Comparison of the Effectiveness of Leaf Extracts of Anredera cordifolia, Psidium guajava and Pogostemon cablin on Inhibitory Power Over Escherichia coliBacteria / Comparación de la eficacia de los extractos de hojas de Anredera cordifolia, Psidium guajava y Pogostemon cablinen su poder inhibidor sobre la bacteria Escherichia coli

Background: the current research studies why it is effective using Anrederacordifolia, Psidium guajava, and Pogostemon cablin by the local community as a traditional medicine for diarrhea treatment caused by Escherichiacoli bacteria. Objectives: We compared the inhibitor effectiveness of three leaf extracts against Escherichia coli; we also identified the anti-bacterial substances contained in leaf extracts. Methods: We determined the bacterial test activity using the "agar diffusion" method and the thin layer chromatography (TLC) as qualitative analysis for determining the anti-bacterial substances contained in the extract. Results: The Pogostemon cablin leaf extract contained terpenoids, phenolic, and flavonoids compound as bacterial inhibitors, and the comparison showed that Pogostemon cablin leaf extract had the greatest bacterial inhibition power. Conclusion: The antibiotic substances found in the leaf extracts of Anredera cordifolia, Psidium guajava, and Pogostemon cablin can be used as traditional medicine. The breakthrough was evidenced by the ability to inhibit Escherichia coli bacteria. This research shows that traditional medicine has ancient knowledge used by this paper

Antecedentes: la presente investigación estudia la eficacia del uso de Anredera cordifolia, Psidium guajava y Pogostemoncablin por la comunidad local como medicina tradicional para el tratamiento de la diarrea causada por la bacteria Escherichia coli. Objetivos: Comparamos la eficacia inhibidora de los extractos de tres hojas contra Escherichia coli; también identificamos las sustancias antibacterianas contenidas en los extractos de hojas. Métodos: Determinamos la actividad de la prueba bacteriana mediante el método de "difusión en agar" y la cromatografía en capa fina (TLC) como análisis cualitativo para determinar las sustancias antibacterianas contenidas en el extracto. Resultados: el extracto de hoja de Pogostemoncablin contenía compuestos terpenoides, fenólicos y flavonoides como inhibidores bacterianos, y la comparación mostró que el extracto de hoja de Pogostemon cablin tenía el mayor poder de inhibición bacteriana. Conclusión: El contenido de sustancias antibióticas que se encuentran en el extracto de hoja de Anredera cordifolia, Psidium guajava y Pogostemoncablin puede utilizarse como medicina tradicional. Esto se evidencia por la capacidad de inhibir la bacteria Escherichiacoli. Esta investigación muestra que la medicina tradicional tiene un conocimiento antiguo utilizado por este artículo

In Vitro Antimicrobial Activity and Aggregation Abilities of Probiotic Lactobacillus casei and Lactobacillus salivarius Against Oral Pathogens

ABSTRACT@#The antagonistic effect of probiotics against oral pathogens merits exploration because these bacteria are beneficial to the host’s health. The antimicrobial activity of two probiotic strains, Lactobacillus casei and Lactobacillus salivarius, as well as L. casei and L. salivarius combination (1:1), was investigated against Streptococcus mutans, Streptococcus sobrinus, Candida albicans, Candida glabrata and Candida tropicalis using agar-well diffusion, auto-aggregation and coaggregation assays. L. salivarius cell-free supernatant (CFS) alone exhibited greater inhibitory effect against Streptococci spp. compared to L. casei CFS alone and the combination. However, no inhibition was observed for Candida spp. L. salivarius alone exhibited significantly stronger auto-aggregation than L. casei alone (p ≤ 0.05) and L. casei and L. salivarius combination. L. salivarius exhibited strong coaggregation ability with Candida spp., followed by Streptococci spp. while L. casei exhibited coaggregation only with Streptococci spp. However, L. casei and L. salivarius combination did not display any coaggregation with all strains. L. salivarius alone exhibited a stronger antagonistic effect on the tested organisms than L. casei alone or in combination. Based on the results, both probiotic strains showed good antimicrobial activities against oral pathogens and should be further studied for their human health benefits.

Desenvolvimento de métodos microbiológicos rápidos (MMRs) para avaliação da potência de agentes antimicrobianos e suas incertezas de medição / Development of rapid microbiological methods (RMMs) for evaluation of potency of antimicrobial agents and their measurement uncertainties

O método de difusão em ágar tem sido utilizado na avaliação da atividade antimicrobiana desde a descoberta da penicilina. Apesar disso, pouco avanço ocorreu no sentido de reduzir o tempo necessário para a determinação dos halos de inibição de crescimento. O objetivo deste projeto foi desenvolver, otimizar e validar métodos microbiológicos rápidos (MMRs) para a avaliação da potência de agentes antimicrobianos, além de identificar, quantificar e avaliar as principais fontes de incerteza associadas à determinação da potência. O projeto foi dividido em quatro etapas: 1) influência da composição do meio de cultura na formação dos halos de inibição; 2) estudo da incerteza de medição associada à determinação da potência de agentes antimicrobianos; 3) desenvolvimento, otimização e validação de métodos microbiológicos rápidos (MMRs) para determinação da potência de agentes antimicrobianos e 4) determinação dos parâmetros envolvidos na formação dos halos de inibição de crescimento e estudo dos mecanismos de difusão e crescimento microbiano. Os resultados deste projeto possibilitaram a redução do tempo necessário para a determinação do tamanho dos halos de inibição. Adicionalmente, contribuiu com a elucidação dos mecanismos de difusão e crescimento microbiano, possibilitando identificar e quantificar as principais fontes de incerteza de medição associadas à formação dos halos de inibição

Agar diffusion method has been used in the evaluation of antimicrobial activity since the discovery of penicillin. Nevertheless, little progress has occurred in order to reduce the time required for the determination of growth inhibition zones. The goal of this project was to develop, optimize and validate rapid microbiological methods (RMMs) for evaluation of potency of antimicrobials, as well as to identify, quantify and assess the main sources of uncertainty associated with potency. The project was divided into four steps: 1) influence of culture medium composition on inhibition zones; 2) study of measurement uncertainty associated with antimicrobials potencies; 3) development, optimization and validation of rapid microbiological methods (RMMs) for the determination of antimicrobials potencies and 4) determination of the parameters involved in the formation of inhibition zones and study of mechanisms of diffusion and microbial growth. The results of this project allowed the reduction of the time required for the determination of inhibition zone sizes. Additionally, it contributed to the elucidation of the mechanisms of diffusion and microbial growth, making it possible to identify and quantify the main sources of measurement uncertainty associated with formation of inhibition zone sizes

Relative potency of different generic brands of meropenem, colistin and fosfomycin: Implications for antimicrobial therapy and antimicrobial formulary

There is a need of a relatively simple and inexpensive method for the determination of relative potency of various generic brands of antibiotics in comparison to original products. The current study describes an agar diffusion method which can be performed in any microbiology laboratory, is cheap (costs $2 per test) and its results can be available after overnight incubation. The results show that neither all generics are reliable nor are all generic antibiotics of poor quality.

Antibacterial Effect of Shenju Lotion in Vitro / 医药导报

Objective To study the antibacterial effect of Shenju lotion in vitro. Methods The diameter of inhibition zone was determined by paper-disc agar-diffusion method. Minimum inhibitory concentration ( MIC) and Minimum bactericidal concentration ( MBC ) was determined by culture medium dilution methodand agar medium plate method, respectively. Antibacterial effect was compared between Shenju lotion and city sale of the gynecological lotion. Results Inhibitory effects of Shenju lotion on 5 pathogenic strains were significantly better than that of city sale of the gynecological lotion at the same concentrations (P<0. 05). MIC of Shenju lotion on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Candida albicans was 33. 75, 67. 5, 67. 5, 67. 5 and 33. 75 mg ·mL-1 , respectively. MBC of Shenju lotion on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis and Candida albicans was 33. 75, 67. 5, 67. 5, 135 and 33. 75 mg ·mL-1 , respectively. Conclusion Shenju lotion has obvious bacteriostasis and sterilization effect.

Antibacterial Activity of Phytoalexins from Infected Theobroma cacao L.

Aims: To study the antimicrobial activities of the compounds produced due to reactions of cocoa (Theobroma cacao) with Phytophthora palmivora during infection. Place and Duration of Study: Department of Microbiology, Ekiti State University, Ado Ekiti, Nigeria and the Department of Pharmacognosy, Obafemi Awolowo University, Ile-Ife, Nigeria between September, 2009 and July, 2011. Methodology: Phytophthora palmivora was used to infect healthy cocoa pods. The phytoalexins were extracted using solvent extraction and purified using standard methods. Agar diffusion and paper disc methods were used to study the antibacterial activities of the compounds extracted. Results: Two major compounds were subsequently isolated, purified and characterized as FC-3- B21 and FC-4-B22 using the 1HNMR and 13CNMR as well as the 2D cosy data. Compound FC-3-B21 was characterized as 7,8,9,-trihydroxy-2,8-dihydroxy naphtha-10-one while FC-4-B22 was characterized as ester of glycerol: Bacillus subtilis, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa and Staphylococcus aureus, were all sensitive to 7,8,9,-trihydroxy-2,8- dihydroxy naphtha-10-one even at 20 mg/ml. Pseudomonas aeruginosa showed the least sensitivity with 2.0 mm zone of inhibition at 20 mg/ml and 12 mm at 100 mg/ml while B. subtilis was the most sensitive with zone of inhibition of 4.0 mm at 20 mg/ml and 21.0 mm at 100 mg/ml. With FC-4-B22 (ester of glycerol) using paper disc method, P. aeruginosa was the most resistant with no zone of inhibition at 20 mg/ml. Meanwhile, S. aureus was the most sensitive with zone of inhibition of 3.0 mm at 20 mg/ml. However, B. subtilis exhibited a zone of 15.0 mm at 100 mg/ml. Using the agar diffusion method, 7,8,9,-trihydroxy-2,8-dihydroxy naphtha-10-one showed an appreciable effect on the tested pathogens. Pseudomonas aeruginosa was the least sensitive with the zone of inhibition of 3.0 mm at 20 mg/ml and 8.0 mm at 100 mg/ml while S. aureus was the most sensitive to the extract at 20 mg/ml with the zone of inhibition of 6.0 mm at 100 mg/ml. Bacillus subtilis was most sensitive to the extract at 100 mg/ml with the zone of inhibition of 19.0 mm. Testing the efficacy of ester of glycerol using agar diffusion method, P. aeruginosa showed the least resistance while B. subtilis was the most sensitive. Conclusion: From this study, it can be concluded that the two novel compounds exhibited differential antibacterial activities towards the test bacteria.

Comparação de métodos para avaliação da atividade antimicrobiana e determinação da concentração inibitória mínima (cim) de extratos vegetais aquosos e etanólicos / Comparison of methods for evaluation of antimicrobial activity and determination of minimum inhibitory concentration (mic) of aqueous and ethanol plant extracts

Vários estudos estão sendo conduzidos para a descoberta de novos agentes antimicrobianos provenientes de plantas, para que possam ser utilizados em produtos farmacêuticos, cosméticos e na indústria alimentícia. A ausência de padronização de métodos utilizados para a avaliação de extratos vegetais com potencial antimicrobiano dificulta a comparação de resultados. Considerando a necessidade de estabelecer um método com resultados consistentes para avaliar a atividade antimicrobiana dos extratos vegetais, este trabalho propôs-se a avaliar a atividade antimicrobiana e determinar a concentração mínima inibitória de extratos de plantas da família Myrtaceae sobre diferentes micro-organismos, utilizando três métodos para avaliação de antimicrobianos. Os métodos empregados foram microdiluição em caldo e difusão em ágar por disco e poço. Foram avaliados os extratos de Psidium guajava, Myrciaria cauliflora e Syzygium cumini sobre bactérias Gram-positivas, negativas e levedura. Em geral, a inibição promovida pelos extratos no teste de difusão em ágar por poço foi maior do que os valores obtidos por disco, independentemente do extrato vegetal testado. Contudo, a atividade inibitória de todos os micro-organismos só pôde ser determinada com o método de microdiluição em caldo, que também apresentou os resultados mais reprodutíveis, e mostrou-se o mais econômico e confiável para se avaliar a atividade antimicrobiana de extratos vegetais quando comparado aos outros métodos.(AU)

Several studies have been conducted to discover new antimicrobial agents from plants to be used in pharmaceuticals, cosmetics and in the food industry. The lack of standardized methods for the evaluation of plant extracts with antimicrobial potential complicates the comparison of results. Taking into consideration the need to establish a method with consistent results to evaluate the antimicrobial activity of plant extracts, this study aimed to evaluate the antimicrobial activity of extracts of some plants from the Myrtaceae family on different micro-organisms based on a comparative assay with three methods that are commonly used for the assess antimicrobials. The methods used were broth microdilution, and agar diffusion by disc and well. The evaluated extracts were those of Psidium guajava, Myrciaria cauliflora, and Syzygium cumini for Gram-positive and negative bacteria and yeast. In general, inhibition extracts promoted by the agar diffusion test by well was higher than the values ​​obtained by disc, regardless of the plant extracts tested. However, the inhibitory activity of all micro-organisms was only possible to be determined with the microdilution broth method, which also presented the more reproducible results, and proved to be the most economic and reliable way to evaluate the antimicrobial activity of plant extracts in contrast with other methods.(AU)

Antibacterial effect of self-etching adhesive systems on Streptococcus mutans

OBJECTIVES: In this study, we evaluated the antibacterial activity of self-etching adhesive systems against Streptococcus mutans using the agar diffusion method. MATERIALS AND METHODS: Three 2-step systems, Clearfil SE Bond (SE, Kuraray), Contax (CT, DMG), and Unifil Bond (UnB, GC), and three 1-step systems, Easy Bond (EB, 3M ESPE), U-Bond (UB, Vericom), and All Bond SE (AB, BISCO) were used. 0.12% chlorhexidine (CHX, Bukwang) and 37% phosphoric acid gel (PA, Vericom) were used as positive controls. RESULTS: The antibacterial activity of CHX and PA was stronger than that of the other groups, except SE. After light activation, the inhibition zone was reduced in the case of all 2-step systems except CT. However, all 1-step systems did not exhibit any inhibition zone upon the light activation. CONCLUSIONS: SE may be better than CT or UnB among the 2-step systems with respect to antibacterial activity, however, 1-step systems do not exhibit any antibacterial activity after light curing.

Antimicrobial activity and Characterization of Marine bacteria.

Marine bacteria were isolated from seawater was collected from different coastal areas of the Tamilnadu Sea. The antimicrobial activities of these bacteria were investigated. Ethyl acetate extracts of marine bacterial fermentation were screened for antimicrobial activities using the method of agar diffusion. The results showed that 25 strains of the isolates have antimicrobial activity. The proportion of active bacteria associated with isolated from seawater. The active marine bacteria were assigned to the genera Alteromonas, Pseudomonas, Bacillus and Marinobacter. The TLC autobiographic overlay assay implied that the antimicrobial metabolites produced by four strains with wide antimicrobial spectrum were different. These marine bacteria were expected to be potential resources of natural antibiotic products. It can be concluded that isolation of Marine bacterial samples can offer a numbers of microbial strains for sources of new biomolecules from Marine sources.

In Vitro Antimicrobial Activity of Acalypha Chengalpattensis. (Narasimhan) –A New Species.

The present study was designed to evaluate comparatively the antimicrobial potentiality of acetone, alcohol, chloroform, and ethyl acetate extract of stem and leaf of Acalypha chengalpattensis. (Narasimhan) using the agar diffusion method against five strains of bacterial species, namely, Bacillus substilis, Pseudomonas aeruginaosa, Vibrio cholerae, Shigella sinogei, Proteus vulgaricus, Salmonella typhi, Klebsiella pneumonia. Among the various extracts studied, the acetone stem extract showed highest antibacterial activity against B. Subtillis (2.75 ± 0.95 mm): following by methanol extract (2.5 ± 0.57 mm). The greatest inhibition zone was observed for acetone extract of Acalypha chengalpattensis leaf against Shigella sinogei (2.8 ± 0.83 mm). The alcohol stem extract showed significant antimicrobial activity against Pseudomonas aeruginosa. The chloroform stem extract of A. Chengalpattensis showed moderate activity against four pathogens. However, the stem extract exhibited higher inhibitory effect than the leaf extracts. This research suggests that these findings provide a support for the public to use the plant in traditional medicine for the society.

Comparación in vitro de la actividad antimicrobiana de AhPlus, RSA y Ledermix contra Enterococcus faecalis / In vitro comparison of anti-microbial activity of AH Plus, RSA and Ledermix against Enterococcus faecalis

Objetivo: Evaluar in vitro la actividad antimicrobiana de dos selladores endodónticos RSA, AH Plus y de la pasta LedermixN sobre Enterococcus faecalis con tres diferentes técnicas. Método: Prueba de contacto directo. En una superficie de acrílico se colocó el sellador y se inoculó una suspensión de E. faecalis, se dejó en un microtubo con 1mL de caldo BHI, se realizaron diluciones logarítmicas sembrándose en placas de agar sangre para cuantificar las unidades formadoras de colonia. Prueba de dilución. Los selladores y la pasta se colocaron en un cilindro de plástico, la bacteria se inoculó en el caldo de cultivo y se realizó el mismo procedimiento de cuantificación. Prueba de dilución en agar. Se realizaron tres pozos en una placa de agar sangre y se rellenaron con los dos cementos, la pasta de LedermixN se inoculó una suspensión de E. faecalis en la superficie, para evaluar zonas de inhibición de crecimiento. Resultados: La pasta de Lesdermix N tuvo mayor porcentaje de actividad antimicrobiana en la prueba de contacto directo. Ningún cemento ni la pasta presentó actividad antimicrobiana en la prueba de dilución y en la prueba de dilución en agar; en ésta el sellador AH plus y la pasta LedermixN presentaron un halo de hemólisis en las placas de agar sangre. Conclusiones: La técnica de contacto directo es la más adecuada para evaluar el efecto antimicrobiano de los cementos.

Aim: In vitro assessment of antimicrobial activity sustained by two root canal sealers: RSA®, AH Plus® as well as LedermixN® paste upon Enterococcus faecalis using three different techniques. Method: Direct contact test (DCT). Sealers were placed on an acrylic surface. A E. faecalis suspension was inoculated and left in a microtube with 1 mL of BHI broth. Logarithmic dilutions were conducted spreading them in blood agar plates so as to quantify CFU's (colony forming units). Dilution test (DT). Sealers and paste were placed in a plastic cylinder. Bacteriae were inoculated in the culture broth and the same quantification procedure was undertaken. Agar dilution test (ADT). On a blood agar plate three wells were manufactured: they were filled with both cements. On the LedermixN paste surface a E. faecalis suspension was inoculated so as to assess growth inhibition areas. Results: In the Direct contact test, LedermixN paste showed higher antimicrobial activity percentage. Neither of both cements nor the paste presented antimicrobial activity in dilution and Agar dilution test. In the Agar dilution test, AH Plus sealer and LedermixN paste exhibited a hemolysis halo in the blood agar plates. Conclusions: Direct contact test technique was considered the most appropriate to assess antimicrobial effects of cements.

Clonagem e análise da expressão de genes de proteínas de mamão papaia com atividade inibitória sobre poligalacturonases fúngicas / Cloning and expression analysis of papaya genes encoding proteins with inhibitory activity against fungal polygalacturonases

As proteínas inibidoras de poligalacturonases (PGIPs) presentes na parede celular são capazes de limitar o potencial destrutivo da poligalacturonase (PG) fúngica e, assim, constituem um tipo importante dentre os diversos sistemas de defesa do tecido vegetal frente à infecção fúngica. No mamão, o ataque fitopatogênico é o principal causador de danos pós-colheita, e sua alta susceptibilidade pode estar relacionada com a baixa eficácia ou pouca abundância dos meios de defesa anti-fitopatogênica. Uma vez que isso pode estar relacionado com as PGIPs e nada se conhece sobre o papel dessas proteínas nesse fruto, o objetivo do trabalho foi clonar os genes das PGIPs de mamoeiro e definir seu padrão de expressão em diferentes órgãos e tecidos e ao longo do amadurecimento. Para tanto, foram identificadas no genoma do mamoeiro, a partir de critérios que definem a identidade de uma PGIP, duas prováveis sequências dentre 13 candidatas iniciais. Ambas foram clonadas a partir das sequências genômicas e de cDNA, sequenciadas e sua identidade confirmada, sendo denominadas Cppgip4 e Cppgip6. As análises de expressão relativa em diversos tecidos e idades fisiológicas do mamoeiro demonstraram que os dois genes apresentaram diminuição da expressão com o desenvolvimento dos frutos, sendo que com a polpa apresentou redução dos níveis de expressão relativa de Cppgip4 em até 18 vezes dos 30 dias pós-antese (DPA) ao 9 dias pós-colheita (DPC). Na casca também houve redução significativa da expressão com o desenvolvimento. Para a expressão absoluta, nos frutos, sementes, caules, raízes e folhas, o número de cópias de ambos os transcritos decresceu com o desenvolvimento, sendo cerca de cem mil vezes mais abundante para Cppgip6 que para Cppgip4. As tentativas de expressão de proteínas recombinantes em Pichia pastoris não geraram resultado positivo, provavelmente em virtude das condições ideais de indução ainda não terem sido estabelecidas corretamente para o ensaio. A atividade de PGIPs extraídas diretamente do tecido foi medida por análise de difusão em ágar empregando pectinase de Aspergillus niger e revelou uma tendência à diminuição da porcentagem de inibição à medida que os frutos se desenvolveram, em concordância com os resultados da análise por qPCR. O conjunto de resultados sugere que a expressão varia com o estádio de desenvolvimento do fruto e é tecido-específica, possivelmente em resposta à diferente susceptibilidade dos tecidos ao ataque fitopatogênico, indicando que menores níveis de transcritos e atividade no amadurecimento, período de maior susceptibilidade, poderiam sinalizar para a regulação do processo degradativo marcando o início da senescência

Polygalacturonase inhibiting proteins (PGIPs) present in plant cell walls are able to inhibit the destructive action of fungal polygalacturonase (PG). In this way, they constitute an important type of plant defense system against fungal infections. In papaya fruit, the pathogenic attack is the main cause of post harvesting loss, and its high susceptibility may be related to the low efficiency or low abundance of anti-phytopathogenic defense. Since this fact could be related to PGIPs expression and little is known about the response of these proteins in the fruit, the aim of the present work was to clone the genes of PGIPs papaya fruit and set their expression pattern in different organs and tissues throughout fruit ripening. Thus, two probable PGIP sequences among 13 initial candidates were identified in the papaya genome by using specific criteria. Both sequences were cloned from cDNA and genomic samples, sequenced and confirmed its identity, and then being named Cppgip4 and Cppgip6. Analysis of relative expression in various tissues at different physiological stages demonstrated that both genes were down regulated during fruit development. The relative expression levels of Cppgip4 in papaya pulp was reduced by 18 times from the 30 days post-anthesis (DPA) to the 9 days post-harvest (DPH). Similarly, gene expression in papaya peel was significant down regulated during fruit development. Absolute expression analysis revealed gene expressions in the fruit pulp, seed, stem, root and leaf were also down regulated within development. Moreover, Cppgip6 gene expression was a hundred thousand times more abundant than Cppgip4. The recombinant protein expression in Pichia pastoris did not result positive, probably because of the ideal conditions of induction have not been properly established the yet. The activity of PGIPs extracted directly from the tissue was measured by the agar diffusion assay using pectinase from Aspergillus niger and showed decrease of inhibition during fruit developed in accordance with the results of the qPCR analysis. Based on the results it is possible to suggest the expression of these genes varies temporally with the developmental stage of the fruit and is tissue-specific, possibly in response to the different susceptibility of tissues to pathogenic attack. In addition, the lowest levels of PGIP expression were achieved at the fruit ripening, when the susceptibility to fungal infection is high and could signal for regulating the degradation process characterized by the onset of senescence

Basic biological characteristics of three fungi inducing the formation of Agilawood from Aquilaria sinensis / 中国药学杂志

OBJECTIVE: To study the basic characteristics of three bioactive fungi, the interrelationship of three fungi and the relationship between three fungi and their host, thus to provide data for the theoretical research and the application practice. METHODS: The colonial morphology and microscopic characteristics were studied by light microscopy, and the relationships were studied by agar diffusion method. RESULTS: The basic characteristics of three bioactive fungi were obtained, and the relationships under in vitro conditions were clarified. CONCLUSION: The results of this study will be of great value to the studies and use of the fungi, and it will provide important data for research on the mechanism of fungi inducing Aquilaria sinensis to produce Agilawood.

Development and validation of a microbiological assay for determination of chlorhexidine digluconate in aqueous solution

Chlorhexidine (CHX) is a broad-spectrum antiseptic that is used in many topical pharmaceutical formulations. Because there is no official microbiological assay reported in the literature that is used to quantify CHX, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method for the dosage of chlorhexidine digluconate (CHX-D) in an aqueous solution. The assay is based on the inhibitory effect of CHX-D upon the strain of Staphylococcus aureus ATCC 25923, which is used as the test microorganism. The design 3x3 parallel-line model was used. The results were treated statistically by analysis of variance (ANOVA), and they were excellent in terms of linearity (r = 0.9999), presenting a significant regression between the zone diameter of growth inhibition and the logarithm of the concentration within the range of 0.5 to 4.5%. The results obtained were precise, having relative standard deviations (RSD) for intra-day and inter-day precision of 2.03% and 2.94%, respectively. The accuracy was 99.03%. The method proved to be very useful and appropriate for the microbiological dosage of CHX-D in pharmaceutical formulations; it might also be used for routine drug analysis during quality control in pharmaceutical industries.

Clorexidina (CHX) é um antisséptico com amplo espectro de ação utilizada em muitos tipos de preparações farmacêuticas para uso tópico. Uma vez que não há na literatura ensaio microbiológico oficial para quantificar a clorexidina, este trabalho objetivou o desenvolvimento e validação de um ensaio microbiológico simples, sensível, exato e reprodutível, por difusão em ágar, para doseamento de digliconato de clorexidina (CHX-D) em solução aquosa. O ensaio é baseado no efeito da inibição de Staphylococcus aureus ATCC 25923, utilizado como microorganismo teste, pela CHX-D. Utilizou-se o delineamento 3x3. Os resultados foram verificados estatisticamente pela análise de variância (ANOVA) e apresentaram excelente linearidade (r = 0,9999), demonstrando que o método segue o modelo linear com regressão significativa entre o diâmetro da zona de inibição e o lagaritmo da concentração no intervalo de 0,5 a 4,5%. Os resultados obtidos foram precisos apresentando desvio padrão relativo (DPR) para precisão intra-dia de 2,03% e DPR para precisão inter-dias de 2,94%. A exatidão foi 99,03%. O método provou ser muito útil e apropriado para doseamento microbiológico da CHX-D em formas farmacêuticas e pode ser empregado para análise desta substância no controle de qualidade em indústrias farmacêuticas.

In vitro antimicrobial activity of AH Plus, EndoREZ and Epiphany against microorganisms.

Objective : The aim of the present study was to evaluate the antimicrobial activity of endodontic sealers against microorganisms. Materials and Methods : The agar diffusion method was used. A double base layer of Mueller Hinton agar was done. The microorganisms used were: Candida albicans, Enterococcus faecalis, Escherichia coli and Staphylococcus aureus. The wells were obtained by removing a standardized portion of the agar. After the distribution of the sealers, Petri plates were incubated for 24 h. Inhibition halos formed around the wells were measured. Results : Epiphany did not show any antimicrobial activity on the tested microorganisms (without inhibition halo). The AH Plus showed the greatest inhibition halo on C. albicans followed by EndoREZ on S. aureus. EndoREZ also showed greater inhibition halo in comparison to AH Plus on E. faecalis and E. coli. Conclusion : It could be concluded that AH Plus and EndoREZ showed antimicrobial activity against all the tested microorganisms. No antimicrobial activity was observed for Epiphany.

Synthesis and antimicrobial study of N-[4-(2-piperidine-1-yl-ethoxy) phenyl] acetamide analogues.

In the present study, a novel series of N-[4-(2-piperidine-1-yl-ethoxy) phenyl]- acetamides were synthesized from 4-aminophenol and characterised by IR, 1H-NMR, Mass spectral studies and elemental analysis. The antimicrobial potency of compounds is tested against variety of fungal and bacterial strains by disc agar diffusion technique. in comparison to to fluconazole and chloramphenicol respectively. Some of the synthesized compounds exhibit the potency comparable to that of standard drugs.

Antibacterial activity of psidium guajava l. methanol leaf extract against plant pathogenic bacteria in the genera pectobacterium and xanthomonas.

The antibacterial activity of methanol leaf extract of Psidium guajava L. was performed on six plant pathogenic bacteria, namely Xanthomonas citri, Xanthomonas euvesicatoria, Xanthomonas oryzae, Xanthomonas oryzicola, Pectobacterium carotovorum and Pectobacterium chrysanthemi by cup-plate agar diffusion method. Different concentrations gave different range of means diameter inhibition zones where at concentrations o f 25, 50, 100 and 200 mg/ml, the range was 10.00±0.00 mm to 15.00±0.00 mm, 12.00±0.00 mm to 17.00±0.00 mm, 15.00±0.00 mm to 20.00±0.00 mm and 16.00±0.00 mm to 25.00±0.00 mm, respectively. X. oryzae gave the highest mean diameter inhibition zone when tested with all concentrations compared to the mean diameter inhibition zones of other plant pathogenic bacteria. The minimal inhibitory concentration (MIC) of the methanol extracts was performed by macrobroth dilution technique and the lowest concentration used that was still able to inhibit the bacterial growth was 0.391 mg/ml for X. oryzae.

Development of agar diffusion method for dosage of gramicidin / Desenvolvimento do método de difusão em agar para dosagem de gramicidina

Gramicidin, an antimicrobial peptide active against Gram positive bacteria, is commonly used in pharmaceutical preparations for topical use. Considering that only the turbidimetric method has been described in the literature, the present study sought to develop and validate an agar diffusion method for the dosage of gramicidin. The method was developed and validated using the Kocuria rhizophila ATCC 9341 as a test microorganism. Two designs were used: a 3x3 parallel-line model, and a 5x1 standard curve. The validation demonstrated that the method follows the linear model (r²= 0.994), presenting a significant regression between the zone diameter of growth inhibition and the logarithm of the concentration within the range of 5 to 25.3 µg/mL. The results obtained for both designs were precise, having a relative standard deviation (R.S.D.) for intra-day precision of 0.81 for the 3x3 assay and 1.90 for the 5x1 assay. For the inter-day precision, the R.S.D. was 1.35 for the 3x3 and 2.64 for the 5x1. The accuracy was verified and results confirmed to be accurate, having a tolerance interval of 95 percent, which lay within permitted limits and appropriate trueness. In addition, the method was considered selective, with limit of detection and upper and lower limits of quantification of 2.00, 5.00 and 25.3 µg/mL, respectively. No difference in precision between the designs used in the agar diffusion method was evident (p>0.05). The method proved to be appropriate for the microbiological dosage of the raw material gramicidin.

A gramicidina, um peptídeo antimicrobiano ativo contra bactérias Gram positivo, é utilizada em preparações farmacêuticas de uso tópico. Neste trabalho procurou-se desenvolver e validar outro método para o doseamento de gramicidina tendo em vista que somente o método turbidimétrico é descrito. O método de difusão em ágar foi desenvolvido e validado utilizando como microrganismo teste Kocuria rhizophila ATCC 9341. Foram utilizados dois delineamentos: retas paralelas 3x3 e curva padrão 5x1. A validação demonstrou que o método segue o modelo linear (r²= 0,994) havendo regressão significativa entre o diâmetro dos halos de inibição e o logaritmo da concentração na faixa de 5,00 a 25,3 µg/mL. Os resultados obtidos por ambos os delineamentos foram precisos apresentando desvio padrão relativo (DPR) para precisão intra-dia de 0,81 para ensaio 3x3 e de 1,90 para ensaio 5x1. Para a precisão inter-dias o DPR foi de 1,35 para 3x3 e de 2,64 para 5x1. A exatidão foi verificada e os resultados foram exatos apresentando intervalo de tolerância a 95 por cento dentro dos limites permitidos e veracidade adequada. O método foi seletivo com limites de detecção e quantificação inferior e superior iguais a 2,00, 5,00 e 25,3 µg/mL, respectivamente. Não foi observada diferença entre a precisão dos delineamentos empregados no método de difusão em ágar (p>0.05). O método se mostrou adequado para a dosagem microbiológica de gramicidina matéria-prima.

Validación de la técnica para la cuantificación de tilosina en un producto sólido / Validation of technique for the quantification of tylosin in a solid product

Se validó la técnica para la cuantificación de tilosina en polvo, para lo cual previamente se estandarizó la técnica recomendada por la United States Pharmacopeia versión 30 del 2007, con el fin de ajustarse y dar cumplimiento a la normativa internacional. La muestra se compuso del 10 por ciento de tilosina fosfato y 90 por ciento de Carrier 40-60. El microorganismo sometido a prueba fue Micrococcus luteus ATCC 9341 y se empleó el método de difusión en agar. Los resultados de las pruebas se sometieron al programa de validación microbiológica "Validation Manager". El método de difusión en agar cumplió con los valores esperados, y así quedó validada la técnica.

The quantification technique of powdered tylosin was validated. To this end, the technique recommended by the United States Pharmacopeia, 30th version, 2007 was standardized to adapt it to and to comply with the international regulations. The sample was composed of 10 percent tylosin phosphate and 90 percent Carrier 40-60. The agar diffusion was used to test the micro-organism Micrococcus luteus ATCC 9341 and all results were microbiologically validated by the program "Validation Manager". The agar diffusion method met the prospective values, thus validating the technique.

Validación del método analítico para la cuantificación de bacitracina / Validation of the analytical method to quantify the bacitracine

Se desarrolló y validó un método analítico para la determinación cuantitativa de bacitracina zinc al 15 por ciento y bacitracina metilen disalicilato al 11 por ciento, por el método de cilindro en placa (difusión en agar), con el fin de ser usado en el control de calidad de las materias primas y productos farmacéuticos. Se evaluaron los parámetros de especificidad, selectividad, linealidad del sistema, y del método, exactitud, límite de cuantificación y precisión. Mediante el diseño experimental y la evaluación estadística de los resultados, se demostró que el método analítico es específico, selectivo, lineal, preciso (CV< 5 por ciento) y exacto (sesgo< 3 por ciento, Gexp< Gtab y t exp< t tab) en el intervalo de las concentraciones estudiadas. El límite de cuantificación y de detección fue de 0,02 y 0,005 UI/mL respectivamente. Las características de desempeño analítico cumplen con los requisitos para la aplicación analítica propuesta.

An analytical method was developed and validated for quantitative determination of 15 percent zinc bacitracine and 11 percent disalicylate methylene-bacitracine by the plate-cylinder method (agar diffusion) to be used in quality control of raw products and pharmaceutical products. Specificity, selectivity, system and method linearity, accuracy, quantification and precision parameters were assessed. By the experimental design and the statistic evaluation of results, it was demonstrated that the analytical method is specific, selective, linear, precise (CV< 5 percent) and exact (bias < 3 percent, Gexp< Gtab< t exp< t tab) during the study concentrations. The quantification and detection limit was of 0.02 and 0.005 Ul/mL, respectively. The analytical performance characteristics fulfill the requirement for the proposal analytical implementation.