Formation Of Inhibition Zones Research Articles

Formation of Pseudomonas aeruginosa inhibition zone during tobramycin disk diffusion is due to transition from planktonic to biofilm mode of growth

Pseudomonas aeruginosa PAO1 (tobramycin MIC = 0.064 µg/mL) was used to perform agar diffusion tests employing tobramycin-containing tablets. Bacterial growth and formation of inhibition zones were studied by stereomicroscopy and by blotting with microscope slides and staining with methylene blue, Alcian blue and a fluorescent lectin for the P. aeruginosa PSL, which was studied by confocal laser scanning microscopy. Diffusion of tobramycin from the deposit was modelled using a 3D geometric version of Fick's second law of diffusion. The time-dependent gradual increase in the minimum biofilm eradication concentration (MBEC) was studied using a Calgary Biofilm Device. The early inhibition zone was visible after 5 h of incubation. The corresponding calculated tobramycin concentration at the border was 1.9 µg/mL, which increased to 3.2 µg/mL and 6.3 µg/mL after 7 h and 24 h, respectively. The inhibition zone increased to the stable final zone after 7 h of incubation. Bacterial growth and small aggregate formation (young biofilms) took place inside the inhibition zone until the small aggregates contained less than ca. 64 cells and production of polysaccharide matrix including PSL had begun; thereafter, the small bacterial aggregates were killed by tobramycin. Bacteria at the border of the stable inhibition zone and beyond continued to grow to a mature biofilm and produced large amount of polysaccharide-containing matrix. Formation of the inhibition zone during agar diffusion antimicrobial susceptibility testing is due to a switch from a planktonic to biofilm mode of growth and gives clinically important information about the increased antimicrobial tolerance of biofilms.

Lemon (Citrus limon) Juice Has Antibacterial Potential against Diarrhea-Causing Pathogen

This purpose of this study was to determine the potential of lemon juice in inhibiting the growth of diarrhea-causing bacteria and analyze the optimum dose. The type of this study was a laboratory experiment. The variations of the lemon juice dose used in this study were 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 mg/ml by using Enterotoxin Escherichia coli (ETEC) as the test bacteria. This potential test used a well diffusion method with three repetitions for each dose. The results of this study indicated that lemon juice had the potential to inhibit pathogenic bacteria that cause diarrhea. In doses of 500 mg/ml to 80 mg/ml it inhibited the growth of test bacteria which were characterized by the formation of inhibition zones in a sequence of 10.56, 12.05, 13.02, and 14.58 mm with intermediate categories. Whereas in doses of 900 mg/ml and 1000 mg/ml it inhibited the growth of test bacteria with zone diameter area of 16.04 and 18.70 mm with sensitive categories. Kruskal Wallis test revealed a p-value of 0.000 < α = 0.05, which means that there was an influence among treatments. This result showed that the optimum dose of lemon juice in inhibiting diarrhea- causing pathogenic bacteria was 900 mg/ml.

Endophytic Bacteria from Faloak Plant Seed (Sterculia comosa Wallich) as Antibacterial Agent

Endophytic bacteria isolated from some various kind of plants are able to yield some active compounds which have a role as an antibacterial compound. This work aimed to isolate and to screen the Endophytic bacteria from Faloak seed in its charge in inhibiting two kinds of pathogenic bacteria, Staphylococcus aureus and Escherichia coli. There were six isolates of Endophytic bacteria isolated in this work. According to the screening result, one isolate which had the most potential antibacterial activity (marked by the formation of inhibition zone) against S. aureus and E. coli. That most potential isolate was then tested and identified for both biochemical properties and molecular 16S rRNA gene. The result of this study showed that the endophytic bacteria isolate of Faloak seed with the code of S1 had the similarity with Enterobacter xiangfangensis strain 10-17 by 93 %. The research about endophytic bacteria of Faloak plants was never conducted before. Thus this research was expected to give information about the potential of antimicrobial ability Faloak plants which can be utilized in the discovery of new antibiotic compounds which in the future are expected to overcome the problem of microorganism resistance to antibiotics. The use of endophytic bacteria is expected to prevents the extinction of Faloak plants due to excessive use.

Antimicrobial activity of functionalized single‐walled carbon nanotube with herbal extract of Hempedu bumi

The primary purpose of this study was to determine the antimicrobial activity of functionalized single‐walled carbon nanotube (SWNT) using an extract of the herb, Hempedu bumi. H bumi extract and H bumi extract complexed SWNT were evaluated for biological activities against Bacillus sp., (pathogen) Escherichia coli (opportunistic pathogen), and Aspergillus niger (pathogen). The formation of inhibition zones of these 3 microbes was measured to be evident for the functionalized SWNT with H bumi. Further, morphological and structural analyses were conducted to investigate the functionalized SWNT with H bumi using scanning electron microscopy, atomic force microscopy, X‐ray photoelectron spectroscopy, X‐ray powder diffraction, and Fourier transform infrared spectroscopy, well supporting the intact and crystalline nature of the SWNT. Fourier transform infrared spectroscopy result shows the highest peak at 3371.48 cm−1, representing an andrographolide group from the plant extract. An apparent clear zone has been noticed with SWNT conjugated H bumi extract, displaying a zone of inhibition larger than 1.0 cm against the tested microbes. The results indicate that SWNT has the potential for use as a carrier of components from plant extracts.

UJI AKTIVITAS ANTIBAKTERI EKSTRAK ETANOL BIJI PINANG (Areca catechu L.) TERHADAP PERTUMBUHAN BAKTERI Escherichia coli, Shigella dysentriae, DAN Salmonella typhi

One of the medicinal plants is the areca nut (Areca catechu L.) from the Arecae family which has the potential as an anticancer having antioxidant and antimutagenic, astringent, and anthelmintic effects. Areca nut seeds contain alkaloids, such as arekoline, arekolidine, arekain, guvakolin, guvasine and isoguvasine. This study aims to determine the characteristics of the betel nut (Areca catechu L.) simplicia, class of compounds, and the antibacterial activity of the ethanol extract of areca nut (Areca catechu L.) against the growth of Escherichia coli, Shigella dysentriae, and Salmonella typhi bacteria. The method used is the ethanol extract of areca nut (Areca catechu L.) obtained from the maceration process with 96% ethanol. The results of phytochemical screening showed that the ethanolic extract of areca nut (Areca catechu L.) contains a group of alkaloid compounds, tannins, flavonoids, saponins, and triterpenoids. The effect of giving young betel nut ethanol extract to Escherichia coli, Shigella dysentriae, and Salmonella typhi bacteria was indicated by the formation of an inhibition zone of optimum concentration. The ethanol extract of old betel nut against Escherichia coli, Shigella dysentriae, and Salmonella typhi bacteria was characterized by the formation of an optimum concentration inhibition zone. Based on the results, it can be concluded that the ethanol extract of areca nut (Areca catechu L.) has antibacterial activity against Escherichia coli, Shigella dysentriae, and Salmonella typhi.

Antibacterial effectiveness in vitro of different formulations of calcium hydroxide paste

ABSTRACT Objective: To evaluate the antibacterial activity of four formulations of calcium hydroxide paste against microorganisms commonly found in infected root canals. Methods: To evaluate antibacterial activity through the agar diffusion method, pastes of calcium hydroxide were made from its pro-analysis form, diffused into four separate vehicles: distilled water, camphorated p-monochlorophenol, propylene glycol and Otosporin®, testing the antimicrobial activity of these on strains of Staphylococcus aureus, Bacillus subtilis and Enterococcus faecalis. After the incubation period, the presence or otherwise of inhibition zones were observed and their sizes in three stages: 24h, 48h and 72h. With this data, the median between the four dishes was obtained and the consequent value was submitted to Kruskal-Wallis nonparametric statistical analysis, with post-tests of Mann-Whitney and Bonferroni correction, at a significance level of 5%. Results: Only pastes with camphorated p-monochlorophenol and Otosporin vehicles caused the formation of significant inhibition zones, with medians of 8.0 mm. Against the strains of Enterococcus faecalis, only pastes with the camphorated p-monochlorophenol vehicle resulted in the formation of significant inhibition zones, with a median of 3.0 mm. Conclusion : Otosporin and CMCP vehicles provide greater antimicrobial potential to calcium hydroxide against the studied bacteria. However, only the Ca(OH)2 and CMCP combination was effective against all the strains, and can thus be regarded as the paste formulation with the greatest antimicrobial effectiveness in this study.

ANTAGONISTIC ACTIVITY OF METABOLIС PRODUCTS OF BACTERIA LACTOBACILLUS PLANTARUM AND ENTEROCOCCUS ITALICUS WITH JOINT ACTION AGAINST PHYTOPATHOGENIC BACTERIA

Aim. Detection of antagonistic activity of metabolic products of Lactobacillus plantarum and Enterococcus italicus ONU547 bacterial strains with joint action against phytopathogenic bacteria in vitro. Methods. Antagonistic activity of bacterial strains of E. italicus ONU547, L. plantarum ONU12 and L. plantarum ONU311 against phytopathogenic bacteria Rhizobium radiobacter C58, Rhizobium vitis UA6, Rhizobium rhizogenes 15834, Erwinia carotovora ZM1, Ralstonia solanacearum B-1109-УКМ, Pseudomonas syringae pv. syringae 8511 and P. syringae pv. atrofaciens D13 was studied in vitro by the agar well diffusion method. Results. The combination of metabolic products of two lactobacilli strains showed the highest inhibition level among the tested mixtures (p≤0,05) against plant pathogens Rhizobium vitis and Pseudomonas syringae pv. syringae with formation of inhibition zones with radius 7,2±0,4 and 7,8±0,4 mm. Antagonistic activity of metabolic products combinations of bacterial strains L. plantarum ОNU12 and L. plantarum ONU311 was not increased compared with the activity of separated strains in most cases. The separated strain E. italicus ONU547 did not inhibit the growth of plant pathogenic bacteria. Antagonistic activity of the studied combinations was not statistically different against Rhizobium radiobacter and Erwinia carotovora. Conclusions. All of the tested lactobacteria mixtures showed antagonistic activity with different levels against phytopathogenic bacteria used in this work because of the activity of produced organic acids.

Isolasi Bakteri Endofit dari Tanaman Sirih Hijau (&lt;i&gt;Piper betle&lt;/i&gt; L.) dan Potensinya sebagai Penghasil Senyawa Antibakteri

Endophytic bacteria are beneficial microorganisms that interact with host plants without causing disruption or damage to the host. Some studies suggest that certain endophytic bacteria can produce chemical compounds that have an effect on health, especially endophytic bacteria isolated from medicinal plants. Green betel (Piper betle L.) is a medicinal plant that has been used for years and has many benefits. The purposes of this study are to isolating and screening of endophytic bacteria from green betel against four pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Bacillus cereus and Salmonella enteritidis). The number of endophytic bacteria that has been isolated are 14 isolates. Based on the screening results, three isolates of endophytic bacteria have potential activity (characterized by the formation of inhibition zone) against S. aureus. The inhibition zone may indicate that those isolates produce compounds that have antibacterial effects. Those isolates are AS1, BS1 and BS2. The biggest inhibition zone showed by BS1, so it can be concluded that BS1 is the most potential isolate as a novel source of antibacterial compound.

Potensi Daun Trembilungan (Begonia hirtella Link) sebagai Antibakteri dan Antifungi

Begonia hirtella leaf are commonly used by people in mountainous areas to treat itchy due to insect bites and skin infection. This study aims to (1) determine proper solvent extract of B. hirtella leaf on antibacterial activity of S. aureus and E. coli and on antifungal activity of C. albicans (2) determine the lowest concentration of leaf extract of B. hirtella that indicate the formation of inhibition zone (3) know the content of bioactive compounds contained in each leaf extract of B. hirtella. The method used in this study is experimental with completely randomized design (CRD). The treatments were type of solvents (n-hexane, ethyl acetate, ethanol and water) and a serie of the ethyl acetate extract concentration of 500 ppm, 450 ppm, 400 ppm, 350 ppm, 300 ppm and 250 ppm against S. aureus, E. coli and C. albicans. Data were analyzed using analysis of variance (Anova) and the significant differences between the treatments were analyzed by Duncan test at 95% confidence level. The result showed that each solvent extracts affect microbes growth with a highly significant difference p &lt;0.05. Solvent extracts that have the best inhibitory zone is ethyl acetate against S. aureus with an average diameter of inhibitory zone 13.75 ± 1.26 mm. Increasing concentrations of ethyl acetate extract of 250 ppm to 500 ppm increase inhibition zone against microbes. The lowest concentration that show inhibition zone was 300 ppm. The formation inhibition of zone on microbes growth happened due to their compounds in the extract. Extract of n-hexane contains stigmasterol, ethyl acetate contains neophytadiene, while the ethanol extract contains ethyl palmitate

Cu-α-NiMoO4 photocatalyst for degradation of Methylene blue with pathways and antibacterial performance

Abstract Cu doped α-NiMoO 4 photocatalyst has been synthesized by microwave hydrothermal method. The existence of Cu 2+ ions at lattice position of α-NiMoO 4 was observed on the basis of XRD, HRTEM, SAED, and EDS analysis. The negative zeta potential values indicate the stability of samples. Solar light driven photocatalytic degradation of Methylene blue (MB) dye in water was used to evaluate the photocatalytic performance of Cu doped α-NiMoO 4 photocatalyst. The results revealed that there is an optimum Cu (4 mol%) doping level leads to highly enhanced photocatalytic activity of Cu-α-NiMoO 4 , as compared to α-NiMoO 4 host. The experiment also suggested that active species (OH , O 2 − and h + ) play a crucial role in the scavenging system. The reduced energy band gap, oxygen vacancy, high BET surface area, and efficient separation of photogenerated electron/hole are responsible for enhancement of photocatalytic performance. MB photodegradation intermediates were identified by high resolution-quadruple time of flight electrospray ionization mass spectrometry (HR-QTOF ESI/MS) in positive ion mode and degradation pathway was proposed. Antibacterial performance was analyzed against Gram-positive (methicillin resistant Staphylococcus aureus and Bacillus Subtilis ) and Gram-negative bacteria ( Pseudomonas aeruginosa ) via well-diffusion method. The formation of larger inhibition zone by small quantity of photocatalyst powder proved the excellent antibacterial performance. The inactivation of microorganism were found in following order: B . Subtilis ˃ S . aureus ˃ P . aeruginosa . The result of our study suggested that copper doped α-NiMoO 4 photocatalyst is suitable for degradation of organic contaminates as well as effective for growth inhibition of multidrug-resistant microorganisms.

Evaluation of ornidazole-loaded nanofibers as an alternative material for direct pulp capping

Direct pulp capping is an alternative treatment for dental pulp injuries caused by decay, trauma, or cavity preparation. Ornidazole is an antibiotic that is commonly used to treat dental infections against anaerobic bacteria. The purpose of this study was to examine the feasibility of using ornidazole-loaded nanofibers as a coating material for pulp capping. Ornidazole-free and ornidazole-loaded nanofibers were prepared with various polymeric biomaterials, including chitosan, polycaprolactone, and polyethylene oxide using electro-spinning method. After characterization (scanning electron microscopy, mechanical properties, contact angle measurements) of the nanofibers, WST-1 tests performed at 24, 48, and 72 h showed that the nanofibers of both groups had minimal cytotoxic effects on pulp cells. Furthermore, pathological examinations showed higher numbers of cells on the nanofibers in the 72-h samples. Antimicrobial activity tests with ornidazole showed more significant formation of inhibition zones in with the ornidazole-loaded nanofibers, demonstrating their potential applicability for direct pulp capping.

Transcriptional and Antagonistic Responses of Biocontrol Strain Lysobacter enzymogenes OH11 to the Plant Pathogenic Oomycete Pythium aphanidermatum.

Lysobacter enzymogenes is a ubiquitous, beneficial, plant-associated bacterium emerging as a novel biological control agent. It has the potential to become a new source of antimicrobial secondary metabolites such as the Heat-Stable Antifungal Factor (HSAF), which is a broad-spectrum antimycotic with a novel mode of action. However, very little information about how L. enzymogenes detects and responds to fungi or oomycetes has been reported. An in vitro confrontation bioassay between the pathogenic oomycete Pythium aphanidermatum and the biocontrol bacterial strain L. enzymogenes OH11 was used to analyze the transcriptional changes in the bacteria that were induced by the oomycetes. Analysis was performed at three time points of the interaction, starting before inhibition zone formation until inhibition zone formation. A L. enzymogenes OH11 DNA microarray was constructed for the analysis. Microarray analysis indicated that a wide range of genes belonging to 14 diverse functions in L. enzymogenes were affected by P. aphanidermatum as critical antagonistic effects occurred. L. enzymogenes detected and responded to the presence of P. aphanidermatum early, but alteration of gene expression typically occurred after inhibition zone formation. The presence of P. aphanidermatum increased the twitching motility and HSAF production in L. enzymogenes. We also performed a contact interaction between L. enzymogenes and P. aphanidermatum, and found that HSAF played a critical role in the interaction. Our experiments demonstrated that L. enzymogenes displayed transcriptional and antagonistic responses to P. aphanidermatum in order to gain advantages in the competition with this oomycete. This study revealed new insights into the interactions between bacteria and oomycete.

Influence of temperature and pH on the production of biosurfactant, bacteriocin and lactic acid by Lactococcus lactis CECT-4434

ABSTRACTOperational conditions such as temperature and pH are well known to influence the production of biosurfactants, bacteriocins, and lactic acid by lactic acid bacteria. The bacterial strain Lactococcus lactis subsp. lactis CECT-4434 was used to investigate the effects of temperature (30°C, 37°C and 40°C) and pH control on the production of these biomolecules, in order to establish whether they are able to preferentially address its metabolism towards one product or another. It was observed that the pH control within the range 5.0–5.3 favored the production of lactic acid, which was 38% higher than that obtained without control. The bacteriocin production was higher in the temperature range between 30°C and 37°C, evidenced by the formation of inhibition zones against Lactobacillus sakei and Staphylococcus aureus, 5–22% and 4–14% higher, respectively, compared with those achieved at 40°C. Finally, the best results for biosurfactant synthesis occurred at 37°C without pH control, with a surface tension reduction between 22.5 and 24.7 mN/m after 6–24 h of culture, respectively.

Isolation, identification and in vitro screening of Chongqing orangery yeasts for the biocontrol of Penicillium digitatum on citrus fruit

The aim of this study was to explore the diversity of yeasts in the orangery of Beibei Chongqing and their potential for biological control of Penicillium digitatum on oranges. Yeasts were isolated from the surface of fruit, leaves and soil in three citrus orchards in this district. The yeasts were identified by PCR amplification and partial sequencing of internally transcribed spacer (ITS) regions and 5.8S ribosomal DNA (rDNA). The 71 yeast isolates belonged to 8 genera: Metschnikowia, Pichia, Candida, Pseudozyma, Kazachstania, Issatchenkia, Hanseniaspora, and Barnettozyma. All yeast isolates were tested for the inhibition of green mold on potato dextrose agar (PDA) medium, and 45 isolates reduced the growth of fungal mycelium as shown by inhibition zone formation. Twelve isolates were tested for antagonistic activity against Penicillium digitatum on navel oranges, and the biocontrol activity of the various isolates in reducing disease incidence ranged between 26% and 93%. In particular, Metschnikowia sp. FL02 completely inhibited the occurrence of green mold rot on the seventh day after inoculation. The results of this study suggest that antagonist yeasts frequently found on leaves and fruit in Beibei Chongqing orangery have potential for inhibiting citrus green mold.

HaCaT 세포주에서 캐모마일 (Matricaria chamomilla) 추출물의 항병원 성 및 항염 효과에 관한 연구

Chamomile (Matricaria chamomilla), a member of the Asteraceae family, is a well-known for medicinal plant and can be found in India and Europe. Chamomile is an effective sedative and various medical effects. But, the effects of acne treatment by chamomile were not investigated. Therefore, we assessed the anti-oxidant effects, anti-microbial activity and anti-inflammatory effects by chamomile extracts in HaCaT keratinocyte cells. Anti-oxidant effects of chamomile extracts were investigated by DPPH assay. Also, results of MTT assay was demonstrated that chamomile extracts did not have a cytotoxic effect in HaCaT cells. To assess the antimicrobial activity, we determined formation of inhibition zone of Propionibacterium acnes by extracts from chamomile. Tumor necrosis factor-α (TNF-α) induces production of inflammatory cytokines such as interleukin-1β (IL-1β), IL-6 and IL-8 and expression of COX-2. Chamomile extracts could inhibit TNF-α-induced mRNA expression levels of IL-1β, IL-6, IL-8 and COX-2 gene. These results demonstrated the possibility of chamomile for prevention and treatment of skin inflammatory diseases such as acne.

First ever report on the antimicrobial activities of some selected mangrove halophytes of Sundarban against milk spoilage microflora

The study was governed by the objective of investigating the antimicrobial effects of mangrove leaf extracts. The fresh and dried leaf extracts from Avicennia marina (Forssk.) Vierh., Avicennia officinalis L., Aegiceras corniculatum (L.) Blanco, Aegialitis rotundifolia Roxb., Acanthus ilicifolius L, Lumnitzera racemosa Willd., Excoecaria agallocha L. and Sonneratia apetala Buch-Ham. were found to have inhibitory effects on the milk spoilage microflora obtained from curd sample. Methanol and Acetone were used as extraction solvents and in comparison, extracts by acetone were observed to suppress the microbial growth to lesser extents. Leaf extracts of A. marina, A. officinalis L. racemosa and A. rotundifolia were able to exert relatively greater inhibitory effect on the milk spoilage microbial broth than others, although all the species expressed some degree of suppression. Interestingly A. rotundifolia, S. apetala, L. racemosa and E. agallocha demonstrated greater efficiency in formation of larger growth inhibition zones on the petri plates. The extracts obtained from dry leaves produced greater adverse effects of the microbes than the raw leaf extracts. The data generated were analyzed with the help of 'ANOVA: Single factor' and 'F-test: Two sample for variance' and data sets were of statistical significance at 0.05 level of significance as null hypothesis was rejected.

ANTIBACTERIAL ACTIVITY IN EARTHWORM COELOMIC FLUID LAMPITO MAURITII

Earthworms are the first annulated coelomate organism with haemoglobin in the plasma as carrier of oxygen and carbon dioxide. They have the antimicrobial activity against the disease causing micro organisms. In the present study antibacterial activity of earthworm coelomic fluid Lampito mauritii were confinedagainst disease causing micro organisms through the inhibition zone formation by well diffusion method as well as disc diffusion method.

An insight study on HPTLC fingerprinting of Mukia maderaspatna: Mechanism of bioactive constituents in metal nanoparticle synthesis and its activity against human pathogens.

The present work reports the development of a Simple, rapid and eco-friendly route for the biosynthesis of gold and silver nanoparticles and their antimicrobial activity against gram positive and gram negative bacterial pathogens in the wound infected area. The synthesis was done using Mukia maderasapatna plant extract as a reducing agent. FT-IR analysis reported that the methanol extract was found to contain maximum number of functional groups which is responsible for the reduction of metal ions to metal nanoparticles. Further, the presence of bioactive molecules present in the methanol extract was confirmed by GC-MS analysis. The major phytochemical constituents observed in this Mukia maderaspatna leaf extract were n-hexadecanoic acid (15.51%), Octadecanoic acid (11.92%), stigmasterol (9.12%), Octadecanoic acid, 2, 3 hydroxypropyl ester (8.7%), Bicycloheptane, 2,6,6- trimethyl (5.57%) and stearic acid (4.23%). Initially, the formation of gold and silver nanoparticles was confirmed from their absorption spectra at 535nm and 434nm using UV- visible spectroscopy. The crystalline nature of the obtained gold and silver nanoparticles was confirmed by X-ray diffraction analysis. The average size of the gold and silver nanoparticles found around 50nm and 20nm respectively was confirmed by TEM analysis. The antimicrobial activities of silver and gold nanoparticles were checked against bacterial strains and the fungal strains. The formation of inhibition zones concluded that both the nanoparticles showed efficient antimicrobial activity against both the pathogens. Further, different concentrations of gold and silver nanoparticles, the antibiotics Ciprofloxacin and chloramphenicol as the positive control were carried out. The results concluded that the silver nanoparticles showed efficient activity against bacterial pathogens and fungal pathogens with the lowest concentration of 0.35μg/ml and 0.45μg/ml respectively.

Modulation of Antibiotic Activity Against Streptococcus pneumoniae by N-acetylcysteine and ascorbic acid

Streptococcus pneumoniae is one of the bacterial pathogens that cause pneumonia. Pneumonia is the biggest cause of infant mortality in Indonesia around 23%. The main therapy pneumonia is antibiotics, but in some cases combined with ascorbic acid or N-acetylcysteine, which serves as a complementary therapy. The purpose of this study was to determine the effect of adding ascorbic acid or N-acetylcysteine ​​on antibiotics towards the growth of S. pneumoniae in vitro. The method used in this research is the method of germ-disc diffusion susceptibility test with S. pneumoniae growth inhibition is indicated by the formation of inhibition zone. Positive controls used clindamycin and erythromycin. The average diameter of inhibition zone on the negative control, positive control, and treatment of 1 to 5 on the addition of clindamycin with ascorbic acid are respectively 5; 24.12; 24.62; 26.08; 27.58; 28.74; and 29.76 mm. The data has a strong correlation to the Pearson test (R=+0,910). On a logarithmic regression analysis found minimal concentration of ascorbic acid can inhibit is 1.767 mg/ml. While the addition of erythromycin with N-acetylcysteine ​​are respectively 28.02; 25.62; 23.46; 22.42; and 21.68 mm. Pearson correlation test results of these data are the opposite relationship between the diameter of inhibition zone and the concentration of N-acetylcysteine ​​with a very strong correlation coefficient. Logarithmic regression of the minimum concentration of N-acetylcysteine ​​which may decrease the antibacterial activity of erythromycin inhibit the growth of Sreptococcus pneumoniae amounted 1,66mg/ml. It is concluded that ascorbic acid increases the activity of clindamycin in inhibiting the growth of S. pneumoniae in vitro and N-acetylcysteine ​​may decrease the antibacterial activity of erythromycin in inhibiting the growth of S. pneumoniae in vitro. Keywords: S. Pneumoniae, ascorbic acid, N-asetilsitein, inhibition zone

Quantificação de fenóis, flavonoides totais e atividades farmacológicas de geoprópolis de Plebeia aff. Flavocincta do Rio Grande do Norte

Resumo: Esse estudo objetivou avaliar a composição química e potencial terapêutico do extrato hidroalcóolico de geoprópolis produzidas por abelhas Plebeia aff. flavocincta no semiárido do Rio Grande do Norte. Oito amostras (A-H) foram submetidas a quantificação dos teores de fenóis e flavonoides totais e avaliação da atividade antioxidante através do método DPPH (2,2-difenil-1-picril-hidrazilo). Além disso, foram investigadas as atividades antibacteriana, através do método de difusão em ágar, e a cicatrizante, através da indução de feridas cirúrgicas experimentais em Rattus norvegicus Berkenhout, 1769, linhagem Wistar, tratados com creme à base de geoprópolis. Duas amostras (F e G) se destacaram por apresentar altos valores de fenóis e flavonoides totais. A capacidade antioxidante acima de 90% foi observada em cinco amostras. Os extratos foram considerados eficazes no que se refere a atividade antibacteriana, pois das oito amostras, cinco promoveram a formação de halos de inibição ≥9mm para todas as cepas testadas. Duas amostras (D e G) se destacaram em relação as demais por apresentar excelentes resultados, uma vez que, promoveram a formação de halos de inibição para as bactérias Staphylococcus epidermidis e Escherichia coli, superiores estatisticamente aos valores dos antibióticos controles, quando na concentração de 100%. As amostras A e G promoveram, respectivamente, a formação de halos de inibição, que não diferiram significativamente dos halos produzidos pelos antibióticos controles em todas as concentrações testadas para E. coli e Staphylococcus aureus. A análise do processo de cicatrização sob os pontos de vista clínico, macroscópico e histológico permitiu concluir, que o uso do creme à base de geoprópolis apresentou influência positiva na cicatrização de feridas cutâneas experimentais, por promover reação inflamatória menos intensa e fechamento mais rápido das feridas em relação ao grupo controle.