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  • Open access
  • 102 Reads
PTML-ANN Model for Simultaneous Prediction of Cytotoxic and Ecotoxic Effect of Nanoparticles

Biological data on the cytotoxic and the ecotoxic effects of coated and uncoated nanoparticles were retrieved from the scientific literature. The mathematical treatment of these data was based on the use of perturbation theory (PT) operators. This enabled the development of a model that combined perturbation theory concepts with artificial neural networks (PTML-ANN). New nanoparticles not reported during the generation of the PTML-ANN model were used in a virtual screening experiment. For these new nanoparticles, the predictions performed by the PTML-ANN model converged with the experimental results.

  • Open access
  • 146 Reads
Modulating Effect of 4,6,6-trimethylbicyclo [3.1.1] hept-3-ene on Antimicrobials Used to Combat Escherichia coli

The growing number of resistant microorganisms is considered a global public health problem. In this context, several control initiatives have been proposed, such as the preparation of medicines from the herbal raw material that may have an antibacterial and antifungal effect as an alternative to fight against pathogens such as Escherichia coli, which is related to approximately 50% of hospital infections. Among the monoterpenes with antibacterial potential, there is the potential enantiomer of α-pinene, which has antimicrobial activity against some microorganisms. The aim of this research was to evaluate the modulating effect of (+) - α-pinene on the activity of synthetic antimicrobials acting on the bacterial cell wall. The phytoconstituent (+) - α - pinene obtained from Sigma-Aldrich Brazil LTDA. The solutions were dissolved in 1% Tween 80 and 5% DMSO. Sterile distilled water was used to achieve the desired concentrations. The tests were carried out on the E. coli strain ATTC 25922. For the modulation and adaptation tests, discs containing commercial antimicrobial (ATMs) acting on the bacterial cell wall were used: cephalothin, ceftazidime, amoxicillin, ampicillin, cefepime, cefoxitin , meropenem and cefuroxime. The modulating action of monoterpene was determined by the disc diffusion method. After incubation of the plates at 35 + 2 °C for 24 hours, the diameters of the inhibition halos of microbial growth were measured. Applying the classification proposed by Cleeland and Squires for the effect of interaction between the substances, we could classify the effect of the association of the phytoconstituent for the ATMs ceftazidime, amoxicillin, cefepime and cefoxitina as a synergistic effect. However, for the other ATMs, there was no statistically significant difference, and the association effect was classified as indifferent. It is concluded that the phytoconstituent (+) - α-pinene, has synergistic effects with some drugs tested in this work and can be suggested as a promising associated and potentiating substance against E. coli ATCC 25922, provided that it is subjected to tests that verify its toxic potential for humans. In the same way, the association of this monoterpene with the antibiotics that have antagonistic or indifferent effects in this study should be avoided, thus not allowing the growth of resistant bacterial strains.

  • Open access
  • 163 Reads
Prediction of adverse reactions to antibacterials using MODESLAB methodology

Due to the high interest represented by the study of adverse drug reactions and the importance of anticipating them, the use of molecular modeling methods for this purpose becomes a novel fact. In this work the calculation of the spectral moments of the adjacency matrix between edges of the molecular graph with suppressed hydrogens, weighted on the main diagonal with different parameters that characterize both the bonds and the atoms in the molecules of 63 compounds composed of 63 antibacterial action, using the MODESLAB methodology. 91 descriptors were calculated, which were used in a series of training divided into four groups, according to the most frequent type of adverse reaction. In order to identify the descriptors that best discriminate between the compounds of each group and define the set of functions of these descriptors capable of distinguishing as accurately as possible the members of one or another group, a discriminant analysis was developed using the software Statistical Statistical 8.5. Three functions were generated that constitute linear combinations of 6 molecular descriptors, which encode both steric and electronic information of the molecules of each group. The obtained functions have a very low minimum Wilks Lambda (0.07) and a high canonical correlation (0.82), which demonstrates its discriminant power

  • Open access
  • 78 Reads
Obtaining a computer-assisted QSAR model for the prediction of anti-inflammatory activity

The main objective of this study was to develop quantitative structure-activity relationships (QSAR) for the classification and prediction of anti-inflammatory activity. To this end, the ToSS-MoDE approximation was applied for the calculation of the spectral moments of the adjacency matrix between edges of the molecular graph with suppressed hydrogens, weighted on the main diagonal with moments of link dipoles, link distance, Van radius der Waals, polarizability and hydrophobicity to 509 active and inactive compounds. The calculated descriptors were used in the design of a training series and a prediction series. With the training series, a discriminant function was developed for the anti-inflammatory activity and another function to characterize the potential of these drugs using the Multivariate Linear Discriminant analysis, obtaining a good total classification of 96.07%. The model was validated by using the external prediction series, obtaining a good classification of 92.59%.

  • Open access
  • 80 Reads
Bacteriophages as an alternative to the use of antibiotics in poultry breeding

Bacterial resistance to antibiotics is an emerging problem worldwide (World Health Organization, 2015). The use of antimicrobials is responsible for resistance in commensal bacteria of animals that have never received antibiotics, due to horizontally transferred genes (Ventola, 2015). The antimicrobials used as growth promoters or prophylactic agents in animal husbandry are the most important factor in the propagation of resistance genes, since the amount of antibiotics used in the animal industry is greater than in the medical field (Davies & Davies, 2010). The use of phages constitutes a safe alternative for the control of human pathogenic bacteria, with the consequent reduction in the incidence of foodborne diseases (ETAs), and the high costs of rejecting or destroying food products when there is an outbreak.

Phages are used as a biological alternative to eliminate pathogenic bacteria from food, because they do not affect eukaryotic cells and are safe for beneficial microorganisms that are also found in food and the human intestinal tract. They provide a high degree of safety due to their specificity of host bacteria since they produce rapid host death (Fiorentin, Vieira, & Barioni, 2005; Huang et al., 2018; Pang, Lambertini, Buchanan, Schaffner, & Pradhan, 2017). These viruses are widely distributed in human and animal feces, sewage and the environment of edible animals (Dueñas et al., 2017).

Salmonella is an important pathogen, mainly transmitted to humans through contaminated food, and causing a high rate of morbidity and mortality worldwide. The zoonotic Salmonella serotypes that cause foodborne diseases are found in the intestinal tract of warm-blooded animals, such as birds, which allows their passage to the meat during the slaughter of the animal and the processing, considering chicken meat as the main infectious source of non-typhoidal Salmonella.

This project aimed to isolate and characterize bacteriophages of Salmonella spp. and use them to reduce the presence of this pathogen in poultry at the farm level, without the use of antibiotics.

To carry it out, phage cocktails were isolated from river waters, sewage from chicken processing facilities and samples from chicken beds. The enrichment was carried out following the methodology of Benson (1980). The host range and the titer of the phage cocktails were determined following the methodology of Huang et al. (2018) and those that were specific only against Salmonella spp. were applied in a poultry farm where pilot trials are carried out. The application routes were orally (with water) and by sprinkling.

We obtained phage cocktails that showed lytic activity in vitro against 83% of Salmonella strains isolated from poultry farms (serotypes Infantis, Braenderup, and Saintpaul). The phage cocktails with the highest spectrum of activity against our Salmonella strains were those obtained from contaminated rivers. There were positive results (elimination of Salmonella in the chicken intestine) when phages were applied 48 hours before the animals were slaughtered.

The results were similar when phages were administered orally and when combined with spray, because the evaluation was performed only on the cecum of slaughtered chickens. In future trials, we will take simples of chicken coops to determine if the spray is effective to eliminate the pathogen from the poultry litters.

As bacteria have mechanisms by which they can become immune to virus attacks, such as the CRISPR-Cas system (Shariat et al., 2015), it is necessary to maintain a permanent monitoring of lithic activity of the phages against resistant Salmonella strains.

Currently, we are beginning the isolation and characterization of individual phages from the best cocktails.

  • Open access
  • 110 Reads
Carbamazepine degradation with isolated bacterias of Machángara river in Quito - Ecuador.

Carbamazepine (CBZ) is an antiepileptic-psychiatric drug, which is eliminated directly in water effluents by urinary or fecal routes; causing toxicity and mutagenic effects in living beings.

According to the study by Voloshenko, A, et al (2015), in Ecuador carbamazepine is one of the most persistent emerging pollutants, which despite going through conventional wastewater treatments, it cannot be eliminated. Therefore, there is evidence of the need to develop investigations of alternative degradation processes, such as biological treatments that incorporate microorganisms that use the contaminant as a carbon source.

In this work, two sampling points were selected in the Machángara River to isolate microorganisms able to consume carbamazepine as carbon source. These points were selected, due to their greater concentration of emerging pollutants. Water samples were characterized physical - chemical and microbiologically, presenting values ​​outside the maximum permissible limits for fecal and total coliforms, which make this resource not suitable for human consumption. Microorganisms capable of using carbamazepine as a carbon source were Isolated and molecularly identified.

For degradation tests, two bacteria belonging to genus Pseudomonas were selected, one isolated from the water source and an ATCC certified bacterium; observing that the best treatment was with Psedomonas aeruginosa ATCC 9027, 2% v / v of inoculum, 30 ° C, with 15 ppm of CBZ for 37 days of treatment.

  • Open access
  • 113 Reads
Fluoroquinolonas susceptibility analysis of arcobacter spp isolated of fresh cheese, from the city of guaranda
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The Arcobacter genus is an emerging microorganism of free life that is widely distributed in the environment and forms micro intestinal biota of animals and humans. Most of these, are zoonotic, as is the case of Arcobacter butzleri, currently considered an emerging pathogen and transmitted by food, microorganism and of growing importance for public health. It should be noted that said microorganism in certain cases has presented resistance to antibiotics such as Fluoroquinolones (specific for ε-bacteria). Considering the previously described, the main of this investigation was to study of susceptibility to Fluoroquinolones by the Disco-Plate Diffusion technique for Arcobacter spp. isolated from fresh cheeses, obtained from the municipal markets of Guaranda (Ecuador). Fluoroquinolones are broad-spectrum chemotherapeutic agents, which constitute one of the most important contributions that can prevent or cure infectious diseases. For which, 100 samples of cheese were analyzed, 50 from the Bellavista market and 50 from the 10 November market, then Arcobacter was isolated by selective culture, DNA was extracted and then amplified by PCR. The type of analysis used was a descriptive statistical model where tests of analysis of means, percentages and frequencies were studied. After culture, 66 strains of Arcobacter were isolated from 47 samples, (25 strains from the Bellavista market; and 41 from the 10 November market, by PCR, resulting 26 isolates positive of the 16S rRNA gene established by Figueras et al. (2012 ). In the susceptibility test to Fluoroquinolones, 2/26 cases, were found to be resistant to the bacteria, making up 7.69%; 19/26 cases reflected an intermediate resistance to Arcobacter, these being 73.08%; finally 5 / 26 cases were found to be susceptible, forming the remaining 19.23% The criteria used for the analysis were those established for Campylobacter according to the Clinical Laboratory and Standards Institute (CLSI 2010, M45-A2).

  • Open access
  • 346 Reads
A Machine learning approach for the prediction of efficient iPSC modeling

Cancer stands as major cause of mortality in the world, and it's the morbidity has significantly increased in both developing and developed nations. In spite of the recent advancement in cancer therapies, the clinical follow-up still lags far behind.Recent studies show that, stem cells are bestowed with distinctive functions, like tumor cells relocation, immunosuppression and production of bioactive elements, that helps in cancer targeting that bypassobstacles.Recent understanding show that Preclinical stem cell-based strategies has proved potential for targeted anti-tumor therapy applications. Stem cell applications in modulation and remodeling of immune system happens to be frequent procedure used past ten years in successfully treating tumor.Generation of human somatic cells into induced pluripotent stem cells (iPSCs) has often been a time consuming laborious intensive and expensive process. Additionally, the major problem with iPSCs is their tendency to revert to original somatic state. Hence, a robust computational model in discovering genes/molecules necessary for iPSC generation and maintenance can be a major leap towards in stem cell research.The synergistic combination of genetic relationship data, advanced computing hardware and nonlinear algorithms and could make artificially-induced pluripotent stem cells (aiPSC) a near future reality. Genes or proteins that are known to be essential in human pluripotent stem cells (hPSC) could possibly be used for system modelling. The present investigation is aimed to develop an unsupervised deep machine learning technology for the prediction of genes relevant in aiPSC production and its maintenance for both common and rare diseases making it a cost-effective approach.

  • Open access
  • 66 Reads
Chemical composition of the taro tuber (Colocasia esculenta L. Schott) of waste with and without processing for use in pigs
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To evaluate the chemical composition of the taro tuber (Colocasia esculenta (L) Schott) of waste with and without processing for use in pig diets. In samples of natural tubers, solid state fermentation (SEF) and flour, it was determined: dry matter (DM), organic matter (OM), crude protein (CP), crude fiber (CF), ash, extract ethereal (EE), nitrogen-free extracts (NFE), gross energy (GE), digestible energy (DE) and metabolizable energy (ME). The experiment was conducted according to a completely randomized design, in the necessary cases the means were contrasted with the Duncan test with (p<0.05). The major (p<0.05) content in DM presented the flour. In relation to the OM, the highest contents were evidenced in the natural tuber and in flour. As for CP and ashes, the SEF had the best (p<0.05) contents. As for the CF and NFE, there were no differences (p>0.05) between the unprocessed and processed tuber. Regarding EE, GE, DE and ME, the natural tuber had the highest (p<0.05) concentrations, respectively. In conclusion, processed waste taro tubers constitute a good source of nutrients, guaranteeing a local alternative food of adequate nutritional characteristics for use in pigs.

  • Open access
  • 148 Reads
Comparative study of biochemical composition and enzymatic activity of Bothrops atrox venom

In Ecuadorian Amazon, Bothrops atrox is the main snake associated with ophidic accidents. The only approved treatment for snakebite envenomation are antivenoms and their efficiency depends on the reference venom used in their production. It is important to mention that B. atrox is a species with wide geographic distribution, which can generate differences in the composition and phenotype of the venom between its different populations. This variability can be responsible for changes in the toxicological effects of snakebite among populations of the same species. With this in mind, the present study analyzed two venom samples from individuals from two Amazonian areas. Based on the results, differences in the abundance of the main families of toxins and their activities between both venoms were identified