Antagonist activities and phylogenetic relationships of actinomycetes isolated from an Artemisia habitat / Actividades antagónicas y relaciones filogenéticas de actinomicetos aislados de un hábitat de Artemisia

Abstract Diverse habitats have been screened for novel antimicrobial actinomycetes, while others remain unexplored. In this study, we analyzed the bioactivities of actinomycetes cul-tured from rhizosphere soils of the desert plant Artemisia tridentata and the nearby bulk soils. Actinomycetes were screened for antifungal and antibacterial activities toward a panel of plant pathogens; all comparisons were between activities of rhizosphere soil isolates toward those of its counterpart bulk soil. A selected group of the strongest antifungal isolates were also tested against two antifungal-drug resistant strains of Candida albicans. 16S rDNA partial sequences and phylogenetic analysis of isolates that showed broad-spectrum antifungal activities were performed. Forty-two out of 200 and two soil isolated actinomycetes were selected for their strong antifungal activities. The highest proportion of isolates (p <0.05) from rhizosphere soil of an old plant showed antagonism against gram-positive bacteria (0.483 and 0.224 propor-tions against Bacillus subtilis and Rathayibacter tritici, respectively), and phytopathogenic fungi (0.259, 0.431, and 0.345 proportions against Fusarium oxysporum, Rhizoctonia solani and Pythium ultimum, respectively), while the highest antagonism against the gram-negative bacteria predominated in isolates from the bulk soils. Isolates from a rhizosphere soil of a young plant were characterized for strong antagonist activities against Fusarium oxysporum (0.333 proportion, p<0.05). Phylogenetic analysis of 16S rDNA sequences showed that isolates that exhibited strong antifungal activity were genetically similar. We conclude that the rhizosphere soil of A. tridentata is an excellent source for discovery of actinomycetes with potentially novel antifungal compounds.

Resumen En la búsqueda de actinomicetos antimicrobianos se han estudiado diversos hábitats, pero muchos permanecen aún sin explorar. En este estudio analizamos las actividades biológicas de cultivos de actinomicetos provenientes de suelos rizosféricos de la planta desértica Artemisia tridentata y de suelos no asociados a sus raíces. Los actinomicetos fueron seleccionados por sus actividades antifúngicas y antibacterianas contra un panel de patógenos de plantas. Todas las comparaciones fueron entre las actividades de los aislados rizosféricos y aquellas de los aislados no asociados a las raíces. Un grupo selecto de los aislados con las mayores actividades antifúngicas fueron también evaluados contra 2 cepas de Candida albicans resistentes a antifúngicos. Se realizó la secuenciación parcial del ARNr 16S y el análisis filogenético de los aislados que mostraron actividades antifúngicas de amplio espectro. Se seleccionaron 42 de 202 actinomicetos aislados por sus fuertes actividades antifúngicas. La mayor proporción de aislados de suelo rizosférico de plantas viejas mostraron antagonismo contra bacterias gram positivas y hongos fitopatógenos (proporciones de 0,259; 0,431 y 0,345 contra Fusarium oxyspo-rum, Rhizoctonia solani y Pythium ultimum, respectivamente), mientras que la mayor actividad antagónica contra las bacterias gram negativas predominaron en aislados de suelo no asociado a raíces. Los aislados de suelo rizosférico de plantas jóvenes se caracterizaron por una fuerte actividad antagónica contra F. oxysporum (proporción de 0,333, p < 0,05). El análisis filogenético de secuencias del ADNr 16S mostró que los aislados que presentaron fuerte actividad antifúng-ica fueron genéticamente similares. Concluimos que el suelo rizosférico de A. tridentata es una fuente excelente para el descubrimiento de actinomicetos productores de compuestos antifúngicos potencialmente novedosos.

Production and Investigation of the Antiseptic Properties of Soaps Made from the Barks, Seeds and Leaves Extracts of Neem Tree

The main aim of this work is to investigate the antiseptic properties of Azadirachta indica (Neem) tree parts (leaves, barks and seeds). The extracts were used in the production of soap samples of various concentrations (20 mg/cm3, 15 mg/cm3, 10 mg/cm3 and 5 mg/cm3). Inhibitory Activity sensitivity test using Agar-well Diffusion Method was employed to test the antibacterial activities of the soap samples on two bacteria, Staphylococcus aureus bacteria and Propionibacterium acnes. The results show that soap samples from the Neem parts exhibited antiseptic properties against the bacteria tested. According to the results, the Neem bark soap produces the highest level of effectiveness across the entire concentration spectrum, followed by the Neem seed soap. The Neem leaves soap produced the lowest level of effectiveness against the two bacteria. The order of effectiveness of the soap samples is: NBRK (Neem barks) > NSED (Neem seeds) > NLVS (Neem leaves). The commercial soap (NRMS) used as a control sample did not exhibit antibacterial activity against the two microbes.

Antimicrobial evaluation and molecular properties prediction of pyrazolines incorporating benzofuran and pyrazole moieties

A series of chalcones 3–5, 1H-pyrazolines 6–8, N-phenylpyrazolines 9–11, and N-acetylpyrazolines 12–14incorporating benzofuran and pyrazole moieties were synthesized and screened for their in vitro antimicrobial activityagainst some of pathogenic microorganisms. Among the screened compounds, 7 and 13 showed the most promisingantibacterial activity against Escherichia coli (G-). Compound 11 displayed broad spectrum antibacterial activityagainst Bacillus subtilis (G+). Moreover, compounds 10 and 4 were found to be the most potent antifungal agentagainst Candida albicans and Aspergillus niger, respectively. Also, the molecular properties prediction and druglikeness model score (DLS) of all the synthesized compounds were calculated by SwissADME and MolSoft websites,respectively. The two compounds 7 and 13 were found to be maximum DLS of 0.75 and 0.83, respectively.

Chemical constituents from stems and leaves of Aphanamixis sinensis and their antibacterial activities / 中草药

Objective: To study the chemical constituents of stems and leaves from Aphanamixis sinensis and evaluate their antibacterial activities. Methods: The compounds were isolated and purified by various column chromatography techniques, such as silica gel, ODS, Sephadex LH-20, and MCI, and their structures were identified by physiochemical properties and spectroscopic data. Moreover, antimicrobial activities against Staphylococcus aureus ATCC 25923, Escherichia coli CICC 10003, and Salmonella enterica UK-1 8956 of compounds 1-13 were evaluated by filter paper method. Results: Fifteen compounds were isolated from A. polystachya which were elucidated as (23E)-25-methoxycycloart-23-en-3β-ol (1), 25-hydroxy-cycloart-23-en-3-one (2), 23 (Z)-9,19-cycloart-23-ene-3β,25-diol (3), 23 (E)-cycloart-23-en-3β,25-diol (4), ent-labd-8 (17), 13E-dien-15-ol (5), vulgaro (6), ambroxdiok (7), α-cadinol (8), 1 (10)-en-oxo-7α-isopropanoleremophilane (9), (5R,7R,10S)-isopterocarpolone (10), 1S,4S,5S,10R- 4,10-guaianediol (11), (4R,5R,7S,9S,10S)-(-)-eudesma-11 (13)-en-4,9-diol (12), phytol (13), ergosterol endoperoxide (14) and 7α-hydroxysitosterol (15). Conclusion: All isolates were obtained from this plant for the first time, and compounds 2, 5, 7-10, and 12-15 were isolated from the genus Aphanamixis for the first time. Compound 5 showed obvious activity against S. aureus ATCC 25923 with the MIC value of 5 μg/mL.

Effect of ethyl acetate crude extract of Lasiodiplodia pseudotheobromae IBRL OS-64 against oral cavity bacteria with emphasis on Streptococcus mutans

Streptococcus mutans and Streptococcus agalactiae have been reported in human oral diseases including cariesand periodontitis. Thus, the present study was performed to investigate the effect of ethyl acetate crude extract ofLasiodiplodia pseudotheobromae IBRL OS-64, an endophytic fungus isolated from Ocimum sanctum leaf againstS. mutans and S. agalactiae. Disk diffusion and broth microdilution assays were used to determine the antimicrobialactivities with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values.Meanwhile, the microscopic analysis was used to study the structural degeneration of bacterial cells. The fungal crudeextracts demonstrated favorable antibacterial activity toward both test bacteria and produced an inhibition zone rangingfrom 16.0 to 21.2 mm. The MIC and MBC values of the fungal crude extract toward S. mutans and S. agalactiae weredetermined and the results showed that the MIC and MBC values were in the range of 125–500 µg/ml and 125–1,000µg/ml, respectively. The time-kill study suggested that the ethyl acetate crude extract possessed bactericidal effectwith concentration and time-dependent. Structural degeneration studies revealed the major abnormalities occurredto S. mutans cells after treated with the fungal crude extract where completed alterations of their morphology withthe formation of cavities and collapsed cells beyond repair occurred. Therefore, the current study suggested the ethylacetate crude extract of L. pseudotheobromae IBRL OS-64 could be an effective antibacterial agent to treat oral cavitybacteria.

Pseudomonas Aeruginosa: Virulence Factors and Antibiotic Resistance Genes

Abstract In this review, we explore some aspects of Pseudomonas aeruginosa virulence factors that are related to disease development in healthy organisms and resistance to antibiotics. This pathogen is one of the most clinically and epidemiologically important bacteria in Brazil, being the major cause of opportunistic infections. Among the virulence factors, biofilm formation acting of manner different in the organism. Furthermore, we review several P. aeruginosa genes that act in antimicrobial resistance, such as β-lactamases against β-lactamers. The resistance to pied-lactamases in P. aeruginosa is associated to resistance to the broad-spectrum cephalosporin. On the other hand, there is a group of synthetic broad-spectrum antibiotics acting on DNA synthesis is the quinolones that destroy the microorganism. We also explore the occurence of super bacterium: P. aerufinosa carrying genes blaKPC and blaNDM, which are associated with patient death above the average of other bacterial infections in hospitals. Those genes encode carbapenemases that can potentially hydrolyse all β-lactam antibiotics

Assessment of Secondary Metabolites and Antimicrobial activities of four solvent extracts of Vernonia amygdalina leaves on some selected Pathogenic Microorganisms

@#Acetone, Hexane, Ethylacetate and Acetone / Hexane / Ethylacetate (50/30/20 v/v/v) extracts of Vernonia amygdalina leaves (Del, belonging to the family Asteraceae) were investigated for antimicrobial activities. Three different concentrations (100 mg/mL, 50 mg/mL and 25 mg/mL) of each extract were used against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25920 and Candida albicans. The disc diffusion method was used. Phytochemical screening and High Performance Liquid Chromatography (HPLC) analysis of constituents of the extracts were also carried out. Highest yield (14.25 %) after extraction was obtained for acetone extract followed by hexane extract (8.2 %), Acetone/Hexane/Ethylacetate extract (7.4 %) and ethylacetate (7.1 %) extract. Tannin, steroids, saponin, terpenoid, flavonoid, anthraquinones were present in each of the solvent extracts. Coumarin was present in both acetone and Acetone/Hexane/Ethylacetate extracts while glycosides were present only in the Acetone/Hexane/Ethylacetate extract. Protein was present in ethylacetate extract and absent in the other solvent extracts. The extracts revealed dose-dependent activities against all the test organisms. Highest range of inhibition zone (15.00 mm- 18.00 mm) was obtained for Acetone/Hexane/Ethylacetate extract at 25 mg/mL against the test organisms while lowest range of inhibition zone (7.00 mm- 10.00 mm) was obtained for acetone extract at 100 mg/mL. Various compounds (Oxalate, Phyrate, Epivernodalol, Vernodalol, Venonioside A, Vernonioside B, Vernodalin, Luteolin, Andrographolide, Andrographoside) were separated at different peak heights (mV) and at varying retention times from all the solvent extracts. The solvent extracts of Vernonia amygdalina can serve as good alternative to orthodox medicine in the treatment of infections associated with the three test organisms.

Antibacterial, anti fungal and E. coli DNA cleavage of Euphorbia prostrata and Pelargonium graveolens extract and their combination with novel nanoparticles

As there are a lot of antibacterial and anti-fungal resistant pathogens, researchers attempt to substitute antimicrobial drugs with various medical plants and novel nanoparticles. The present study was conducted to characterize antimicrobial activities of Euphorbia prostrata and Pelargonium graveolens extract alone and in combination with Mn-Ni@Fe3O4-NPs & Mn: Fe (OH)3-NPs on the DNA cleavage of E. coli and also Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Aspergillus oryzae, and Candida albicans. The effects of antimicrobial activities on above scenarios were evaluated using disc diffusion, MIC, MBC, and E. coli DNA electrophoresis methods. The results showed that the effects of antibacterial assay values of Euphorbia prostrata & Mn: Fe(OH)3 was 21.00 mm for E. coli and while it was 19.5 mm for Euphorbia prostrata & Mn-Ni@Fe3O4 against Pseudomonas aeruginosa at a concentration of 100mg/mL. The highest level of DNA cleavage was seen in mixed of Euphorbia prostrata & Mn: Fe(OH)3 nanoparticles. In conclusion, the combination of Euphorbia prostrata and Pelargonium graveolens extracts with nanostructures showed synergic effects on eliminating the bacteria via DNA destruction and others mechanisms. Moreover, the synergistic effect of nanoparticles with plant extracts seems to bring about new choices for the treatment of infectious diseases

Novel sesquiterpenoids isolated from Chimonanthus praecox and their antibacterial activities / 中国天然药物

In the present study, four new sesquiterpenoids, chimonols A-D (compounds 1-4), together with four known compounds (5-8) were isolated from the EtOAc extract of Chimonanthus praecox Link. The structures of these new compounds were elucidated on the basis of spectroscopic techniques (UV, IR, MS, and 1D and 2D NMR), and their absolute configurations were established by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1-8 were evaluated for antimicrobial activities and the minimum inhibitory concentrations (MICs) were determined by the broth microdilution method in 96-well culture plates. Compounds 1, 2, and 7 exhibited weak antibacterial effects for S. aureus (ATCC 6538), E. coli (ATCC 11775), and P. aeruginosa (ATCC 10145) with MIC values being 158-249 µg·mL. Compounds 3-7 showed activities against C. glabrata (ATCC 2001) and S. aureus (ATCC 43300) with MIC values being 128-197 µg·mL. Compounds 1-4 showed activity against S. aureus (ATCC 25923) with MIC values being 162-254 µg·mL. The present study provided a basis for future evaluation of these compounds as antibacterial agents.

Novel sesquiterpenoids isolated from Chimonanthus praecox and their antibacterial activities / 中国天然药物

In the present study, four new sesquiterpenoids, chimonols A-D (compounds 1-4), together with four known compounds (5-8) were isolated from the EtOAc extract of Chimonanthus praecox Link. The structures of these new compounds were elucidated on the basis of spectroscopic techniques (UV, IR, MS, and 1D and 2D NMR), and their absolute configurations were established by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1-8 were evaluated for antimicrobial activities and the minimum inhibitory concentrations (MICs) were determined by the broth microdilution method in 96-well culture plates. Compounds 1, 2, and 7 exhibited weak antibacterial effects for S. aureus (ATCC 6538), E. coli (ATCC 11775), and P. aeruginosa (ATCC 10145) with MIC values being 158-249 µg·mL. Compounds 3-7 showed activities against C. glabrata (ATCC 2001) and S. aureus (ATCC 43300) with MIC values being 128-197 µg·mL. Compounds 1-4 showed activity against S. aureus (ATCC 25923) with MIC values being 162-254 µg·mL. The present study provided a basis for future evaluation of these compounds as antibacterial agents.

Chemical constituents of Euodia rutaecarpa var. officinalis and their antifungal activities / 中草药

Objective: To study the chemical constituents from the fruits of Evodia rutaecarpa var. officinalis. Methods: The constituents were isolated and purified by chromatographic methods. The structures were elucidated by physicochemical properties and spectroscopic methods. The antifungal activities were tested with mycelium growth method. Results: Fifteen compounds were obtained from the 70% ethanol extract of E. rutaecarpa var. officinalis, and were identified as evodiamine (1), rutaecarpine (2), dehydroevodiamine (3), dihydroevocarpine (4), evocarpine (5), 1-methyl-2-undecyl-4 (1H)-quinolone (6), 1-methyl-2-[(4Z,7Z)- 4,7-tridecadienyl]-4 (1H)-quinolone (7), 1-methyl-2-[(6Z,9Z)-6,9-pentadecadienyl-4 (1H)-quinolone (8), limonin (9), shihulimonin A (10), isolimonexic acid (11), wuzhuyurutine B (12), stigmasterol (13), β-sitosterol (14), and β-daucosterin. (15). Conclusion: Compounds 5-8 and 11-13 are isolated from E. rutaecarpa var. officinalis for the first time. Different types of compounds show diverse antimicrobial activities against plant-pathogenic fungi.

Evaluation of antimicrobial activities of Bacillus megaterium with a third-generation cephalosporin (ceftriaxone).

Bacillus megaterium T04 isolated from Rach Lang stream in Vietnam was tested for antimicrobial activities. The antimicrobial activities of Bacillus megaterium T04 (57.3x108 cfu/mL) against Candida albicans, Salmonella typhi, Pseudomonas aeruginosa, Staphylococcus sciuri, Micrococcus luteus were detected by agar well diffusion method in different cultivation conditions at three temperatures (25, 37, and 45oC) in three incubation periods (24, 48, and 72 hours). The efficacy of antimicrobial activities of this strain were determined in comparison with ceftriaxone activity against Candida albicans, Salmonella typhi, Pseudomonas aeruginosa, Staphylococcus scuiri, Micrococcus luteus. The antimicrobial activity potency was equivalent to ceftriaxone in a range ( 3.3 0.6 μg/mL to 46.5 6.2 μg/mL) for Candida albicans (0.9 0.2 μg/mL to 35.5 7.7 μg/mL) for Salmonella typhi, , (0.4 0.1 μg/mL to 28.4 4.4 μg/mL) for Pseudomonas aeruginosa, (119.8 21.2 μg/mL to 283.7 26.0 μg/mL) for Staphylococcus scuiri, (3.3 0.4 μg/mL to 64.4 7.4 μg/mL) for Micrococcus luteus.

Chemical composition and antimicrobial activities of leaves of sweet basil (Ocimum basilicum L.) herb.

Background: Leaves and flowering parts of Ocimum basilicum are believed to be rich of different phytochemicals and are traditionally used as antispasmodic, aromatic, carminative, digestive, galactogogue, stomachic, and tonic agents. Hence, the study was designed to evaluate the phytochemical constituents and antimicrobial activities of the leaves of sweet basil (O. basilicum) herb. Methods: The leaf extract was used for screening of phytochemicals. A small amount of the powdered leaves of the plant was subjected to hydrodistillation to extract the essential oil, and the components of the essential oil were evaluated by gas chromatography-mass spectroscopy instrument. The extract was tested in vitro for its antibacterial activity against two bacteria; Escherichia coli and Staphylococcus aureus and antifungal activity against two fungi; Aspergillus niger and Rhizoctonia bataticola by paper disc diffusion method. Results: Results revealed the presence of many phytochemicals such as alkaloids, tannins, flavonoids, cholesterol, terpernoids, glycosides, phenols, cardiac glycosides, carbohydrates, and phlobatannins. The essential oil extracted from the leaves of O. basilicum was found to have estragole (38.22%) as a major constituent followed by 1-isopropyl-4-methylenecyclohex-1-ene (11.10%). Tests of antimicrobial activity showed that the hydrodistilled oil was effective against all the tested bacterial and fungal strains. However, the crude extract was found not to have antimicrobial activity toward the tested bacteria and fungi. Conclusion: So, the study has showed that the observed antimicrobial effect of O. basilicum essential oil on the bacterial and fungal isolate, though in vitro appear interesting and promising. So, emphasize have to made on the antimicrobial activities of the plant during the time of drug extraction.

Antibacterial Activities And GC-MS Analysis of Phytocomponents of Ehretia Abyssinica R.BR. Ex Fresen.

The Ehretiaabyssinica, a small tree, belong to Boraginaceae family is traditionally known for its medicinal properties. The present study was therefore carried out to investigate the antibacterial activities and to unveil the Phytochemicals of the bioactive components in the leaves extract of this plant species. The antimicrobial activities of leaves extract was investigated against 7 medically important bacterial strains, namely Bacillus subtilius, MRSA, Micrococcus ,Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aurues and Klebsella pneumoniae. The antibacterial activity was determined using agar well diffusion method. The most susceptible bacteria to this extract were Pseudomonas aeruginosa, followed by Staphylococcus aurues, while the most resistant bacteria were Micrococcus. GC-MS analysis revealed that the ethanol leave extract of Ehretiaabyssinica contained mainly Octadecenamide (5.77%); Lucenin 2 (5.46%); Docosane and Nonacosane (3.75%); Cyclopropene (3.50%); Hematoporphyrin (2.68%); Tetratetracontane (2.36%); Dotriacontane (1.57); Acetic acid (1.53); Nmethylglycine (1.49%); Propyne antimicrobial (1.41%). All identified compounds are known to have antimicrobial activity.

Two new bioactive salsolanol and biphenylsalsinol from the aerial parts of Salsola villosa Delile. ex Schul. (Chenopodiaceae) growing in Saudi Arabia

Objective: To isolate and characterize the bioactive secondary metabolites from aerial parts of widespread Chenopodiaceae taxa growing in Saudi Arabia: Salsola villosa Delile. ex Schul. Methods: Antibacterial activities of chloroformic extract, fractions and isolate compounds was evaluated against five bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus and Staphylococcus epidermidis), using a paper disc diffusion method. The purification of compound(s) of chloroform extract was done by chromatographic column of silica gel. The structure elucidation was determined by extensive spectroscopic analysis (1H and 13C nuclear magnetic resonance, correlation spectroscopy, heteronuclear multiple bond correlation, heteronuclear multiple quantum coherence and nuclear overhauser enhancement spectroscopy) and high resolution electrospray ionization mass spectroscopy analysis. Results: Bioactivity guided fractionation of the chloroformic extract led to the isolation of two bioactive compounds: 4-(4'-hydroxy-2'-methylcyclopent-2'-enyloxy)- 4-methylcyclopent-2-enol (1) named salsolanol and 4'-[3-(hydroxymethyl)oxiran-2-yl]-3- [(E)-3-hydroxyprop-1-en-1-yl]-6, 2'-dimethoxy [1, 1'-biphenyl]-2-ol (2) named biphenylsalsinol. The antibacterial effects of the chloroform extracts, fractions and isolated compounds 1 and 2 were also evaluated in this work. Results showed that the compounds 1 and 2 exhibited antibacterial activities against four strains: Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa with diameter of zone of inhibition ranging between (9.33 ± 0.94) to (26.33 ± 0.94) mm. Conclusions: Based on data presented here, two new natural compounds secondary cyclic alcohol 1 and biphenylpropanoid 2 isolated from bioactive chloroformic extract from aerial parts of Salsola villosa can be responsible for its antibacterial activities.

Characterization of Antimicrobial Activities of Pediococcus pentosaceus Vtcc-B-601.

In this study, Pediococcus pentosaceus VTCC-B-601 was investigated and characterized for bacteriocin production. The antimicrobial activities were produced strongly at the late exponential phase (5x108 CFU/ml), corresponding to the activity of cephalosporin (13.3μg/ml) against Salmonella typhimurium ATCC 19430, Pseudomonas aeruginosa ATCC 27853, Staphylococus aureus ATCC 25923, and Micrococcus luteus ATCC 10240. The bacteriocin activity was reduced after proteinase K treatment while the activity was still stable in high temperature. This work supplied a Pediococcus pentosaceus bacteriocin identification that was useful in food preservation, clinical use, and agriculture.

Avaliação in vitro das propriedades antimicrobianas de vasopressores / In vitro evaluation of antimicrobial features of vasopressors / Evaluación in vitro de las propiedades antimicrobianas de vasopresores

Justificativa e objetivo: os medicamentos administrados como perfusão intravenosa podem ser contaminados durante as várias etapas de produção ou preparação. No entanto, estudos sobre os efeitos antibacterianos de vasopressores são muito raros. Este estudo investiga a atividade antimicrobiana in vitro das formas de vasopressores usados clinicamente. Materiais e métodos: atividades antimicrobianas in vitro de substâncias vasopressoras de diferentes concentrações foram investigadas com o uso da técnica de microdiluição. Os microrganismos empregados no teste foram: Escherichia coli ATCC 25922, Yersinia pseudotuberculosis ATCC 911, Pseudomonas aeruginosa ATCC 10145, Listeria monocytogenes ATCC 43251, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Bacillus cereus 702 Roma, Mycobacterium smegmatis ATCC607, Candida albicans ATCC 60193 e Saccharomyces cerevisiae RSKK 251. Os ensaios antibacterianos foram feitos em caldo de cultura Mueller-Hinton (pH 7,3) e os ensaios antifúngicos em solução tampão de base nitrogenada para levedura (pH 7,0). Resultados: duas preparações diferentes de dopamina mostraram atividade antimicrobiana. Nenhuma outra substância do estudo mostrou qualquer atividade antimicrobiana. Conclusões: em nossa opinião, os efeitos antibacterianos da dopamina podem ser vantajosos para inibir a propagação de contaminação bacteriana durante a preparação das soluções para perfusão. Contudo, salientamos a importância do seguimento rigoroso das diretrizes de esterilização dos equipamentos e de assepsia durante todos os procedimentos feitos em unidades de terapia intensiva. .

Background: Drugs administered as intravenous infusion may be contaminated during several stages of production or preparation. However studies focusing on antibacterial effects of vasopressor drugs are very rare. This study investigates the in vitro antimicrobial activity of the clinically used forms of vasopressors. Materials and methods: In vitro antimicrobial activities of vasopressor drugs of different concentrations were investigated by using the micro dilution technique. Microorganisms used in the test were Escherichia coli ATCC 25922, Yersinia pseudotuberculosis ATCC 911, Pseudomonas aeruginosa ATCC 10145, Listeria monocytogenes ATCC 43251, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Bacillus cereus 702 Roma, Mycobacterium smegmatis ATCC607, Candida albicans ATCC 60193, and Saccharomyces cerevisiae RSKK 251. Antibacterial assays were performed in Mueller-Hinton broth at pH 7.3 and antifungal assays were performed in buffered Yeast Nitrogen Base at pH 7.0. Results: Two different dopamine preparations showed antimicrobial activity. No other study drug showed any antimicrobial activity. Conclusions: In our opinion, dopamine's antibacterial effects may be advantageous for inhibiting the spread of bacterial contamination during the preparation of the infusion solutions. However, it is important that strict guidelines regarding the need for sterile equipment and deliverables be adhered to during all procedures performed in the intensive care units. .

Justificativa y objetivo: Los medicamentos administrados como perfusión intravenosa pueden ser contaminados durante las diversas etapas de producción o preparación. Sin embargo, son muy raros los estudios existentes sobre los efectos antibacterianos de los vasopresores. Este estudio investiga la actividad antimicrobiana in vitro de las formas de vasopresores usados clínicamente. Materiales y métodos: Actividades antimicrobianas in vitro de sustancias vasopresoras de diferentes concentraciones fueron investigadas con el uso de la técnica de microdilución. Los microrganismos usados en el test fueron: Escherichia coli ATCC 25922, Yersinia pseudotuberculosis ATCC 911, Pseudomonas aeruginosa ATCC 10145, Listeria monocytogenes ATCC 43251, Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Bacillus cereus 702 Roma, Mycobacterium smegmatis ATCC607, Candida albicans ATCC 60193 y Saccharomyces cerevisiae RSKK 251. Los ensayos antibacterianos se hicieron en un caldo de cultivo Mueller-Hinton (pH 7,3) y los ensayos antifúngicos en una solución tapón de base nitrogenada para levadura (pH 7,0). Resultados: Dos preparaciones diferentes de dopamina mostraron actividad antimicrobiana. Ninguna otra sustancia del estudio mostró alguna actividad antimicrobiana. Conclusiones: En nuestra opinión, los efectos antibacterianos de la dopamina pueden ser ventajosos para inhibir la propagación de la contaminación bacteriana durante la preparación de las soluciones para perfusión. Sin embargo, destacamos la importancia del seguimiento riguroso de las directrices de esterilización de los equipos y de asepsia durante todos los procedimientos realizados en las unidades de cuidados intensivos. .

In vitro Studies on Antimicrobial Activities of Lactic Acid Bacteria Isolated from Fresh Vegetables for Biocontrol of Tomato Pathogens.

Aims: This study was focused on using Lactic Acid Bacteria (LAB) isolated from fresh vegetables which has been molecularly identified for in vitro control of some tomato pathogens. Study Design: The inhibitory potentials of supernatant obtained from previously characterized LAB isolates or vegetable origin were investigated against some tomato phytopathogens using agar-well method with the view to develop biological agents for some tomato disease causing organisms. Place and Duration of Study: Biotechnology Centre of Federal University of Agriculture, Abeokuta, Ogun State, Nigeria, between January 2011 and February 2012. Methodology: The antimicrobial activities of LAB against some tomato phytopathogenic bacteria which include (Xanthomonas campestries, Erwinia caratovora, and Pseudomonas syringae) were obtained by using the agar well diffusion method. Results: The result indicates that cell free culture of LAB from fresh vegetables origin (Weissella paramesenteroides, Lactobacillus pentosus, Weissella cibaria, Pediococcus pentosaceus, Weissella kimchi and Lactobacillus plantarum) can inhibits these bacteria by creating clear zones of inhibition around the wells containing cell free supernatants of the above mentioned strains of lactic acid bacteria. Pediococcus pentosaceus showed the highest zone of inhibition against Xanthomonas campestries at 15 mm radius, Weissella kimchi was the least effective against Pseudomonas syringae at 3.67 mm and Erwinia caratovora at 3.50 mm radius. Conclusion: Tomato disease causing organisms can be most likely biologically controlled by using extracts from LAB. This finding will reduce the potential hazard from the use of chemical herbicides on plant.

Study on Minicell Generation of Lactobacillus acidophilus VTCC-B-871 for Drug Delivery.

The practice of developing molecularly targeted drugs to achieve a higher degree of cancer therapy and antibiotic resistance is indispensable. Recently, bacterially derived 400nm sized minicells was reported on the ability of encapsulation with chemotherapeutic drugs. Lactobacillus acidophilus strain participated in the anti-cancer effects and performed the high-level specificity for cancer cell lines. Here we discuss minicells generation of Lactobacillus acidophilus VTCC-B-871 for drug delivery. The present work was the first report on that L. acidophilus VTCC-B-871 formed minicells with highly significant ratio (25 %) in modified MRS broth with fructose 10 g/l carbon source concentration. The minicells were packaged with Paclitaxel (10 μg/ml) and Cephalosporin (10 μg/ml) at different times of incubation (10, 15, 24 hours) at 37°C. As a result, minicells could completely absorbed in 10 hours by detecting the extraction after drug packaged minicells on antimicrobial activities on S. aureus ATCC 25923, E. coli ATCC 9637, Salmonella typhi ATCC 19430, C. albicans ATCC 14053, P . aeruginosa ATCC 27853.

Atividade antimicrobiana in vitro de produtos antissépticos por meio de técnica time kill / Analysis of in vitro antimicrobial activity of antiseptics products by means of time kill assay

Inúmeros agentes químicos (álcoois, iodóforos, clorexidina, etc.) são utilizados em laboratórios e indústrias.Ao contrário dos desinfetantes, não há padrões e critérios específicos para avaliar a atividade de antissépticos.Neste trabalho foi estudada a atividade antimicrobiana de antissépticos, utilizando-se o ensaio Time Kill (Hobson & Bolsen), que avalia a população de micro-organismos aeróbios em período de tempo específico,diante de agentes antimicrobianos. Foram avaliadas duas metodologias de recuperação dos microorganismos: filtração por membrana e semeadura em profundidade. A filtração por membrana foi menos sensível. A semeadura em profundidade demonstrou maior sensibilidade com maior contagem de colônias.De 25 amostras de produtos, os antissépticos à base de digluconato de clorexidina foram insatisfatórios e ineficazes para todas as cepas de micro-organismos de referência, correspondendo a 20 % das amostras analisadas. Estes produtos apresentaram-se satisfatórios frente às cepas de origem clínica. Portanto, estes produtos devem ser utilizados com cautela e estudos adicionais são necessários, pois são escassas as informações sobre sua eficácia. Os dados deste estudo poderão auxiliar as ações de vigilância sanitária e de saúde pública na elaboração de futuras legislações, pois estes produtos são encontrados no comércio, massem seguir nenhuma legislação específica.

Many chemicals (alcohol, iodophor, chlorhexidine, etc) are used in laboratories and industries. Unlikedisinfectants, no specific norms and criteria have been standardized for evaluating the antiseptics activity.This study analyzed the antimicrobial activity of antiseptics using Time Kill Test (Hobson & Bolsen).This assay assessed the evolution of a population of aerobic microorganisms in a specific period oftime when tested against antimicrobial agents. Two different recovery methodologies were evaluated:membrane filtration and pour plate technique The membrane filtration assay was less sensitive. Pour platetechnique showed high sensitivity with high colonies counts. Of 25 samples of products analyzed, onlythe chlorhexidine digluconate-based antiseptics were unsatisfactory, showing no efficacy on all referencemicro-organisms strains, and corresponded to 20 % of analyzed samples. However, they were efficaciousagainst clinical strains. Therefore, these products should be used with caution and further studies areneeded, as data on its efficacy have still been scarce. These findings might give support to the healthsurveillance and public health in establishing the future legislation, as these products have been availableon the market, but without following any specific legislation.