMC+F) obteve os piores resultados. CONCLUSÃO: A clorexidina obteve os melhores resultados. O PMC+F apresentou os menores halos de inibição.

Avaliação do potencial alelopático, atividade antimicrobiana e antioxidante dos extratos orgânicos das folhas de Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae)

Este trabalho apresenta os resultados de atividade alelopática, antimicrobiana e antioxidante dos extratos orgânicos (hexano, acetato de etila e metanol) das folhas de Pyrostegia venusta (Ker Gawl.) Miers (Bignoniaceae). Para alelopatia, foi estudado o desenvolvimento de Cucumis sativus (pepino), sendo avaliados o comprimento da raiz principal, o número de raízes secundárias e o comprimento do hipocótilo. Os dois primeiros parâmetros foram afetados por todos os três extratos testados enquanto o comprimento do hipocótilo só não foi afetado pelo extrato acetato de etila. Quanto à atividade antimicrobiana, avaliada pelo ensaio de CIM, o extrato hexânico apresentou inibição moderada frente ao Staphylococcus aureus (0,9 mg mL-1) e forte ao Enterococcus hirae (0,5 mg mL-1). O extrato acetato de etila apresentou forte atividade frente Candida albicans (0,3 mg mL-1) enquanto o extrato metanólico não mostrou-se ativo para os microrganismos testados. Por outro lado, o extrato metanólico apresentou a maior capacidade de seqüestrar radicais livres (Concentração Efetiva 50%-CE50 =102,0 ± 56,9 mg mL-1, com TCE50 = 30 min) no ensaio com DPPH (2,2-difenil-1-picril-hidrazila) e o maior teor de compostos fenólicos (116,2 ± 83,0 mg ácido gálico g amostra-1), avaliado pelo ensaio de Folin-Ciocalteau.

Chemical structure, surface properties and biological activities of the biosurfactant produced by Pseudomonas aeruginosa LBI from soapstock

Pseudomonas aeruginosa LBI isolated from petroleum-contaminated soil produced rhamnolipids (RLLBI) when cultivated on soapstock as the sole carbon source. HPLC-MS analysis of the purified culture supernatant identified 6 RL homologues (%): R-2 C-10 C-10 28.9; R-2 C-10 C-12:1 23.0; R-1 C-10 C-10 23.4; R-2 C-10 C-12 11.3; R-2 C-10 C-12 7.9; R-2 C-10 C-12 C-12 5.5. To assess the potential antimicrobial activity of the new rhamnolipid product, RLLBI, its physicochemical properties were studied. RLLBI had a surface tension of 24 mN m(-1) and an interfacial tension 1.31 mN m(-1); the cmc was 120 mg l(-1). RLLBI produced stable emulsions with hydrocarbons and vegetable oils. This product showed good antimicrobial behaviour against bacteria: MIC for Bacillus subtilis, Staphylococcus aureus and Proteus vulgaris was 8 mg l(-1), for Streptococcus faecalis 4 mg l(-1), and for Pseudomonas aeruginosa 32 mg l(-1). RLLBI was active against phytopathogenic fungal species, MIC values of 32 mg l(-1) being found against Penicillium, Alternaria, Gliocadium virens and Chaetonium globosum. Due to its physicochemical properties and antimicrobial behaviour, RLLBI could be used in bioremediation treatment and in the food, cosmetic and pharmaceutical industries.

ANTS AS POTENTIAL VECTORS OF PATHOGENS IN HOSPITALS IN THE STATE OF SAO-PAULO, BRAZIL

Baiting studies performed in large, medium and small hospitals in Brazil revealed the presence of 14 ant species, with up to nine recorded in one hospital. Dominant species were exotic ants, and in the large hospital, Tapinoma melanocephalum was the most prevalent. Ants were not uniformly spread through the hospitals, but tended to be found in the more critical areas, particularly in nursery, intensive care, obstetrics, neurology and dermatology units. Bacteriological studies using specific media for bacteria associated with intra-hospital infections indicated the potential for the mechanical vectoring of species of Staphylococcus, Serratia, Klebsiella, Acinetobacter, Enterobacter, Candida and Enterococcus by ants. Although T. melanocephalum did not have the highest rate of association with these bacteria, its ubiquitous occurrences resulted in the highest overall potential as a vector of these bacteria. Because of a large number of ant species occurring in Brazilian hospitals, ants pose a potential problem to the spread of diseases in hospitals. Because of the number of associated ant species in hospitals, the control of this potential problem is much more difficult than in registered temperate areas.

Microbial leakage of MTA, Portland cement, Sealapex and zinc oxide-eugenol as root-end filling materials

Objective: The aim of this study was to compare the microbial leakage of mineral trioxide aggregate (MTA), Portland cement (PC), Sealapex and zinc oxide-eugenol (ZOE) as root-end filling materials.Study design: An in vitro microbial leakage test (MLT) with a split chamber was used in this study. A mixture of facultative bacteria and one yeast (S. aureus + E. faecalis + P. aeruginosa + B. subtilis + C. albicans) was placed in the upper chamber and it could only reach the lower chamber containing Brain Heart Infusion broth by way of leakage through the root-end filling. Microbial leakage was observed daily for 60 days. Sixty maxillary anterior human teeth were randomly assigned to different groups - MTA and PC (gray and white), Sealapex + zinc oxide and ZOE, control groups and subgroups to evaluate the influence of EDTA for smear layer removal. These materials were further evaluated by an agar diffusion test (ADT) to verify their antimicrobial efficacy. Data were analyzed statistically by Kruskal-Wallis and Mann-Whitney test.Results: In the MLT, Sealapex + zinc oxide and ZOE did not show evidence of microbial leakage over the 60-day experimental period. The other materials showed leakage from the 15th day. The presence of smear layer influenced microbial leakage. Microbial inhibition zones were not observed in all samples tested by ADT.Conclusion: Sealapex + zinc oxide and ZOE did not show microbial leakage over the experimental period, whereas it was verified within 15 to 45 days in MTA and Portland cement.

Development of a novel fermented soymilk product with potential probiotic properties

The study was carried out to test the ability of Enterococcus faecium, Lactobacillus acidophilus, L. jugurti, Streptococcus thermophilus and L. delbrueckii ssp bulgaricus to decrease cholesterol in vitro and to grow in the presence of bile salts. Both properties were dependent on the species under study. The cultures were also inoculated into soymilk fortified with dry milk whey powder as single or mixed starters. The physicochemical and sensory evaluations of the fermented products showed that E. faecium plus L. jugurti (ratio 1:1) is the best combination, and this mixture also produces a 43% decrease in cholesterol. © Springer-Verlag 1999.

Efeito de um novo produto fermentado de soja sobre os lípides séricos de homens adultos normocolesterolêmicos

This study was undertaken to verify the effect of a daily intake of a new fermented soy milk produced with Enterococcus faecium and Lactobacillus jugurti on the serum lipid levels in normocholesterolemic middle-aged men. The study was randomized, double-blind and placebo-controlled and was performed for a period of 6 weeks. Forty-four normocholesterolemic healthy, male volunteers, aged 40-55 years old were randomly separated in two groups: The F-group received 200 ml of the fermented product daily and the P-group received 200 ml of placebo (chemically fermented). The blood samples were drawn initially and after 3 and 6 weeks and serum values for total cholesterol, HDL-cholesterol and triglyceride were determined. The LDL-cholesterol value was estimated. No significant changes in the fermented group (F) were observed for total cholesterol, LDL-cholesterol or triglyceride levels, while the HDL-cholesterol level was significantly higher (p≤ 0,05) after 6 weeks. The total cholesterol and LDL-cholesterol levels were significantly higer (p≤ 0,05) in the placebo group (P), but no changes were found for the HDL-cholestrol and triglyceride levels during the experimental period. In conclusion, the intake of 200 ml/day of the fermented soy milk, produced with E.faecium and L. jugurti, for 6 weeks, did not affect the serum total cholesterol and LDL-cholesterol, and led an increase of 10% in the HDL-cholesterol level.

Fermented soy product supplemented with isoflavones affected fat depots in juvenile rats

Objectives: This study investigated the effects of soy product fermented by Enterococcus faecium and Lactobacillus jugurti supplemented with isoflavones on adipose tissue, blood lipid, and glucose levels on juvenile rats. Methods: Rats were fed a cholesterol-enriched diet for 3 wk as a preliminary treatment to create hypercholesterolemia. They were then fed a chow diet (HC), a chow diet plus fermented soy product supplemented with isoflavones (HCFI), a chow diet plus placebo (HCP), or a chow diet plus placebo supplemented with isoflavones (HCPI), respectively, for an additional 3 wk. Results: The beneficial effects of fermented soy product supplemented with isoflavones on epididymal (EPI) and retroperitoneal (RET) fat pads was likely due to isoflavones because adipocyte circumference (micrometers) in the HC group was significantly larger (EPI: 105.66 ± 13.36; RET: 134.95 ± 25.40) than that in the HCFI group (EPI: 93.17 ± 12.80; RET: 108.62 ± 15.50) and HCPI group (EPI: 93.06 ± 15.10; RET: 112.34 ± 18.21). The probiotic micro-organism accentuated the antilipogenic effect of isoflavones on RET (HCFI: 108.62 ± 15.50 micrometers versus HCPI: 112.34 ± 18.21 micrometers). Moreover, the fermented product increased glucose concentration similar to that in the chow group but did not change blood lipids. Conclusion: This product may offer new approaches to obesity prevention. © 2005 Elsevier Inc. All rights reserved.

Recurrent urinary tract infections: Evaluation of the prophylactic efficacy of urinary antiseptics methenamine and methylthioninium chloride

Introduction: Urinary tract infection (UTI) is a very common condition in clinical practice, affecting an estimated 50% of all adult women during a lifetime. The most common causative agent is E. coli; UTI may also be caused by S. saprophyticus, Enterobacteria (Klebsiella sp and Serratia sp.), Enterococcus sp., and P aeruginosa. Recurrent UTIs occur at least twice per semester or three times a year. Prophylactic measures to prevent recurrent UTIs include changes in contraception methods, cranberry products, increased fluid intake, urination after intercourse, vaginal estrogen therapy for post-menopausal women, antibiotics, and urinary tract antiseptic agents. Objectives: To evaluate the use of a combination of methenamine and methyl-thioninium chloride in the prophylaxis of recurrent uncomplicated lower UTIs, with respect to: • Signs and symptoms of UTI • Etiologic agent(s) • Recurrence rates • Need for antibiotic therapy in case of recurrence • Incidence of adverse events associated with the treatment, including any reported alterations of laboratory tests Materials & methods: A descriptive, analytic, restrospective study was performed at Hospital Universitário Constantino Otaviano - UNIFESO. Medical charts from patients presenting recurrent uncomplicated lower UTI attended from 2001-present were analyzed, including the following information: Demographic data (age, gender, weight, ethnicity, living conditions): medical history/signs and symptoms of UTI; identification of treatment and dosing regimens; treatment duration; recurrence rates and need for antibiotic therapy in case of recurrence; other medications prescribed; and records of adverse events. Results: E. coli was identified as etiologic agent in 80% of the patients. Following antibiotic therapy, all patients received prophylactic treatment with the combination of methenamine and methylthioninium chloride. Treatment duration ranged from three to six months. Adverse events were observed in 13/60 patients (21.7%). At the end of the respective treatment periods, a statistically significant (p<0.0001) number of patients showed no UTI recurrence. Conclusion: Based on the results from the collected data, we conclude that an orally administered combination of methenamine and methylthioninium chloride is safe and effective in the prophylactic treatment of recurrent uncomplicated lower urinary tract infection. © Copyright Morelra Jr. Editora.

Influence of local tetracycline on the microbiota of alveolar osteitis in rats

The aim of the present study was to evaluate the effects of local tetracycline on the occurrence of alveolar osteitis in rats, and on the microbiota associated to this infection. Forty Wistar rats were randomly assigned to 4 groups (n=10): I - the rats had the maxillary right incisor extracted and the alveolar wound did not receive any treatment; II - adrenaline and Ringer-PRAS were introduced into the alveolar wound; III - the alveolar wound was irrigated with sterile saline; and IV - the alveolar wound was irrigated with an aqueous solution of tetracycline. Microbial samples from the alveolar wounds were collected 2 days after surgery and inoculated on blood agar (with and without 8 μg/mL of tetracycline) and other selective media, and were incubated in either aerobiosis or anaerobiosis at 37°C, for 2 to 14 days. It was verified that tetracycline reduced the occurrence of alveolar osteitis in the rats and caused significant changes in the microbiota of the surgical sites, decreasing the number of anaerobes and increasing the participation of tetracycline-resistant and multi-resistant microorganisms.

Uso de probióticos em ração de rã-touro (Rana catesbeiana): Desempenho produtivo

This experiment had as objective to evaluate the effect of two probiotics, added in the commercial ration (40% PB) on the productive performance of bullfrog Rana catesbeiana. The test was lead with two dosages of each probiotic (5 g/kg of food and 10 g/kg of food), plus a control group, with three repetitions, totalizing five treatments. The weight gain, the feed conversion (CA) and the specific growth rate (TCE) have been analyzed. The results show that the probiotics affect the weight gain of Rana catesbeiana until reaching 200 g, thus decreasing the time of productivity in 28 days but not improving the CA and the TCE. With bases in these experimental conditions probiotic 1 (Lactobacillus acidofillus, Bifidobacterium bifidum and Enterococcus faecium -3×10 6 UFC/g) at lower dose (5 g/kg of ration) provided the best performance of the animals.

Optimization of a synbiotic formulation of soy yoghurt containing yacon extract by response surface methodology

A synbiotic yoghurt based on a combination of soymilk and yacon water extract (from yacon root tubers) was developed as a novel food product fermented with a probiotic culture of Enterococcus faecium CRL 183 and Lactobacillus helveticus ssp jugurti 4l6. Response surface methodology (RSM) was used to optimize the independent variables soymilk protein concentration and percentage of yacon extract in the formulation through a Central Composite Rotatable Design (CCRD), consisting of a 22 factorial design with two levels (-1, +1), two central points (0) and four axial points (± a, 0) (0, ± α). The responses were assessed by consumer acceptance tests. The optimization indicated that a formulation with a soymilk protein concentration of 1.74g/L and 25.86% of yacon extract gave the best average values, 5.91 for the taste and 6.00 for the overall impression responses. The formulation with 40% of yacon extract and the same concentration of soymilk protein achieved similar acceptance values: taste (5.94) and overall impression (5.87), however, with the extra yacon, it probably had a greater content of prebiotic fructooligosaccharides. Consequently, both formulations may give useful functional foods, with sensory properties comparable with those of soy yoghurt (control formulation). Copyright © 2010 by New Century Health Publishers.

Influence of radiopacifying agents on the solubility, pH and antimicrobial activity of Portland cement

The aim of this study was to evaluate the interference of the radiopacifiers bismuth oxide (BO), bismuth carbonate (BC), bismuth subnitrate (BS), and zirconiun oxide (ZO) on the solubility, alkalinity and antimicrobial properties of white Portland cement (WPC). The substances were incorporated to PC, at a ratio of 1:4 (v/v) and subjected to a solubility test. To evaluate the pH, the cements were inserted into retrograde cavities prepared in simulated acrylic teeth and immediately immersed in deionized water. The pH of the solution was measured at 3, 24, 72 and 168 h. The antimicrobial activity was evaluated by a radial diffusion method against the microorganisms S. aureus (ATCC 25923), P. aeruginosa (ATCC 27853), E. faecalis (ATCC 29212) and C. albicans (ATCC 10231). The zone of microbial growth inhibition was measured after 24 h. The addition of BS and BC increased the solubility of the cement. The pH values demonstrated that all materials produced alkaline levels. At 3 h, BS showed lower pH than WPC (p<0.05). At 168 h, all materials showed similar pHs (p>0.05). The materials did not present antimicrobial activity for S. aureus, P. aeruginosas and E. faecalis (p>0.05). With regards to C. albicans, all materials formed an inhibition zone, mainly the mixture of WPC with ZO (p<0.05). The type of radiopacifier incorporated into WPC interfered with its physical and antimicrobial properties. ZO was found to be a viable radiopacifier that can be used with WPC.

Quantitative variations in heterotrophic plate count and in the presence of indicator microorganisms in bottled mineral water

Quantitative variations in heterotrophic plate count (HPC) and in the presence of indicator microorganisms in 0.5, 1.5 and 20-L bottles of different brands of Brazilian mineral water were analyzed during their shelf life. No variations were identified in the presence of indicator microorganisms, but quantitative variations in HPC were observed in some brands, which suggests that changes may be occurring in the water quality during storage. The aim of this study was also to evaluate the quality of the bottled mineral waters and the presence of enterococci and Pseudomonas aeruginosa were verified in six and two bottles, respectively, which is in disagreement with the microbiological quality criteria established in the current legislation. Although no limit is set for HPC in mineral water, this study relies on the limit of 500 colony-forming units per mL of sample (CFU/mL). Seventy-two bottles presented levels above 500 CFU/mL and up to 560,000 CFU/mL. This study showed that the control of HPC (<500 CFU/mL) for non-returnable packaging seems to be adequate to ensure the quality of mineral water during storage. The high values of HPC and its variations detected during storage seem to fully justify the need for a reevaluation of the use of HPC in bottled mineral water quality management. More detailed studies on the potential health risk of HPC and its variations in mineral water are also needed. © 2012 Elsevier Ltd.