Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 30
Filter
1.
Arq. Inst. Biol ; 87: e0142020, 2020. tab
Article in English | LILACS, VETINDEX | ID: biblio-1130108

ABSTRACT

The genus Streptomyces is associated with the ability to produce and excrete a variety of bioactive compounds, such as antibiotic, antifungal and antiviral. Biological active polyketide and peptide compounds with applications in medicine, agriculture and biochemical research are synthesized by PKS-I and NRPS genes. The evaluation of the presence of these genes associated with the biosynthesis of secondary metabolites in different phytopathogenic Streptomyces strains were performed using degenerated primers. The positive signal was observed in 58/63 Streptomyces strains for NRPS gene, 43/63 for PKS-I, and for PKS-II all the 63 strains showed positive signal of amplification. These strains also were tested with double layer agar-well technique against bacterial with clinical importance, and it was possible to observe the Streptomyces spp. strains were able to inhibit the growth of 14, 20, 13 and 3 isolates Gram-positive and Gram-negative bacteria, Staphylococcus aureus (ATCC 25923), Bacillus cereus (ATCC 14579), Pseudomonas aeruginosa (ATCC 27853) and Escherichia coli (ATCC 11775) respectively. The Streptomyces sp. strains IBSBF 2019 and IBSBF 2397 showed antibacterial activity against all four bacteria-target tested.(AU)


O gênero Streptomyces apresenta alta capacidade de produzir e excretar uma grande variedade de compostos biologicamente ativos, como antibióticos, antifúngicos e antivirais. Compostos biologicamente ativos de policetídeos e peptídeos com aplicações na medicina, agricultura e pesquisas bioquímicas são sintetizados pelos genes PKS-I e NRPS. A avaliação da presença desses genes associados à biossíntese de metabólitos secundários em diferentes linhagens de Streptomyces fitopatogênicas foi realizada através do uso de primers degenerados. O sinal positivo foi observado em 58/63 linhagens de Streptomyces para o gene NRPS, 43/63 para o gene PKS-I e, para o gene PKS-II, todas as 63 linhagens apesentaram o sinal positivo de amplificação. Essas linhagens também foram testadas através da técnica de dupla camada contra bactérias de importância clínica e foi possível observar que as linhagens de Streptomyces spp. foram capazes de inibir o crescimento de 14, 20, 13 e 3 isolados de bactérias Gram-positivas e Gram-negativas, Staphylococcus aureus (ATCC 25923), Bacillus cereus (ATCC 14579), Pseudomonas aeruginosa (ATCC 27853) e Escherichia coli (ATCC 11775), respectivamente. As linhagens de Streptomyces sp. ISBSF 2019 e 2397 apresentaram atividade antibacteriana contra todas as bactérias-alvo testadas.(AU)


Subject(s)
Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/growth & development , Streptomyces/metabolism , Bacillus cereus/growth & development , Escherichia coli/growth & development , Anti-Bacterial Agents/metabolism , Peptide Synthases/genetics , Streptomyces/genetics , Gene Amplification , Polymerase Chain Reaction , Sequence Analysis, DNA , DNA Primers , Polyketide Synthases/genetics , Anti-Bacterial Agents/pharmacology
2.
J. appl. oral sci ; 22(5): 442-449, Sep-Oct/2014. tab, graf
Article in English | LILACS, BBO | ID: lil-729843

ABSTRACT

The adhesion of biofilm on dental prostheses is a prerequisite for the occurrence of oral diseases. Objective: To assess the antimicrobial activity and the mechanical properties of an acrylic resin embedded with nanostructured silver vanadate (β-AgVO3). Material and Methods: The minimum inhibitory concentration (MIC) of β-AgVO3 was studied in relation to the species Staphylococcus aureus ATCC 25923, Streptococcus mutans ATCC 25175, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. The halo zone of inhibition method was performed in triplicate to determine the inhibitory effect of the modified self-curing acrylic resin Dencor Lay - Clássico®. The surface hardness and compressive strength were examined. The specimens were prepared according to the percentage of β-AgVO3 (0%-control, 0.5%, 1%, 2.5%, 5%, and 10%), with a sample size of 9x2 mm for surface hardness and antimicrobial activity tests, and 8x4 mm for the compression test. The values of the microbiologic analysis were compared and evaluated using the Kruskal-Wallis test (α=0.05); the mechanical analysis used the Shapiro-Wilk's tests, Levene's test, ANOVA (one-way), and Tukey's test (α=0.05). Results: The addition of 10% β-AgVO3 promoted antimicrobial activity against all strains. The antimicrobial effect was observed at a minimum concentration of 1% for P. aeruginosa, 2.5% for S. aureus, 5% for C. albicans, and 10% for S. mutans. Surface hardness and compressive strength increased significantly with the addition of 0.5% β-AgVO3 (p<0.05). Higher rates of the nanomaterial did not alter the mechanical properties of the resin in comparison with the control group (p>0.05). Conclusions: The incorporation of β-AgVO3 has the potential to promote antimicrobial activity in the acrylic resin. At reduced rates, it improves the mechanical properties, and, at higher rates, it does not promote changes in the control. .


Subject(s)
Acrylic Resins/pharmacology , Anti-Infective Agents/pharmacology , Silver/pharmacology , Vanadates/pharmacology , Acrylic Resins/chemistry , Analysis of Variance , Anti-Infective Agents/chemistry , Candida albicans/drug effects , Candida albicans/growth & development , Compressive Strength , Dental Prosthesis/microbiology , Hardness Tests , Materials Testing , Microbial Sensitivity Tests , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Reproducibility of Results , Silver/chemistry , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Statistics, Nonparametric , Streptococcus mutans/drug effects , Streptococcus mutans/growth & development , Surface Properties , Time Factors , Vanadates/chemistry
3.
Indian J Biochem Biophys ; 2014 Apr; 51(2): 142-148
Article in English | IMSEAR | ID: sea-154254

ABSTRACT

A new chitin-binding lectin was purified from a Bangladeshi cultivar ‘Deshi’ of potato (Solanum tuberosum L.) through anion-exchange and affinity chromatographies using a chitin column. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed the molecular mass of the lectin as 20,000 Daltons. This molecular mass was almost half of the molecular masses of chitin-binding lectins derived from other potatoes. The lectin showed both bactericidal and growth-inhibiting activities against Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli, Salmonella enteritidis and Shigella boydii) pathogenic bacteria. It also showed antifungal activity against Rhizopus spp., Penicillium spp. and Aspergillus niger. Biofilm produced by the bacterium Pseudomonas aeruginosa was dose-dependently reduced by 5-20% in 24 h after administration of the lectin, which was attributed to the glycan-binding property of the lectin having affinity to GlcNAc polymers. It was the first observation that any potato lectin prevented biofilm formation by P. aeruginosa and, therefore, could have possible applications in clinical microbiology and biomedical science.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Biofilms/drug effects , /metabolism , Plant Lectins/isolation & purification , Plant Lectins/pharmacology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Solanum tuberosum/classification , Solanum tuberosum/growth & development , Solanum tuberosum/metabolism
4.
São Paulo; s.n; s.n; 2014. 82 p. tab, graf, ilus.
Thesis in Portuguese | LILACS | ID: biblio-847153

ABSTRACT

Pseudomonas aeruginosa é uma gamaproteobactéria com capacidade de colonizar diversos tipos de ambiente e infectar hospedeiros filogeneticamente distintos. Em humanos, comporta-se como um patógeno oportunista,estando frequentemente relacionada à infecções em indivíduos imunocomprometidos e indivíduos portadores de fibrose cística. Um mecanismo importante para a versatilidade de P. aeruginosa é o sistema de percepção de quórum (QS), onde a bactéria pode vincular expressão gênica à densidade populacional e às características do ambiente. Atualmente, sabe-se que muitos outros reguladores estão interligados com QS, entre eles, a proteína reguladora RsmA e os pequenos RNAs RsmZ e RsmY. Além disso, diversos fatores importantes para a patogenicidade da bactéria são reguladas por QS. Em P. aeruginosa PA14, um fator importante para a patogenicidade em diversos hospedeiros é a proteína KerV, cujo envolvimento com QS foi descrito pela primeira vez neste trabalho. A linhagem D12, que possui uma deleção no gene kerV, mostrou alterações em fenótipos regulados por QS, como a maior produção de piocianina, composto que contribui para virulência e persistência das infecções causada por P. aeruginosa. Por ser facilmente detectável e pela regulação de sua síntese não ter sido completamente explorada em PA14, a expressão dos genes responsáveis pela produção de piocianina é um interessante repórter na investigação do possível envolvimento de KerV com QS. Além de piocianina, D12 apresenta níveis reduzidos de ramnolipídeos. Esses fenótipos somados se assemelham aos fenótipos da mutação de rsmA, sugerindo o envolvimento de KerV com os sistemas QS e Gac-Rsm direta ou indiretamente. Neste trabalho, mostramos que KerV exerce um efeito negativo na regulação dos operons phz1 e phz2, responsáveis pela síntese de piocianina, alterando a expressão desses genes. KerV exerce também um efeito positivo na expressão da proteína RsmA, responsável pela repressão de diversos genes alvos, onde RsmA se liga ao sítio de ligação ao ribossomo no mRNA, impedindo a tradução. Ensaios de gel shift mostraram que a ligação direta de RsmA na sequência líder de phzA1 e phzA2 ocorre, elucidando a maneira pela qual KerV está envolvido na regulação da expressão dos operons phz em P. aeruginosa PA14. Mostramos também que phz2 é ativo e contribui para a síntese de piocianina, pois na ausência de phz1, os níveis do pigmento são maiores do que aqueles detectados em PA14. Isso sugere uma maior expressão de phz2 e uma regulação diferencial dos operons de acordo com as condições ambientais como possível estratégia para manter os níveis desse composto. Uma evidência dessa regulação diferencial é vista no mutante lasR. Na fase inicial de crescimento, esse mutante não produz piocianina, porém quando exposto a tempos mais longos de cultivo, a produção de piocianina é maior quando comparada a PA14. Isso é reflexo da ativação da expressão de phz1 no mutante lasR em fase estacionária tardia, enquanto phz2 permanece não expresso. Isso indica que phz2 é dependente de LasR, ainda que indiretamente. Já phz1, embora tenha sua expressão influenciada por LasR no estágio inicial de crescimento, na fase estacionária é regulado por outros fatores independentes de las


Pseudomonas aeruginosa is a gammaproteobacterium that colonizes several environments and infects phylogenetically distinct hosts. It behaves as an opportunistic pathogen in humans, often related to infection in immunocompromised individuals and cystic fibrosis patients. An important mechanism for P. aeruginosa versatility is the quorum sensing (QS) network, that allows bacteria to link gene expression to population density and environmental traits. Several additional regulators are interconnected with QS, as the regulatory mRNA binding protein RsmA and the non-coding small RNAs RsmZ and RsmY. Futhermore, key factors for pathogenicity are QS-regulated. In P. aeruginosa PA14, an important pathogenicity-related factor is the KerV protein, described for the first time here as involved in QS. D12 strain, that harbor a deletion in the kerV gene, shows alterations in QS-regulated phenotypes, such as high production of pyocyanin, a compound that contributes to virulence and persistence of P. aeruginosa infections. As the production of pyocyanin is easily detected and all mechanisms involved in its synthesis regulation are not fully described, the expression of genes responsible for production of this pigment is a good reporter to investigate KerV involvement in the QS network. Additionally, D12 also shows lower levels of rhamnolipids, another QS-regulated trait. Taken together, these phenotypes resemble the effects of a rsmA mutation, suggesting KerV involvement with QS and Gac-Rsm systems. In this work, we propose that KerV exerts a negative effect in the regulation of phz1 and phz2 operons, responsible for pyocyanin synthesis, by alterating the expression of these genes. KerV also has a positive effect on rsmA expression, responsible for the repression of several genes by blocking the ribosome binding site preventing the translation. Gel shift assays showed that RsmA binds directly in the leader sequence of phzA1 and phzA2, elucidating the manner in which KerV is involved in the regulation of phz operons expression in P. aeruginosa PA14. We also demonstrate that phz2 is actively expressed and contributes to pyocyanin production in PA14, since in the phz1 mutant the levels of pyocyanin are even higher than in the wild type strain. This suggests a phz2 higher expression and a differential regulation of phz operons according to environmental changes as a mechanism to maintain the levels of pyocyanin synthesis. An evidence for this regulation is the synthesis of pyocyanin by the lasR mutant, which does not make pyocyanin at early growth stages. However, at late stationary phase, pyocyanin production is even higher than in the wild-type strain, reflecting the LasR-independent regulation of phz1 expression, while phz2 operon remains silent


Subject(s)
Pseudomonas aeruginosa/growth & development , Quorum Sensing , Bacterial Infections , Gene Expression Profiling/methods , Gene Expression Regulation/genetics , Molecular Biology/instrumentation , Polymerase Chain Reaction/methods , Proteobacteria , Pseudomonas/cytology , Pyocyanine/pharmacology
5.
Journal of Gorgan University of Medical Sciences. 2014; 15 (4): 18-22
in English, Persian | IMEMR | ID: emr-139750

ABSTRACT

Ferula gummosa Boiss. [Barije.] contain medical and antimicrobial properties. This study was done to determine the effect of aqueous and alcoholic extracts of roots of Ferula gummosa Boiss. on the growth of Pseudomonas aeruginosa. In this laboratory study, the plant was dried in dark place and aqueous, alcoholic extracts of Barije's root, powder were prepared using Soxhlet method. The efficacy of 0.1 dilution of different values of extracts of Ferula gummosa Boiss. on the strain of Pseudomonas aeruginosa [PTCC 1430] were evaluated by disk diffusion, Agar-well diffusion, minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] methods. Pseudomonas aeruginosa was completely resistant to the aqueous extract, and the MIC for the methanol and ethanol extracts was 1.25x10[4] microg/ml and 6.25x10[3] microg/ml, respectively. Methanolic and ethanolic extracts of Ferula gummosa Boiss. have antimicrobial activity against Pseudomonas aeruginosa in in-vitro model


Subject(s)
Pseudomonas aeruginosa/growth & development , Plant Preparations/pharmacology , Plant Extracts/pharmacology , Pseudomonas aeruginosa/drug effects , Plant Structures/chemistry
6.
J. pediatr. (Rio J.) ; 89(4): 394-399, ju.-ago. 2013. ilus
Article in Portuguese | LILACS | ID: lil-684139

ABSTRACT

OBJETIVO: Comparar o crescimento bacteriano em colostro puro e colostro com aditivo do leite materno contendo ferro. MÉTODOS: Foram comparadas 78 amostras de colostro puro ou colostro com adição de aditivo do leite materno contendo ferro para avaliar o crescimento de Escherichia coli, Staphylococcus aureus e Pseudomonas aeruginosa. Para a análise qualitativa, discos de papel-filtro foram imersos em amostras de cada grupo e incubados por 48 horas com 10¹ Unidades Formadoras de Colônias/mL de cada cepa. Para a avaliação quantitativa, 1 mL de cada cepa contendo 10(7) Unidades Formadoras de Colônias/mL foi homogeneizado com 1 mL, tanto de colostro puro quanto de colostro com aditivo do leite materno, espalhado em placa de Petri e incubado a 37ºC. O número de Unidades Formadoras de Colônias foi contado 24 horas depois. RESULTADOS: A análise qualitativa não mostrou nenhuma diferença no crescimento bacteriano. Na avaliação quantitativa, o crescimento de Escherichia coli (EC) no grupo C foi de 29,4±9,7 x 10(6) CFU/mL, enquanto no grupo FM85 foi de 31,2±10,8 x 10(6) CFU/mL. A diferença entre o crescimento médio foi de 1,9±4,9 x 10(6) CFU/mL (p = 0,001). Não houve diferenças no crescimento de Staphylococcus aureus e Pseudomonas aeruginosa. CONCLUSÃO: A adição de ferro a essa concentração reduz a ação bacteriostática do leite materno contra Escherichia coli.


OBJECTIVE: To compare bacterial growth in pure colostrum versus colostrum with human milk fortifier (HMF) containing iron. METHODS: The growth of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa in 78 samples of pure colostrum or colostrum with added iron-containing HMF was compared. For qualitative analysis, filter paper discs were immersed in samples from each group and incubated for 48 hours with 10¹ colony forming units (CFUs)/mL of each strain. For quantitative assessment, 1 mL of each strain containing 10(7) CFUs/mL was homogenized with 1 mL of either colostrum or colostrum with human milk fortifier, seeded into a Petri dish, and incubated at 37ºC. Twenty-four hours later, the number of CFUs was counted. RESULTS: The qualitative analysis showed no difference in bacterial growth. In the quantitative evaluation, E. coli growth in the control group was 29.4±9.7 x 10(6) CFU/ mL, while in the HMF group it was 31.2±10.8 x 10(6) CFU/mL. The difference between the average growth was 1.9±4.9 x 10(6) CFU/mL (p = 0.001). There were no differences in S. aureus and P. aeruginosa growth. CONCLUSION: Addition of iron at this concentration reduces breast milk bacteriostatic action against E. coli.


Subject(s)
Animals , Female , Humans , Pregnancy , Colostrum/microbiology , Food, Fortified , Gram-Negative Bacteria/growth & development , Gram-Positive Bacteria/growth & development , Gram-Positive Bacterial Infections/immunology , Iron , Milk, Human , Colostrum/immunology , Escherichia coli/growth & development , Gram-Negative Bacteria/immunology , Gram-Positive Bacteria/immunology , Gram-Positive Bacterial Infections/prevention & control , Iron/administration & dosage , Lactoferrin/physiology , Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/growth & development
7.
Article in English | WPRIM | ID: wpr-214993

ABSTRACT

BACKGROUND: Delayed entry of blood culture bottles is inevitable when microbiological laboratories do not operate for 24 hr. There are few studies reported for prestorage of these bottles. The growth dynamics of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were investigated with respect to various preincubation conditions. METHODS: Fifteen or 150 colony-forming units (CFU) of bacteria were inoculated into standard aerobic or anaerobic blood culture bottles. Bottles were preincubated at 25degrees C or 37degrees C for 0, 2, 4, 8, 12, 24, or 48 hr. The time to detection (TTD) then was monitored using the BacT/Alert 3D system (bioMerieux Inc., USA). RESULTS: Significant difference in TTD was observed following preincubation for 8 hr at 25degrees C vs. 4 hr at 37degrees C for S. aureus, 4 hr at 25degrees C vs. 4 hr at 37degrees C for E. coli, 12 hr at 25degrees C vs. 4 hr at 37degrees C for P. aeruginosa, compared to no preincubation (P<0.005). TTD values did not vary significantly with bacterial CFU or with aerobic or anaerobic bottle type. The BacT/Alert 3D system returned false negatives following preincubation of P. aeruginosa for 48 hr at 25degrees C or 24 hr at 37degrees C. CONCLUSIONS: TTD was mainly affected by preincubation temperature and duration rather than by input CFU quantity or bottle type for the 3 experimental bacteria.


Subject(s)
Bacteriological Techniques/instrumentation , Culture Media , Escherichia coli/growth & development , Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/growth & development , Temperature , Time Factors
8.
Braz. j. microbiol ; 42(4): 1329-1333, Oct.-Dec. 2011. ilus, tab
Article in English | LILACS | ID: lil-614592

ABSTRACT

We report the antibiofilm activity by the sponge-associated bacterium Cobetia marina upon Staphylococcus epidermidis clinical isolates obtained from central venous catheters. Antibiofilm activity/antimicrobial susceptibility correlation might predict the action of the metabolite(s) upon Staphylococcus epidermidis in the clinic, making it a possible adjuvant in therapies against biofilm-associated infections.


Subject(s)
Humans , Anti-Bacterial Agents/isolation & purification , Biofilms , Biotransformation , Disease Susceptibility , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa/isolation & purification , Staphylococcal Infections , Staphylococcus epidermidis/growth & development , Staphylococcus epidermidis/isolation & purification , Methods , Patients , Methods , Virulence
9.
Indian J Pathol Microbiol ; 2011 Jul-Sept 54(3): 569-571
Article in English | IMSEAR | ID: sea-142045

ABSTRACT

Background: Microorganisms develop biofilm on various medical devices. The process is particularly relevant in public health since biofilm associated organisms are much more resistant to antibiotics and have a potential to cause infections in patients with indwelling medical devices. Materials and Methods: To determine the efficiency of an antibiotic against the biofilm it is inappropriate to use traditional technique of determining Minimum Inhibitory Concentration (MIC) on the free floating laboratory phenotype. Thus we have induced formation of biofilm in two strains (Pseudomonas aeruginosa and Staphylococcus aureus, which showed heavy growth of biofilm in screening by Tube method) in a flow cell system and determined their antibiotic susceptibility against ciprofloxacin by agar dilution method in the range (0.25 mg/ml to 8 mg/ml). The MIC value of ciprofloxacin for the biofilm produced organism was compared with its free form and a standard strain as control on the same plates. Observations: Both the biofilm produced strains showed a higher resistance (MIC > 8 mg/ml) than its free form, which were 2 μg/ml for Pseudomonas aeruginosa and 4 mg/ml for Staphylococcus aureus. Thus biofilm can pose a threat in the patient treatment.


Subject(s)
Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Biofilms/growth & development , Ciprofloxacin/pharmacology , Humans , Microbial Sensitivity Tests , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa/physiology , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Staphylococcus aureus/physiology
10.
Arq. bras. oftalmol ; 72(5): 626-630, set.-out. 2009. ilus, tab
Article in English | LILACS | ID: lil-534180

ABSTRACT

OBJETIVO: Avaliar a influência da ação antimicrobiana das soluções multiuso para desinfecção de lentes de contato hidrofílicas. MÉTODOS: Duas soluções multiuso denominadas solução A (poliquaternário-1 a 0,001 por cento e miristamidopropil dimetilamina a 0,0005 por cento) e solução B (poliaminopropil biguanida a 0,0001 por cento) foram testadas em lentes de contato hidrofílicas contaminadas com Pseudomonas aeruginosa (ATCC27583), Staphylococcus epidermidis (ATCC1226), Klebsiella pneumoniae (ATCC13883), Staphylococcus aureus (ATCC25923) e Candida albicans (ATCC 10231) para verificar a quantidade de redução do crescimento dos microrganismos após o enxágue com as soluções. Foram seguidas as instruções preconizadas pelos fabricantes. RESULTADOS: Houve redução de 90 por cento do crescimento de Pseudomonas aeruginosa, Staphylococcus epidermidis, Staphylococcus aureus e Candida albicans. Não houve crescimento de Klebsiella pneumoniae. CONCLUSÃO: As soluções testadas neste trabalho mostraram redução do número de microrganismos testados.


PURPOSE: To evaluate the efficacy of disinfecting solutions in hydrophilic contact lenses (CL). METHODS: Two multi-use solutions denominated solution A (0.001 percent polyquaternium-1 and 0.0005 percent myristamidopropyl dimethylamine) and solution B (0.0001 percent polyaminopropyl biguanide) were used. The solutions were tested in hydrophilic contact lenses infected with Pseudomonas aeruginosa (ATCC27583), Staphylococcus epidermidis (ATCC1226), Klebsiella pneumoniae (ATCC13883), Staphylococcus aureus (ATCC25923) and Candida albicans (ATCC 10231) and the decrease in microorganisms growth after the hydrophilic contact lenses were cleaned with the respective solutions was verified. The manufacture's instructions were followed. RESULTS: A decrease of 90 percent of Pseudomonas aeruginosa, Staphylococcus epidermidis, Staphylococcus aureus, Candida albicans and a decrease 100 percent of Klebsiella pneumoniae was observed. CONCLUSION: The solutions decreased the amount of microorganisms tested.


Subject(s)
Animals , Bacteria/drug effects , Candida albicans/drug effects , Contact Lens Solutions/pharmacology , Contact Lenses, Hydrophilic/microbiology , Disinfectants/pharmacology , Bacteria/growth & development , Biguanides/pharmacology , Colony Count, Microbial , Candida albicans/growth & development , Klebsiella/drug effects , Klebsiella/growth & development , Polymers/pharmacology , Propylamines/pharmacology , Propylamines/standards , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Staphylococcus epidermidis/drug effects , Staphylococcus epidermidis/growth & development
11.
Electron. j. biotechnol ; 12(3): 10-11, July 2009. ilus, tab
Article in English | LILACS | ID: lil-551888

ABSTRACT

The formation of biofilms on indwelling/implanted medical devices is a common problem. One of the approaches used to prevent biofilm formation on medical devices is to inhibit bacterial attachment by modification of the synthetic polymers used to fabricate the device. In this work, we assessed how micro-scale features (patterns) imprinted onto the surface of silicone elastomer similar to that used for medical applications influenced biofilm formation by Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. Patterns were transferred from a multi-patterned oxidized silicon-wafer master-template to silicone elastomer. Features consisted of bars, squares, and circles each extending 0.51 µm above the surface. Feature sizes ranged between 1.78 and 22.25 µm. Distances separating features ranged between 0.26 and 17.35 µm. Bacterial biofilm formation on discs cut from imprinted silicone elastomer was assessed by direct microscopic observation and quantified as the surface area covered by biofilm. Unpatterned silicone elastomer served as a control. Several of the micro-scale patterns imprinted into the silicone elastomer significantly reduced biofilm formation by each bacterium and interrupted biofilm continuity. Although there were differences in detail among strains, bacteria tended to attach in the area between features more than to the surface of the feature itself.


Subject(s)
Animals , Biofilms/growth & development , Biofilms , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa , Staphylococcus aureus/growth & development , Staphylococcus epidermidis/growth & development , Staphylococcus epidermidis , Silicone Elastomers/isolation & purification , Silicone Elastomers/analysis , Silicone Elastomers/adverse effects , Equipment and Supplies/microbiology
12.
Journal of Mazandaran University of Medical Sciences. 2009; 19 (71): 10-19
in Persian | IMEMR | ID: emr-111954

ABSTRACT

Chitin, which entails the most abundant biopolymer in nature after cellulose, having found numerous applications in food processing, cosmetics, agriculture, medical and environment. Natural sources of this polymer are component of exoskeletons of crustaceans and insects as well as cell walls from some bacteria and fungi. Chitosan is a partially deacetylated polymer of chitin, which is more soluble than chitin. The goal of this research is to investigate the diversity of antimicrobial effects of deacetylated chitosan extracted from a certain Persian Gulf shrimp waste [Penaeus semisculcatus], against clinical Pseudomonas aeroginosa. At first, chitin and chitosan were extracted from Penaeus semisulcatus waste by chemical and microbial methods at optimum situation. Deacetylation process of chitin was carried out in alkaline solution at 85°C for 15, 20, 45 minutes and 10 hours respectively and subsequently washed with anhydrous EtOH to remove the residual water. Degree of deacetylation of chitosan samples and its structure were measured by FTIR and Scanning electronic microscopy respectively. Antimicrobial activity was tested against clinical Pseudomonas aeroginosa by agar disc diffusion method. Finally, wound band was made by these compounds and antimicrobial activity was studied invitro. The result of present study confirmed the degree of deacetylation of chitosan samples up to 65% by FTIR method. There was no indication of shift on increasing acetylation degree by heating duration from 15 minutes to 10 hours. Pore diameter was decreased from 0.5-1 micro to 0.065-0.25 micro by the increasing of heating duration. Increased clinical Pseudomonas aeroginosa growth inhibitory up to 50% was obtained by usage of more effective materials up to 3 times on disc. The result of our study showed that there was no relationship between increased heating duration and deacetylation degree. Membrane pores were smaller and antimicrobial activity was more effective by increasing of deacetylation and Ca[+2] presences. The method which was used in this research to prepare porous chitosan membranes with different pore diameter, is suitable and cost effective. Because chitin and chitosan are not toxic, better antimicrobial activity results can be obtained by using more concentrated versions of these components


Subject(s)
Chitin/analogs & derivatives , Pseudomonas aeruginosa/growth & development , Microbial Sensitivity Tests
13.
Braz. j. microbiol ; 39(3): 423-426, July-Sept. 2008. graf, tab
Article in English | LILACS | ID: lil-494525

ABSTRACT

Our objective was to compare some plant growth promoting rhizobacteria (PGPR) properties of Bacillus subtilis and Pseudomonas aeruginosa as representatives of their two genera. Solanum lycopersicum L. (tomato), Abelmoschus esculentus (okra), and Amaranthus sp. (African spinach) were inoculated with the bacterial cultures. At 60 days after planting, dry biomass for plants treated with B. subtilis and P. aeruginosa increased 31 percent for tomato, 36 percent and 29 percent for okra, and 83 percent and 40 percent for African spinach respectively over the non-bacterized control. Considering all the parameters tested, there were similarities but no significant difference at P < 0.05 between the overall performances of the two organisms.


Nosso objetivo foi comparar as propriedades PGPR (rizobactérias promotoras de crescimento de plantas) de Bacillus subtilis e Pseudomonas aeruginosa. Solanum licopersicum (tomate), Asbelmoschus esculentus (ocra) e Amaranthus sp (espinafre africano) foram inoculados com as culturas bacterianas. Após 60 dias de plantio, a biomassa seca das plantas tratadas com B.subtilis e P. aeruginosa aumentou 31 por cento para o tomate, 36 por cento e 29 por cento para ocra, e 83 por cento e 40 por cento para espinafre africano, respectivamente, em comparação com o controle não inoculado. Considerando os parâmetros testados, o desempenho dos dois microrganismos foi similar, sem diferença estatisticamente significativa (p< 0,05).


Subject(s)
Biomass , Bacillus subtilis/growth & development , Bacillus subtilis/isolation & purification , In Vitro Techniques , Pseudomonas aeruginosa/growth & development , Pseudomonas aeruginosa/isolation & purification , Plants/growth & development , Methods , Reference Standards , Polymerase Chain Reaction , Methods
15.
Indian J Exp Biol ; 2007 Mar; 45(3): 258-60
Article in English | IMSEAR | ID: sea-59957

ABSTRACT

Pseudomonas aeruginosa is one of the commonest pathogens among the pseudomonads. This organism can grow in minimal nutritional requirements. Because of the ability of pseudomonads to grow on paraffin is not commonly found among other human pathogens and the primary human pathogen being P. aeruginosa, we studied the adaptation of this organism to paraffin baiting system for growth and biofilm formation. Strains were tested for the capacity to use paraffin as the sole source of carbon using Czapek's minimal salt medium. Of the 53 clinical isolates of P. aeruginosa, 20 strains exhibited growth by 24 hrs and 42 strains by 48 hrs. The remaining strains did not show any growth in the paraffin baiting system. The oxidase test with the paraffin baiting system was also performed. This simple and inexpensive method can be used to isolate and demonstrate the biochemical and biofilm forming capacity of the organism.


Subject(s)
Biofilms , Paraffin/metabolism , Pseudomonas aeruginosa/growth & development
16.
Arq. bras. oftalmol ; 64(4): 329-331, jul.-ago. 2001. tab
Article in Portuguese | LILACS | ID: lil-292583

ABSTRACT

Objetivo: Verificar o crescimento de P. aeruginosa e S. aureus em perfluoroctano líquido (PFO). Métodos: Utilizaram-se três meios de cultura: PFO, caldo de digestäo de soja e caseína e soluçäo salina a 0,9 por cento. Dividiram-se 5 ml de PFO em frascos contendo 1 ml cada. Nos frascos 1 e 2 inoculou-se 1 colônia inteira de P. aeruginosa e nos recipientes 3 e 4 a mesma quantidade de S. aureus. O frasco 5 serviu como controle sem sofrer contaminaçäo. Inoculou-se também 1 colônia de cada bactéria em 1 ml dos demais meios de cultura. As soluçöes foram mantidas em incubadora a 37ºC por 10 dias. Em câmara de fluxo laminar realizou-se o repique utilizando-se alça calibrada de 1:1000 no tempo zero, 72 h,168 h e 240 h após contaminaçäo. Verificou-se o crescimento bacteriano por meio da contagem de colônias em placas de agar sangue 24 h após cada repique. Resultados: Houve crescimento de P. aeruginosa e S. aureus no tempo zero em todos os meios, confirmando a inoculaçäo bacteriana. Nas horas seguintes o crescimento näo mais foi observado em PFO. Ambas as bactérias desenvolveram-se abundantemente nos demais meios de cultura em todos os tempos. No frasco controle näo houve crescimento bacteriano. Conclusäo: Os resultados demonstram que o PFO näo representa meio favorável para o crescimento bacteriano.


Subject(s)
Fluorocarbons/metabolism , In Vitro Techniques , Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/growth & development , Colony Count, Microbial/methods , Culture Media/metabolism
17.
Arq. bras. oftalmol ; 64(1): 53-55, jan.-fev. 2001. tab
Article in Portuguese | LILACS | ID: lil-287872

ABSTRACT

Objetivo: Verificar o crescimento de P. aeruginosa e S. aureus em perfluoroctano líquido .Métodos: Foram utilizados três meios de cultura: perfluoroctano, caldo de digestäo de soja mais caseína e soluçäo salina a 0,9 por cento. Dividiram-se 5 ml de perfluoroctano em frascos contendo 1 ml cada. Nos frascos 1 e 2 inoculou-se 1 colônia inteira de P. aeruginosa e nos recipientes 3 e 4 a mesma quantidade de S. aureus. O frasco 5 serviu como controle sem sofrer contaminação. Inoculou-se também 1 colônia de cada bactéria em 1 ml dos demais meios de cultura. Colônias inteiras foram utilizadas pois o perfluoroctano é imiscível em água. As soluçöes foram mantidas em incubadora 37ºC por 10 dias. Em câmara de fluxo laminar foi realizado o repique utilizando-se alça calibrada 1: 1000 no tempo zero, 72 h, 168 h e 240 h após a contaminaçäo. O crescimento bacteriano foi verificado por meio da contagem de colônias em placas de agar sangue 24 h após cada repique. Resultados: Houve crescimento de P. aeruginosa e S. aureus no tempo zero em todos os meios, confirmando a inoculaçäo bacteriana. Nas horas seguintes o crescimento näo mais foi observado em perfluoroctano. Ambas as bactérias desenvolveram-se abundantemente nos demais meios de cultura em todos os tempos. No frasco controle näo houve crescimento bacteriano. Conclusäo: Os resultados deste estudo "in vitro" demonstraram que o perfluoroctano parece näo representar um meio favorável para o crescimento bacteriano.


Subject(s)
Bacterial Growth , Fluorocarbons , In Vitro Techniques , Caseins , Sodium Chloride , Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/growth & development
18.
Alexandria Journal of Pharmaceutical Sciences. 1998; 12 (2): 69-73
in English | IMEMR | ID: emr-47455

ABSTRACT

Pseudomonas aeruginosa biofilms were prepared on membrane filters incubated at 37C for 10 days. The biofilms were characterized by dense colonization of bacteria as measured by viable counting and scanning electron microscopy. Incubation of formed biofilms with zinc concentrations between 0.03 and 26.25 UM resulted in a gradual decrease [68.2 - 99.95%] in the number of viable cells. Such decrease was accompanied with a gradual eradication of the biofilms as shown by scanning electron micrographs. Ps. aeruginosa biofilms were found to retard the diffusion of gentamicin, neomycin, tobramycin and ofloxacin. Prior treatment of the biofilms with zinc [2.6 and 26.3 muM] resulted in overcoming such retardation. The implication of such result is possible in the treatment of biofilm associated infections was discussed


Subject(s)
Pseudomonas aeruginosa/growth & development , Anti-Bacterial Agents/pharmacology , Zinc
19.
Bulletin of Faculty of Pharmacy-Cairo University. 1998; 36 (1): 77-80
in English | IMEMR | ID: emr-47777

ABSTRACT

Threshold concentrations of heavy metal and ionic salts defining the range of Concentrations, that do not suppress growth, were determined in tryptic soya agar medium. It has been found that the salts of NH4, Mg, Cd and Hg at low concentrations disrupt the symbiotic relationship between the solid surface culture medium and the microorganisms, but do not suppress the growth of the bacteria. These compounds have been included under two different groups as infection inhibitors [Cd and Hg] and as an infection stimulators [NH4, Mg and K]


Subject(s)
Bacteria, Aerobic/growth & development , Escherichia coli/growth & development , Pseudomonas aeruginosa/growth & development , Klebsiella pneumoniae , Cadmium/pharmacology , Mercury Compounds/pharmacology , Ammonium Sulfate/pharmacology , Magnesium Sulfate/pharmacology , Potassium Compounds/pharmacology , Temperature , Culture Media
20.
Acta bioquím. clín. latinoam ; 31(2): 189-94, jun. 1997. tab
Article in Spanish | LILACS | ID: lil-207575

ABSTRACT

Se aislaron cepas de Pseudomonas aeruginosa de distintos procesos infecciosos con el objeto de estudiar la capacidad de producir microcinas y la sensibilidad a las elaboradas por otras cepas. Se investigaron por el método de estrías cruzadas en condiciones mínimas de crecimiento y en agar nutritivo, siendo más adecuado el primero. Se analizó el efecto de la presencia de metionina en medio mínimo. El tamaño molecular de las bacteriocinas se estimó con membranas capaces de retener moléculas mayores de 8000 daltons. Los resultados obtenidos indicaron una alta incidencia de cepas productoras de microcinas (85,7 por ciento). La sensibilidad a las mismas fue variada desde 0 a 10 cepas susceptible. Al mantener P. aeruginosa en el laboratorio se redujo el espectro de actividad, mientras que las recientemente aisladas inhibieron mayor número de cepas. Se observó también que disminuyó la sensibilidad a microcinas al conservarse las cepas por más de seis meses. Es conveniente realizar tipificación mediante microcinas con bacterias mantenidas por poco tiempo en cultivo


Subject(s)
Bacterial Typing Techniques/standards , Bacteriocins , Drug Resistance, Microbial , In Vitro Techniques , Microbial Sensitivity Tests/standards , Pseudomonas aeruginosa/chemistry , Bacteriocins/isolation & purification , Bacteriocins/pharmacology , Methionine/pharmacology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Pseudomonas Infections , Pyocins/antagonists & inhibitors , Pyocins/isolation & purification
SELECTION OF CITATIONS
SEARCH DETAIL