Dynamized Aloysia Polystachya (Griseb.) Essential Oil: A Promising Antimicrobial Product.

BACKGROUND: Compounds from vegetal matter have therapeutic potential to control highly prevalent microorganisms that are resistant to commonly used antimicrobial drugs. Dynamization of compounds can either maintain or improve their therapeutic effects, and make their use safer, especially those compounds whose therapeutic dose is close to the toxic limit. Aloysia polystachya (Griseb.) stands out among aromatic plants with antimicrobial potential. OBJECTIVE: The aim of this study was to evaluate the antimicrobial activity of dynamized and crude forms of A. polystachya essential oil against Candida albicans, Escherichia coli and Staphylococcus aureus. METHODS: Essential oil was extracted from A. polystachya dry leaves, solubilized, and dynamized at 1 cH potency as recommended by the Brazilian Homeopathic Pharmacopoeia. Antimicrobial activity against C. albicans, E. coli and S. aureus of the samples was assayed using the plate microdilution method. RESULTS: Dynamized A. polystachya essential oil at the concentration of 1 µg/mL inhibited the growth of all the microbial species analyzed. The minimum inhibitory concentration of dynamized essential oil was smaller than crude essential oil for S. aureus, E. coli and C. albicans. CONCLUSION: It is reported for the first time that A. polystachya dynamized essential oil can effectively suppress microbial growth, and it is a promising adjuvant to treat infections with pathogenic S. aureus, E. coli and C. albicans.

In-Vitro Evaluation of Antimicrobial Activities of Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Neisseria gonorrhoeae, and Candida albicans Nosodes.

BACKGROUND: This study presents the results of the minimum inhibitory concentration (MIC) assay of a series of nosodes: namely Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Neisseria gonorrhoeae, and Candida albicans. Each was tested against its corresponding infection as well as cross infections. METHODS: In-vitro efficacy of polyvalent nosodes was tested using the MIC assay technique. The nosodes, namely C. albicans polyvalent nosode (35c, 100c), N. gonorrhoeae (35c), K. pneumoniae (35c, 100c), E. coli polyvalent nosode (35c, 100c) and Salmonella typhi polyvalent nosode (30c, 100c), were tested along with positive and negative controls. Nosodes were studied in different potencies and at 1:1 dilution. RESULTS: C. albicans polyvalent nosode 35c, 100c, N. gonorrhoeae 35c, and positive control amphotericin B showed inhibition of the growth of C. albicans species. K. pneumoniae 35c, E. coli polyvalent nosode 100c, and meropenem (positive control) showed inhibition of the growth of K. pneumoniae; this effect was not seen with ceftriaxone, ofloxacin and amoxicillin antibiotics. E. coli polyvalent nosode 30c in 10% alcohol (direct and dilution 1:1) and the positive controls ciprofloxacin, ofloxacin, and amoxicillin showed inhibition of the growth of E. coli. The S. typhi polyvalent nosode 30c in 10% alcohol showed inhibition of growth of S. typhi. CONCLUSION: This study reveals that the tested nosodes exhibited antibacterial potential against the corresponding micro-organisms and against other selected organisms studied using this assay.

Action of antibiotic oxacillin on in vitro growth of methicillin-resistant Staphylococcus aureus (MRSA) previously treated with homeopathic medicines.

BACKGROUND: Resistance to antibiotics is a major public health concern worldwide. New treatment options are needed and homeopathy is one such option. We sought to assess the effect of the homeopathic medicine Belladonna (Bell) and a nosode (biotherapy) prepared from a multi-drug resistant bacterial species, methicillin-resistant Staphylococcus aureus (MRSA), on the same bacterium. METHODS: Bell and MRSA nosode were prepared in 6cH and 30cH potencies in 30% alcohol and sterile water, according to the Brazilian Homeopathic Pharmacopeia and tested on MRSA National Collection of Type Cultures (NCTC) 10442. We assessed in vitro bacterial growth, deoxyribonuclease (DNAase) and hemolysin activity, and in vitro bacterial growth in combination with oxacillin (minimum inhibitory concentration - MIC). All values were compared to control: 30% alcohol and water. RESULTS: In vitro growth of MRSA was statistically significantly inhibited in the presence of Bell and nosode 6cH and 30cH compared to controls (p < 0.0001); and with combination of Bell or nosode 6cH and 30cH and oxacillin (p < 0.001). Bell 30cH and nosode 6cH and 30cH significantly decreased bacterial DNAse production (p < 0.001) and reduced red blood cell lysis. CONCLUSIONS: Cultures of MRSA treated with Belladonna or MRSA nosode exhibited reduced growth in vitro, reduced enzymatic activity and became more vulnerable to the action of the antibiotic oxacillin. Further studies are needed on the biomolecular basis of these effects.

[Comparison of the effects of traditional and modern processing methods on antibacterial and anti-inflammatory effects of Musca domestica].

OBJECTIVE: To investigate the different effects of traditional and modern processing methods onantibacterial and anti-inflammatory effects of Musca domestica. METHODS: Antibacterial and anti-inflammatory effects of traditional and modem processing products were carried out on Staphylococcus aureus, Escherichia coli and macrophage RAW264.7 which activated by LPS. RESULTS: The antibacterial and anti-inflammatory effects were more pronounced in modern processing product treatment group than those of traditional processing product treatment group. CONCLUSION: Modern processing technology can protect the substances in Musca domestica which have antibacterial and anti-inflammatory effects.

Antimicrobial activity of wild mushroom extracts against clinical isolates resistant to different antibiotics.

AIMS: This work aimed to screen the antimicrobial activity of aqueous methanolic extracts of 13 mushroom species, collected in Bragança, against several clinical isolates obtained in Hospital Center of Trás-os-Montes and Alto Douro, Portugal. METHODS AND RESULTS: Microdilution method was used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). MIC results showed that Russula delica and Fistulina hepatica extracts inhibited the growth of gram-negative (Escherichia coli, Morganella morganni and Pasteurella multocida) and gram-positive (Staphylococcus aureus, MRSA, Enterococcus faecalis, Listeria monocytogenes, Streptococcus agalactiae and Streptococcus pyogenes) bacteria. A bactericide effect of both extracts was observed in Past. multocida, Strep. agalactiae and Strep. pyogenes with MBC of 20, 10 and 5 mg ml⁻¹, respectively. Lepista nuda extract exhibited a bactericide effect upon Past. multocida at 5 mg ml⁻¹ and inhibited Proteus mirabilis at 20 mg ml⁻¹. Ramaria botrytis extract showed activity against Enterococcus faecalis and L. monocytogenes, being bactericide for Past. multocida, Strep. agalactiae (MBCs 20 mg ml⁻¹) and Strep. pyogenes (MBC 10 mg ml⁻¹). Leucopaxillus giganteus extract inhibited the growth of E. coli and Pr. mirabilis, being bactericide for Past. multocida, Strep. pyogenes and Strep. agalactiae. CONCLUSIONS: Fistulina hepatica, R. botrytis and R. delica are the most promising species as antimicrobial agents. SIGNIFICANCE AND IMPACT OF THE STUDY: Mushroom extracts could be an alternative as antimicrobials against pathogenic micro-organisms resistant to conventional treatments.

A biodegradable antibacterial alginate/carboxymethyl chitosan/Kangfuxin sponges for promoting blood coagulation and full-thickness wound healing.

Conventional wound-dressing materials with structural and functional deficiencies are not effective in promoting wound healing. The development of multifunctional wound dressings is emerging as a promising strategy to accelerate blood coagulation, inhibit bacterial infection, and trigger full-thickness wound into a regenerative process. Herein, multifunctional composite sponges were developed by incorporation of traditional Chinese medicine Kangfuxin (KFX) into alginate (AG)/carboxymethyl chitosan (CMC) via green crosslinking, electrostatic interaction, and freeze-drying methods. It is demonstrated that the AG/CMC/KFX (ACK) sponges exhibit a highly interconnected and porous structure, suitable water vapor transmittance, excellent elastic properties, antibacterial behavior, cytocompatibility, and rapid hemostasis. Further, in a rat full-thickness wounds model, the ACK sponge containing 10% KFX (ACK-10) significantly facilitates wound closure compared to the AC group and ACK sponge containing 5% and 15% KFX. Thus, the multifunctional ACK-10 composite sponge has great promise for the application of full-thickness wound healing.

Bioinspired morphology-controlled silver nanoparticles for antimicrobial application.

Phytochemicals sources have been extensively used as reducing and capping agents for synthesis of nanoparticles (NPs). However, morphology-controlled synthesis and shape/size dependent applications of these NPs still need to be explored further, and there is a need to develop a way in which particular and optimized phytochemicals result in the desired NPs in lesser time and cost with higher reproducibility rate. The present study is focused on morphology-controlled synthesis and shape/size dependent application of silver NPs based on the fractionated phytochemicals of Elaeagnus umbellata extract (EU). Unlike other approaches, in this study the reaction parameters such as time, temperature, pH, stirring speed and concentration of the precursor solutions were not altered during the optimization process. The fractionated phytochemicals were used separately for the synthesis of AgNPs, and the synthesized NPs were characterized by UV-visible, FT-IR, atomic force microscopy (AFM) and scanning electron microscopy (SEM). Our findings suggested that the constituents of the extract fractions varied with the selection of the extraction solvent, and the shape/size, bactericidal properties and toxicity of the NPs have a strong correlation with the phytochemicals of the plant extract. The fractionated phytochemicals present in the water fractions (EUW) resulted in monodispersed spherical AgNPs in the size about 40 nm. The NPs have significant stability in physiological conditions (i.e. temperature, pH and salt), have good antibacterial activity, and were found to be non-toxic. Furthermore, AFM and SEM analysis exposed that the NPs killed the bacteria by disturbing the cellular morphology and releasing the cellular matrix. Our results justify the use of different fractions of plant extract to obtain detail implications on shape, size, antibacterial potential and toxicity of AgNPs. This is the first step in a controllable, easy and cheap approach for the synthesis of highly stable, uniform, non-toxic and bactericidal AgNPs using five fractions of EU. The findings suggested that the synthesized NPs, particularly from EUW, could be used in pharmaceutical and homeopathic industry for the development of antibacterial medications.

[In vitro activities of Odorrana grahami antimicrobial peptides from skin against 5 pathogenic bacteria].

OBJECTIVE: To evaluate the efficiency of 4 Odorrana grahami antimicrobial peptides from skin against 5 pathogenic bacteria, include 2 wild strains and 7 resistant strains. METHODS: Broth microdilution antimicrobial susceptibility test was used for bacteria that growed aerobically. RESULTS: The 4 Odorrana grahami antimicrobial peptides were basically in vitro efficient agents for inhibition against to methicillin-resistant coagulase negative Staphylococcus (MRSCN, 85460), wild Staphylococcus aureus (24157), penicillin-resistant Streptococcus pneumoniae (PRSP, 84688 and 91452), class I beta-lactamase Enterobacter cloacae (AmpC, 85439 and 93543), wild Escherichia coli (84492), extended-spectrum beta-lactamases Escherichia coli (ESBL, 84492), inhabitor-resistant TEM beta-lactamase Escherichia coli (IRT, 85580). CONCLUSION: The 4 Odorrana grahami antimicrobial peptides from skin have broad spectrum antimicrobial activity; especially have in vitro activity to resistant strains. So it is hopeful to be developed as the antimicrobial agent as well as the disinfectant and the antiseptic.

Characterization and synergistic antibacterial potential of green synthesized silver nanoparticles using aqueous root extracts of important medicinal plants of Pakistan.

In the past few years, biologically synthesized silver nanoparticles (AgNPs) have been standout amongst the most utilized nanoparticles both in the field of therapeutics and clinical practices. Therefore, the current study aimed to synthesize AgNPs for the first time using aqueous root extracts of important plants of Pakistan i.e. Bergenia ciliata, Bergenia stracheyi, Rumex dantatus and Rumex hastatus and characterize them. In addition, antibacterial activity of synthesized AgNPs at 30-150 µg/well was assessed using well diffusion method against Staphylococcus aureus, Staphylococcus haemolyticus, Bacillus cereus, Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa bacterial strains that are considered most harmful bacteria for human beings. The characterization of synthesized AgNPs showed the absorption maxima ranged from 434 to 451 nm and XRD confirmed the crystalline nature of AgNPs as well as FTIR elucidated the involvement of biomolecules for reduction and capping of AgNPs. SEM determined the average size of AgNPs ranging from 25 to 73 nm and strong signals of silver were captured in EDX images. The result of antibacterial activity showed that only aqueous root extracts of all selected plants were inactive against all the tested bacterial strains. However, importantly, direct relationship between zone of inhibition of S. aureus, S. typhi and P. aeruginosa was found with increasing concentration of AgNPs of each selected plant. Moreover, S. haemolyticus was only inhibited by R. hastatus based AgNPs at only high concentrations and E. coli was inhibited by R. dantatus and R. hastatus based AgNPs. However, B. cereus was not inhibited by any AgNPs except R. hastatus and R. hastatus based AgNPs have greater antibacterial potential among all the synthesized AgNPs. These results suggest that synthesized AgNPs have improved antibacterial potential of root extracts of each selected plant and these synthesized AgNPs could be used in pharmaceutical and homeopathic industry for the cure of human diseases.

[Antibacterial activity of water soluble fraction from Scolopendra subspinipes mutilans].

The water soluble fraction (SWSF) of centipede Scolopendra subspinipes mautilans, injected with Escherichia coli K12 D31 for 3-4 days showed broad-spectrum antimicrobial activity against Gram-positive, Gram-negative bacteria and fungi. It showed strong antibacterial activity against E. coli K12D31 at different temperatures, pH and ionic strengths. It did not show any hemolytic and agglutination activities at the concentration below 600 microg/ml. After E. coli K12 D31 treated with SWSF, the ultrastructure showed that its outer cell wall was broken, surface collapsed and intracellular substances leaked out.

Aspergillus niger as a new allergic agent associated with bindis and its efficacy against homeopathic drugs.

Aspergillus was found as a dominant fungi to associate with brands of bindis. Among three potencies of four homeopathic drugs, Lycopodium 1M, Sulphur 1M, and Sepia 30 showed maximum inhibition zone of Aspergillus niger in inhibition zone technique. In poison food technique, Sepia 30M, Tellurium 30M, Sulphur 1M and Lycopodium 200 showed maximum percentage inhibition against A. niger

Effects of ultrahigh dilutions of 3,5-dichlorophenol on the luminescence of the bacterium Vibrio fischeri.

There is a great need for research in the field of homeopathy for laboratory test systems to investigate the actions of ultrahighly diluted biological effectors. With this in mind, we used the luminescent bacterium Vibrio fischeri, which is used throughout the world in testing water quality. Luminescence inhibition is utilized as a test parameter for the toxicity of a sample. We used ultrahigh dilutions (UHD) of 3,5-dichlorophenol as effector and adapted the standard test procedure for water toxicity in a way that let us evaluate very minute effects. Three groups of samples were prepared and then blinded: 45 dilutions of 3,5-dichlorophenol in steps of 10, starting with 4.2 x 10(-2) M, with vigorous shaking between dilution steps; 45 identical dilutions of 3,5-dichlorophenol without vigorous shaking; and 49 control samples of the diluent. The results of, and the discussion based on, a thorough statistical analysis led to the conclusion that an effect based on UHD, which results in an inhibition of luminescence of less than 1.5%, can be confirmed for some of the potency samples. There were both effective and ineffective samples in the three sample groups. The size of the effect was very small (ca. 1.5%), though statistically significant. The number of effective samples was significantly higher among the vigorously shaken samples than among the controls and the unshaken samples (14, 6 and 7 effective samples, respectively).

Study on mutations and antiretroviral therapy (SMART): preliminary results.

Resistance to antiretroviral drugs is believed to be an important cause of treatment failure in human immunodeficiency virus (HIV)-infected patients, however, the role of susceptibility assays in the management of these individuals needs to be defined. SMART (study on mutations and antiretroviral therapy) is an ongoing study on mutations and antiretroviral therapy focused particularly on HIV-infected patients treated with two nucleoside analogue reverse transcriptase inhibitors (NRTIs). Plasma HIV-1 RNA was assessed by NASBA (nucleic acid sequence-based amplifications) (Organon Teknika, Boxtel, The Netherlands) with a detection limit of 80 copies/ml, whereas resistance was assessed by direct sequencing of the RT pol gene in patients with detectable viraemia, and by Antivirogram (Virco) in non-responder patients. The preliminary results of this study show that both genotypic and phenotypic assays identify mutated viral strains in the majority of patients failing a dual regimen. Furthermore, the data indicate a high rate of genotypic resistance to lamivudine in both responders and non-responders, a high rate of phenotypic resistance to lamivudine in non-responders, no genotypic resistance to didanosine and stavudine in responders, and a very low rate of both genotypic and phenotypic resistance to didanosine and stavudine in non-responders.

Comparison of Mycobacterium tuberculosis susceptibility testing performed with BACTEC 460TB (Becton Dickinson) and MB/BacT (Organon Teknika) systems.

The recently introduced automated culture systems MB/BacT (Organon Teknika, Belgium) was compared with radiometric BACTEC 460TB (Becton Dickinson, USA) to test antimicrobial susceptibility of Mycobacterium tuberculosis to first line drugs. On 113 strains 97.5% agreement was obtained, with the difference being not significant. Concordance was practically complete for the most important drugs, isoniazid and rifampin. The two methods however significantly differed for the time needed to complete the test; in fact MB/BacT required on the average five days more than BACTEC 460TB. Despite the delay in the completion of the test, the excellent reliability along with the elimination of radioactivity and full automation make MB/BacT an attractive alternative for susceptibility testing of M. tuberculosis.

Biosynthesized silver nanoparticles by ethanolic extracts of Phytolacca decandra, Gelsemium sempervirens, Hydrastis canadensis and Thuja occidentalis induce differential cytotoxicity through G2/M arrest in A375 cells.

The capability of crude ethanolic extracts of certain medicinal plants like Phytolacca decandra, Gelsemium sempervirens, Hydrastis canadensis and Thuja occidentalis used as homeopathic mother tinctures in precipitating silver nanoparticles from aqueous solution of silver nitrate has been explored. Nanoparticles thus precipitated were characterized by spectroscopic, dynamic light scattering, X-ray diffraction, atomic force and transmission electron microscopic analyses. The drug-DNA interactions of silver nanoparticles were analyzed from data of circular dichroism spectroscopy and melting temperature profiles using calf thymus DNA (CT-DNA) as target. Biological activities of silver nanoparticles of different origin were then tested to evaluate their effective anti-proliferative and anti-bacterial properties, if any, by exposing them to A375 skin melanoma cells and to Escherichia coli C, respectively. Silver nanoparticles showed differences in their level of anti-cancer and anti-bacterial potentials. The nanoparticles of different origin interacted differently with CT-DNA, showing differences in their binding capacities. Particle size differences of the nanoparticles could be attributed for causing differences in their cellular entry and biological action. The ethanolic extracts of these plants had not been tested earlier for their possible efficacies in synthesizing nanoparticles from silver nitrate solution that had beneficial biological action, opening up a possibility of having therapeutic values in the management of diseases including cancer.

Disclosure of the quackery: testing of the bactericidal action of products based on the "hydronic" technology ("informed glass") on ATCC strains of Enterococcus faecalis, Salmonella enteritidis and Candida albicans.

To disclose a quackery called "revitalisation of tired water by hydronic technology", scientific experiments have been conducted with drinking water kept in "ordinary, everyday-use" drinking glasses and so-called 'informed' glasses, a patent-protected product supposed to have an effect on the "structure, vitality and memory of water". Drinking "informed" water is claimed to have a wide range of positive revitalising health effects (blue informed glass), to facilitate weight loss (red informed glass) and to have a stress-relieving action (green informed glass). Allegedly, by the use of the "orgon methodology", information is coded into the glass, which action is additionally enforced by the addition of the "magic life" symbol - a specially designed energy condenser which, together with the selected information, is permanently introduced into the liquid contained in the glass. Since the manufacturer claimed the products to have a broad bactericidal action, regardless of the external conditions and completely independent from additional factor that would lead to the activation of the system, the efficacy of the informed drinking glass was tested using standardised, microbiological tests. Respecting the principle of a single-blind test for each of 5 samples of each type of the informed glass, growth reduction factor (RF) (difference log cfu/ml - colony per unit/ml of control glass and log cfu/ml of each informed glass) was determined after 0,2,4,6 and 8 h in spring water experimentally contaminated with standardised ATCC strains of two types of bacteria and one yeast. The results showed a statistically significant bactericidal action of the blue informed glass with all strains-Enterococcus faecalis (RF 0.62/0.76), Salmonella enteritidis (RF 0.87/0.97), and Candida albicans (RF 0.5/0.60) - as opposed to the red and green glasses where this effect was negligible (RF < 0.1). However, when the tests were repeated in complete darkness, none of the three informed glasses showed any bactericidal action. The obtained results indicate a fraud: bactericidal effect is rather a result of photocatalytic action of a hidden component used on purpose in the production of glass or subsequently applied by the use of nanotechnology (possibly antimony trioxide or titanium oxide) than of the so-called "orgon and hydronic technology".

Chemical composition and antifungal activity of essential oil from Cicuta virosa L. var. latisecta Celak.

The essential oil extracted from the fruits of Cicuta virosa L. var. latisecta Celak was tested in vitro and in vivo against four foodborne fungi, Aspergillus flavus, Aspergillus oryzae, Aspergillus niger, and Alternaria alternata. Forty-five different components accounting for 98.4% of the total oil composition were identified by gas chromatography-mass spectrometry. The major components were γ-terpinene (40.92%), p-cymene (27.93%), and cumin aldehyde (21.20%). Antifungal activity was tested by the poisoned food technique against the four fungi. Minimum inhibitory concentration against the fungi was 5 µL/mL and percentage inhibition of mycelial growth was determined at day 9. The essential oil had a strong inhibitory effect on spore production and germination in all tested fungi proportional to concentration. The oil exhibited noticeable inhibition on dry mycelium weight and synthesis of aflatoxin B1 (AFB1) by A. flavus, completely inhibiting AFB(1) production at 4 µL/mL. The effect of the essential oil on inhibition of decay development in cherry tomatoes was tested in vivo by exposing inoculated and control fruit to essential oil vapor at a concentration of 200 µL/mL. Results indicated that the essential oil from C. virosa var. latisecta (CVEO) has potential as a preservative to control food spoilage.

Effect of opium smoking cessation on the nasopharyngeal microbial flora.

OBJECTIVE: To determine the effect of opium smoking cessation on the frequency and type of microorganisms in the nasopharynx of opium smokers. METHODS: This cross-sectional study was performed in the Psychiatry, and Ear, Nose, and Throat Departments, Moradi Hospital, Rafsanjan University of Medical Sciences, Rafsanjan, Iran from June to November 2008. Nasopharyngeal cultures were taken from 50 opium smokers before, and 2-3 months after cessation of opium smoking. Potential pathogens were identified. Patients were not advised to change their number of cigarettes, and we used methadone for the substitution of opium. RESULTS: Eight potential pathogens were isolated from nasopharyngeal cultures obtained from 43 individuals before opium smoking cessation, and 4 were recovered from 33 individuals after cessation (p=0.03). Streptococcus pneumoniae, Staphylococcus saprophyticus, Streptococcus alpha hemolytic, and Staphylococcus aureus were not found in the second culture. The most sensitivity to antibiotics was for ceftriaxone (84%), ciprofloxacin (74%), and cloxacillin (72%), and the most resistance for amoxicillin (26%) and the least resistance for chloramphenicol. CONCLUSION: Some potential pathogens decrease or are even absent after opium cessation. Opium smoking affects the nasopharyngeal flora.

Concentração inibitória mínima e concentração bactericida mínima de extratos hidroalcoólicos das folhas de Myracrodruon urundeuva All. e Qualea grandiflora Mart. sobre Streptococcus mutans e Lactobacillus casei / Minimum inhibitory concentration and minimum bactericidal concentration of hydroalcoholic extracts of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves on Streptococcus mutans and Lactobacillus casei

A cárie dentária é uma doença bucal de alta prevalência e impactante em países em desenvolvimento. É causada pela presença de biofilme dentário rico em bactérias acidogênicas e acidúricas, como Streptococcus mutans e Lactobacillus casei. Neste sentido, a fitoterapia tem sido aplicada na odontologia devido ao seu conhecido efeito antimicrobiano, tendo potencial para prevenir doenças como a cárie dentária. Portanto, o presente estudo tem como objetivo testar o potencial antimicrobiano de extratos bruto e etanólico das folhas de Myracrodruon urundeuva (M. urundeuva.) e Qualea grandiflora (Q. grandiflora) sobre S.mutans e L. casei. Para tal, determinaram-se a Concentração Inibitória Mínima (CIM) e a Concentração Bactericida Mínima (CBM). A CIM foi definida como a menor concentração do agente antimicrobiano capaz de inibir 100% o crescimento microbiano (absorbância) em relação aos controles negativos. Para a CBM, alíquotas foram removidas dos poços que não apresentaram nenhuma absorbância (viabilidade, concentrações CIM) e semeadas em placas de ágar BHI, incubadas por 24 h a 37°C em estufa de CO2 5%. A CBM foi determinada considerando a menor concentração dos extratos capaz de impedir o crescimento bacteriano visível. Cepas de S. mutans (ATCC 21175) e L. casei (ATTC 334) foram ativadas em BHI e caldo Rogosa, respectivamente. A CIM foi determinada pela técnica de diluição em microplacas de 96 poços (100 l de extrato + 80 l BHI/Rogosa + 20 l da bactéria diluída em BHI/Rogosa equivalente a 5x105 UFC/mL), as quais foram incubadas por 24 h (S. mutans) e 48 h (L. casei) a 37°C em estufa de CO2 5%. Os extratos de M. urundeuva e Q. grandiflora inicialmente foram diluídos em BHI/Rogosa variando as concentrações entre 2 mg/ml a 0,00012207 mg/ml e os mesmos extratos diluídos em álcool foram avaliados nas concentrações entre 20 mg/ml a 0,00244 mg/ml para S. mutans e L. casei. Não foi possível determinar a CIM e a CBM para os extratos diluídos no BHI/Rogosa. Foram utilizados como controle positivo a clorexidina e como controles negativos BHI/Rogosa com e sem álcool a 5%. As CIMs (CBMs) da M. urundeuva e Q. grandiflora, diluídas em álcool, e clorexidina contra S. mutans foram 2,5 mg/ml (2,5 mg/ml), 5,0 mg/ml (--) e 0,00468 mg/ml (0,00937 mg/ml), respectivamente. Em relação ao L. casei, as CIMs (CBMs) da M. urundeuva e Q. grandiflora, diluídas em álcool, e da clorexidina foram 0,156 mg/ml (0,312 mg/ml), 0,156 0,625 mg/ml (0,312 0,625mg/ml) e 0,00468 mg/ml (0,3 mg/ml), respectivamente. Como conclusão, nosso estudo mostrou que L. casei (ATTC 334) é mais susceptível aos extratos que S. mutans (ATCC 21175) e o extrato M. urundeuva apresenta melhor efeito antimicrobiano que a Q. grandiflora em S. mutans (ATCC 21175), porém os dois extratos apresentam efeito similar sobre L. casei (ATTC 334) e ambos foram inferiores à CHX.(AU)

Dental caries is an oral disease of high prevalence and impact in developing countries. It is caused by the presence of a dental biofilm rich in acidogenic and aciduric bacteria, such as Streptococcus mutans and Lactobacillus casei. Accordingly, phytotherapy has been applied in dentistry due to its known antimicrobial effect, having potential to prevent diseases such as dental caries. Therefore, the present study aims to test the antimicrobial potential of crude and ethanolic extracts of Myracrodruon urundeuva (M. urundeuva) and Qualea grandiflora (Q. grandiflora) leaves on S. mutans and L. casei. For this, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined. MIC was defined as the lowest concentration of the antimicrobial agent capable of inhibiting 100% the microbial growth in comparison to the negative controls. For MBC, aliquots were removed from the wells that did not show any absorbance (viability, concentrations than MIC) and seeded on BHI agar plates, incubated for 24 h at 37°C and 5% CO2. The MBC was determined considering the lowest concentration of extracts capable of preventing visible bacterial growth. Strains of S. mutans (ATCC 21175) and L. casei (ATTC 334) were activated in BHI and Rogosa broth. MIC was determined by the dilution technique in 96-wells microplates (100 l of extract + 80 l BHI/ Rogosa + 20 l of bacterium diluted in BHI/Rogosa equivalent to 5x105 CFU/ml), which were incubated for 24 h (S. mutans) and 48 h (L. casei) at 37°C and 5% CO2. The extracts were firstly diluted in BHI/Rogosa varying the concentrations between 2 mg/mL and 0.00012207 mg/ml; the same extracts were also diluted in alcohol at concentrations ranging from 20 mg/ml to 0.00244 mg/ml and both tested against S. mutans and L. casei. It was not possible to determine the MIC and MBC for the extracts diluted in BHI/Rogosa. Chlorhexidine was used as positive control, while BHI/Rogosa with or without 5% alcohol were used as negative controls. The MICs (MBCs) of M. urundeuva and Q. grandiflora diluted in alcohol, and clorexidine against S. mutans were 2.5 mg/ml (2.5 mg/ml), 5.0 mg/ml (--) and 0.00468 mg/ml (0.00937 mg/ml), respectively. In respect to L. casei, the MICs (MBCs) of M. urundeuva and Q. grandiflora, diluted in alcohol, and chlorhexidine were 0.156 mg/ml (0.312 mg/ml), 0.156 0.625 mg/ml (0.312 0.625 mg/ml) and 0.00468 mg/ml (0.3 mg/ml), respectively. In conclusion, our study showed that L. casei (ATTC 334) is more susceptible than S. mutans (ATCC 21175) to the extracts and the extract of M. urundeuva has a better antimicrobial effect than Q. grandiflora against S. mutans (ATCC 21175), but both extracts have similar effect on L. casei (ATTC 334) and they were inferior to CHX.(AU)