Estudo da produ����o de metab��litos por Pseudomonas aeruginosa: Ramnolip��dios e Polihidroxialcanoatos (PHAs)

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Produ����o de ramnolip��dios por mutantes de Pseudomonas aeruginosa LBI

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Desenvolvimento de estrat��gias de alimenta����o para produ����o de ramnolip��dios por Pseudomonas aeruginosa LBI 2A1 em biorreator

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Biorremedia����o de solo contaminado com ��leo lubrificante pela aplica����o de diferentes solu����es de surfactante qu��mico e biossurfactante produzido por Pseudomonas aeruginosa LBI

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

High genetic diversity among Pseudomonas aeruginosa and Acinetobacter spp. isolated in a public hospital in Brazil

In Brazil and other regions of the world, Pseudomonas aeruginosa and Acinetobacter spp. have emerged as important agents of nosocomial infection and are commonly involved in outbreaks. The main objective of the present study was to evaluate the genetic relationship among P. aeruginosa and Acinetobacter spp. isolated from patients in a public university hospital in northwestern Parana, Brazil, and report their antimicrobial resistance profile. A total of 75 P. aeruginosa and 94 Acinetobacter spp. isolates were phenotypically identified and tested for antibiotic susceptibility using automated methodology. Polymyxin B was tested by disk diffusion for P. aeruginosa. Metallo-beta-lactamase (MBL) was detected using a disk approximation test. Genotyping was performed using enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR). Approximately 55% of the P. aeruginosa isolates and 92% of the Acinetobacter spp. isolates were multiresistant, but none were MBL-producers. ERIC-PCR revealed the presence of small clusters of carbapenem-resistant Acinetobacter spp., most likely OXA-type carbapenemase producers. Furthermore, high genetic diversity in P. aeruginosa and Acinetobacter spp. clinical isolates was observed, suggesting that cross-transmission is not very frequent in the studied hospital.

Produ����o e aplica����o de ramnolip��dios produzidos por Pseudomonas aeruginosa LBI 2A1

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Avalia����o do efeito do tratamento com surfactante qu��mico e Pseudomonas aeruginosa LBI na toxicidade de solo contaminado com ��leo lubrificante usado

Petroleum and its subproducts are considered a treat for the environmental quality because of the many environmental accidents that may occur during exploitation, transport and storage. A common remediation technique used in the contaminated areas is based on the use of surfactants, mainly the chemical ones, because they have low production costs. In the other hand, some microorganisms have indicate capacities of producing surfactants that emulsify substances and as result, offer a bigger contact surface for the microbiota degradation. This biossurfactants stand out in comparison with the chemical surfactants because they present lower micelar concentration values, are more tolerant for temperature and pH variation, because they are biodegradable, have low toxicity, higher emulsification and hydrocarbon solubilization index. In this way, after the surfactant application, a toxicity evaluation have to be made to identify the treatment effects. In soil, the activity of some microbial enzymes can show the environmental behavior of the contaminant under different treatment conditions. Dehydrogenase is one example of those enzymes that can demonstrate indirectly the effect of the pollutant on the soil microorganisms. The aim of this paper was to evaluate the toxicity after the addition of a surfactant and/or Pseudomonas aeruginosa LBI in soil contaminated by a mineral automotive lubricant. The previous mentioned bacteria are a potential biossurfactant (rhamnolipid) producer. In order to evaluate the toxicity, the dehydrogenase test was run. In this test, trifeniltetrazolium compound (TTC) after utilized as an electron acceptor, turns into trifenil formazan (TPF), that can be indirectly quantified using the absorbance measured by the spectrophotometer UV-visible. In this way, it was possible to quantify the dehydrogenase activity from the contaminated soil samples... (Complete abstract click electronic access below)

Caracteriza����o de Bacteri��fagos Infectando Isolados Cl��nicos de Pseudomonas aeruginosa Armazenados em uma Cole����o de Cultura

To isolate, to concentrate and to purify bacteriophages from isolates of P. aeruginosa; To observe the capacity of bacteriophages to infect isolates of P. aeruginosa susceptible and multiresitant to antimicrobial; To caractherize bacteriphages by electronic microscopy techniques. 10 isolates of Pseudomonas aeruginosa from LEMC culture collection were submitted to the experiments of ideal temperature for the lyse region appearance in the MaConkey culture plate and 2 extraction methods for the concentration of the phages, clorophorm (Silankorva) and filtration plus centrifugation (Bergan). Three infected clinical isolates of multiresistant P. aeruginosa an one susceptible isolate ( PA01) were evaluated by 3 transmission electron microscopy techniques to caractherize phages morphologically (���on grid���, ���on drop��� and direct extraction from the lyse region of the culture plate). The ideal temperature to obtain lyses region was 37��C. The stock solutions, obtained through the methodologies of Sillankorva and Bergan, had satisfactory results in infecting the multiresistant isolate and the negative control. Among the 3 techniques of electronic microscopy tested the direct from the lyse plate was the best to obtain the micrography of the phages

Estudo dos micronutrientes na produ����o de ramnolip��dios por mutante de Pseudomonas aeruginosa LBI

Os biossurfactantes apresentam in��meras vantagens, como baixa toxicidade, biodegradabilidade e alta estabilidade, mas n��o s��o amplamente utilizados devido ao custo de produ����o. A utiliza����o de substratos baratos, linhagens mutantes que associados �� otimiza����o das condi����es de cultivo pode levar a uma redu����o nos custos, possibilitando assim a substitui����o dos surfactantes sint��ticos pelos biol��gicos. Uma maneira empregada para maximizar a produ����o dos biossurfactantes �� a limita����o de nutrientes. Os esfor��os empregados nesse sentido s��o direcionado para as propor����es carbono: nitrog��nio, entretanto os efeitos dos elementos tra��os s��o pouco conhecidos. Devido a esses fatores, o presente trabalho avaliou a import��ncia dos seguintes elementos tra��os: ferro, zinco, cobalto, cobre, mangan��s e do sal citrato de s��dio dihidratado, nas fermenta����es realizadas utilizando o mutante de Pseudomonas aeruginosa LBI 2A1. Para tanto foram realizadas fermenta����es em frascos Erlenmeyer, onde se utilizou diferentes concentra����es desses elementos. A influ��ncia dos mesmos na produ����o de ramnolip��dios foi constatada, uma vez que a produ����o desse biotensoativo foi aumentada em mais de tr��s vezes alterando apenas a concentra����o de um ��nico elemento tra��o (Fe). Os experimentos realizados permitem, tamb��m, inferir a respeito das melhores concentra����es desses micronutrientes para a produ����o de ramnolip��dios

Fotocat��lise heterog��nea de enterococcus faecalis e pseudomonas aeruginosa desencadeada pela a����o da luz UV e branca em esp��tulas com revestimento de nanopart��culas TiO2 e Ag

Nanotechnology, the science of minuscule, has developed products which are able t o manipulate atoms and molecules that could be applied in the sterilization process of dental instruments. Objetives: The objective of the present study was to evaluate the self-cleaning action of TiO2 and Ag nanoparticles coating on dental instruments by the photocataliys process under UV and visible light irradiation. Material and method: Microbiologic tests were done using dental cement spatulas coated with TiO2 and Ag nanoparticles (one or three layers), and contaminated with 10 mcrl of Pseudomonas aeruginosa and Enterococcus faecalis, respectively. After contamination, they were exposed to ultraviolet light and visible light for 120 minutes. Next, they were transferred to and stored in test tubes with BHI (Brain Heart Infusion) and incubated in 35 to 37 ��C. Checking times for bacterial growth and for control and retrieval tests were done at: 24, 48, 72 and 96 hours. Result: The Pseudomonas aeruginosa was inactive after 120 minutes of ultraviolet light irradiation, thus confirming the heterogeneous photocatalytic activity of TiO2 and Ag. The Pseudomonas aeruginosa was not inactivated under visible light irradiation and the Enterococcus faecalis was not inactivated under UV and visible light irradiation of the dental cement spatulas coated with TiO2 and Ag nanoparticles in the readings to 96 hours, showing bacterial growth. Conclusion: There were no influence of one or three layers of TiO2 and Ag nanoparticles coating of the spatulas in the results. The heterogeneous photocatalysis activity of TiO2 and Ag under UV light irradiation was confirmed for Pseudomonas aeruginosa but not under visible light. Enterococcus faecalis did not confirmed the photocatalytics activity of TiO2 and Ag under UV light irradiation and visible lights irradiation.

Rhamnolipids and PHAs: Recent reports on Pseudomonas-derived molecules of increasing industrial interest

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Detection of P. aeruginosa harboring bla(CTX-M-2), bla(GES-1) and bla(GES-5), bla(IMP-1) and bla(SPM-1) causing infections in Brazilian tertiary-care hospital

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Rhamnolipids Production by a Pseudomonas eruginosa LBI Mutant: Solutions and Homologs Characterization

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Rhamnolipid produced from agroindustrial wastes enhances hydrocarbon biodegradation in contaminated soil

A crude biosurfactant solution was produced by Pseudomonas aeruginosa growing on agroindustrial wastes as the substrate and used to study its effect on hydrocarbon biodegradation by the indigenous soil microflora under laboratory conditions. Two concentrations were studied at first and 1 mg of biosurfactant/g of soil showed to be the most efficient for the total petroleum hydrocarbon reduction, which reached 85% at the first 20 days in soil microcosms. Respirometric and microbial analyses showed that the biosurfactant added did not have toxic effects over the microbial population. The use of a biosurfactant for bioremediation has been limited because of its high cost production. Biosurfactants produced from cost-free by-products combines waste minimization with economic potential bioremediation process.